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 /* -*- 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/. */

 #ifndef nsView_h__

 #define nsView_h__

 #include "nsCoord.h"

 #include "nsRect.h"

 #include "nsPoint.h"

 #include "nsRegion.h"

 #include "nsCRT.h"

 #include "nsWidgetInitData.h" // for nsWindowType

 #include "nsIWidgetListener.h"

 #include "mozilla/EventForwards.h"

 class nsViewManager;

 class nsIWidget;

 class nsIFrame;

 // Enumerated type to indicate the visibility of a layer.

 // hide - the layer is not shown.

 // show - the layer is shown irrespective of the visibility of 

 //        the layer's parent.

 enum nsViewVisibility {

   nsViewVisibility_kHide = 0,

   nsViewVisibility_kShow = 1

 };

 // Public view flags

 // Indicates that the view is using auto z-indexing

 #define NS_VIEW_FLAG_AUTO_ZINDEX          0x0004

 // Indicates that the view is a floating view.

 #define NS_VIEW_FLAG_FLOATING             0x0008

 //----------------------------------------------------------------------

 /**

  * View interface

  *

  * Views are NOT reference counted. Use the Destroy() member function to

  * destroy a view.

  *

  * The lifetime of the view hierarchy is bounded by the lifetime of the

  * view manager that owns the views.

  *

  * Most of the methods here are read-only. To set the corresponding properties

  * of a view, go through nsViewManager.

  */

 class nsView MOZ_FINAL : public nsIWidgetListener

 {

 public:

   friend class nsViewManager;

   NS_DECL_AND_IMPL_ZEROING_OPERATOR_NEW

   /**

    * Get the view manager which "owns" the view.

    * This method might require some expensive traversal work in the future. If you can get the

    * view manager from somewhere else, do that instead.

    * @result the view manager

    */

   nsViewManager* GetViewManager() const { return mViewManager; }

   /**

    * Find the view for the given widget, if there is one.

    * @return the view the widget belongs to, or null if the widget doesn't

    * belong to any view.

    */

   static nsView* GetViewFor(nsIWidget* aWidget);

   /**

    * Destroy the view.

    *

    * The view destroys its child views, and destroys and releases its

    * widget (if it has one).

    *

    * Also informs the view manager that the view is destroyed by calling

    * SetRootView(NULL) if the view is the root view and calling RemoveChild()

    * otherwise.

    */

   void Destroy();

   /**

    * Called to get the position of a view.

    * The specified coordinates are relative to the parent view's origin, but

    * are in appunits of this.

    * This is the (0, 0) origin of the coordinate space established by this view.

    * @param x out parameter for x position

    * @param y out parameter for y position

    */

   nsPoint GetPosition() const {

     NS_ASSERTION(!IsRoot() || (mPosX == 0 && mPosY == 0),

                  "root views should always have explicit position of (0,0)");

     return nsPoint(mPosX, mPosY);

   }

   /**

    * Called to get the dimensions and position of the view's bounds.

    * The view's bounds (x,y) are relative to the origin of the parent view, but

    * are in appunits of this.

    * The view's bounds (x,y) might not be the same as the view's position,

    * if the view has content above or to the left of its origin.

    * @param aBounds out parameter for bounds

    */

   nsRect GetBounds() const { return mDimBounds; }

   /**

    * The bounds of this view relative to this view. So this is the same as

    * GetBounds except this is relative to this view instead of the parent view.

    */

   nsRect GetDimensions() const {

     nsRect r = mDimBounds; r.MoveBy(-mPosX, -mPosY); return r;

   }

   /**

    * Get the offset between the coordinate systems of |this| and aOther.

    * Adding the return value to a point in the coordinate system of |this|

    * will transform the point to the coordinate system of aOther.

    *

    * The offset is expressed in appunits of |this|. So if you are getting the

    * offset between views in different documents that might have different

    * appunits per devpixel ratios you need to be careful how you use the

    * result.

    *

    * If aOther is null, this will return the offset of |this| from the

    * root of the viewmanager tree.

    * 

    * This function is fastest when aOther is an ancestor of |this|.

    *

    * NOTE: this actually returns the offset from aOther to |this|, but

    * that offset is added to transform _coordinates_ from |this| to aOther.

