diff -r 000000000000 -r 6474c204b198 layout/base/nsDisplayList.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/layout/base/nsDisplayList.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,3413 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=2 sw=2 et tw=78: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +/* + * structures that represent things to be painted (ordered in z-order), + * used during painting and hit testing + */ + +#ifndef NSDISPLAYLIST_H_ +#define NSDISPLAYLIST_H_ + +#include "mozilla/Attributes.h" +#include "nsCOMPtr.h" +#include "nsIFrame.h" +#include "nsPoint.h" +#include "nsRect.h" +#include "nsCaret.h" +#include "plarena.h" +#include "nsRegion.h" +#include "FrameLayerBuilder.h" +#include "nsLayoutUtils.h" +#include "nsDisplayListInvalidation.h" +#include "DisplayListClipState.h" + +#include + +#include +#include + +class nsIContent; +class nsRenderingContext; +class nsDisplayTableItem; +class nsISelection; +class nsDisplayLayerEventRegions; + +namespace mozilla { +namespace layers { +class Layer; +class ImageLayer; +class ImageContainer; +} //namepsace +} //namepsace + +/* + * An nsIFrame can have many different visual parts. For example an image frame + * can have a background, border, and outline, the image itself, and a + * translucent selection overlay. In general these parts can be drawn at + * discontiguous z-levels; see CSS2.1 appendix E: + * http://www.w3.org/TR/CSS21/zindex.html + * + * We construct a display list for a frame tree that contains one item + * for each visual part. The display list is itself a tree since some items + * are containers for other items; however, its structure does not match + * the structure of its source frame tree. The display list items are sorted + * by z-order. A display list can be used to paint the frames, to determine + * which frame is the target of a mouse event, and to determine what areas + * need to be repainted when scrolling. The display lists built for each task + * may be different for efficiency; in particular some frames need special + * display list items only for event handling, and do not create these items + * when the display list will be used for painting (the common case). For + * example, when painting we avoid creating nsDisplayBackground items for + * frames that don't display a visible background, but for event handling + * we need those backgrounds because they are not transparent to events. + * + * We could avoid constructing an explicit display list by traversing the + * frame tree multiple times in clever ways. However, reifying the display list + * reduces code complexity and reduces the number of times each frame must be + * traversed to one, which seems to be good for performance. It also means + * we can share code for painting, event handling and scroll analysis. + * + * Display lists are short-lived; content and frame trees cannot change + * between a display list being created and destroyed. Display lists should + * not be created during reflow because the frame tree may be in an + * inconsistent state (e.g., a frame's stored overflow-area may not include + * the bounds of all its children). However, it should be fine to create + * a display list while a reflow is pending, before it starts. + * + * A display list covers the "extended" frame tree; the display list for a frame + * tree containing FRAME/IFRAME elements can include frames from the subdocuments. + * + * Display item's coordinates are relative to their nearest reference frame ancestor. + * Both the display root and any frame with a transform act as a reference frame + * for their frame subtrees. + */ + +// All types are defined in nsDisplayItemTypes.h +#ifdef MOZ_DUMP_PAINTING +#define NS_DISPLAY_DECL_NAME(n, e) \ + virtual const char* Name() { return n; } \ + virtual Type GetType() { return e; } +#else +#define NS_DISPLAY_DECL_NAME(n, e) \ + virtual Type GetType() { return e; } +#endif + +/** + * This manages a display list and is passed as a parameter to + * nsIFrame::BuildDisplayList. + * It contains the parameters that don't change from frame to frame and manages + * the display list memory using a PLArena. It also establishes the reference + * coordinate system for all display list items. Some of the parameters are + * available from the prescontext/presshell, but we copy them into the builder + * for faster/more convenient access. + */ +class nsDisplayListBuilder { +public: + typedef mozilla::FramePropertyDescriptor FramePropertyDescriptor; + typedef mozilla::FrameLayerBuilder FrameLayerBuilder; + typedef mozilla::DisplayItemClip DisplayItemClip; + typedef mozilla::DisplayListClipState DisplayListClipState; + typedef nsIWidget::ThemeGeometry ThemeGeometry; + typedef mozilla::layers::Layer Layer; + typedef mozilla::layers::FrameMetrics::ViewID ViewID; + + /** + * @param aReferenceFrame the frame at the root of the subtree; its origin + * is the origin of the reference coordinate system for this display list + * @param aIsForEvents true if we're creating this list in order to + * determine which frame is under the mouse position + * @param aBuildCaret whether or not we should include the caret in any + * display lists that we make. + */ + enum Mode { + PAINTING, + EVENT_DELIVERY, + PLUGIN_GEOMETRY, + IMAGE_VISIBILITY, + OTHER + }; + nsDisplayListBuilder(nsIFrame* aReferenceFrame, Mode aMode, bool aBuildCaret); + ~nsDisplayListBuilder(); + + void SetWillComputePluginGeometry(bool aWillComputePluginGeometry) + { + mWillComputePluginGeometry = aWillComputePluginGeometry; + } + void SetForPluginGeometry() + { + NS_ASSERTION(mMode == PAINTING, "Can only switch from PAINTING to PLUGIN_GEOMETRY"); + NS_ASSERTION(mWillComputePluginGeometry, "Should have signalled this in advance"); + mMode = PLUGIN_GEOMETRY; + } + + /** + * @return true if the display is being built in order to determine which + * frame is under the mouse position. + */ + bool IsForEventDelivery() { return mMode == EVENT_DELIVERY; } + /** + * Be careful with this. The display list will be built in PAINTING mode + * first and then switched to PLUGIN_GEOMETRY before a second call to + * ComputeVisibility. + * @return true if the display list is being built to compute geometry + * for plugins. + */ + bool IsForPluginGeometry() { return mMode == PLUGIN_GEOMETRY; } + /** + * @return true if the display list is being built for painting. + */ + bool IsForPainting() { return mMode == PAINTING; } + /** + * @return true if the display list is being built for determining image + * visibility. + */ + bool IsForImageVisibility() { return mMode == IMAGE_VISIBILITY; } + bool WillComputePluginGeometry() { return mWillComputePluginGeometry; } + /** + * @return true if "painting is suppressed" during page load and we + * should paint only the background of the document. + */ + bool IsBackgroundOnly() { + NS_ASSERTION(mPresShellStates.Length() > 0, + "don't call this if we're not in a presshell"); + return CurrentPresShellState()->mIsBackgroundOnly; + } + /** + * @return true if the currently active BuildDisplayList call is being + * applied to a frame at the root of a pseudo stacking context. A pseudo + * stacking context is either a real stacking context or basically what + * CSS2.1 appendix E refers to with "treat the element as if it created + * a new stacking context + */ + bool IsAtRootOfPseudoStackingContext() { return mIsAtRootOfPseudoStackingContext; } + + /** + * @return the selection that painting should be restricted to (or nullptr + * in the normal unrestricted case) + */ + nsISelection* GetBoundingSelection() { return mBoundingSelection; } + + /** + * @return the root of given frame's (sub)tree, whose origin + * establishes the coordinate system for the child display items. + */ + const nsIFrame* FindReferenceFrameFor(const nsIFrame *aFrame) + { + if (aFrame == mCachedOffsetFrame) { + return mCachedReferenceFrame; + } + for (const nsIFrame* f = aFrame; f; f = nsLayoutUtils::GetCrossDocParentFrame(f)) + { + if (f == mReferenceFrame || f->IsTransformed()) { + mCachedOffsetFrame = aFrame; + mCachedReferenceFrame = f; + mCachedOffset = aFrame->GetOffsetToCrossDoc(f); + return f; + } + } + mCachedOffsetFrame = aFrame; + mCachedReferenceFrame = mReferenceFrame; + mCachedOffset = aFrame->GetOffsetToCrossDoc(mReferenceFrame); + return mReferenceFrame; + } + + /** + * @return the root of the display list's frame (sub)tree, whose origin + * establishes the coordinate system for the display list + */ + nsIFrame* RootReferenceFrame() + { + return mReferenceFrame; + } + + /** + * @return a point pt such that adding pt to a coordinate relative to aFrame + * makes it relative to ReferenceFrame(), i.e., returns + * aFrame->GetOffsetToCrossDoc(ReferenceFrame()). The returned point is in + * the appunits of aFrame. It may be optimized to be faster than + * aFrame->GetOffsetToCrossDoc(ReferenceFrame()) (but currently isn't). + */ + const nsPoint& ToReferenceFrame(const nsIFrame* aFrame) { + if (aFrame != mCachedOffsetFrame) { + FindReferenceFrameFor(aFrame); + } + return mCachedOffset; + } + /** + * When building the display list, the scrollframe aFrame will be "ignored" + * for the purposes of clipping, and its scrollbars will be hidden. We use + * this to allow RenderOffscreen to render a whole document without beign + * clipped by the viewport or drawing the viewport scrollbars. + */ + void SetIgnoreScrollFrame(nsIFrame* aFrame) { mIgnoreScrollFrame = aFrame; } + /** + * Get the scrollframe to ignore, if any. + */ + nsIFrame* GetIgnoreScrollFrame() { return mIgnoreScrollFrame; } + /** + * Get the ViewID of the nearest scrolling ancestor frame. + */ + ViewID GetCurrentScrollParentId() const { return mCurrentScrollParentId; } + /** + * Calling this setter makes us include all out-of-flow descendant + * frames in the display list, wherever they may be positioned (even + * outside the dirty rects). + */ + void SetIncludeAllOutOfFlows() { mIncludeAllOutOfFlows = true; } + bool GetIncludeAllOutOfFlows() const { return mIncludeAllOutOfFlows; } + /** + * Calling this setter makes us exclude all leaf frames that aren't + * selected. + */ + void SetSelectedFramesOnly() { mSelectedFramesOnly = true; } + bool GetSelectedFramesOnly() { return mSelectedFramesOnly; } + /** + * Calling this setter makes us compute accurate visible regions at the cost + * of performance if regions get very complex. + */ + void SetAccurateVisibleRegions() { mAccurateVisibleRegions = true; } + bool GetAccurateVisibleRegions() { return mAccurateVisibleRegions; } + /** + * Allows callers to selectively override the regular paint suppression checks, + * so that methods like GetFrameForPoint work when painting is suppressed. + */ + void IgnorePaintSuppression() { mIgnoreSuppression = true; } + /** + * @return Returns if this builder will ignore paint suppression. + */ + bool IsIgnoringPaintSuppression() { return mIgnoreSuppression; } + /** + * @return Returns if this builder had to ignore painting suppression on some + * document when building the display list. + */ + bool GetHadToIgnorePaintSuppression() { return mHadToIgnoreSuppression; } + /** + * Call this if we're doing normal painting to the window. + */ + void SetPaintingToWindow(bool aToWindow) { mIsPaintingToWindow = aToWindow; } + bool IsPaintingToWindow() const { return mIsPaintingToWindow; } + /** + * Call this to prevent descending into subdocuments. + */ + void SetDescendIntoSubdocuments(bool aDescend) { mDescendIntoSubdocuments = aDescend; } + bool GetDescendIntoSubdocuments() { return mDescendIntoSubdocuments; } + + /** + * Returns true if merging and flattening of display lists should be + * performed while computing visibility. + */ + bool AllowMergingAndFlattening() { return mAllowMergingAndFlattening; } + void SetAllowMergingAndFlattening(bool aAllow) { mAllowMergingAndFlattening = aAllow; } + + nsDisplayLayerEventRegions* GetLayerEventRegions() { return mLayerEventRegions; } + void SetLayerEventRegions(nsDisplayLayerEventRegions* aItem) + { + mLayerEventRegions = aItem; + } + bool IsBuildingLayerEventRegions() + { + // Disable for now. + return false; + // return mMode == PAINTING; + } + + bool GetAncestorHasTouchEventHandler() { return mAncestorHasTouchEventHandler; } + void SetAncestorHasTouchEventHandler(bool aValue) + { + mAncestorHasTouchEventHandler = aValue; + } + + bool HaveScrollableDisplayPort() const { return mHaveScrollableDisplayPort; } + void SetHaveScrollableDisplayPort() { mHaveScrollableDisplayPort = true; } + + bool SetIsCompositingCheap(bool aCompositingCheap) { + bool temp = mIsCompositingCheap; + mIsCompositingCheap = aCompositingCheap; + return temp; + } + bool IsCompositingCheap() const { return mIsCompositingCheap; } + /** + * Display the caret if needed. + */ + void DisplayCaret(nsIFrame* aFrame, const nsRect& aDirtyRect, + nsDisplayList* aList) { + nsIFrame* frame = GetCaretFrame(); + if (aFrame == frame) { + frame->DisplayCaret(this, aDirtyRect, aList); + } + } + /** + * Get the frame that the caret is supposed to draw in. + * If the caret is currently invisible, this will be null. + */ + nsIFrame* GetCaretFrame() { + return CurrentPresShellState()->mCaretFrame; + } + /** + * Get the caret associated with the current presshell. + */ + nsCaret* GetCaret(); + /** + * Notify the display list builder that we're entering a presshell. + * aReferenceFrame should be a frame in the new presshell and aDirtyRect + * should be the current dirty rect in aReferenceFrame's coordinate space. + */ + void EnterPresShell(nsIFrame* aReferenceFrame, const nsRect& aDirtyRect); + /** + * For print-preview documents, we sometimes need to build display items for + * the same frames multiple times in the same presentation, with different + * clipping. Between each such batch of items, call + * ResetMarkedFramesForDisplayList to make sure that the results of + * MarkFramesForDisplayList do not carry over between batches. + */ + void ResetMarkedFramesForDisplayList(); + /** + * Notify the display list builder that we're leaving a presshell. + */ + void LeavePresShell(nsIFrame* aReferenceFrame, const nsRect& aDirtyRect); + + /** + * Returns true if we're currently building a display list that's + * directly or indirectly under an nsDisplayTransform. + */ + bool IsInTransform() const { return