gecko-dev/layout/generic/nsPageContentFrame.cpp

124 строки
4.6 KiB
C++

/* -*- 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/. */
#include "nsPageContentFrame.h"
#include "nsCSSFrameConstructor.h"
#include "nsPresContext.h"
#include "nsGkAtoms.h"
#include "nsIPresShell.h"
#include "nsSimplePageSequenceFrame.h"
using namespace mozilla;
nsPageContentFrame*
NS_NewPageContentFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsPageContentFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsPageContentFrame)
void
nsPageContentFrame::Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus)
{
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT("nsPageContentFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
aStatus.Reset(); // initialize out parameter
if (GetPrevInFlow() && (GetStateBits() & NS_FRAME_FIRST_REFLOW)) {
nsresult rv = aPresContext->PresShell()->FrameConstructor()
->ReplicateFixedFrames(this);
if (NS_FAILED(rv)) {
return;
}
}
// Set our size up front, since some parts of reflow depend on it
// being already set. Note that the computed height may be
// unconstrained; that's ok. Consumers should watch out for that.
nsSize maxSize(aReflowInput.ComputedWidth(),
aReflowInput.ComputedHeight());
SetSize(maxSize);
// A PageContentFrame must always have one child: the canvas frame.
// Resize our frame allowing it only to be as big as we are
// XXX Pay attention to the page's border and padding...
if (mFrames.NotEmpty()) {
nsIFrame* frame = mFrames.FirstChild();
WritingMode wm = frame->GetWritingMode();
LogicalSize logicalSize(wm, maxSize);
ReflowInput kidReflowInput(aPresContext, aReflowInput,
frame, logicalSize);
kidReflowInput.SetComputedBSize(logicalSize.BSize(wm));
// Reflow the page content area
ReflowChild(frame, aPresContext, aDesiredSize, kidReflowInput, 0, 0, 0, aStatus);
// The document element's background should cover the entire canvas, so
// take into account the combined area and any space taken up by
// absolutely positioned elements
nsMargin padding(0,0,0,0);
// XXXbz this screws up percentage padding (sets padding to zero
// in the percentage padding case)
kidReflowInput.mStylePadding->GetPadding(padding);
// This is for shrink-to-fit, and therefore we want to use the
// scrollable overflow, since the purpose of shrink to fit is to
// make the content that ought to be reachable (represented by the
// scrollable overflow) fit in the page.
if (frame->HasOverflowAreas()) {
// The background covers the content area and padding area, so check
// for children sticking outside the child frame's padding edge
nscoord xmost = aDesiredSize.ScrollableOverflow().XMost();
if (xmost > aDesiredSize.Width()) {
nscoord widthToFit = xmost + padding.right +
kidReflowInput.mStyleBorder->GetComputedBorderWidth(eSideRight);
float ratio = float(maxSize.width) / widthToFit;
NS_ASSERTION(ratio >= 0.0 && ratio < 1.0, "invalid shrink-to-fit ratio");
mPD->mShrinkToFitRatio = std::min(mPD->mShrinkToFitRatio, ratio);
}
}
// Place and size the child
FinishReflowChild(frame, aPresContext, aDesiredSize, &kidReflowInput, 0, 0, 0);
NS_ASSERTION(aPresContext->IsDynamic() || !aStatus.IsFullyComplete() ||
!frame->GetNextInFlow(), "bad child flow list");
}
// Reflow our fixed frames
nsReflowStatus fixedStatus;
ReflowAbsoluteFrames(aPresContext, aDesiredSize, aReflowInput, fixedStatus);
NS_ASSERTION(fixedStatus.IsComplete(), "fixed frames can be truncated, but not incomplete");
// Return our desired size
WritingMode wm = aReflowInput.GetWritingMode();
aDesiredSize.ISize(wm) = aReflowInput.ComputedISize();
if (aReflowInput.ComputedBSize() != NS_UNCONSTRAINEDSIZE) {
aDesiredSize.BSize(wm) = aReflowInput.ComputedBSize();
}
FinishAndStoreOverflow(&aDesiredSize);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize);
}
nsIAtom*
nsPageContentFrame::GetType() const
{
return nsGkAtoms::pageContentFrame;
}
#ifdef DEBUG_FRAME_DUMP
nsresult
nsPageContentFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("PageContent"), aResult);
}
#endif