    */

   nsPoint GetOffsetTo(const nsView* aOther) const;

   /**

    * Get the offset between the origin of |this| and the origin of aWidget.

    * Adding the return value to a point in the coordinate system of |this|

    * will transform the point to the coordinate system of aWidget.

    *

    * The offset is expressed in appunits of |this|.

    */

   nsPoint GetOffsetToWidget(nsIWidget* aWidget) const;

   /**

    * Takes a point aPt that is in the coordinate system of |this|'s parent view

    * and converts it to be in the coordinate system of |this| taking into

    * account the offset and any app unit per dev pixel ratio differences.

    */

   nsPoint ConvertFromParentCoords(nsPoint aPt) const;

   /**

    * Called to query the visibility state of a view.

    * @result current visibility state

    */

   nsViewVisibility GetVisibility() const { return mVis; }

   /**

    * Get whether the view "floats" above all other views,

    * which tells the compositor not to consider higher views in

    * the view hierarchy that would geometrically intersect with

    * this view. This is a hack, but it fixes some problems with

    * views that need to be drawn in front of all other views.

    * @result true if the view floats, false otherwise.

    */

   bool GetFloating() const { return (mVFlags & NS_VIEW_FLAG_FLOATING) != 0; }

   /**

    * Called to query the parent of the view.

    * @result view's parent

    */

   nsView* GetParent() const { return mParent; }

   /**

    * The view's first child is the child which is earliest in document order.

    * @result first child

    */

   nsView* GetFirstChild() const { return mFirstChild; }

   /**

    * Called to query the next sibling of the view.

    * @result view's next sibling

    */

   nsView* GetNextSibling() const { return mNextSibling; }

   /**

    * Set the view's frame.

    */

   void SetFrame(nsIFrame* aRootFrame) { mFrame = aRootFrame; }

   /**

    * Retrieve the view's frame.

    */

   nsIFrame* GetFrame() const { return mFrame; }

   /**

    * Get the nearest widget in this view or a parent of this view and

    * the offset from the widget's origin to this view's origin

    * @param aOffset - if non-null the offset from this view's origin to the

    * widget's origin (usually positive) expressed in appunits of this will be

    * returned in aOffset.

    * @return the widget closest to this view; can be null because some view trees

    * don't have widgets at all (e.g., printing), but if any view in the view tree

    * has a widget, then it's safe to assume this will not return null

    */

   nsIWidget* GetNearestWidget(nsPoint* aOffset) const;

   /**

    * Create a widget to associate with this view.  This variant of

    * CreateWidget*() will look around in the view hierarchy for an

    * appropriate parent widget for the view.

    *

    * @param aWidgetInitData data used to initialize this view's widget before

    *        its create is called.

    * @return error status

    */

   nsresult CreateWidget(nsWidgetInitData *aWidgetInitData = nullptr,

                         bool aEnableDragDrop = true,

                         bool aResetVisibility = true);

   /**

    * Create a widget for this view with an explicit parent widget.

    * |aParentWidget| must be nonnull.  The other params are the same

    * as for |CreateWidget()|.

    */

   nsresult CreateWidgetForParent(nsIWidget* aParentWidget,

                                  nsWidgetInitData *aWidgetInitData = nullptr,

                                  bool aEnableDragDrop = true,

                                  bool aResetVisibility = true);

   /**

    * Create a popup widget for this view.  Pass |aParentWidget| to

    * explicitly set the popup's parent.  If it's not passed, the view

    * hierarchy will be searched for an appropriate parent widget.  The

    * other params are the same as for |CreateWidget()|, except that

    * |aWidgetInitData| must be nonnull.

    */

   nsresult CreateWidgetForPopup(nsWidgetInitData *aWidgetInitData,

                                 nsIWidget* aParentWidget = nullptr,

                                 bool aEnableDragDrop = true,

                                 bool aResetVisibility = true);

   /**

    * Destroys the associated widget for this view.  If this method is

    * not called explicitly, the widget when be destroyed when its

    * view gets destroyed.

