The Tor Browser: layout/base/RestyleManager.h@b8a032363ba2 (annotated)

layout/base/RestyleManager.h@b8a032363ba2 (annotated)

layout/base/RestyleManager.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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/. */
 /**
  * Code responsible for managing style changes: tracking what style
  * changes need to happen, scheduling them, and doing them.
  */
 #ifndef mozilla_RestyleManager_h
 #define mozilla_RestyleManager_h
 #include "nsISupportsImpl.h"
 #include "nsChangeHint.h"
 #include "RestyleTracker.h"
 #include "nsPresContext.h"
 class nsRefreshDriver;
 class nsIFrame;
 struct TreeMatchContext;
 namespace mozilla {
   class EventStates;
 namespace dom {
   class Element;
 } // namespace dom
 class RestyleManager MOZ_FINAL {
 public:
   friend class ::nsRefreshDriver;
   friend class RestyleTracker;
   typedef mozilla::dom::Element Element;
   RestyleManager(nsPresContext* aPresContext);
 private:
   // Private destructor, to discourage deletion outside of Release():
   ~RestyleManager()
   {
   }
 public:
   NS_INLINE_DECL_REFCOUNTING(mozilla::RestyleManager)
   void Disconnect() {
     mPresContext = nullptr;
   }
   nsPresContext* PresContext() const {
     MOZ_ASSERT(mPresContext);
     return mPresContext;
   }
   nsCSSFrameConstructor* FrameConstructor() const
     { return PresContext()->FrameConstructor(); }
   // Should be called when a frame is going to be destroyed and
   // WillDestroyFrameTree hasn't been called yet.
   void NotifyDestroyingFrame(nsIFrame* aFrame);
   // Forwarded nsIDocumentObserver method, to handle restyling (and
   // passing the notification to the frame).
   nsresult ContentStateChanged(nsIContent*   aContent,
                                EventStates aStateMask);
   // Forwarded nsIMutationObserver method, to handle restyling.
   void AttributeWillChange(Element* aElement,
                            int32_t  aNameSpaceID,
                            nsIAtom* aAttribute,
                            int32_t  aModType);
   // Forwarded nsIMutationObserver method, to handle restyling (and
   // passing the notification to the frame).
   void AttributeChanged(Element* aElement,
                         int32_t  aNameSpaceID,
                         nsIAtom* aAttribute,
                         int32_t  aModType);
   // Get an integer that increments every time there is a style change
   // as a result of a change to the :hover content state.
   uint32_t GetHoverGeneration() const { return mHoverGeneration; }
   // Get a counter that increments on every style change, that we use to
   // track whether off-main-thread animations are up-to-date.
   uint64_t GetAnimationGeneration() const { return mAnimationGeneration; }
   /**
    * Reparent the style contexts of this frame subtree.  The parent frame of
    * aFrame must be changed to the new parent before this function is called;
    * the new parent style context will be automatically computed based on the
    * new position in the frame tree.
    *
    * @param aFrame the root of the subtree to reparent.  Must not be null.
    */
   NS_HIDDEN_(nsresult) ReparentStyleContext(nsIFrame* aFrame);
   /**
    * Re-resolve the style contexts for a frame tree, building
    * aChangeList based on the resulting style changes, plus aMinChange
    * applied to aFrame.
    */
   NS_HIDDEN_(void)
     ComputeStyleChangeFor(nsIFrame* aFrame,
                           nsStyleChangeList* aChangeList,
                           nsChangeHint aMinChange,
                           RestyleTracker& aRestyleTracker,
                           bool aRestyleDescendants);
 #ifdef DEBUG
   /**
    * DEBUG ONLY method to verify integrity of style tree versus frame tree
    */
   NS_HIDDEN_(void) DebugVerifyStyleTree(nsIFrame* aFrame);
 #endif
   // Note: It's the caller's responsibility to make sure to wrap a
   // ProcessRestyledFrames call in a view update batch and a script blocker.
   // This function does not call ProcessAttachedQueue() on the binding manager.
   // If the caller wants that to happen synchronously, it needs to handle that
   // itself.
   nsresult ProcessRestyledFrames(nsStyleChangeList& aRestyleArray);
 private:
   void RestyleForEmptyChange(Element* aContainer);
 public:
   // Restyling for a ContentInserted (notification after insertion) or
   // for a CharacterDataChanged.  |aContainer| must be non-null; when
   // the container is null, no work is needed.
   void RestyleForInsertOrChange(Element* aContainer, nsIContent* aChild);
   // This would be the same as RestyleForInsertOrChange if we got the
   // notification before the removal.  However, we get it after, so we need the
   // following sibling in addition to the old child.  |aContainer| must be
   // non-null; when the container is null, no work is needed.  aFollowingSibling
   // is the sibling that used to come after aOldChild before the removal.
   void RestyleForRemove(Element* aContainer,
                         nsIContent* aOldChild,
                         nsIContent* aFollowingSibling);
   // Same for a ContentAppended.  |aContainer| must be non-null; when
