layout/generic/nsCanvasFrame.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* rendering object that goes directly inside the document's scrollbars */
   7
   8 #ifndef nsCanvasFrame_h___
   9 #define nsCanvasFrame_h___
  10
  11 #include "mozilla/Attributes.h"
  12 #include "mozilla/EventForwards.h"
  13 #include "nsContainerFrame.h"
  14 #include "nsIScrollPositionListener.h"
  15 #include "nsDisplayList.h"
  16 #include "nsIAnonymousContentCreator.h"
  17
  18 class nsPresContext;
  19 class nsRenderingContext;
  20
  21 /**
  22  * Root frame class.
  23  *
  24  * The root frame is the parent frame for the document element's frame.
  25  * It only supports having a single child frame which must be an area
  26  * frame
  27  */
  28 class nsCanvasFrame MOZ_FINAL : public nsContainerFrame,
  29                                 public nsIScrollPositionListener,
  30                                 public nsIAnonymousContentCreator
  31 {
  32 public:
  33   explicit nsCanvasFrame(nsStyleContext* aContext)
  34   : nsContainerFrame(aContext),
  35     mDoPaintFocus(false),
  36     mAddedScrollPositionListener(false) {}
  37
  38   NS_DECL_QUERYFRAME_TARGET(nsCanvasFrame)
  39   NS_DECL_QUERYFRAME
  40   NS_DECL_FRAMEARENA_HELPERS
  41
  42
  43   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
  44
  45 #ifdef DEBUG
  46   virtual void SetInitialChildList(ChildListID     aListID,
  47                                    nsFrameList&    aChildList) MOZ_OVERRIDE;
  48   virtual void AppendFrames(ChildListID     aListID,
  49                             nsFrameList&    aFrameList) MOZ_OVERRIDE;
  50   virtual void InsertFrames(ChildListID     aListID,
  51                             nsIFrame*       aPrevFrame,
  52                             nsFrameList&    aFrameList) MOZ_OVERRIDE;
  53   virtual void RemoveFrame(ChildListID     aListID,
  54                            nsIFrame*       aOldFrame) MOZ_OVERRIDE;
  55 #endif
  56
  57   virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
  58   virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
  59   virtual void Reflow(nsPresContext*           aPresContext,
  60                       nsHTMLReflowMetrics&     aDesiredSize,
  61                       const nsHTMLReflowState& aReflowState,
  62                       nsReflowStatus&          aStatus) MOZ_OVERRIDE;
  63   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
  64   {
  65     return nsContainerFrame::IsFrameOfType(aFlags &
  66              ~(nsIFrame::eCanContainOverflowContainers));
  67   }
  68
  69   // nsIAnonymousContentCreator
  70   virtual nsresult CreateAnonymousContent(nsTArray<ContentInfo>& aElements) MOZ_OVERRIDE;
  71   virtual void AppendAnonymousContentTo(nsTArray<nsIContent*>& aElements, uint32_t aFilter) MOZ_OVERRIDE;
  72
  73   // Touch caret handle function
  74   mozilla::dom::Element* GetTouchCaretElement() const
  75   {
  76      return mTouchCaretElement;
  77   }
  78
  79   // Selection Caret Handle function
  80   mozilla::dom::Element* GetSelectionCaretsStartElement() const
  81   {
  82     return mSelectionCaretsStartElement;
  83   }
  84
  85   mozilla::dom::Element* GetSelectionCaretsEndElement() const
  86   {
  87     return mSelectionCaretsEndElement;
  88   }
  89
  90   /** SetHasFocus tells the CanvasFrame to draw with focus ring
  91    *  @param aHasFocus true to show focus ring, false to hide it
  92    */
  93   NS_IMETHOD SetHasFocus(bool aHasFocus);
  94
  95   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
  96                                 const nsRect&           aDirtyRect,
  97                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
  98
  99   void PaintFocus(nsRenderingContext& aRenderingContext, nsPoint aPt);
 100
 101   // nsIScrollPositionListener
 102   virtual void ScrollPositionWillChange(nscoord aX, nscoord aY) MOZ_OVERRIDE;
 103   virtual void ScrollPositionDidChange(nscoord aX, nscoord aY) MOZ_OVERRIDE {}
 104
 105   /**
 106    * Get the "type" of the frame
 107    *
 108    * @see nsGkAtoms::canvasFrame
 109    */
 110   virtual nsIAtom* GetType() const MOZ_OVERRIDE;
 111
 112   virtual nsresult StealFrame(nsIFrame* aChild, bool aForceNormal) MOZ_OVERRIDE
 113   {
 114     NS_ASSERTION(!aForceNormal, "No-one should be passing this in here");
 115
 116     // nsCanvasFrame keeps overflow container continuations of its child
 117     // frame in main child list
 118     nsresult rv = nsContainerFrame::StealFrame(aChild, true);
 119     if (NS_FAILED(rv)) {
 120       rv = nsContainerFrame::StealFrame(aChild);
 121     }
 122     return rv;
 123   }
 124
 125 #ifdef DEBUG_FRAME_DUMP
 126   virtual nsresult GetFrameName(nsAString& aResult) const MOZ_OVERRIDE;
 127 #endif
 128   virtual nsresult GetContentForEvent(mozilla::WidgetEvent* aEvent,
 129                                       nsIContent** aContent) MOZ_OVERRIDE;
 130
 131   nsRect CanvasArea() const;
 132
 133 protected:
 134   // Data members
 135   bool                      mDoPaintFocus;
 136   bool                      mAddedScrollPositionListener;
 137
 138   nsCOMPtr<mozilla::dom::Element> mTouchCaretElement;
 139   nsCOMPtr<mozilla::dom::Element> mSelectionCaretsStartElement;
 140   nsCOMPtr<mozilla::dom::Element> mSelectionCaretsEndElement;
 141 };
 142
 143 /**
 144  * Override nsDisplayBackground methods so that we pass aBGClipRect to
 145  * PaintBackground, covering the whole overflow area.
