gecko-dev/layout/generic/ViewportFrame.h

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3.8 KiB
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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/. */
/*
* rendering object that is the root of the frame tree, which contains
* the document's scrollbars and contains fixed-positioned elements
*/
#ifndef mozilla_ViewportFrame_h
#define mozilla_ViewportFrame_h
#include "mozilla/Attributes.h"
#include "nsContainerFrame.h"
class nsPresContext;
namespace mozilla {
/**
* 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 {
public:
NS_DECL_QUERYFRAME_TARGET(ViewportFrame)
NS_DECL_QUERYFRAME
NS_DECL_FRAMEARENA_HELPERS
explicit ViewportFrame(nsStyleContext* aContext)
: nsContainerFrame(aContext)
{}
virtual ~ViewportFrame() { } // useful for debugging
virtual void Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) override;
virtual mozilla::WritingMode GetWritingMode() const override
{
nsIFrame* firstChild = mFrames.FirstChild();
if (firstChild) {
return firstChild->GetWritingMode();
}
return nsIFrame::GetWritingMode();
}
#ifdef DEBUG
virtual void AppendFrames(ChildListID aListID,
nsFrameList& aFrameList) override;
virtual void InsertFrames(ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList) override;
virtual void RemoveFrame(ChildListID aListID,
nsIFrame* aOldFrame) override;
#endif
virtual void BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists) override;
void BuildDisplayListForTopLayer(nsDisplayListBuilder* aBuilder,
nsDisplayList* aList);
virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) override;
virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) override;
virtual void Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) override;
/**
* Get the "type" of the frame
*
* @see nsGkAtoms::viewportFrame
*/
virtual nsIAtom* GetType() const override;
virtual bool ComputeCustomOverflow(nsOverflowAreas& aOverflowAreas) override;
/**
* Adjust aReflowInput to account for scrollbars and pres shell
* GetScrollPositionClampingScrollPortSizeSet and
* GetContentDocumentFixedPositionMargins adjustments.
* @return the rect to use as containing block rect
*/
nsRect AdjustReflowInputAsContainingBlock(ReflowInput* aReflowInput) const;
#ifdef DEBUG_FRAME_DUMP
virtual nsresult GetFrameName(nsAString& aResult) const override;
#endif
private:
virtual mozilla::layout::FrameChildListID GetAbsoluteListID() const override { return kFixedList; }
protected:
/**
* 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 aReflowInput accordingly.
* @return the current scroll position, or 0,0 if not scrollable
*/
nsPoint AdjustReflowInputForScrollbars(ReflowInput* aReflowInput) const;
};
} // namespace mozilla
#endif // mozilla_ViewportFrame_h