mInTransform; } + /** + * Indicate whether or not we're directly or indirectly under and + * nsDisplayTransform or SVG foreignObject. + */ + void SetInTransform(bool aInTransform) { mInTransform = aInTransform; } + + /** + * Returns true if we're currently building display items that are in + * true fixed position subtree. + */ + bool IsInFixedPos() const { return mInFixedPos; } + + /** + * @return true if images have been set to decode synchronously. + */ + bool ShouldSyncDecodeImages() { return mSyncDecodeImages; } + + /** + * Indicates whether we should synchronously decode images. If true, we decode + * and draw whatever image data has been loaded. If false, we just draw + * whatever has already been decoded. + */ + void SetSyncDecodeImages(bool aSyncDecodeImages) { + mSyncDecodeImages = aSyncDecodeImages; + } + + /** + * Helper method to generate background painting flags based on the + * information available in the display list builder. Currently only + * accounts for mSyncDecodeImages. + */ + uint32_t GetBackgroundPaintFlags(); + + /** + * Subtracts aRegion from *aVisibleRegion. We avoid letting + * aVisibleRegion become overcomplex by simplifying it if necessary --- + * unless mAccurateVisibleRegions is set, in which case we let it + * get arbitrarily complex. + */ + void SubtractFromVisibleRegion(nsRegion* aVisibleRegion, + const nsRegion& aRegion); + + /** + * Mark the frames in aFrames to be displayed if they intersect aDirtyRect + * (which is relative to aDirtyFrame). If the frames have placeholders + * that might not be displayed, we mark the placeholders and their ancestors + * to ensure that display list construction descends into them + * anyway. nsDisplayListBuilder will take care of unmarking them when it is + * destroyed. + */ + void MarkFramesForDisplayList(nsIFrame* aDirtyFrame, + const nsFrameList& aFrames, + const nsRect& aDirtyRect); + /** + * Mark all child frames that Preserve3D() as needing display. + * Because these frames include transforms set on their parent, dirty rects + * for intermediate frames may be empty, yet child frames could still be visible. + */ + void MarkPreserve3DFramesForDisplayList(nsIFrame* aDirtyFrame, const nsRect& aDirtyRect); + + /** + * Get the area of the final transparent region. + */ + const nsRegion* GetFinalTransparentRegion() { return mFinalTransparentRegion; } + /** + * Record the area of the final transparent region after all visibility + * calculations were performed. + */ + void SetFinalTransparentRegion(const nsRegion& aFinalTransparentRegion) + { + mFinalTransparentRegion = &aFinalTransparentRegion; + } + + const nsTArray& GetThemeGeometries() { return mThemeGeometries; } + + /** + * Returns true if we need to descend into this frame when building + * the display list, even though it doesn't intersect the dirty + * rect, because it may have out-of-flows that do so. + */ + bool ShouldDescendIntoFrame(nsIFrame* aFrame) const { + return + (aFrame->GetStateBits() & NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO) || + GetIncludeAllOutOfFlows(); + } + + /** + * Notifies the builder that a particular themed widget exists + * at the given rectangle within the currently built display list. + * For certain appearance values (currently only + * NS_THEME_MOZ_MAC_UNIFIED_TOOLBAR, NS_THEME_TOOLBAR and + * NS_THEME_WINDOW_TITLEBAR) this gets called during every display list + * construction, for every themed widget of the right type within the + * display list, except for themed widgets which are transformed or have + * effects applied to them (e.g. CSS opacity or filters). + * + * @param aWidgetType the -moz-appearance value for the themed widget + * @param aRect the device-pixel rect relative to the widget's displayRoot + * for the themed widget + */ + void RegisterThemeGeometry(uint8_t aWidgetType, + const nsIntRect& aRect) { + if (mIsPaintingToWindow && mPresShellStates.Length() == 1) { + ThemeGeometry geometry(aWidgetType, aRect); + mThemeGeometries.AppendElement(geometry); + } + } + + /** + * Allocate memory in our arena. It will only be freed when this display list + * builder is destroyed. This memory holds nsDisplayItems. nsDisplayItem + * destructors are called as soon as the item is no longer used. + */ + void* Allocate(size_t aSize); + + /** + * Allocate a new DisplayListClip in the arena. Will be cleaned up + * automatically when the arena goes away. + */ + const DisplayItemClip* AllocateDisplayItemClip(const DisplayItemClip& aOriginal); + + /** + * Transfer off main thread animations to the layer. May be called + * with aBuilder and aItem both null, but only if the caller has + * already checked that off main thread animations should be sent to + * the layer. When they are both null, the animations are added to + * the layer as pending animations. + */ + static void AddAnimationsAndTransitionsToLayer(Layer* aLayer, + nsDisplayListBuilder* aBuilder, + nsDisplayItem* aItem, + nsIFrame* aFrame, + nsCSSProperty aProperty); + /** + * A helper class to temporarily set the value of + * mIsAtRootOfPseudoStackingContext, and temporarily + * update mCachedOffsetFrame/mCachedOffset from a frame to its child. + * Also saves and restores mClipState. + */ + class AutoBuildingDisplayList; + friend class AutoBuildingDisplayList; + class AutoBuildingDisplayList { + public: + AutoBuildingDisplayList(nsDisplayListBuilder* aBuilder, bool aIsRoot) + : mBuilder(aBuilder), + mPrevCachedOffsetFrame(aBuilder->mCachedOffsetFrame), + mPrevCachedReferenceFrame(aBuilder->mCachedReferenceFrame), + mPrevLayerEventRegions(aBuilder->mLayerEventRegions), + mPrevCachedOffset(aBuilder->mCachedOffset), + mPrevIsAtRootOfPseudoStackingContext(aBuilder->mIsAtRootOfPseudoStackingContext), + mPrevAncestorHasTouchEventHandler(aBuilder->mAncestorHasTouchEventHandler) + { + aBuilder->mIsAtRootOfPseudoStackingContext = aIsRoot; + } + AutoBuildingDisplayList(nsDisplayListBuilder* aBuilder, + nsIFrame* aForChild, bool aIsRoot) + : mBuilder(aBuilder), + mPrevCachedOffsetFrame(aBuilder->mCachedOffsetFrame), + mPrevCachedReferenceFrame(aBuilder->mCachedReferenceFrame), + mPrevLayerEventRegions(aBuilder->mLayerEventRegions), + mPrevCachedOffset(aBuilder->mCachedOffset), + mPrevIsAtRootOfPseudoStackingContext(aBuilder->mIsAtRootOfPseudoStackingContext), + mPrevAncestorHasTouchEventHandler(aBuilder->mAncestorHasTouchEventHandler) + { + if (aForChild->IsTransformed()) { + aBuilder->mCachedOffset = nsPoint(); + aBuilder->mCachedReferenceFrame = aForChild; + } else if (mPrevCachedOffsetFrame == aForChild->GetParent()) { + aBuilder->mCachedOffset += aForChild->GetPosition(); + } else { + aBuilder->mCachedOffset = aBuilder->ToReferenceFrame(aForChild); + } + aBuilder->mCachedOffsetFrame = aForChild; + aBuilder->mIsAtRootOfPseudoStackingContext = aIsRoot; + } + ~AutoBuildingDisplayList() { + mBuilder->mCachedOffsetFrame = mPrevCachedOffsetFrame; + mBuilder->mCachedReferenceFrame = mPrevCachedReferenceFrame; + mBuilder->mLayerEventRegions = mPrevLayerEventRegions; + mBuilder->mCachedOffset = mPrevCachedOffset; + mBuilder->mIsAtRootOfPseudoStackingContext = mPrevIsAtRootOfPseudoStackingContext; + mBuilder->mAncestorHasTouchEventHandler = mPrevAncestorHasTouchEventHandler; + } + private: + nsDisplayListBuilder* mBuilder; + const nsIFrame* mPrevCachedOffsetFrame; + const nsIFrame* mPrevCachedReferenceFrame; + nsDisplayLayerEventRegions* mPrevLayerEventRegions; + nsPoint mPrevCachedOffset; + bool mPrevIsAtRootOfPseudoStackingContext; + bool mPrevAncestorHasTouchEventHandler; + }; + + /** + * A helper class to temporarily set the value of mInTransform. + */ + class AutoInTransformSetter; + friend class AutoInTransformSetter; + class AutoInTransformSetter { + public: + AutoInTransformSetter(nsDisplayListBuilder* aBuilder, bool aInTransform) + : mBuilder(aBuilder), mOldValue(aBuilder->mInTransform) { + aBuilder->mInTransform = aInTransform; + } + ~AutoInTransformSetter() { + mBuilder->mInTransform = mOldValue; + } + private: + nsDisplayListBuilder* mBuilder; + bool mOldValue; + }; + + /** + * A helper class to temporarily set the value of mInFixedPos. + */ + class AutoInFixedPosSetter; + friend class AutoInFixedPosSetter; + class AutoInFixedPosSetter { + public: + AutoInFixedPosSetter(nsDisplayListBuilder* aBuilder, bool aInFixedPos) + : mBuilder(aBuilder), mOldValue(aBuilder->mInFixedPos) { + aBuilder->mInFixedPos = aInFixedPos; + } + ~AutoInFixedPosSetter() { + mBuilder->mInFixedPos = mOldValue; + } + private: + nsDisplayListBuilder* mBuilder; + bool mOldValue; + }; + + /** + * A helper class to temporarily set the value of mCurrentScrollParentId. + */ + class AutoCurrentScrollParentIdSetter; + friend class AutoCurrentScrollParentIdSetter; + class AutoCurrentScrollParentIdSetter { + public: + AutoCurrentScrollParentIdSetter(nsDisplayListBuilder* aBuilder, ViewID aScrollId) + : mBuilder(aBuilder), mOldValue(aBuilder->mCurrentScrollParentId) { + aBuilder->mCurrentScrollParentId = aScrollId; + } + ~AutoCurrentScrollParentIdSetter() { + mBuilder->mCurrentScrollParentId = mOldValue; + } + private: + nsDisplayListBuilder* mBuilder; + ViewID mOldValue; + }; + + // Helpers for tables + nsDisplayTableItem* GetCurrentTableItem() { return mCurrentTableItem; } + void SetCurrentTableItem(nsDisplayTableItem* aTableItem) { mCurrentTableItem = aTableItem; } + + struct OutOfFlowDisplayData { + OutOfFlowDisplayData(const DisplayItemClip& aContainingBlockClip, + const nsRect &aDirtyRect) + : mContainingBlockClip(aContainingBlockClip) + , mDirtyRect(aDirtyRect) + {} + OutOfFlowDisplayData(const nsRect &aDirtyRect) + : mDirtyRect(aDirtyRect) + {} + DisplayItemClip mContainingBlockClip; + nsRect mDirtyRect; + }; + static void DestroyOutOfFlowDisplayData(void* aPropertyValue) + { + delete static_cast(aPropertyValue); + } + + NS_DECLARE_FRAME_PROPERTY(OutOfFlowDisplayDataProperty, DestroyOutOfFlowDisplayData) + NS_DECLARE_FRAME_PROPERTY(Preserve3DDirtyRectProperty, nsIFrame::DestroyRect) + + nsPresContext* CurrentPresContext() { + return CurrentPresShellState()->mPresShell->GetPresContext(); + } + + /** + * Accumulates the bounds of box frames that have moz-appearance + * -moz-win-exclude-glass style. Used in setting glass margins on + * Windows. + */ + void AddExcludedGlassRegion(nsRect &bounds) { + mExcludedGlassRegion.Or(mExcludedGlassRegion, bounds); + } + const nsRegion& GetExcludedGlassRegion() { + return mExcludedGlassRegion; + } + void SetGlassDisplayItem(nsDisplayItem* aItem) { + if (mGlassDisplayItem) { + // Web pages or extensions could trigger this by using + // -moz-appearance:win-borderless-glass etc on their own elements. + // Keep the first one, since that will be the background of the root + // window + NS_WARNING("Multiple glass backgrounds found?"); + } else { + mGlassDisplayItem = aItem; + } + } + bool NeedToForceTransparentSurfaceForItem(nsDisplayItem* aItem) { + return aItem == mGlassDisplayItem; + } + + void SetContainsPluginItem() { mContainsPluginItem = true; } + bool ContainsPluginItem() { return mContainsPluginItem; } + + /** + * mContainsBlendMode is true if we processed a display item that + * has a blend mode attached. We do this so we can insert a + * nsDisplayBlendContainer in the parent stacking context. + */ + void SetContainsBlendMode(bool aContainsBlendMode) { mContainsBlendMode = aContainsBlendMode; } + bool ContainsBlendMode() const { return mContainsBlendMode; } + + DisplayListClipState& ClipState() { return mClipState; } + +private: + void MarkOutOfFlowFrameForDisplay(nsIFrame* aDirtyFrame, nsIFrame* aFrame, + const nsRect& aDirtyRect); + + struct PresShellState { + nsIPresShell* mPresShell; + nsIFrame* mCaretFrame; + uint32_t mFirstFrameMarkedForDisplay; + bool mIsBackgroundOnly; + }; + PresShellState* CurrentPresShellState() { + NS_ASSERTION(mPresShellStates.Length() > 0, + "Someone forgot to enter a presshell"); + return &mPresShellStates[mPresShellStates.Length() - 1]; + } + + nsIFrame* mReferenceFrame; + nsIFrame* mIgnoreScrollFrame; + nsDisplayLayerEventRegions* mLayerEventRegions; + PLArenaPool mPool; + nsCOMPtr mBoundingSelection; + nsAutoTArray mPresShellStates; + nsAutoTArray mFramesMarkedForDisplay; + nsAutoTArray mThemeGeometries; + nsDisplayTableItem* mCurrentTableItem; + DisplayListClipState mClipState; + const nsRegion* mFinalTransparentRegion; + // When mCachedOffsetFrame is non-null, mCachedOffset is the offset from + // mCachedOffsetFrame to mReferenceFrame. + const nsIFrame* mCachedOffsetFrame; + const nsIFrame* mCachedReferenceFrame; + nsPoint mCachedOffset; + nsRegion mExcludedGlassRegion; + // The display item for the Windows window glass background, if any + nsDisplayItem* mGlassDisplayItem; + nsTArray mDisplayItemClipsToDestroy; + Mode mMode; + ViewID mCurrentScrollParentId; + bool mBuildCaret; + bool mIgnoreSuppression; + bool mHadToIgnoreSuppression; + bool mIsAtRootOfPseudoStackingContext; + bool mIncludeAllOutOfFlows; + bool mDescendIntoSubdocuments; + bool mSelectedFramesOnly; + bool mAccurateVisibleRegions; + bool mAllowMergingAndFlattening; + bool mWillComputePluginGeometry; + // True when we're building a display list that's directly or indirectly + // under an nsDisplayTransform + bool mInTransform; + bool mInFixedPos; + bool mSyncDecodeImages; + bool mIsPaintingToWindow; + bool mIsCompositingCheap; + bool mContainsPluginItem; + bool mContainsBlendMode; + bool mAncestorHasTouchEventHandler; + // True when the first async-scrollable scroll frame for which we build a + // display list has a display port. An async-scrollable scroll frame is one + // which WantsAsyncScroll(). + bool mHaveScrollableDisplayPort; +}; + +class nsDisplayItem; +class nsDisplayList; +/** + * nsDisplayItems are put in singly-linked lists rooted in an nsDisplayList. + * nsDisplayItemLink holds the link. The lists are linked from lowest to + * highest in z-order. + */ +class nsDisplayItemLink { + // This is never instantiated directly, so no need to count constructors and + // destructors. +protected: + nsDisplayItemLink() : mAbove(nullptr) {} + nsDisplayItem* mAbove; + + friend class nsDisplayList; +}; + +/** + * This is the unit of rendering and event testing. Each instance of this + * class represents an entity that can be drawn on the screen, e.g., a + * frame's CSS background, or a frame's text string. + * + * nsDisplayListItems