 146  * We can also paint an "extra background color" behind the normal
 147  * background.
 148  */
 149 class nsDisplayCanvasBackgroundColor : public nsDisplayItem {
 150 public:
 151   nsDisplayCanvasBackgroundColor(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame)
 152     : nsDisplayItem(aBuilder, aFrame)
 153     , mColor(NS_RGBA(0,0,0,0))
 154   {
 155   }
 156
 157   virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
 158                                  nsRegion* aVisibleRegion) MOZ_OVERRIDE
 159   {
 160     return NS_GET_A(mColor) > 0;
 161   }
 162   virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
 163                                    bool* aSnap) MOZ_OVERRIDE
 164   {
 165     if (NS_GET_A(mColor) == 255) {
 166       return nsRegion(GetBounds(aBuilder, aSnap));
 167     }
 168     return nsRegion();
 169   }
 170   virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE
 171   {
 172     *aColor = mColor;
 173     return true;
 174   }
 175   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE
 176   {
 177     nsCanvasFrame* frame = static_cast<nsCanvasFrame*>(mFrame);
 178     *aSnap = true;
 179     return frame->CanvasArea() + ToReferenceFrame();
 180   }
 181   virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
 182                        HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE
 183   {
 184     // We need to override so we don't consider border-radius.
 185     aOutFrames->AppendElement(mFrame);
 186   }
 187
 188   virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE
 189   {
 190     return new nsDisplayItemBoundsGeometry(this, aBuilder);
 191   }
 192
 193   virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
 194                                          const nsDisplayItemGeometry* aGeometry,
 195                                          nsRegion* aInvalidRegion) MOZ_OVERRIDE
 196   {
 197     const nsDisplayItemBoundsGeometry* geometry = static_cast<const nsDisplayItemBoundsGeometry*>(aGeometry);
 198     ComputeInvalidationRegionDifference(aBuilder, geometry, aInvalidRegion);
 199   }
 200
 201   virtual void Paint(nsDisplayListBuilder* aBuilder,
 202                      nsRenderingContext* aCtx) MOZ_OVERRIDE;
 203
 204   void SetExtraBackgroundColor(nscolor aColor)
 205   {
 206     mColor = aColor;
 207   }
 208
 209   NS_DISPLAY_DECL_NAME("CanvasBackgroundColor", TYPE_CANVAS_BACKGROUND_COLOR)
 210 #ifdef MOZ_DUMP_PAINTING
 211   virtual void WriteDebugInfo(nsACString& aTo) MOZ_OVERRIDE;
 212 #endif
 213
 214 private:
 215   nscolor mColor;
 216 };
 217
 218 class nsDisplayCanvasBackgroundImage : public nsDisplayBackgroundImage {
 219 public:
 220   nsDisplayCanvasBackgroundImage(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
 221                                  uint32_t aLayer, const nsStyleBackground* aBg)
 222     : nsDisplayBackgroundImage(aBuilder, aFrame, aLayer, aBg)
 223   {}
 224
 225   virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
 226
 227   virtual void NotifyRenderingChanged() MOZ_OVERRIDE
 228   {
 229     mFrame->Properties().Delete(nsIFrame::CachedBackgroundImage());
 230     mFrame->Properties().Delete(nsIFrame::CachedBackgroundImageDT());
 231   }
 232
 233   virtual bool ShouldFixToViewport(LayerManager* aManager) MOZ_OVERRIDE
 234   {
 235     // Put background-attachment:fixed canvas background images in their own
 236     // compositing layer. Since we know their background painting area can't
 237     // change (unless the viewport size itself changes), async scrolling
 238     // will work well.
 239     return mBackgroundStyle->mLayers[mLayer].mAttachment == NS_STYLE_BG_ATTACHMENT_FIXED &&
 240            !mBackgroundStyle->mLayers[mLayer].mImage.IsEmpty();
 241   }
 242
 243   // We still need to paint a background color as well as an image for this item,
 244   // so we can't support this yet.
 245   virtual bool SupportsOptimizingToImage() MOZ_OVERRIDE { return false; }
 246
 247
 248   NS_DISPLAY_DECL_NAME("CanvasBackgroundImage", TYPE_CANVAS_BACKGROUND_IMAGE)
 249 };
 250
 251 class nsDisplayCanvasThemedBackground : public nsDisplayThemedBackground {
 252 public:
 253   nsDisplayCanvasThemedBackground(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
 254     : nsDisplayThemedBackground(aBuilder, aFrame)
 255   {}
 256
 257   virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
 258
 259   NS_DISPLAY_DECL_NAME("CanvasThemedBackground", TYPE_CANVAS_THEMED_BACKGROUND)
 260 };
 261
 262 #endif /* nsCanvasFrame_h___ */