author L. David Baron <>
Sat, 13 Sep 2014 06:17:36 -0700
changeset 228423 c81eb3a1336b2ab5f4e83b8b5df394dfea8be37e
parent 224484 9d4e083655b993f73ba3eca84e0f14cdd270bcda
child 230258 de388c070eafe57bca0ae84d79e51056c9373587
permissions -rw-r--r--
Bug 977991 patch 1 - Expose variant of RulesMatching on nsHTMLCSSStyleSheet that is less work to call. r=birtles This allows nsStyleSet::RuleNodeWithReplacement to call it without constructing an entire (and unnecessary) ElementRuleProcessorData, which will happen in patch 3.

/* -*- 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 */

 * rendering object that is the root of the frame tree, which contains
 * the document's scrollbars and contains fixed-positioned elements

#ifndef nsViewportFrame_h___
#define nsViewportFrame_h___

#include "mozilla/Attributes.h"
#include "nsContainerFrame.h"

class nsPresContext;

  * ViewportFrame is the parent of a single child - the doc root frame or a scroll frame 
  * containing the doc root frame. ViewportFrame stores this child in its primary child 
  * list.
class ViewportFrame : public nsContainerFrame {

  typedef nsContainerFrame Super;

  explicit ViewportFrame(nsStyleContext* aContext)
    : nsContainerFrame(aContext)
  virtual ~ViewportFrame() { } // useful for debugging

  virtual void Init(nsIContent*       aContent,
                    nsContainerFrame* aParent,
                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;

#ifdef DEBUG
  virtual void SetInitialChildList(ChildListID     aListID,
                                   nsFrameList&    aChildList) MOZ_OVERRIDE;
  virtual void AppendFrames(ChildListID     aListID,
                            nsFrameList&    aFrameList) MOZ_OVERRIDE;
  virtual void InsertFrames(ChildListID     aListID,
                            nsIFrame*       aPrevFrame,
                            nsFrameList&    aFrameList) MOZ_OVERRIDE;
  virtual void RemoveFrame(ChildListID     aListID,
                           nsIFrame*       aOldFrame) MOZ_OVERRIDE;

  virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                const nsRect&           aDirtyRect,
                                const nsDisplayListSet& aLists) MOZ_OVERRIDE;

  virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
  virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
  virtual void Reflow(nsPresContext*           aPresContext,
                      nsHTMLReflowMetrics&     aDesiredSize,
                      const nsHTMLReflowState& aReflowState,
                      nsReflowStatus&          aStatus) MOZ_OVERRIDE;

   * Get the "type" of the frame
   * @see nsGkAtoms::viewportFrame
  virtual nsIAtom* GetType() const MOZ_OVERRIDE;

   * Adjust aReflowState to account for scrollbars and pres shell
   * GetScrollPositionClampingScrollPortSizeSet and
   * GetContentDocumentFixedPositionMargins adjustments.
   * @return the rect to use as containing block rect
  nsRect AdjustReflowStateAsContainingBlock(nsHTMLReflowState* aReflowState) const;

  virtual nsresult GetFrameName(nsAString& aResult) const MOZ_OVERRIDE;

  virtual mozilla::layout::FrameChildListID GetAbsoluteListID() const MOZ_OVERRIDE { return kFixedList; }

   * Calculate how much room is available for fixed frames. That means
   * determining if the viewport is scrollable and whether the vertical and/or
   * horizontal scrollbars are visible.  Adjust the computed width/height and
   * available width for aReflowState accordingly.
   * @return the current scroll position, or 0,0 if not scrollable
  nsPoint AdjustReflowStateForScrollbars(nsHTMLReflowState* aReflowState) const;

#endif // nsViewportFrame_h___