can be containers --- i.e., they can perform hit testing + * and painting by recursively traversing a list of child items. + * + * These are arena-allocated during display list construction. A typical + * subclass would just have a frame pointer, so its object would be just three + * pointers (vtable, next-item, frame). + * + * Display items belong to a list at all times (except temporarily as they + * move from one list to another). + */ +class nsDisplayItem : public nsDisplayItemLink { +public: + typedef mozilla::ContainerLayerParameters ContainerLayerParameters; + typedef mozilla::DisplayItemClip DisplayItemClip; + typedef mozilla::layers::FrameMetrics::ViewID ViewID; + typedef mozilla::layers::Layer Layer; + typedef mozilla::layers::LayerManager LayerManager; + typedef mozilla::LayerState LayerState; + + // This is never instantiated directly (it has pure virtual methods), so no + // need to count constructors and destructors. + nsDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : mFrame(aFrame) + , mClip(aBuilder->ClipState().GetCurrentCombinedClip(aBuilder)) + , mInFixedPos(aBuilder->IsInFixedPos()) +#ifdef MOZ_DUMP_PAINTING + , mPainted(false) +#endif + { + mReferenceFrame = aBuilder->FindReferenceFrameFor(aFrame); + mToReferenceFrame = aBuilder->ToReferenceFrame(aFrame); + } + nsDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + const nsIFrame* aReferenceFrame, + const nsPoint& aToReferenceFrame) + : mFrame(aFrame) + , mClip(aBuilder->ClipState().GetCurrentCombinedClip(aBuilder)) + , mReferenceFrame(aReferenceFrame) + , mToReferenceFrame(aToReferenceFrame) + , mInFixedPos(aBuilder->IsInFixedPos()) +#ifdef MOZ_DUMP_PAINTING + , mPainted(false) +#endif + { + } + /** + * This constructor is only used in rare cases when we need to construct + * temporary items. + */ + nsDisplayItem(nsIFrame* aFrame) + : mFrame(aFrame) + , mClip(nullptr) + , mReferenceFrame(nullptr) + , mInFixedPos(false) +#ifdef MOZ_DUMP_PAINTING + , mPainted(false) +#endif + { + } + virtual ~nsDisplayItem() {} + + void* operator new(size_t aSize, + nsDisplayListBuilder* aBuilder) CPP_THROW_NEW { + return aBuilder->Allocate(aSize); + } + +// Contains all the type integers for each display list item type +#include "nsDisplayItemTypes.h" + + struct HitTestState { + typedef nsTArray ShadowArray; + + HitTestState(ShadowArray* aShadows = nullptr) + : mShadows(aShadows) { + } + + ~HitTestState() { + NS_ASSERTION(mItemBuffer.Length() == 0, + "mItemBuffer should have been cleared"); + } + + nsAutoTArray mItemBuffer; + + // It is sometimes useful to hit test for frames that are not in this + // process. Display items may append IDs into this array if it is + // non-null. + ShadowArray* mShadows; + }; + + /** + * Some consecutive items should be rendered together as a unit, e.g., + * outlines for the same element. For this, we need a way for items to + * identify their type. We use the type for other purposes too. + */ + virtual Type GetType() = 0; + /** + * Pairing this with the GetUnderlyingFrame() pointer gives a key that + * uniquely identifies this display item in the display item tree. + * XXX check ScrollLayerWrapper/nsOptionEventGrabberWrapper/nsXULEventRedirectorWrapper + */ + virtual uint32_t GetPerFrameKey() { return uint32_t(GetType()); } + /** + * This is called after we've constructed a display list for event handling. + * When this is called, we've already ensured that aRect intersects the + * item's bounds and that clipping has been taking into account. + * + * @param aRect the point or rect being tested, relative to the reference + * frame. If the width and height are both 1 app unit, it indicates we're + * hit testing a point, not a rect. + * @param aState must point to a HitTestState. If you don't have one, + * just create one with the default constructor and pass it in. + * @param aOutFrames each item appends the frame(s) in this display item that + * the rect is considered over (if any) to aOutFrames. + */ + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, nsTArray *aOutFrames) {} + /** + * @return the frame that this display item is based on. This is used to sort + * items by z-index and content order and for some other uses. Never + * returns null. + */ + inline nsIFrame* Frame() const { return mFrame; } + /** + * Compute the used z-index of our frame; returns zero for elements to which + * z-index does not apply, and for z-index:auto. + * @note This can be overridden, @see nsDisplayWrapList::SetOverrideZIndex. + */ + virtual int32_t ZIndex() const; + /** + * The default bounds is the frame border rect. + * @param aSnap *aSnap is set to true if the returned rect will be + * snapped to nearest device pixel edges during actual drawing. + * It might be set to false and snap anyway, so code computing the set of + * pixels affected by this display item needs to round outwards to pixel + * boundaries when *aSnap is set to false. + * This does not take the item's clipping into account. + * @return a rectangle relative to aBuilder->ReferenceFrame() that + * contains the area drawn by this display item + */ + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) + { + *aSnap = false; + return nsRect(ToReferenceFrame(), Frame()->GetSize()); + } + /** + * Returns the result of GetBounds intersected with the item's clip. + * The intersection is approximate since rounded corners are not taking into + * account. + */ + nsRect GetClippedBounds(nsDisplayListBuilder* aBuilder); + nsRect GetBorderRect() { + return nsRect(ToReferenceFrame(), Frame()->GetSize()); + } + nsRect GetPaddingRect() { + return Frame()->GetPaddingRectRelativeToSelf() + ToReferenceFrame(); + } + nsRect GetContentRect() { + return Frame()->GetContentRectRelativeToSelf() + ToReferenceFrame(); + } + + /** + * Checks if the frame(s) owning this display item have been marked as invalid, + * and needing repainting. + */ + virtual bool IsInvalid(nsRect& aRect) { + bool result = mFrame ? mFrame->IsInvalid(aRect) : false; + aRect += ToReferenceFrame(); + return result; + } + + /** + * Creates and initializes an nsDisplayItemGeometry object that retains the current + * areas covered by this display item. These need to retain enough information + * such that they can be compared against a future nsDisplayItem of the same type, + * and determine if repainting needs to happen. + * + * Subclasses wishing to store more information need to override both this + * and ComputeInvalidationRegion, as well as implementing an nsDisplayItemGeometry + * subclass. + * + * The default implementation tracks both the display item bounds, and the frame's + * border rect. + */ + virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) + { + return new nsDisplayItemGenericGeometry(this, aBuilder); + } + + /** + * Compares an nsDisplayItemGeometry object from a previous paint against the + * current item. Computes if the geometry of the item has changed, and the + * invalidation area required for correct repainting. + * + * The existing geometry will have been created from a display item with a + * matching GetPerFrameKey()/mFrame pair to the current item. + * + * The default implementation compares the display item bounds, and the frame's + * border rect, and invalidates the entire bounds if either rect changes. + * + * @param aGeometry The geometry of the matching display item from the + * previous paint. + * @param aInvalidRegion Output param, the region to invalidate, or + * unchanged if none. + */ + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) + { + const nsDisplayItemGenericGeometry* geometry = static_cast(aGeometry); + bool snap; + if (!geometry->mBounds.IsEqualInterior(GetBounds(aBuilder, &snap)) || + !geometry->mBorderRect.IsEqualInterior(GetBorderRect())) { + aInvalidRegion->Or(GetBounds(aBuilder, &snap), geometry->mBounds); + } + } + + /** + * An alternative default implementation of ComputeInvalidationRegion, + * that instead invalidates only the changed area between the two items. + */ + void ComputeInvalidationRegionDifference(nsDisplayListBuilder* aBuilder, + const nsDisplayItemBoundsGeometry* aGeometry, + nsRegion* aInvalidRegion) + { + bool snap; + nsRect bounds = GetBounds(aBuilder, &snap); + + if (!aGeometry->mBounds.IsEqualInterior(bounds)) { + nscoord radii[8]; + if (aGeometry->mHasRoundedCorners || + Frame()->GetBorderRadii(radii)) { + aInvalidRegion->Or(aGeometry->mBounds, bounds); + } else { + aInvalidRegion->Xor(aGeometry->mBounds, bounds); + } + } + } + + /** + * For display items types that just draw a background we use this function + * to do any invalidation that might be needed if we are asked to sync decode + * images. + */ + void AddInvalidRegionForSyncDecodeBackgroundImages( + nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion); + + /** + * Called when the area rendered by this display item has changed (been + * invalidated or changed geometry) since the last paint. This includes + * when the display item was not rendered at all in the last paint. + * It does NOT get called when a display item was being rendered and no + * longer is, because generally that means there is no display item to + * call this method on. + */ + virtual void NotifyRenderingChanged() {} + + /** + * @param aSnap set to true if the edges of the rectangles of the opaque + * region would be snapped to device pixels when drawing + * @return a region of the item that is opaque --- that is, every pixel + * that is visible (according to ComputeVisibility) is painted with an opaque + * color. This is useful for determining when one piece + * of content completely obscures another so that we can do occlusion + * culling. + * This does not take clipping into account. + */ + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) + { + *aSnap = false; + return nsRegion(); + } + /** + * If this returns true, then aColor is set to the uniform color + * @return true if the item is guaranteed to paint every pixel in its + * bounds with the same (possibly translucent) color + */ + virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) { return false; } + /** + * @return false if the painting performed by the item is invariant + * when the item's underlying frame is moved relative to aFrame. + * In other words, if you render the item at locations P and P', the rendering + * only differs by the translation. + * It return true for all wrapped lists. + */ + virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder, + nsIFrame* aFrame) + { return false; } + /** + * @return true if the contents of this item are rendered fixed relative + * to the nearest viewport. + */ + virtual bool ShouldFixToViewport(nsDisplayListBuilder* aBuilder) + { return false; } + + /** + * Returns true if all layers that can be active should be forced to be + * active. Requires setting the pref layers.force-active=true. + */ + static bool ForceActiveLayers(); + + /** + * Returns the maximum number of layers that should be created + * or -1 for no limit. Requires setting the pref layers.max-acitve. + */ + static int32_t MaxActiveLayers(); + + /** + * @return LAYER_NONE if BuildLayer will return null. In this case + * there is no layer for the item, and Paint should be called instead + * to paint the content using Thebes. + * Return LAYER_INACTIVE if there is a layer --- BuildLayer will + * not return null (unless there's an error) --- but the layer contents + * are not changing frequently. In this case it makes sense to composite + * the layer into a ThebesLayer with other content, so we don't have to + * recomposite it every time we paint. + * Note: GetLayerState is only allowed to return LAYER_INACTIVE if all + * descendant display items returned LAYER_INACTIVE or LAYER_NONE. Also, + * all descendant display item frames must have an active scrolled root + * that's either the same as this item's frame's active scrolled root, or + * a descendant of this item's frame. This ensures that the entire + * set of display items can be collapsed onto a single ThebesLayer. + * Return LAYER_ACTIVE if the layer is active, that is, its contents are + * changing frequently. In this case it makes sense to keep the layer + * as a separate buffer in VRAM and composite it into the destination + * every time we paint. + * + * Users of GetLayerState should check ForceActiveLayers() and if it returns + * true, change a returned value of LAYER_INACTIVE to LAYER_ACTIVE. + */ + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) + { return mozilla::LAYER_NONE; } + /** + * Return true to indicate the layer should be constructed even if it's + * completely invisible. + */ + virtual bool ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder) + { return false; } + /** + * Actually paint this item to some rendering context. + * Content outside mVisibleRect need not be painted. + * aCtx must be set up as for nsDisplayList::Paint. + */ + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) {} + +#ifdef MOZ_DUMP_PAINTING + /** + * Mark this display item as being painted via FrameLayerBuilder::DrawThebesLayer. + */ + bool Painted() { return mPainted; } + + /** + * Check if this display item has been painted. + */ + void SetPainted() { mPainted = true; } +#endif + + /** + * Get the layer drawn by this display item. Call this only if + * GetLayerState() returns something other than LAYER_NONE. + * If GetLayerState returned LAYER_NONE then Paint will be called + * instead. + * This is called while aManager is in the construction phase. + * + * The caller (nsDisplayList) is responsible for setting the visible + * region of the layer. + * + * @param aContainerParameters should be passed to + * FrameLayerBuilder::BuildContainerLayerFor if a ContainerLayer is + * constructed. + */ + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) + { return nullptr; } + + /** + * On entry, aVisibleRegion contains the region (relative to ReferenceFrame()) + * which may be visible. If the display item opaquely covers an area, it + * can remove that area from aVisibleRegion before returning. + * nsDisplayList::ComputeVisibility automatically subtracts the region + * returned by GetOpaqueRegion, and automatically removes items whose bounds + * do not intersect the visible area, so implementations of + * nsDisplayItem::ComputeVisibility do not need to do these things. + * nsDisplayList::ComputeVisibility