layout/generic/nsViewportFrame.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 /*
   7  * rendering object that is the root of the frame tree, which contains
   8  * the document's scrollbars and contains fixed-positioned elements
   9  */
  10
  11 #ifndef nsViewportFrame_h___
  12 #define nsViewportFrame_h___
  13
  14 #include "mozilla/Attributes.h"
  15 #include "nsContainerFrame.h"
  16
  17 class nsPresContext;
  18
  19 /**
  20   * ViewportFrame is the parent of a single child - the doc root frame or a scroll frame
  21   * containing the doc root frame. ViewportFrame stores this child in its primary child
  22   * list.
  23   */
  24 class ViewportFrame : public nsContainerFrame {
  25 public:
  26   NS_DECL_QUERYFRAME_TARGET(ViewportFrame)
  27   NS_DECL_QUERYFRAME
  28   NS_DECL_FRAMEARENA_HELPERS
  29
  30   typedef nsContainerFrame Super;
  31
  32   explicit ViewportFrame(nsStyleContext* aContext)
  33     : nsContainerFrame(aContext)
  34   {}
  35   virtual ~ViewportFrame() { } // useful for debugging
  36
  37   virtual void Init(nsIContent*       aContent,
  38                     nsContainerFrame* aParent,
  39                     nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
  40
  41 #ifdef DEBUG
  42   virtual void SetInitialChildList(ChildListID     aListID,
  43                                    nsFrameList&    aChildList) MOZ_OVERRIDE;
  44   virtual void AppendFrames(ChildListID     aListID,
  45                             nsFrameList&    aFrameList) MOZ_OVERRIDE;
  46   virtual void InsertFrames(ChildListID     aListID,
  47                             nsIFrame*       aPrevFrame,
  48                             nsFrameList&    aFrameList) MOZ_OVERRIDE;
  49   virtual void RemoveFrame(ChildListID     aListID,
  50                            nsIFrame*       aOldFrame) MOZ_OVERRIDE;
  51 #endif
  52
  53   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
  54                                 const nsRect&           aDirtyRect,
  55                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
  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
  64   /**
  65    * Get the "type" of the frame
  66    *
  67    * @see nsGkAtoms::viewportFrame
  68    */
  69   virtual nsIAtom* GetType() const MOZ_OVERRIDE;
  70
  71   /**
  72    * Adjust aReflowState to account for scrollbars and pres shell
  73    * GetScrollPositionClampingScrollPortSizeSet and
  74    * GetContentDocumentFixedPositionMargins adjustments.
  75    * @return the rect to use as containing block rect
  76    */
  77   nsRect AdjustReflowStateAsContainingBlock(nsHTMLReflowState* aReflowState) const;
  78
  79 #ifdef DEBUG_FRAME_DUMP
  80   virtual nsresult GetFrameName(nsAString& aResult) const MOZ_OVERRIDE;
  81 #endif
  82
  83 private:
  84   virtual mozilla::layout::FrameChildListID GetAbsoluteListID() const MOZ_OVERRIDE { return kFixedList; }
  85
  86 protected:
  87   /**
  88    * Calculate how much room is available for fixed frames. That means
  89    * determining if the viewport is scrollable and whether the vertical and/or
  90    * horizontal scrollbars are visible.  Adjust the computed width/height and
  91    * available width for aReflowState accordingly.
  92    * @return the current scroll position, or 0,0 if not scrollable
  93    */
  94   nsPoint AdjustReflowStateForScrollbars(nsHTMLReflowState* aReflowState) const;
  95 };
  96
  97
  98 #endif // nsViewportFrame_h___