gecko-dev/layout/generic/nsViewportFrame.cpp
2015-08-18 14:27:18 -04:00

318 lines
11 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/. */
/*
* rendering object that is the root of the frame tree, which contains
* the document's scrollbars and contains fixed-positioned elements
*/
#include "nsViewportFrame.h"
#include "nsGkAtoms.h"
#include "nsIScrollableFrame.h"
#include "nsSubDocumentFrame.h"
#include "nsAbsoluteContainingBlock.h"
#include "GeckoProfiler.h"
using namespace mozilla;
ViewportFrame*
NS_NewViewportFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) ViewportFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(ViewportFrame)
NS_QUERYFRAME_HEAD(ViewportFrame)
NS_QUERYFRAME_ENTRY(ViewportFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
void
ViewportFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow)
{
Super::Init(aContent, aParent, aPrevInFlow);
nsIFrame* parent = nsLayoutUtils::GetCrossDocParentFrame(this);
if (parent) {
nsFrameState state = parent->GetStateBits();
mState |= state & (NS_FRAME_IN_POPUP);
}
}
void
ViewportFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
PROFILER_LABEL("ViewportFrame", "BuildDisplayList",
js::ProfileEntry::Category::GRAPHICS);
nsIFrame* kid = mFrames.FirstChild();
if (!kid)
return;
// make the kid's BorderBackground our own. This ensures that the canvas
// frame's background becomes our own background and therefore appears
// below negative z-index elements.
BuildDisplayListForChild(aBuilder, kid, aDirtyRect, aLists);
}
#ifdef DEBUG
void
ViewportFrame::SetInitialChildList(ChildListID aListID,
nsFrameList& aChildList)
{
nsFrame::VerifyDirtyBitSet(aChildList);
nsContainerFrame::SetInitialChildList(aListID, aChildList);
}
void
ViewportFrame::AppendFrames(ChildListID aListID,
nsFrameList& aFrameList)
{
NS_ASSERTION(aListID == kPrincipalList, "unexpected child list");
NS_ASSERTION(GetChildList(aListID).IsEmpty(), "Shouldn't have any kids!");
nsContainerFrame::AppendFrames(aListID, aFrameList);
}
void
ViewportFrame::InsertFrames(ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList)
{
NS_ASSERTION(aListID == kPrincipalList, "unexpected child list");
NS_ASSERTION(GetChildList(aListID).IsEmpty(), "Shouldn't have any kids!");
nsContainerFrame::InsertFrames(aListID, aPrevFrame, aFrameList);
}
void
ViewportFrame::RemoveFrame(ChildListID aListID,
nsIFrame* aOldFrame)
{
NS_ASSERTION(aListID == kPrincipalList, "unexpected child list");
nsContainerFrame::RemoveFrame(aListID, aOldFrame);
}
#endif
/* virtual */ nscoord
ViewportFrame::GetMinISize(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_MIN_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetMinISize(aRenderingContext);
return result;
}
/* virtual */ nscoord
ViewportFrame::GetPrefISize(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_PREF_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetPrefISize(aRenderingContext);
return result;
}
nsPoint
ViewportFrame::AdjustReflowStateForScrollbars(nsHTMLReflowState* aReflowState) const
{
// Get our prinicpal child frame and see if we're scrollable
nsIFrame* kidFrame = mFrames.FirstChild();
nsIScrollableFrame* scrollingFrame = do_QueryFrame(kidFrame);
if (scrollingFrame) {
nsMargin scrollbars = scrollingFrame->GetActualScrollbarSizes();
aReflowState->SetComputedWidth(aReflowState->ComputedWidth() -
scrollbars.LeftRight());
aReflowState->AvailableWidth() -= scrollbars.LeftRight();
aReflowState->SetComputedHeightWithoutResettingResizeFlags(
aReflowState->ComputedHeight() - scrollbars.TopBottom());
return nsPoint(scrollbars.left, scrollbars.top);
}
return nsPoint(0, 0);
}
nsRect
ViewportFrame::AdjustReflowStateAsContainingBlock(nsHTMLReflowState* aReflowState) const
{
#ifdef DEBUG
nsPoint offset =
#endif
AdjustReflowStateForScrollbars(aReflowState);
NS_ASSERTION(GetAbsoluteContainingBlock()->GetChildList().IsEmpty() ||
(offset.x == 0 && offset.y == 0),
"We don't handle correct positioning of fixed frames with "
"scrollbars in odd positions");
// If a scroll position clamping scroll-port size has been set, layout
// fixed position elements to this size instead of the computed size.