will already have set mVisibleRect on + * this item to the intersection of *aVisibleRegion and this item's bounds. + * We rely on that, so this should only be called by + * nsDisplayList::ComputeVisibility or nsDisplayItem::RecomputeVisibility. + * aAllowVisibleRegionExpansion is a rect where we are allowed to + * expand the visible region and is only used for making sure the + * background behind a plugin is visible. + * This method needs to be idempotent. + * + * @return true if the item is visible, false if no part of the item + * is visible. + */ + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) + { return !mVisibleRect.IsEmpty(); } + + /** + * Try to merge with the other item (which is below us in the display + * list). This gets used by nsDisplayClip to coalesce clipping operations + * (optimization), by nsDisplayOpacity to merge rendering for the same + * content element into a single opacity group (correctness), and will be + * used by nsDisplayOutline to merge multiple outlines for the same element + * (also for correctness). + * @return true if the merge was successful and the other item should be deleted + */ + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) { + return false; + } + + /** + * Appends the underlying frames of all display items that have been + * merged into this one (excluding this item's own underlying frame) + * to aFrames. + */ + virtual void GetMergedFrames(nsTArray* aFrames) {} + + /** + * During the visibility computation and after TryMerge, display lists may + * return true here to flatten themselves away, removing them. This + * flattening is distinctly different from FlattenTo, which occurs before + * items are merged together. + */ + virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) { + return false; + } + + /** + * If this has a child list where the children are in the same coordinate + * system as this item (i.e., they have the same reference frame), + * return the list. + */ + virtual nsDisplayList* GetSameCoordinateSystemChildren() { return nullptr; } + virtual void UpdateBounds(nsDisplayListBuilder* aBuilder) {} + + /** + * If this has a child list, return it, even if the children are in + * a different coordinate system to this item. + */ + virtual nsDisplayList* GetChildren() { return nullptr; } + + /** + * Returns the visible rect. Should only be called after ComputeVisibility + * has happened. + */ + const nsRect& GetVisibleRect() { return mVisibleRect; } + + /** + * Stores the given opacity value to be applied when drawing. Returns + * false if this isn't supported for this display item. + */ + virtual bool ApplyOpacity(nsDisplayListBuilder* aBuilder, + float aOpacity, + const DisplayItemClip* aClip) { + return false; + } + +#ifdef MOZ_DUMP_PAINTING + /** + * For debugging and stuff + */ + virtual const char* Name() = 0; + + virtual void WriteDebugInfo(nsACString& aTo) {} +#endif + + nsDisplayItem* GetAbove() { return mAbove; } + + /** + * Like ComputeVisibility, but does the work that nsDisplayList + * does per-item: + * -- Intersects GetBounds with aVisibleRegion and puts the result + * in mVisibleRect + * -- Subtracts bounds from aVisibleRegion if the item is opaque + */ + bool RecomputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion); + + /** + * Returns the result of aBuilder->ToReferenceFrame(GetUnderlyingFrame()) + */ + const nsPoint& ToReferenceFrame() const { + NS_ASSERTION(mFrame, "No frame?"); + return mToReferenceFrame; + } + /** + * @return the root of the display list's frame (sub)tree, whose origin + * establishes the coordinate system for the display list + */ + const nsIFrame* ReferenceFrame() const { return mReferenceFrame; } + + /** + * Returns the reference frame for display item children of this item. + */ + virtual const nsIFrame* ReferenceFrameForChildren() const { return mReferenceFrame; } + + /** + * Checks if this display item (or any children) contains content that might + * be rendered with component alpha (e.g. subpixel antialiasing). Returns the + * bounds of the area that needs component alpha, or an empty rect if nothing + * in the item does. + */ + virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) { return nsRect(); } + + /** + * Disable usage of component alpha. Currently only relevant for items that have text. + */ + virtual void DisableComponentAlpha() {} + + /** + * Check if we can add async animations to the layer for this display item. + */ + virtual bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) { + return false; + } + + virtual bool SupportsOptimizingToImage() { return false; } + + const DisplayItemClip& GetClip() + { + return mClip ? *mClip : DisplayItemClip::NoClip(); + } + void SetClip(nsDisplayListBuilder* aBuilder, const DisplayItemClip& aClip) + { + if (!aClip.HasClip()) { + mClip = nullptr; + return; + } + mClip = aBuilder->AllocateDisplayItemClip(aClip); + } + + void IntersectClip(nsDisplayListBuilder* aBuilder, const DisplayItemClip& aClip) + { + if (mClip) { + DisplayItemClip temp = *mClip; + temp.IntersectWith(aClip); + SetClip(aBuilder, temp); + } else { + SetClip(aBuilder, aClip); + } + } + + // If we return false here it means that if this item creates a layer then + // ProcessDisplayItems will not set the visible region on the layer. The item + // should set the visible region, usually in BuildContainerLayer. + virtual bool SetVisibleRegionOnLayer() { return true; } + + bool IsInFixedPos() { return mInFixedPos; } + +protected: + friend class nsDisplayList; + + nsDisplayItem() { mAbove = nullptr; } + + nsIFrame* mFrame; + const DisplayItemClip* mClip; + // Result of FindReferenceFrameFor(mFrame), if mFrame is non-null + const nsIFrame* mReferenceFrame; + // Result of ToReferenceFrame(mFrame), if mFrame is non-null + nsPoint mToReferenceFrame; + // This is the rectangle that needs to be painted. + // nsDisplayList::ComputeVisibility sets this to the visible region + // of the item by intersecting the current visible region with the bounds + // of the item. Paint implementations can use this to limit their drawing. + // Guaranteed to be contained in GetBounds(). + nsRect mVisibleRect; + bool mInFixedPos; +#ifdef MOZ_DUMP_PAINTING + // True if this frame has been painted. + bool mPainted; +#endif +}; + +/** + * Manages a singly-linked list of display list items. + * + * mSentinel is the sentinel list value, the first value in the null-terminated + * linked list of items. mTop is the last item in the list (whose 'above' + * pointer is null). This class has no virtual methods. So list objects are just + * two pointers. + * + * Stepping upward through this list is very fast. Stepping downward is very + * slow so we don't support it. The methods that need to step downward + * (HitTest(), ComputeVisibility()) internally build a temporary array of all + * the items while they do the downward traversal, so overall they're still + * linear time. We have optimized for efficient AppendToTop() of both + * items and lists, with minimal codesize. AppendToBottom() is efficient too. + */ +class nsDisplayList { +public: + typedef mozilla::layers::Layer Layer; + typedef mozilla::layers::LayerManager LayerManager; + typedef mozilla::layers::ThebesLayer ThebesLayer; + + /** + * Create an empty list. + */ + nsDisplayList() : + mIsOpaque(false) + { + mTop = &mSentinel; + mSentinel.mAbove = nullptr; +#if defined(DEBUG) || defined(MOZ_DUMP_PAINTING) + mDidComputeVisibility = false; +#endif + } + ~nsDisplayList() { + if (mSentinel.mAbove) { + NS_WARNING("Nonempty list left over?"); + } + DeleteAll(); + } + + /** + * Append an item to the top of the list. The item must not currently + * be in a list and cannot be null. + */ + void AppendToTop(nsDisplayItem* aItem) { + NS_ASSERTION(aItem, "No item to append!"); + NS_ASSERTION(!aItem->mAbove, "Already in a list!"); + mTop->mAbove = aItem; + mTop = aItem; + } + + /** + * Append a new item to the top of the list. If the item is null we return + * NS_ERROR_OUT_OF_MEMORY. The intended usage is AppendNewToTop(new ...); + */ + void AppendNewToTop(nsDisplayItem* aItem) { + if (aItem) { + AppendToTop(aItem); + } + } + + /** + * Append a new item to the bottom of the list. If the item is null we return + * NS_ERROR_OUT_OF_MEMORY. The intended usage is AppendNewToBottom(new ...); + */ + void AppendNewToBottom(nsDisplayItem* aItem) { + if (aItem) { + AppendToBottom(aItem); + } + } + + /** + * Append a new item to the bottom of the list. The item must be non-null + * and not already in a list. + */ + void AppendToBottom(nsDisplayItem* aItem) { + NS_ASSERTION(aItem, "No item to append!"); + NS_ASSERTION(!aItem->mAbove, "Already in a list!"); + aItem->mAbove = mSentinel.mAbove; + mSentinel.mAbove = aItem; + if (mTop == &mSentinel) { + mTop = aItem; + } + } + + /** + * Removes all items from aList and appends them to the top of this list + */ + void AppendToTop(nsDisplayList* aList) { + if (aList->mSentinel.mAbove) { + mTop->mAbove = aList->mSentinel.mAbove; + mTop = aList->mTop; + aList->mTop = &aList->mSentinel; + aList->mSentinel.mAbove = nullptr; + } + } + + /** + * Removes all items from aList and prepends them to the bottom of this list + */ + void AppendToBottom(nsDisplayList* aList) { + if (aList->mSentinel.mAbove) { + aList->mTop->mAbove = mSentinel.mAbove; + mSentinel.mAbove = aList->mSentinel.mAbove; + if (mTop == &mSentinel) { + mTop = aList->mTop; + } + + aList->mTop = &aList->mSentinel; + aList->mSentinel.mAbove = nullptr; + } + } + + /** + * Remove an item from the bottom of the list and return it. + */ + nsDisplayItem* RemoveBottom(); + + /** + * Remove all items from the list and call their destructors. + */ + void DeleteAll(); + + /** + * @return the item at the top of the list, or null if the list is empty + */ + nsDisplayItem* GetTop() const { + return mTop != &mSentinel ? static_cast(mTop) : nullptr; + } + /** + * @return the item at the bottom of the list, or null if the list is empty + */ + nsDisplayItem* GetBottom() const { return mSentinel.mAbove; } + bool IsEmpty() const { return mTop == &mSentinel; } + + /** + * This is *linear time*! + * @return the number of items in the list + */ + uint32_t Count() const; + /** + * Stable sort the list by the z-order of GetUnderlyingFrame() on + * each item. 'auto' is counted as zero. Content order is used as the + * secondary order. + * @param aCommonAncestor a common ancestor of all the content elements + * associated with the display items, for speeding up tree order + * checks, or nullptr if not known; it's only a hint, if it is not an + * ancestor of some elements, then we lose performance but not correctness + */ + void SortByZOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor); + /** + * Stable sort the list by the tree order of the content of + * GetUnderlyingFrame() on each item. z-index is ignored. + * @param aCommonAncestor a common ancestor of all the content elements + * associated with the display items, for speeding up tree order + * checks, or nullptr if not known; it's only a hint, if it is not an + * ancestor of some elements, then we lose performance but not correctness + */ + void SortByContentOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor); + + /** + * Generic stable sort. Take care, because some of the items might be nsDisplayLists + * themselves. + * aCmp(item1, item2) should return true if item1 <= item2. We sort the items + * into increasing order. + */ + typedef bool (* SortLEQ)(nsDisplayItem* aItem1, nsDisplayItem* aItem2, + void* aClosure); + void Sort(nsDisplayListBuilder* aBuilder, SortLEQ aCmp, void* aClosure); + + /** + * Compute visiblity for the items in the list. + * We put this logic here so it can be shared by top-level + * painting and also display items that maintain child lists. + * This is also a good place to put ComputeVisibility-related logic + * that must be applied to every display item. In particular, this + * sets mVisibleRect on each display item. + * This sets mIsOpaque if the entire visible area of this list has + * been removed from aVisibleRegion when we return. + * This does not remove any items from the list, so we can recompute + * visiblity with different regions later (see + * FrameLayerBuilder::DrawThebesLayer). + * This method needs to be idempotent. + * + * @param aVisibleRegion the area that is visible, relative to the + * reference frame; on return, this contains the area visible under the list. + * I.e., opaque contents of this list are subtracted from aVisibleRegion. + * @param aListVisibleBounds must be equal to the bounds of the intersection + * of aVisibleRegion and GetBounds() for this list. + * @param aDisplayPortFrame If the item for which this list corresponds is + * within a displayport, the scroll frame for which that display port + * applies. For root scroll frames, you can pass the the root frame instead. + * @return true if any item in the list is visible. + */ + bool ComputeVisibilityForSublist(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aListVisibleBounds, + const nsRect& aAllowVisibleRegionExpansion, + nsIFrame* aDisplayPortFrame = nullptr); + + /** + * As ComputeVisibilityForSublist, but computes visibility for a root + * list (a list that does not belong to an nsDisplayItem). + * This method needs to be idempotent. + * + * @param aVisibleRegion the area that is visible + * @param aDisplayPortFrame The root scroll frame, if a displayport is set + */ + bool ComputeVisibilityForRoot(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + nsIFrame* aDisplayPortFrame = nullptr); + + /** + * Returns true if the visible region output from ComputeVisiblity was + * empty, i.e. everything visible in this list is opaque. + */ + bool IsOpaque() const { + NS_ASSERTION(mDidComputeVisibility, "Need to have called ComputeVisibility"); + return mIsOpaque; + } + + /** + * Returns true if during ComputeVisibility any display item + * set the surface to be transparent. + */ + bool NeedsTransparentSurface() const { + NS_ASSERTION(mDidComputeVisibility, "Need to have called ComputeVisibility"); + return mForceTransparentSurface; + } + /** + * Paint the list to the rendering context. We assume that (0,0) in aCtx + * corresponds to the origin of the reference frame. For best results, + * aCtx's current transform should make (0,0) pixel-aligned. The + * rectangle in aDirtyRect is painted, which *must* be contained in the + * dirty rect used to construct the display list. + * + * If aFlags contains PAINT_USE_WIDGET_LAYERS and + * ShouldUseWidgetLayerManager() is set, then we will paint using + * the reference frame's widget's layer manager (and ctx may be null), + * otherwise we will use a temporary BasicLayerManager and ctx must + * not be null. + * + * If PAINT_FLUSH_LAYERS is set, we'll force a completely new layer + * tree to be created for this paint *and* the next paint. + * + * If PAINT_EXISTING_TRANSACTION is set, the reference frame's widget's + * layer manager has already had BeginTransaction() called on it and + * we should not call it again. + * + * If PAINT_COMPRESSED is set, the FrameLayerBuilder should be set to compressed mode + * to avoid short cut optimizations. + * + * ComputeVisibility must be called before Paint. + * + * This must only be called on the root display list of the display list + * tree. + */ + enum { + PAINT_DEFAULT = 0, + PAINT_USE_WIDGET_LAYERS = 0x01, + PAINT_FLUSH_LAYERS = 0x02, + PAINT_EXISTING_TRANSACTION = 0x04, + PAINT_NO_COMPOSITE = 0x08, + PAINT_COMPRESSED = 0x10 + }; + void PaintRoot(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx, + uint32_t aFlags) const; + /** + * Like PaintRoot, but used for internal display sublists. + * aForFrame is the frame that the list is associated with. + */ + void PaintForFrame(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx, + nsIFrame* aForFrame, uint32_t aFlags) const; + /** + * Get the bounds. Takes the union of the bounds of all children. + */ + nsRect GetBounds(nsDisplayListBuilder* aBuilder) const; + /** + * Find the topmost display item that returns a non-null frame, and return + * the frame. + */ + void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + nsDisplayItem::HitTestState* aState, + nsTArray *aOutFrames) const; + +#if defined(DEBUG) || defined(MOZ_DUMP_PAINTING) + bool DidComputeVisibility() const { return mDidComputeVisibility; } +#endif + + nsRect GetVisibleRect() const { return mVisibleRect; } + +private: + // This class is only used on stack, so we don't have to worry about leaking + // it. Don't let us be heap-allocated! + void* operator new(size_t sz) CPP_THROW_NEW; + + // Utility function used to massage the list during ComputeVisibility. + void FlattenTo(nsTArray* aElements); + + nsDisplayItemLink mSentinel; + nsDisplayItemLink* mTop; + + // This is set by ComputeVisibility + nsRect mVisibleRect; + // This is set to true by ComputeVisibility if the final visible region + // is empty (i.e. everything that was visible is covered by some + // opaque content in this list). + bool mIsOpaque; + // This is set to true by ComputeVisibility if any display item in this + // list needs to force the surface containing this list to be transparent. + bool mForceTransparentSurface; +#if defined(DEBUG) || defined(MOZ_DUMP_PAINTING) + bool mDidComputeVisibility; +#endif +}; + +/** + * This is passed as a parameter to nsIFrame::BuildDisplayList. That method + * will put any generated items onto the appropriate list given here. It's + * basically just a collection with one list for each separate stacking layer. + * The lists themselves are external to this object and thus can be shared + * with others. Some of the list pointers may even refer to the same list. + */ +class nsDisplayListSet { +public: + /** + * @return a list where one should place the border and/or background for + * this frame (everything from steps 1 and 2 of CSS 2.1 appendix E) + */ + nsDisplayList* BorderBackground() const { return mBorderBackground; } + /** + * @return a list where one should place the borders and/or backgrounds for + * block-level in-flow descendants (step 4 of CSS 2.1 appendix E) + */ + nsDisplayList* BlockBorderBackgrounds() const { return mBlockBorderBackgrounds; } + /** + * @return a list where one should place descendant floats (step 5 of + * CSS 2.1 appendix E) + */ + nsDisplayList* Floats() const { return mFloats; } + /** + * @return a list where one should place the (pseudo) stacking contexts + * for descendants of this frame (everything from steps 3, 7 and 8 + * of CSS 2.1 appendix E) + */ + nsDisplayList* PositionedDescendants() const { return mPositioned; } + /** + * @return a list where one should place the outlines + * for this frame and its descendants (step 9 of CSS 2.1 appendix E) + */ + nsDisplayList* Outlines() const { return mOutlines; } + /** + * @return a list where one should place all other content + */ + nsDisplayList* Content() const { return mContent; } + + nsDisplayListSet(nsDisplayList* aBorderBackground, + nsDisplayList* aBlockBorderBackgrounds, + nsDisplayList* aFloats, + nsDisplayList* aContent, + nsDisplayList* aPositionedDescendants, + nsDisplayList* aOutlines) : + mBorderBackground(aBorderBackground), + mBlockBorderBackgrounds(aBlockBorderBackgrounds), + mFloats(aFloats), + mContent(aContent), + mPositioned(aPositionedDescendants), + mOutlines(aOutlines) { + } + + /** + * A copy constructor that lets the caller override the BorderBackground + * list. + */ + nsDisplayListSet(const nsDisplayListSet& aLists, + nsDisplayList* aBorderBackground) : + mBorderBackground(aBorderBackground), + mBlockBorderBackgrounds(aLists.BlockBorderBackgrounds()), + mFloats(aLists.Floats()), + mContent(aLists.Content()), + mPositioned(aLists.PositionedDescendants()), + mOutlines(aLists.Outlines()) { + } + + /** + * Move all display items in our lists to top of the corresponding lists in the + * destination. + */ + void MoveTo(const nsDisplayListSet& aDestination) const; + +private: + // This class is only used on stack, so we don't have to worry about leaking + // it. Don't let us be heap-allocated! + void* operator new(size_t sz) CPP_THROW_NEW; + +protected: + nsDisplayList* mBorderBackground; + nsDisplayList* mBlockBorderBackgrounds; + nsDisplayList* mFloats; + nsDisplayList* mContent; + nsDisplayList* mPositioned; + nsDisplayList* mOutlines; +}; + +/** + * A specialization of nsDisplayListSet where the lists are actually internal + * to the object, and all distinct. + */ +struct nsDisplayListCollection : public nsDisplayListSet { + nsDisplayListCollection() : + nsDisplayListSet(&mLists[0], &mLists[1], &mLists[2], &mLists[3], &mLists[4], + &mLists[5]) {} + nsDisplayListCollection(nsDisplayList* aBorderBackground) : + nsDisplayListSet(aBorderBackground, &mLists[1], &mLists[2], &mLists[3], &mLists[4], + &mLists[5]) {} + + /** + * Sort all lists by content order. + */ + void SortAllByContentOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor) { + for (int32_t i = 0; i < 6; ++i) { + mLists[i].SortByContentOrder(aBuilder, aCommonAncestor); + } + } + +private: + // This class is only used on stack, so we don't have to worry about leaking + // it. Don't let us be heap-allocated! + void* operator new(size_t sz) CPP_THROW_NEW; + + nsDisplayList mLists[6]; +}; + + +class nsDisplayImageContainer : public nsDisplayItem { +public: + typedef mozilla::layers::ImageContainer ImageContainer; + typedef mozilla::layers::ImageLayer ImageLayer; + + nsDisplayImageContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : nsDisplayItem(aBuilder, aFrame) + {} + + virtual already_AddRefed GetContainer(LayerManager* aManager, + nsDisplayListBuilder* aBuilder) = 0; + virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) = 0; + + virtual bool SupportsOptimizingToImage() MOZ_OVERRIDE { return true; } +}; + +/** + * Use this class to implement not-very-frequently-used display items + * that are not opaque, do not receive events, and are bounded by a frame's + * border-rect. + * + * This should not be used for display items which are created frequently, + * because each item is one or two pointers bigger than an item from a + * custom display item class could be, and fractionally slower. However it does + * save code size. We use this for infrequently-used item types. + */ +class nsDisplayGeneric : public nsDisplayItem { +public: + typedef void (* PaintCallback)(nsIFrame* aFrame, nsRenderingContext* aCtx, + const nsRect& aDirtyRect, nsPoint aFramePt); + + nsDisplayGeneric(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + PaintCallback aPaint, const char* aName, Type aType) + : nsDisplayItem(aBuilder, aFrame), mPaint(aPaint) +#ifdef MOZ_DUMP_PAINTING + , mName(aName) +#endif + , mType(aType) + { + MOZ_COUNT_CTOR(nsDisplayGeneric); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayGeneric() { + MOZ_COUNT_DTOR(nsDisplayGeneric); + } +#endif + + virtual void Paint(nsDisplayListBuilder* aBuilder, + nsRenderingContext* aCtx) MOZ_OVERRIDE { + mPaint(mFrame, aCtx, mVisibleRect, ToReferenceFrame()); + } + NS_DISPLAY_DECL_NAME(mName, mType) + + virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE { + if (mType == nsDisplayItem::TYPE_HEADER_FOOTER) { + bool snap; + return GetBounds(aBuilder, &snap); + } + return nsRect(); + } + +protected: + PaintCallback mPaint; +#ifdef MOZ_DUMP_PAINTING + const char* mName; +#endif + Type mType; +}; + +/** + * Generic display item that can contain overflow. Use this in lieu of + * nsDisplayGeneric if you have a frame that should use the visual overflow + * rect of its frame when drawing items, instead of the frame's bounds. + */ +class nsDisplayGenericOverflow : public nsDisplayGeneric { + public: + nsDisplayGenericOverflow(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + PaintCallback aPaint, const char* aName, Type aType) + : nsDisplayGeneric(aBuilder, aFrame, aPaint, aName, aType) + { + MOZ_COUNT_CTOR(nsDisplayGenericOverflow); + } + #ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayGenericOverflow() { + MOZ_COUNT_DTOR(nsDisplayGenericOverflow); + } + #endif + + /** + * Returns the frame's visual overflow rect instead of the frame's bounds. + */ + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE + { + *aSnap = false; + return Frame()->GetVisualOverflowRect() + ToReferenceFrame(); + } +}; + +#if defined(MOZ_REFLOW_PERF_DSP) && defined(MOZ_REFLOW_PERF) +/** + * This class implements painting of reflow counts. Ideally, we would simply + * make all the frame names be those returned by nsFrame::GetFrameName + * (except that tosses in the content tag name!) and support only one color + * and eliminate this class altogether in favor of nsDisplayGeneric, but for + * the time being we can't pass args to a PaintCallback, so just have a + * separate class to do the right thing. Sadly, this alsmo means we need to + * hack all leaf frame classes to handle this. + * + * XXXbz the color thing is a bit of a mess, but 0 basically means "not set" + * here... I could switch it all to nscolor, but why bother? + */ +class nsDisplayReflowCount : public nsDisplayItem { +public: + nsDisplayReflowCount(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + const char* aFrameName, + uint32_t aColor = 0) + : nsDisplayItem(aBuilder, aFrame), + mFrameName(aFrameName), + mColor(aColor) + { + MOZ_COUNT_CTOR(nsDisplayReflowCount); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayReflowCount() { + MOZ_COUNT_DTOR(nsDisplayReflowCount); + } +#endif + + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE { + mFrame->PresContext()->PresShell()->PaintCount(mFrameName, aCtx, + mFrame->PresContext(), + mFrame, ToReferenceFrame(), + mColor); + } + NS_DISPLAY_DECL_NAME("nsDisplayReflowCount", TYPE_REFLOW_COUNT) +protected: + const char* mFrameName; + nscolor mColor; +}; + +#define DO_GLOBAL_REFLOW_COUNT_DSP(_name) \ + PR_BEGIN_MACRO \ + if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \ + PresContext()->PresShell()->IsPaintingFrameCounts()) { \ + aLists.Outlines()->AppendNewToTop( \ + new (aBuilder) nsDisplayReflowCount(aBuilder, this, _name)); \ + } \ + PR_END_MACRO + +#define DO_GLOBAL_REFLOW_COUNT_DSP_COLOR(_name, _color) \ + PR_BEGIN_MACRO \ + if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \ + PresContext()->PresShell()->IsPaintingFrameCounts()) { \ + aLists.Outlines()->AppendNewToTop( \ + new (aBuilder) nsDisplayReflowCount(aBuilder, this, _name, _color)); \ + } \ + PR_END_MACRO + +/* + Macro to be used for classes that don't actually implement BuildDisplayList + */ +#define DECL_DO_GLOBAL_REFLOW_COUNT_DSP(_class, _super) \ + void BuildDisplayList(nsDisplayListBuilder* aBuilder, \ + const nsRect& aDirtyRect, \ + const nsDisplayListSet& aLists) { \ + DO_GLOBAL_REFLOW_COUNT_DSP(#_class); \ + _super::BuildDisplayList(aBuilder, aDirtyRect, aLists); \ + } + +#else // MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF + +#define DO_GLOBAL_REFLOW_COUNT_DSP(_name) +#define DO_GLOBAL_REFLOW_COUNT_DSP_COLOR(_name, _color) +#define DECL_DO_GLOBAL_REFLOW_COUNT_DSP(_class, _super) + +#endif // MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF + +class nsDisplayCaret : public nsDisplayItem { +public: + nsDisplayCaret(nsDisplayListBuilder* aBuilder, nsIFrame* aCaretFrame, + nsCaret *aCaret) + : nsDisplayItem(aBuilder, aCaretFrame), mCaret(aCaret) { + MOZ_COUNT_CTOR(nsDisplayCaret); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayCaret() { + MOZ_COUNT_DTOR(nsDisplayCaret); + } +#endif + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE { + *aSnap = false; + // The caret returns a rect in the coordinates of mFrame. + return mCaret->GetCaretRect() + ToReferenceFrame(); + } + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("Caret", TYPE_CARET) +protected: + nsRefPtr mCaret; +}; + +/** + * The standard display item to paint the CSS borders of a frame. + */ +class nsDisplayBorder : public nsDisplayItem { +public: + nsDisplayBorder(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) : + nsDisplayItem(aBuilder, aFrame) + { + MOZ_COUNT_CTOR(nsDisplayBorder); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayBorder() { + MOZ_COUNT_DTOR(nsDisplayBorder); + } +#endif + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("Border", TYPE_BORDER) + + virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE; + +protected: + nsRect CalculateBounds(const nsStyleBorder& aStyleBorder); +}; + +/** + * A simple display item that just renders a solid color across the + * specified bounds. For canvas frames (in the CSS sense) we split off the + * drawing of the background color into this class (from nsDisplayBackground + * via nsDisplayCanvasBackground). This is done so that we can