   // the container is null, no work is needed.
   void RestyleForAppend(Element* aContainer, nsIContent* aFirstNewContent);
   // Process any pending restyles. This should be called after
   // CreateNeededFrames.
   // Note: It's the caller's responsibility to make sure to wrap a
   // ProcessPendingRestyles call in a view update batch and a script blocker.
   // This function does not call ProcessAttachedQueue() on the binding manager.
   // If the caller wants that to happen synchronously, it needs to handle that
   // itself.
   void ProcessPendingRestyles();
   // ProcessPendingRestyles calls into one of our RestyleTracker
   // objects.  It then calls back to these functions at the beginning
   // and end of its work.
   void BeginProcessingRestyles();
   void EndProcessingRestyles();
   // Rebuilds all style data by throwing out the old rule tree and
   // building a new one, and additionally applying aExtraHint (which
   // must not contain nsChangeHint_ReconstructFrame) to the root frame.
   void RebuildAllStyleData(nsChangeHint aExtraHint);
   // Helper that does part of the work of RebuildAllStyleData, shared by
   // RestyleElement for 'rem' handling.
   void DoRebuildAllStyleData(RestyleTracker& aRestyleTracker,
                              nsChangeHint aExtraHint);
   // See PostRestyleEventCommon below.
   void PostRestyleEvent(Element* aElement,
                         nsRestyleHint aRestyleHint,
                         nsChangeHint aMinChangeHint)
   {
     if (mPresContext) {
       PostRestyleEventCommon(aElement, aRestyleHint, aMinChangeHint,
                              mPresContext->IsProcessingAnimationStyleChange());
     }
   }
   // See PostRestyleEventCommon below.
   void PostAnimationRestyleEvent(Element* aElement,
                                  nsRestyleHint aRestyleHint,
                                  nsChangeHint aMinChangeHint)
   {
     PostRestyleEventCommon(aElement, aRestyleHint, aMinChangeHint, true);
   }
   void PostRestyleEventForLazyConstruction()
   {
     PostRestyleEventInternal(true);
   }
   void FlushOverflowChangedTracker()
   {
     mOverflowChangedTracker.Flush();
   }
 private:
   /**
    * Notify the frame constructor that an element needs to have its
    * style recomputed.
    * @param aElement: The element to be restyled.
    * @param aRestyleHint: Which nodes need to have selector matching run
    *                      on them.
    * @param aMinChangeHint: A minimum change hint for aContent and its
    *                        descendants.
    * @param aForAnimation: Whether the style should be computed with or
    *                       without animation data.  Animation code
    *                       sometimes needs to pass true; other code
    *                       should generally pass the the pres context's
    *                       IsProcessingAnimationStyleChange() value
    *                       (which is the default value).
    */
   void PostRestyleEventCommon(Element* aElement,
                               nsRestyleHint aRestyleHint,
                               nsChangeHint aMinChangeHint,
                               bool aForAnimation);
   void PostRestyleEventInternal(bool aForLazyConstruction);
 public:
   /**
    * Asynchronously clear style data from the root frame downwards and ensure
    * it will all be rebuilt. This is safe to call anytime; it will schedule
    * a restyle and take effect next time style changes are flushed.
    * This method is used to recompute the style data when some change happens
    * outside of any style rules, like a color preference change or a change
    * in a system font size, or to fix things up when an optimization in the
    * style data has become invalid. We assume that the root frame will not
    * need to be reframed.
    */
   void PostRebuildAllStyleDataEvent(nsChangeHint aExtraHint);
 private:
   /* aMinHint is the minimal change that should be made to the element */
   // XXXbz do we really need the aPrimaryFrame argument here?
   void RestyleElement(Element*        aElement,
                       nsIFrame*       aPrimaryFrame,
                       nsChangeHint    aMinHint,
                       RestyleTracker& aRestyleTracker,
                       bool            aRestyleDescendants);
   nsresult StyleChangeReflow(nsIFrame* aFrame, nsChangeHint aHint);
   // Returns true if this function managed to successfully move a frame, and
   // false if it could not process the position change, and a reflow should
   // be performed instead.
   bool RecomputePosition(nsIFrame* aFrame);
 private:
   nsPresContext* mPresContext; // weak, disconnected in Disconnect
   bool mRebuildAllStyleData : 1;
   // True if we're already waiting for a refresh notification
   bool mObservingRefreshDriver : 1;
   // True if we're in the middle of a nsRefreshDriver refresh
   bool mInStyleRefresh : 1;
   uint32_t mHoverGeneration;
   nsChangeHint mRebuildAllExtraHint;
   OverflowChangedTracker mOverflowChangedTracker;
   // The total number of animation flushes by this frame constructor.
   // Used to keep the layer and animation manager in sync.