    */

   void DestroyWidget();

   /**

    * Attach/detach a top level widget from this view. When attached, the view

    * updates the widget's device context and allows the view to begin receiving

    * gecko events. The underlying base window associated with the widget will

    * continues to receive events it expects.

    *

    * An attached widget will not be destroyed when the view is destroyed,

    * allowing the recycling of a single top level widget over multiple views.

    *

    * @param aWidget The widget to attach to / detach from.

    */

   nsresult AttachToTopLevelWidget(nsIWidget* aWidget);

   nsresult DetachFromTopLevelWidget();

   /**

    * Returns a flag indicating whether the view owns it's widget

    * or is attached to an existing top level widget.

    */

   bool IsAttachedToTopLevel() const { return mWidgetIsTopLevel; }

   /**

    * In 4.0, the "cutout" nature of a view is queryable.

    * If we believe that all cutout view have a native widget, this

    * could be a replacement.

    * @param aWidget out parameter for widget that this view contains,

    *        or nullptr if there is none.

    */

   nsIWidget* GetWidget() const { return mWindow; }

   /**

    * Returns true if the view has a widget associated with it.

    */

   bool HasWidget() const { return mWindow != nullptr; }

   void SetForcedRepaint(bool aForceRepaint) { 

     mForcedRepaint = aForceRepaint; 

   }

   /**

    * Make aWidget direct its events to this view.

    * The caller must call DetachWidgetEventHandler before this view

    * is destroyed.

    */

   void AttachWidgetEventHandler(nsIWidget* aWidget);

   /**

    * Stop aWidget directing its events to this view.

    */

   void DetachWidgetEventHandler(nsIWidget* aWidget);

 #ifdef DEBUG

   /**

    * Output debug info to FILE

    * @param out output file handle

    * @param aIndent indentation depth

    * NOTE: virtual so that debugging tools not linked into gklayout can access it

    */

   virtual void List(FILE* out, int32_t aIndent = 0) const;

 #endif // DEBUG

   /**

    * @result true iff this is the root view for its view manager

    */

   bool IsRoot() const;

   nsIntRect CalcWidgetBounds(nsWindowType aType);

   // This is an app unit offset to add when converting view coordinates to

   // widget coordinates.  It is the offset in view coordinates from widget

   // origin (unlike views, widgets can't extend above or to the left of their

   // origin) to view origin expressed in appunits of this.

   nsPoint ViewToWidgetOffset() const { return mViewToWidgetOffset; }

   /**

    * Called to indicate that the position of the view has been changed.

    * The specified coordinates are in the parent view's coordinate space.

    * @param x new x position

    * @param y new y position

    */

   void SetPosition(nscoord aX, nscoord aY);

   /**

    * Called to indicate that the z-index of a view has been changed.

    * The z-index is relative to all siblings of the view.

    * @param aAuto Indicate that the z-index of a view is "auto". An "auto" z-index

    * means that the view does not define a new stacking context,

    * which means that the z-indicies of the view's children are

    * relative to the view's siblings.

    * @param zindex new z depth

    */

   void SetZIndex(bool aAuto, int32_t aZIndex);

   bool GetZIndexIsAuto() const { return (mVFlags & NS_VIEW_FLAG_AUTO_ZINDEX) != 0; }

   int32_t GetZIndex() const { return mZIndex; }

   void SetParent(nsView *aParent) { mParent = aParent; }

   void SetNextSibling(nsView *aSibling)

   {

     NS_ASSERTION(aSibling != this, "Can't be our own sibling!");

     mNextSibling = aSibling;

   }

   nsRegion* GetDirtyRegion() {

     if (!mDirtyRegion) {

       NS_ASSERTION(!mParent || GetFloating(),

                    "Only display roots should have dirty regions");

       mDirtyRegion = new nsRegion();

       NS_ASSERTION(mDirtyRegion, "Out of memory!");

     }

     return mDirtyRegion;