always draw a + * background color to avoid ugly flashes of white when we can't draw a full + * frame tree (ie when a page is loading). The bounds can differ from the + * frame's bounds -- this is needed when a frame/iframe is loading and there + * is not yet a frame tree to go in the frame/iframe so we use the subdoc + * frame of the parent document as a standin. + */ +class nsDisplaySolidColor : public nsDisplayItem { +public: + nsDisplaySolidColor(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + const nsRect& aBounds, nscolor aColor) + : nsDisplayItem(aBuilder, aFrame), mBounds(aBounds), mColor(aColor) + { + NS_ASSERTION(NS_GET_A(aColor) > 0, "Don't create invisible nsDisplaySolidColors!"); + MOZ_COUNT_CTOR(nsDisplaySolidColor); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplaySolidColor() { + MOZ_COUNT_DTOR(nsDisplaySolidColor); + } +#endif + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE { + *aSnap = false; + nsRegion result; + if (NS_GET_A(mColor) == 255) { + result = GetBounds(aBuilder, aSnap); + } + return result; + } + + virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE + { + *aColor = mColor; + return true; + } + + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + + virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { + return new nsDisplaySolidColorGeometry(this, aBuilder, mColor); + } + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE + { + const nsDisplaySolidColorGeometry* geometry = + static_cast(aGeometry); + if (mColor != geometry->mColor) { + bool dummy; + aInvalidRegion->Or(geometry->mBounds, GetBounds(aBuilder, &dummy)); + return; + } + ComputeInvalidationRegionDifference(aBuilder, geometry, aInvalidRegion); + } + +#ifdef MOZ_DUMP_PAINTING + virtual void WriteDebugInfo(nsACString& aTo) MOZ_OVERRIDE; +#endif + + NS_DISPLAY_DECL_NAME("SolidColor", TYPE_SOLID_COLOR) + +private: + nsRect mBounds; + nscolor mColor; +}; + +/** + * A display item to paint one background-image for a frame. Each background + * image layer gets its own nsDisplayBackgroundImage. + */ +class nsDisplayBackgroundImage : public nsDisplayImageContainer { +public: + /** + * aLayer signifies which background layer this item represents. + * aIsThemed should be the value of aFrame->IsThemed. + * aBackgroundStyle should be the result of + * nsCSSRendering::FindBackground, or null if FindBackground returned false. + */ + nsDisplayBackgroundImage(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + uint32_t aLayer, + const nsStyleBackground* aBackgroundStyle); + virtual ~nsDisplayBackgroundImage(); + + // This will create and append new items for all the layers of the + // background. Returns whether we appended a themed background. + static bool AppendBackgroundItemsToTop(nsDisplayListBuilder* aBuilder, + nsIFrame* aFrame, + nsDisplayList* aList); + + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE; + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, nsTArray *aOutFrames) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE; + virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder, + nsIFrame* aFrame) MOZ_OVERRIDE; + virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE; + /** + * GetBounds() returns the background painting area. + */ + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + virtual uint32_t GetPerFrameKey() MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("Background", TYPE_BACKGROUND) + + /** + * Return the background positioning area. + * (GetBounds() returns the background painting area.) + * Can be called only when mBackgroundStyle is non-null. + */ + nsRect GetPositioningArea(); + + /** + * Returns true if existing rendered pixels of this display item may need + * to be redrawn if the positioning area size changes but its position does + * not. + * If false, only the changed painting area needs to be redrawn when the + * positioning area size changes but its position does not. + */ + bool RenderingMightDependOnPositioningAreaSizeChange(); + + virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { + return new nsDisplayBackgroundGeometry(this, aBuilder); + } + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE; + + virtual already_AddRefed GetContainer(LayerManager* aManager, + nsDisplayListBuilder *aBuilder) MOZ_OVERRIDE; + virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) MOZ_OVERRIDE; + + static nsRegion GetInsideClipRegion(nsDisplayItem* aItem, nsPresContext* aPresContext, uint8_t aClip, + const nsRect& aRect, bool* aSnap); + +protected: + typedef class mozilla::layers::ImageContainer ImageContainer; + typedef class mozilla::layers::ImageLayer ImageLayer; + + bool TryOptimizeToImageLayer(LayerManager* aManager, nsDisplayListBuilder* aBuilder); + bool IsSingleFixedPositionImage(nsDisplayListBuilder* aBuilder, + const nsRect& aClipRect, + gfxRect* aDestRect); + nsRect GetBoundsInternal(nsDisplayListBuilder* aBuilder); + + void PaintInternal(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx, + const nsRect& aBounds, nsRect* aClipRect); + + // Cache the result of nsCSSRendering::FindBackground. Always null if + // mIsThemed is true or if FindBackground returned false. + const nsStyleBackground* mBackgroundStyle; + /* If this background can be a simple image layer, we store the format here. */ + nsRefPtr mImageContainer; + gfxRect mDestRect; + /* Bounds of this display item */ + nsRect mBounds; + uint32_t mLayer; +}; + + +/** + * A display item to paint the native theme background for a frame. + */ +class nsDisplayThemedBackground : public nsDisplayItem { +public: + nsDisplayThemedBackground(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame); + virtual ~nsDisplayThemedBackground(); + + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, nsTArray *aOutFrames) MOZ_OVERRIDE; + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE; + virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE; + /** + * GetBounds() returns the background painting area. + */ + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("ThemedBackground", TYPE_THEMED_BACKGROUND) + + /** + * Return the background positioning area. + * (GetBounds() returns the background painting area.) + * Can be called only when mBackgroundStyle is non-null. + */ + nsRect GetPositioningArea(); + + /** + * Return whether our frame's document does not have the state + * NS_DOCUMENT_STATE_WINDOW_INACTIVE. + */ + bool IsWindowActive(); + + virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { + return new nsDisplayThemedBackgroundGeometry(this, aBuilder); + } + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE; + +#ifdef MOZ_DUMP_PAINTING + virtual void WriteDebugInfo(nsACString& aTo) MOZ_OVERRIDE; +#endif +protected: + nsRect GetBoundsInternal(); + + void PaintInternal(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx, + const nsRect& aBounds, nsRect* aClipRect); + + nsRect mBounds; + nsITheme::Transparency mThemeTransparency; + uint8_t mAppearance; +}; + +class nsDisplayBackgroundColor : public nsDisplayItem +{ +public: + nsDisplayBackgroundColor(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + const nsStyleBackground* aBackgroundStyle, + nscolor aColor) + : nsDisplayItem(aBuilder, aFrame) + , mBackgroundStyle(aBackgroundStyle) + , mColor(aColor) + { } + + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE; + virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE; + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, nsTArray *aOutFrames) MOZ_OVERRIDE; + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE + { + *aSnap = true; + return nsRect(ToReferenceFrame(), Frame()->GetSize()); + } + + virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { + return new nsDisplayItemBoundsGeometry(this, aBuilder); + } + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE + { + const nsDisplayItemBoundsGeometry* geometry = static_cast(aGeometry); + ComputeInvalidationRegionDifference(aBuilder, geometry, aInvalidRegion); + } + + NS_DISPLAY_DECL_NAME("BackgroundColor", TYPE_BACKGROUND_COLOR) +#ifdef MOZ_DUMP_PAINTING + virtual void WriteDebugInfo(nsACString& aTo) MOZ_OVERRIDE; +#endif + +protected: + const nsStyleBackground* mBackgroundStyle; + nscolor mColor; +}; + +/** + * The standard display item to paint the outer CSS box-shadows of a frame. + */ +class nsDisplayBoxShadowOuter : public nsDisplayItem { +public: + nsDisplayBoxShadowOuter(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : nsDisplayItem(aBuilder, aFrame) + , mOpacity(1.0) { + MOZ_COUNT_CTOR(nsDisplayBoxShadowOuter); + mBounds = GetBoundsInternal(); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayBoxShadowOuter() { + MOZ_COUNT_DTOR(nsDisplayBoxShadowOuter); + } +#endif + + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("BoxShadowOuter", TYPE_BOX_SHADOW_OUTER) + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE; + + virtual bool ApplyOpacity(nsDisplayListBuilder* aBuilder, + float aOpacity, + const DisplayItemClip* aClip) MOZ_OVERRIDE + { + mOpacity = aOpacity; + if (aClip) { + IntersectClip(aBuilder, *aClip); + } + return true; + } + + nsRect GetBoundsInternal(); + +private: + nsRegion mVisibleRegion; + nsRect mBounds; + float mOpacity; +}; + +/** + * The standard display item to paint the inner CSS box-shadows of a frame. + */ +class nsDisplayBoxShadowInner : public nsDisplayItem { +public: + nsDisplayBoxShadowInner(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : nsDisplayItem(aBuilder, aFrame) { + MOZ_COUNT_CTOR(nsDisplayBoxShadowInner); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayBoxShadowInner() { + MOZ_COUNT_DTOR(nsDisplayBoxShadowInner); + } +#endif + + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("BoxShadowInner", TYPE_BOX_SHADOW_INNER) + + virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { + return new nsDisplayBoxShadowInnerGeometry(this, aBuilder); + } + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE + { + const nsDisplayBoxShadowInnerGeometry* geometry = static_cast(aGeometry); + if (!geometry->mPaddingRect.IsEqualInterior(GetPaddingRect())) { + // nsDisplayBoxShadowInner is based around the padding rect, but it can + // touch pixels outside of this. We should invalidate the entire bounds. + bool snap; + aInvalidRegion->Or(geometry->mBounds, GetBounds(aBuilder, &snap)); + } + } + +private: + nsRegion mVisibleRegion; +}; + +/** + * The standard display item to paint the CSS outline of a frame. + */ +class nsDisplayOutline : public nsDisplayItem { +public: + nsDisplayOutline(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) : + nsDisplayItem(aBuilder, aFrame) { + MOZ_COUNT_CTOR(nsDisplayOutline); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayOutline() { + MOZ_COUNT_DTOR(nsDisplayOutline); + } +#endif + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("Outline", TYPE_OUTLINE) +}; + +/** + * A class that lets you receive events within the frame bounds but never paints. + */ +class nsDisplayEventReceiver : public nsDisplayItem { +public: + nsDisplayEventReceiver(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : nsDisplayItem(aBuilder, aFrame) { + MOZ_COUNT_CTOR(nsDisplayEventReceiver); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayEventReceiver() { + MOZ_COUNT_DTOR(nsDisplayEventReceiver); + } +#endif + + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, nsTArray *aOutFrames) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("EventReceiver", TYPE_EVENT_RECEIVER) +}; + +/** + * A display item that tracks event-sensitive regions which will be set + * on the ContainerLayer that eventually contains this item. + * + * One of these is created for each stacking context and pseudo-stacking-context. + * It accumulates regions for event targets contributed by the border-boxes of + * frames in its (pseudo) stacking context. A nsDisplayLayerEventRegions + * eventually contributes its regions to the ThebesLayer it is placed in by + * FrameLayerBuilder. (We don't create a display item for every frame that + * could be an event target (i.e. almost all frames), because that would be + * high overhead.) + * + * We always make leaf layers other than ThebesLayers transparent to events. + * For example, an event targeting a canvas or video will actually target the + * background of that element, which is logically in the ThebesLayer behind the + * CanvasFrame or ImageFrame. We only need to create a + * nsDisplayLayerEventRegions when an element's background could be in front + * of a lower z-order element with its own layer. + */ +class nsDisplayLayerEventRegions MOZ_FINAL : public nsDisplayItem { +public: + nsDisplayLayerEventRegions(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : nsDisplayItem(aBuilder, aFrame) + { + MOZ_COUNT_CTOR(nsDisplayEventReceiver); + AddFrame(aBuilder, aFrame); + } +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayLayerEventRegions() { + MOZ_COUNT_DTOR(nsDisplayEventReceiver); + } +#endif + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE + { + *aSnap = false; + return mHitRegion.GetBounds().Union(mMaybeHitRegion.GetBounds()); + } + + NS_DISPLAY_DECL_NAME("LayerEventRegions", TYPE_LAYER_EVENT_REGIONS) + + // Indicate that aFrame's border-box contributes to the event regions for + // this layer. aFrame must have the same reference frame as mFrame. + void AddFrame(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame); + + const nsRegion& HitRegion() { return mHitRegion; } + const nsRegion& MaybeHitRegion() { return mMaybeHitRegion; } + const nsRegion& DispatchToContentHitRegion() { return mDispatchToContentHitRegion; } + +private: + // Relative to aFrame's reference frame. + // These are the points that are definitely in the hit region. + nsRegion mHitRegion; + // These are points that may or may not be in the hit region. Only main-thread + // event handling can tell for sure (e.g. because complex shapes are present). + nsRegion mMaybeHitRegion; + // These are points that need to be dispatched to the content thread for + // resolution. Always contained in the union of mHitRegion and mMaybeHitRegion. + nsRegion mDispatchToContentHitRegion; +}; + +/** + * A class that lets you wrap a display list as a display item. + * + * GetUnderlyingFrame() is troublesome for wrapped lists because if the wrapped + * list has many items, it's not clear which one has the 'underlying frame'. + * Thus we force