   uint64_t mAnimationGeneration;
   RestyleTracker mPendingRestyles;
   RestyleTracker mPendingAnimationRestyles;
 };
 /**
  * An ElementRestyler is created for *each* element in a subtree that we
  * recompute styles for.
  */
 class ElementRestyler MOZ_FINAL {
 public:
   typedef mozilla::dom::Element Element;
   // Construct for the root of the subtree that we're restyling.
   ElementRestyler(nsPresContext* aPresContext,
                   nsIFrame* aFrame,
                   nsStyleChangeList* aChangeList,
                   nsChangeHint aHintsHandledByAncestors,
                   RestyleTracker& aRestyleTracker,
                   TreeMatchContext& aTreeMatchContext,
                   nsTArray<nsIContent*>& aVisibleKidsOfHiddenElement);
   // Construct for an element whose parent is being restyled.
   enum ConstructorFlags {
     FOR_OUT_OF_FLOW_CHILD = 1<<0
   };
   ElementRestyler(const ElementRestyler& aParentRestyler,
                   nsIFrame* aFrame,
                   uint32_t aConstructorFlags);
   // Construct for a frame whose parent is being restyled, but whose
   // style context is the parent style context for its parent frame.
   // (This is only used for table frames, whose style contexts are used
   // as the parent style context for their outer table frame (table
   // wrapper frame).  We should probably try to get rid of this
   // exception and have the inheritance go the other way.)
   enum ParentContextFromChildFrame { PARENT_CONTEXT_FROM_CHILD_FRAME };
   ElementRestyler(ParentContextFromChildFrame,
                   const ElementRestyler& aParentFrameRestyler,
                   nsIFrame* aFrame);
   /**
    * Restyle our frame's element and its subtree.
    *
    * Use eRestyle_Self for the aRestyleHint argument to mean
    * "reresolve our style context but not kids", use eRestyle_Subtree
    * to mean "reresolve our style context and kids", and use
    * nsRestyleHint(0) to mean recompute a new style context for our
    * current parent and existing rulenode, and the same for kids.
    */
   void Restyle(nsRestyleHint aRestyleHint);
   /**
    * mHintsHandled changes over time; it starts off as the hints that
    * have been handled by ancestors, and by the end of Restyle it
    * represents the hints that have been handled for this frame.  This
    * method is intended to be called after Restyle, to find out what
    * hints have been handled for this frame.
    */
   nsChangeHint HintsHandledForFrame() { return mHintsHandled; }
 private:
   /**
    * First half of Restyle().
    */
   void RestyleSelf(nsIFrame* aSelf, nsRestyleHint aRestyleHint);
   /**
    * Restyle the children of this frame (and, in turn, their children).
    *
    * Second half of Restyle().
    */
   void RestyleChildren(nsRestyleHint aChildRestyleHint);
   /**
    * Helper for RestyleSelf().
    */
   void CaptureChange(nsStyleContext* aOldContext,
                      nsStyleContext* aNewContext,
                      nsChangeHint aChangeToAssume);
   /**
    * Helpers for RestyleChildren().
    */
   void RestyleUndisplayedChildren(nsRestyleHint aChildRestyleHint);
   void RestyleBeforePseudo();
   void RestyleAfterPseudo(nsIFrame* aFrame);
   void RestyleContentChildren(nsIFrame* aParent,
                               nsRestyleHint aChildRestyleHint);
   void InitializeAccessibilityNotifications();
   void SendAccessibilityNotifications();
   enum DesiredA11yNotifications {
     eSkipNotifications,
     eSendAllNotifications,
     eNotifyIfShown
   };
   enum A11yNotificationType {
     eDontNotify,
     eNotifyShown,
     eNotifyHidden
   };
 private:
   nsPresContext* const mPresContext;
   nsIFrame* const mFrame;
   nsIContent* const mParentContent;
   // |mContent| is the node that we used for rule matching of
   // normal elements (not pseudo-elements) and for which we generate
   // framechange hints if we need them.
   nsIContent* const mContent;
   nsStyleChangeList* const mChangeList;
   // We have already generated change list entries for hints listed in
   // mHintsHandled (initially it's those handled by ancestors, but by
   // the end of Restyle it is those handled for this frame as well).  We
   // need to generate a new change list entry for the frame when its
   // style comparision returns a hint other than one of these hints.
   nsChangeHint mHintsHandled;
   // See nsStyleContext::CalcStyleDifference
   nsChangeHint mParentFrameHintsNotHandledForDescendants;
   nsChangeHint mHintsNotHandledForDescendants;
   RestyleTracker& mRestyleTracker;
   TreeMatchContext& mTreeMatchContext;
   nsIFrame* mResolvedChild; // child that provides our parent style context
 #ifdef ACCESSIBILITY
   const DesiredA11yNotifications mDesiredA11yNotifications;
   DesiredA11yNotifications mKidsDesiredA11yNotifications;
   A11yNotificationType mOurA11yNotification;
   nsTArray<nsIContent*>& mVisibleKidsOfHiddenElement;
   bool mWasFrameVisible;
 #endif
 };
 } // namespace mozilla
 #endif /* mozilla_RestyleManager_h */

The Tor Browser / annotate

layout/base/RestyleManager.h@b8a032363ba2 (annotated)

layout/base/RestyleManager.h