   }

   // nsIWidgetListener

   virtual nsIPresShell* GetPresShell() MOZ_OVERRIDE;

   virtual nsView* GetView() MOZ_OVERRIDE { return this; }

   virtual bool WindowMoved(nsIWidget* aWidget, int32_t x, int32_t y) MOZ_OVERRIDE;

   virtual bool WindowResized(nsIWidget* aWidget, int32_t aWidth, int32_t aHeight) MOZ_OVERRIDE;

   virtual bool RequestWindowClose(nsIWidget* aWidget) MOZ_OVERRIDE;

   virtual void WillPaintWindow(nsIWidget* aWidget) MOZ_OVERRIDE;

   virtual bool PaintWindow(nsIWidget* aWidget, nsIntRegion aRegion) MOZ_OVERRIDE;

   virtual void DidPaintWindow() MOZ_OVERRIDE;

   virtual void DidCompositeWindow() MOZ_OVERRIDE;

   virtual void RequestRepaint() MOZ_OVERRIDE;

   virtual nsEventStatus HandleEvent(mozilla::WidgetGUIEvent* aEvent,

                                     bool aUseAttachedEvents) MOZ_OVERRIDE;

   virtual ~nsView();

   nsPoint GetOffsetTo(const nsView* aOther, const int32_t aAPD) const;

   nsIWidget* GetNearestWidget(nsPoint* aOffset, const int32_t aAPD) const;

 private:

   nsView(nsViewManager* aViewManager = nullptr,

           nsViewVisibility aVisibility = nsViewVisibility_kShow);

   bool ForcedRepaint() { return mForcedRepaint; }

   // Do the actual work of ResetWidgetBounds, unconditionally.  Don't

   // call this method if we have no widget.

   void DoResetWidgetBounds(bool aMoveOnly, bool aInvalidateChangedSize);

   void InitializeWindow(bool aEnableDragDrop, bool aResetVisibility);

   bool IsEffectivelyVisible();

   /**

    * Called to indicate that the dimensions of the view have been changed.

    * The x and y coordinates may be < 0, indicating that the view extends above

    * or to the left of its origin position. The term 'dimensions' indicates it

    * is relative to this view.

    */

   void SetDimensions(const nsRect &aRect, bool aPaint = true,

                      bool aResizeWidget = true);

   /**

    * Called to indicate that the visibility of a view has been

    * changed.

    * @param visibility new visibility state

    */

   void SetVisibility(nsViewVisibility visibility);

   /**

    * Set/Get whether the view "floats" above all other views,

    * which tells the compositor not to consider higher views in

    * the view hierarchy that would geometrically intersect with

    * this view. This is a hack, but it fixes some problems with

    * views that need to be drawn in front of all other views.

    * @result true if the view floats, false otherwise.

    */

   void SetFloating(bool aFloatingView);

   // Helper function to get mouse grabbing off this view (by moving it to the

   // parent, if we can)

   void DropMouseGrabbing();

   // Same as GetBounds but converts to parent appunits if they are different.

   nsRect GetBoundsInParentUnits() const;

   bool HasNonEmptyDirtyRegion() {

     return mDirtyRegion && !mDirtyRegion->IsEmpty();

   }

   void InsertChild(nsView *aChild, nsView *aSibling);

   void RemoveChild(nsView *aChild);

   void ResetWidgetBounds(bool aRecurse, bool aForceSync);

   void AssertNoWindow();

   void NotifyEffectiveVisibilityChanged(bool aEffectivelyVisible);

   // Update the cached RootViewManager for all view manager descendents,

   // If the hierarchy is being removed, aViewManagerParent points to the view

   // manager for the hierarchy's old parent, and will have its mouse grab

   // released if it points to any view in this view hierarchy.

   void InvalidateHierarchy(nsViewManager *aViewManagerParent);

   nsViewManager    *mViewManager;

   nsView           *mParent;

   nsIWidget        *mWindow;

   nsView           *mNextSibling;

   nsView           *mFirstChild;

   nsIFrame         *mFrame;

   nsRegion         *mDirtyRegion;

   int32_t           mZIndex;

   nsViewVisibility  mVis;

   // position relative our parent view origin but in our appunits

   nscoord           mPosX, mPosY;

   // relative to parent, but in our appunits

   nsRect            mDimBounds;

   // in our appunits

   nsPoint           mViewToWidgetOffset;

   uint32_t          mVFlags;

   bool              mWidgetIsTopLevel;

   bool              mForcedRepaint;

 };

 #endif