the creator to specify what the underlying frame is. The + * underlying frame should be the root of a stacking context, because sorting + * a list containing this item will not get at the children. + * + * In some cases (e.g., clipping) we want to wrap a list but we don't have a + * particular underlying frame that is a stacking context root. In that case + * we allow the frame to be nullptr. Callers to GetUnderlyingFrame must + * detect and handle this case. + */ +class nsDisplayWrapList : public nsDisplayItem { + // This is never instantiated directly, so no need to count constructors and + // destructors. + +public: + /** + * Takes all the items from aList and puts them in our list. + */ + nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList); + nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayItem* aItem); + nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayItem* aItem, const nsIFrame* aReferenceFrame, const nsPoint& aToReferenceFrame); + nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : nsDisplayItem(aBuilder, aFrame), mOverrideZIndex(0) {} + virtual ~nsDisplayWrapList(); + /** + * Call this if the wrapped list is changed. + */ + virtual void UpdateBounds(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { + mBounds = mList.GetBounds(aBuilder); + } + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, nsTArray *aOutFrames) MOZ_OVERRIDE; + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE; + virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE; + virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder, + nsIFrame* aFrame) MOZ_OVERRIDE; + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE { + NS_WARNING("This list should already have been flattened!!!"); + return false; + } + virtual void GetMergedFrames(nsTArray* aFrames) MOZ_OVERRIDE + { + aFrames->AppendElements(mMergedFrames); + } + virtual bool IsInvalid(nsRect& aRect) MOZ_OVERRIDE + { + if (mFrame->IsInvalid(aRect) && aRect.IsEmpty()) { + return true; + } + nsRect temp; + for (uint32_t i = 0; i < mMergedFrames.Length(); i++) { + if (mMergedFrames[i]->IsInvalid(temp) && temp.IsEmpty()) { + aRect.SetEmpty(); + return true; + } + aRect = aRect.Union(temp); + } + aRect += ToReferenceFrame(); + return !aRect.IsEmpty(); + } + NS_DISPLAY_DECL_NAME("WrapList", TYPE_WRAP_LIST) + + virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + + virtual nsDisplayList* GetSameCoordinateSystemChildren() MOZ_OVERRIDE + { + NS_ASSERTION(mList.IsEmpty() || !ReferenceFrame() || + !mList.GetBottom()->ReferenceFrame() || + mList.GetBottom()->ReferenceFrame() == ReferenceFrame(), + "Children must have same reference frame"); + return &mList; + } + virtual nsDisplayList* GetChildren() MOZ_OVERRIDE { return &mList; } + + virtual int32_t ZIndex() const MOZ_OVERRIDE + { + return (mOverrideZIndex > 0) ? mOverrideZIndex : nsDisplayItem::ZIndex(); + } + + void SetOverrideZIndex(int32_t aZIndex) + { + mOverrideZIndex = aZIndex; + } + + /** + * This creates a copy of this item, but wrapping aItem instead of + * our existing list. Only gets called if this item returned nullptr + * for GetUnderlyingFrame(). aItem is guaranteed to return non-null from + * GetUnderlyingFrame(). + */ + virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder, + nsDisplayItem* aItem) { + NS_NOTREACHED("We never returned nullptr for GetUnderlyingFrame!"); + return nullptr; + } + +protected: + nsDisplayWrapList() {} + + void MergeFrom(nsDisplayWrapList* aOther) + { + mList.AppendToBottom(&aOther->mList); + mBounds.UnionRect(mBounds, aOther->mBounds); + } + void MergeFromTrackingMergedFrames(nsDisplayWrapList* aOther) + { + MergeFrom(aOther); + mMergedFrames.AppendElement(aOther->mFrame); + mMergedFrames.MoveElementsFrom(aOther->mMergedFrames); + } + + nsDisplayList mList; + // The frames from items that have been merged into this item, excluding + // this item's own frame. + nsTArray mMergedFrames; + nsRect mBounds; + // Overrides the ZIndex of our frame if > 0. + int32_t mOverrideZIndex; +}; + +/** + * We call WrapDisplayList on the in-flow lists: BorderBackground(), + * BlockBorderBackgrounds() and Content(). + * We call WrapDisplayItem on each item of Outlines(), PositionedDescendants(), + * and Floats(). This is done to support special wrapping processing for frames + * that may not be in-flow descendants of the current frame. + */ +class nsDisplayWrapper { +public: + // This is never instantiated directly (it has pure virtual methods), so no + // need to count constructors and destructors. + + virtual bool WrapBorderBackground() { return true; } + virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder, + nsIFrame* aFrame, nsDisplayList* aList) = 0; + virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder, + nsDisplayItem* aItem) = 0; + + nsresult WrapLists(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + const nsDisplayListSet& aIn, const nsDisplayListSet& aOut); + nsresult WrapListsInPlace(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + const nsDisplayListSet& aLists); +protected: + nsDisplayWrapper() {} +}; + +/** + * The standard display item to paint a stacking context with translucency + * set by the stacking context root frame's 'opacity' style. + */ +class nsDisplayOpacity : public nsDisplayWrapList { +public: + nsDisplayOpacity(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayOpacity(); +#endif + + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE; + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE; + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE + { + // We don't need to compute an invalidation region since we have LayerTreeInvalidation + } + virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + bool NeedsActiveLayer(); + NS_DISPLAY_DECL_NAME("Opacity", TYPE_OPACITY) +#ifdef MOZ_DUMP_PAINTING + virtual void WriteDebugInfo(nsACString& aTo) MOZ_OVERRIDE; +#endif + + bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; +}; + +class nsDisplayMixBlendMode : public nsDisplayWrapList { +public: + nsDisplayMixBlendMode(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList, uint32_t aFlags = 0); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayMixBlendMode(); +#endif + + nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE; + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE + { + // We don't need to compute an invalidation region since we have LayerTreeInvalidation + } + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE + { + return mozilla::LAYER_INACTIVE; + } + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("MixBlendMode", TYPE_MIX_BLEND_MODE) +}; + +class nsDisplayBlendContainer : public nsDisplayWrapList { +public: + nsDisplayBlendContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList, uint32_t aFlags = 0); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayBlendContainer(); +#endif + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE + { + return mozilla::LAYER_INACTIVE; + } + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("BlendContainer", TYPE_BLEND_CONTAINER) +}; + +/** + * A display item that has no purpose but to ensure its contents get + * their own layer. + */ +class nsDisplayOwnLayer : public nsDisplayWrapList { +public: + + /** + * nsDisplayOwnLayer constructor flags + */ + enum { + GENERATE_SUBDOC_INVALIDATIONS = 0x01, + VERTICAL_SCROLLBAR = 0x02, + HORIZONTAL_SCROLLBAR = 0x04, + GENERATE_SCROLLABLE_LAYER = 0x08 + }; + + /** + * @param aFlags GENERATE_SUBDOC_INVALIDATIONS : + * Add UserData to the created ContainerLayer, so that invalidations + * for this layer are send to our nsPresContext. + * GENERATE_SCROLLABLE_LAYER : only valid on nsDisplaySubDocument (and + * subclasses), indicates this layer is to be a scrollable layer, so call + * RecordFrameMetrics, etc. + * @param aScrollTarget when VERTICAL_SCROLLBAR or HORIZONTAL_SCROLLBAR + * is set in the flags, this parameter should be the ViewID of the + * scrollable content this scrollbar is for. + */ + nsDisplayOwnLayer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList, uint32_t aFlags = 0, + ViewID aScrollTarget = mozilla::layers::FrameMetrics::NULL_SCROLL_ID); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayOwnLayer(); +#endif + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE + { + return mozilla::LAYER_ACTIVE_FORCE; + } + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE + { + // Don't allow merging, each sublist must have its own layer + return false; + } + uint32_t GetFlags() { return mFlags; } + NS_DISPLAY_DECL_NAME("OwnLayer", TYPE_OWN_LAYER) +protected: + uint32_t mFlags; + ViewID mScrollTarget; +}; + +/** + * A display item for subdocuments. This is more or less the same as nsDisplayOwnLayer, + * except that it always populates the FrameMetrics instance on the ContainerLayer it + * builds. + */ +class nsDisplaySubDocument : public nsDisplayOwnLayer { +public: + nsDisplaySubDocument(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList, uint32_t aFlags); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplaySubDocument(); +#endif + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + + virtual bool SetVisibleRegionOnLayer() MOZ_OVERRIDE { return !(mFlags & GENERATE_SCROLLABLE_LAYER); } + + virtual bool ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + + NS_DISPLAY_DECL_NAME("SubDocument", TYPE_SUBDOCUMENT) +protected: + ViewID mScrollParentId; +}; + +/** + * A display item for subdocuments to capture the resolution from the presShell + * and ensure that it gets applied to all the right elements. This item creates + * a container layer. + */ +class nsDisplayResolution : public nsDisplaySubDocument { +public: + nsDisplayResolution(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList, uint32_t aFlags); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayResolution(); +#endif + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("Resolution", TYPE_RESOLUTION) +}; + +/** + * A display item used to represent sticky position elements. The contents + * gets its own layer and creates a stacking context, and the layer will have + * position-related metadata set on it. + */ +class nsDisplayStickyPosition : public nsDisplayOwnLayer { +public: + nsDisplayStickyPosition(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayStickyPosition(); +#endif + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("StickyPosition", TYPE_STICKY_POSITION) + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE + { + return mozilla::LAYER_ACTIVE; + } + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE; +}; + +/** + * This potentially creates a layer for the given list of items, whose + * visibility is determined by the displayport for the given frame instead of + * what is passed in to ComputeVisibility. + * + * Here in content, we can use this to render more content than is actually + * visible. Then, the compositing process can manipulate the generated layer + * through transformations so that asynchronous scrolling can be implemented. + * + * Note that setting the displayport will not change any hit testing! The + * content process will know nothing about what the user is actually seeing, + * so it can only do hit testing for what is supposed to be the visible region. + * + * It is possible for scroll boxes to have content that can be both above and + * below content outside of the scroll box. We cannot create layers for these + * cases. This is accomplished by wrapping display items with + * nsDisplayScrollLayers. nsDisplayScrollLayers with the same scroll frame will + * be merged together. If more than one nsDisplayScrollLayer exists after + * merging, all nsDisplayScrollLayers will be flattened out so that no new + * layer is created at all. + */ +class nsDisplayScrollLayer : public nsDisplayWrapList +{ +public: + /** + * @param aScrolledFrame This will determine what the displayport is. It should be + * the root content frame of the scrolled area. Note + * that nsDisplayScrollLayer will expect for + * ScrollLayerCount to be defined on aScrolledFrame. + * @param aScrollFrame The viewport frame you see this content through. + */ + nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder, nsDisplayList* aList, + nsIFrame* aForFrame, nsIFrame* aScrolledFrame, + nsIFrame* aScrollFrame); + nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem, + nsIFrame* aForFrame, nsIFrame* aScrolledFrame, + nsIFrame* aScrollFrame); + nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder, + nsIFrame* aForFrame, nsIFrame* aScrolledFrame, + nsIFrame* aScrollFrame); + NS_DISPLAY_DECL_NAME("ScrollLayer", TYPE_SCROLL_LAYER) + +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayScrollLayer(); +#endif + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + + virtual bool ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE { + *aSnap = false; + return nsRegion(); + } + + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE; + + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, + nsDisplayItem* aItem) MOZ_OVERRIDE; + + virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + + // Get the number of nsDisplayScrollLayers for a scroll frame. Note that this + // number does not include nsDisplayScrollInfoLayers. If this number is not 1 + // after merging, all the nsDisplayScrollLayers should flatten away. + intptr_t GetScrollLayerCount(); + + virtual nsIFrame* GetScrollFrame() { return mScrollFrame; } + virtual nsIFrame* GetScrolledFrame() { return mScrolledFrame; } + + virtual bool SetVisibleRegionOnLayer() MOZ_OVERRIDE { return false; } + +#ifdef MOZ_DUMP_PAINTING + virtual void WriteDebugInfo(nsACString& aTo) MOZ_OVERRIDE; +#endif + +protected: + nsIFrame* mScrollFrame; + nsIFrame* mScrolledFrame; + ViewID mScrollParentId; +}; + +/** + * Like nsDisplayScrollLayer, but only has metadata on the scroll frame. This + * creates a layer that has no Thebes child layer, but still allows the + * compositor process to know of the scroll frame's existence. + * + * After visibility computation, nsDisplayScrollInfoLayers should only exist if + * nsDisplayScrollLayers were all flattened away. + * + * Important!! Add info layers to the bottom of the list so they are only + * considered after the others have flattened out! + */ +class nsDisplayScrollInfoLayer : public nsDisplayScrollLayer +{ +public: + nsDisplayScrollInfoLayer(nsDisplayListBuilder* aBuilder, + nsIFrame* aScrolledFrame, nsIFrame* aScrollFrame); + NS_DISPLAY_DECL_NAME("ScrollInfoLayer", TYPE_SCROLL_INFO_LAYER) + + virtual ~nsDisplayScrollInfoLayer(); + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE; + virtual bool ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { return true; } + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, + nsDisplayItem* aItem) MOZ_OVERRIDE; + + virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; +}; + +/** + * nsDisplayZoom is used for subdocuments that have a different full zoom than + * their parent documents. This item creates a container layer. + */ +class nsDisplayZoom : public nsDisplaySubDocument { +public: + /** + * @param aFrame is the root frame of the subdocument. + * @param aList contains the display items for the subdocument. + * @param aAPD is the app units per dev pixel ratio of the subdocument. + * @param aParentAPD is the app units per dev pixel ratio of the parent + * document. + * @param aFlags GENERATE_SUBDOC_INVALIDATIONS : + * Add UserData to the created ContainerLayer, so that invalidations + * for this layer are send to our nsPresContext. + */ + nsDisplayZoom(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList, + int32_t aAPD, int32_t aParentAPD, + uint32_t aFlags = 0); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayZoom(); +#endif + + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE; + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, nsTArray *aOutFrames) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE + { + return mozilla::LAYER_ACTIVE; + } + NS_DISPLAY_DECL_NAME("Zoom", TYPE_ZOOM) + + // Get the app units per dev pixel ratio of the child document. + int32_t GetChildAppUnitsPerDevPixel() { return mAPD; } + // Get the app units per dev pixel ratio of the parent document. + int32_t GetParentAppUnitsPerDevPixel() { return mParentAPD; } + +private: + int32_t mAPD, mParentAPD; +}; + +/** + * A display item to paint a stacking context with effects + * set by the stacking context root frame's style. + */ +class nsDisplaySVGEffects : public nsDisplayWrapList { +public: + nsDisplaySVGEffects(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, + nsDisplayList* aList); +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplaySVGEffects(); +#endif + + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE; + virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, + HitTestState* aState, + nsTArray *aOutFrames) MOZ_OVERRIDE; + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, + bool* aSnap) MOZ_OVERRIDE { + *aSnap = false; + return mEffectsBounds + ToReferenceFrame(); + } + virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder, + nsRegion* aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + virtual bool TryMerge(nsDisplayListBuilder* aBuilder, + nsDisplayItem* aItem) MOZ_OVERRIDE; + NS_DISPLAY_DECL_NAME("SVGEffects", TYPE_SVG_EFFECTS) + + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE; + + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE + { + // We don't need to compute an invalidation region since we have LayerTreeInvalidation + } + + void PaintAsLayer(nsDisplayListBuilder* aBuilder, + nsRenderingContext* aCtx, + LayerManager* aManager); + +#ifdef MOZ_DUMP_PAINTING + void PrintEffects(nsACString& aTo); +#endif + +private: + // relative to mFrame + nsRect mEffectsBounds; +}; + +/* A display item that applies a transformation to all of its descendant + * elements. This wrapper should only be used if there is a transform applied + * to the root element. + * + * The reason that a "bounds" rect is involved in transform calculations is + * because CSS-transforms allow percentage values for the x and y components + * of s, where percentages are percentages of the element's + * border box. + * + * INVARIANT: The wrapped frame is transformed or we supplied a transform getter + * function. + * INVARIANT: The wrapped frame is non-null. + */ +class nsDisplayTransform: public nsDisplayItem +{ +public: + /** + * Returns a matrix (in pixels) for the current frame. The matrix should be relative to + * the current frame's coordinate space. + * + * @param aFrame The frame to compute the transform for. + * @param aAppUnitsPerPixel The number of app units per graphics unit. + */ + typedef gfx3DMatrix (* ComputeTransformFunction)(nsIFrame* aFrame, float aAppUnitsPerPixel); + + /* Constructor accepts a display list, empties it, and wraps it up. It also + * ferries the underlying frame to the nsDisplayItem constructor. + */ + nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame, + nsDisplayList *aList, uint32_t aIndex = 0); + nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame, + nsDisplayItem *aItem, uint32_t aIndex = 0); + nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame, + nsDisplayList *aList, ComputeTransformFunction aTransformGetter, uint32_t aIndex = 0); + +#ifdef NS_BUILD_REFCNT_LOGGING + virtual ~nsDisplayTransform() + { + MOZ_COUNT_DTOR(nsDisplayTransform); + } +#endif + + NS_DISPLAY_DECL_NAME("nsDisplayTransform", TYPE_TRANSFORM) + + virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE + { + if (mStoredList.GetComponentAlphaBounds(aBuilder).IsEmpty()) + return nsRect(); + bool snap; + return GetBounds(aBuilder, &snap); + } + + virtual nsDisplayList* GetChildren() MOZ_OVERRIDE { return mStoredList.GetChildren(); } + + virtual void HitTest(nsDisplayListBuilder *aBuilder, const nsRect& aRect, + HitTestState *aState, nsTArray *aOutFrames) MOZ_OVERRIDE; + virtual nsRect GetBounds(nsDisplayListBuilder *aBuilder, bool* aSnap) MOZ_OVERRIDE; + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder *aBuilder, + bool* aSnap) MOZ_OVERRIDE; + virtual bool IsUniform(nsDisplayListBuilder *aBuilder, nscolor* aColor) MOZ_OVERRIDE; + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE; + virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, + LayerManager* aManager, + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE; + virtual bool ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + virtual bool ComputeVisibility(nsDisplayListBuilder *aBuilder, + nsRegion *aVisibleRegion, + const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE; + virtual bool TryMerge(nsDisplayListBuilder *aBuilder, nsDisplayItem *aItem) MOZ_OVERRIDE; + + virtual uint32_t GetPerFrameKey() MOZ_OVERRIDE { return (mIndex << nsDisplayItem::TYPE_BITS) | nsDisplayItem::GetPerFrameKey(); } + + virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder, + const nsDisplayItemGeometry* aGeometry, + nsRegion* aInvalidRegion) MOZ_OVERRIDE + { + // We don't need to compute an invalidation region since we have LayerTreeInvalidation + } + + virtual const nsIFrame* ReferenceFrameForChildren() const MOZ_OVERRIDE { + // If we were created using a transform-getter, then we don't + // belong to a transformed frame, and aren't a reference frame + // for our children. + if (!mTransformGetter) { + return mFrame; + } + return nsDisplayItem::ReferenceFrameForChildren(); + } + + enum { + INDEX_MAX = UINT32_MAX >> nsDisplayItem::TYPE_BITS + }; + + const gfx3DMatrix& GetTransform(); + + float GetHitDepthAtPoint(nsDisplayListBuilder* aBuilder, const nsPoint& aPoint); + + /** + * TransformRect takes in as parameters a rectangle (in aFrame's coordinate + * space) and returns the smallest rectangle (in aFrame's coordinate space) + * containing the transformed image of that rectangle. That is, it takes + * the four corners of the rectangle, transforms them according to the + * matrix associated with the specified frame, then returns the smallest + * rectangle containing the four transformed points. + * + * @param untransformedBounds The rectangle (in app units) to transform. + * @param aFrame The frame whose transformation should be applied. This + * function raises an assertion if aFrame is null or doesn't have a + * transform applied to it. + * @param aOrigin The origin of the transform relative to aFrame's local + * coordinate space. + * @param aBoundsOverride (optional) Rather than using the frame's computed + * bounding rect as frame bounds, use this rectangle instead. Pass + * nullptr (or nothing at all) to use the default. + */ + static nsRect TransformRect(const nsRect &aUntransformedBounds, + const nsIFrame* aFrame, + const nsPoint &aOrigin, + const nsRect* aBoundsOverride = nullptr); + + static nsRect TransformRectOut(const nsRect &aUntransformedBounds, + const nsIFrame* aFrame, + const nsPoint &aOrigin, + const nsRect* aBoundsOverride = nullptr); + + /* UntransformRect is like TransformRect, except that it inverts the + * transform. + */ + static bool UntransformRect(const nsRect &aTransformedBounds, + const nsRect &aChildBounds, + const nsIFrame* aFrame, + const nsPoint &aOrigin, + nsRect *aOutRect); + + bool UntransformVisibleRect(nsDisplayListBuilder* aBuilder, + nsRect* aOutRect); + + static gfxPoint3D GetDeltaToTransformOrigin(const nsIFrame* aFrame, + float aAppUnitsPerPixel, + const nsRect* aBoundsOverride); + + static gfxPoint3D GetDeltaToPerspectiveOrigin(const nsIFrame* aFrame, + float aAppUnitsPerPixel); + + /** + * Returns the bounds of a frame as defined for resolving percentage + * s in CSS transforms. If + * UNIFIED_CONTINUATIONS is not defined, this is simply the frame's bounding + * rectangle, translated to the origin. Otherwise, returns the smallest + * rectangle containing a frame and all of its continuations. For example, + * if there is a element with several continuations split over + * several lines, this function will return the rectangle containing all of + * those continuations. This rectangle is relative to the origin of the + * frame's local coordinate space. + * + * @param aFrame The frame to get the bounding rect for. + * @return The frame's bounding rect, as described above. + */ + static nsRect GetFrameBoundsForTransform(const nsIFrame* aFrame); + + struct FrameTransformProperties + { + FrameTransformProperties(const nsIFrame* aFrame, + float aAppUnitsPerPixel, + const nsRect* aBoundsOverride); + FrameTransformProperties(nsCSSValueSharedList* aTransformList, + const gfxPoint3D& aToTransformOrigin, + const gfxPoint3D& aToPerspectiveOrigin, + nscoord aChildPerspective) + : mFrame(nullptr) + , mTransformList(aTransformList) + , mToTransformOrigin(aToTransformOrigin) + , mToPerspectiveOrigin(aToPerspectiveOrigin) + , mChildPerspective(aChildPerspective) + {} + + const nsIFrame* mFrame; + nsRefPtr mTransformList; + const gfxPoint3D mToTransformOrigin; + const gfxPoint3D mToPerspectiveOrigin; + nscoord mChildPerspective; + }; + + /** + * Given a frame with the -moz-transform property or an SVG transform, + * returns the transformation matrix for that frame. + * + * @param aFrame The frame to get the matrix from. + * @param aOrigin Relative to which point this transform should be applied. + * @param aAppUnitsPerPixel The number of app units per graphics unit. + * @param aBoundsOverride [optional] If this is nullptr (the default), the + * computation will use the value of GetFrameBoundsForTransform(aFrame) + * for the frame's bounding rectangle. Otherwise, it will use the + * value of aBoundsOverride. This is mostly for internal use and in + * most cases you will not need to specify a value. + */ + static gfx3DMatrix GetResultingTransformMatrix(const nsIFrame* aFrame, + const nsPoint& aOrigin, + float aAppUnitsPerPixel, + const nsRect* aBoundsOverride = nullptr, + nsIFrame** aOutAncestor = nullptr); + static gfx3DMatrix GetResultingTransformMatrix(const FrameTransformProperties& aProperties, + const nsPoint& aOrigin, + float aAppUnitsPerPixel, + const nsRect* aBoundsOverride = nullptr, + nsIFrame** aOutAncestor = nullptr); + /** + * Return true when we should try to prerender the entire contents of the + * transformed frame even when it's not completely visible (yet). + */ + static bool ShouldPrerenderTransformedContent(nsDisplayListBuilder* aBuilder, + nsIFrame* aFrame, + bool aLogAnimations = false); + bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE; + + virtual bool SetVisibleRegionOnLayer() MOZ_OVERRIDE { return false; } + +private: + static gfx3DMatrix GetResultingTransformMatrixInternal(const FrameTransformProperties& aProperties, + const nsPoint& aOrigin, + float aAppUnitsPerPixel, + const nsRect* aBoundsOverride, + nsIFrame** aOutAncestor); + + nsDisplayWrapList mStoredList; + gfx3DMatrix mTransform; + ComputeTransformFunction mTransformGetter; + uint32_t mIndex; +}; + +/** + * This class adds basic support for limiting the rendering to the part inside + * the specified edges. It's a base class for the display item classes that + * does the actual work. The two members, mLeftEdge and mRightEdge, are + * relative to the edges of the frame's scrollable overflow rectangle and is + * the amount to suppress on each side. + * + * Setting none, both or only one edge is allowed. + * The values must be non-negative. + * The default value for both edges is zero, which means everything is painted. + */ +class nsCharClipDisplayItem : public nsDisplayItem { +public: + nsCharClipDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) + : nsDisplayItem(aBuilder, aFrame), mLeftEdge(0), mRightEdge(0) {} + + nsCharClipDisplayItem(nsIFrame* aFrame) + : nsDisplayItem(aFrame) {} + + struct ClipEdges { + ClipEdges(const nsDisplayItem& aItem, + nscoord aLeftEdge, nscoord aRightEdge) { + nsRect r = aItem.Frame()->GetScrollableOverflowRect() + + aItem.ToReferenceFrame(); + mX = aLeftEdge > 0 ? r.x + aLeftEdge : nscoord_MIN; + mXMost = aRightEdge > 0 ? std::max(r.XMost() - aRightEdge, mX) : nscoord_MAX; + } + void Intersect(nscoord* aX, nscoord* aWidth) const { + nscoord xmost1 = *aX + *aWidth; + *aX = std::max(*aX, mX); + *aWidth = std::max(std::min(xmost1, mXMost) - *aX, 0); + } + nscoord mX; + nscoord mXMost; + }; + + ClipEdges Edges() const { return ClipEdges(*this, mLeftEdge, mRightEdge); } + + static nsCharClipDisplayItem* CheckCast(nsDisplayItem* aItem) { + nsDisplayItem::Type t = aItem->GetType(); + return (t == nsDisplayItem::TYPE_TEXT || + t == nsDisplayItem::TYPE_TEXT_DECORATION || + t == nsDisplayItem::TYPE_TEXT_SHADOW) + ? static_cast(aItem) : nullptr; + } + + nscoord mLeftEdge; // length from the left side + nscoord mRightEdge; // length from the right side +}; + +#endif /*NSDISPLAYLIST_H_*/