nsRect rect(0, 0, aReflowState->ComputedWidth(), aReflowState->ComputedHeight());
nsIPresShell* ps = PresContext()->PresShell();
if (ps->IsScrollPositionClampingScrollPortSizeSet()) {
rect.SizeTo(ps->GetScrollPositionClampingScrollPortSize());
}
return rect;
}
void
ViewportFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT("ViewportFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
NS_FRAME_TRACE_REFLOW_IN("ViewportFrame::Reflow");
// Initialize OUT parameters
aStatus = NS_FRAME_COMPLETE;
// Because |Reflow| sets ComputedBSize() on the child to our
// ComputedBSize().
AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
// 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.
SetSize(nsSize(aReflowState.ComputedWidth(), aReflowState.ComputedHeight()));
// Reflow the main content first so that the placeholders of the
// fixed-position frames will be in the right places on an initial
// reflow.
nscoord kidBSize = 0;
WritingMode wm = aReflowState.GetWritingMode();
if (mFrames.NotEmpty()) {
// Deal with a non-incremental reflow or an incremental reflow
// targeted at our one-and-only principal child frame.
if (aReflowState.ShouldReflowAllKids() ||
aReflowState.IsVResize() ||
NS_SUBTREE_DIRTY(mFrames.FirstChild())) {
// Reflow our one-and-only principal child frame
nsIFrame* kidFrame = mFrames.FirstChild();
nsHTMLReflowMetrics kidDesiredSize(aReflowState);
WritingMode wm = kidFrame->GetWritingMode();
LogicalSize availableSpace = aReflowState.AvailableSize(wm);
nsHTMLReflowState kidReflowState(aPresContext, aReflowState,
kidFrame, availableSpace);
// Reflow the frame
kidReflowState.SetComputedBSize(aReflowState.ComputedBSize());
ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
0, 0, 0, aStatus);
kidBSize = kidDesiredSize.BSize(wm);
FinishReflowChild(kidFrame, aPresContext, kidDesiredSize, nullptr, 0, 0, 0);
} else {
kidBSize = LogicalSize(wm, mFrames.FirstChild()->GetSize()).BSize(wm);
}
}
NS_ASSERTION(aReflowState.AvailableISize() != NS_UNCONSTRAINEDSIZE,
"shouldn't happen anymore");
// Return the max size as our desired size
LogicalSize maxSize(wm, aReflowState.AvailableISize(),
// Being flowed initially at an unconstrained block size
// means we should return our child's intrinsic size.
aReflowState.ComputedBSize() != NS_UNCONSTRAINEDSIZE
? aReflowState.ComputedBSize()
: kidBSize);
aDesiredSize.SetSize(wm, maxSize);
aDesiredSize.SetOverflowAreasToDesiredBounds();
if (HasAbsolutelyPositionedChildren()) {
// Make a copy of the reflow state and change the computed width and height
// to reflect the available space for the fixed items
nsHTMLReflowState reflowState(aReflowState);
if (reflowState.AvailableBSize() == NS_UNCONSTRAINEDSIZE) {
// We have an intrinsic-height document with abs-pos/fixed-pos children.
// Set the available height and mComputedHeight to our chosen height.
reflowState.AvailableBSize() = maxSize.BSize(wm);
// Not having border/padding simplifies things
NS_ASSERTION(reflowState.ComputedPhysicalBorderPadding() == nsMargin(0,0,0,0),
"Viewports can't have border/padding");
reflowState.SetComputedBSize(maxSize.BSize(wm));
}
nsRect rect = AdjustReflowStateAsContainingBlock(&reflowState);
nsOverflowAreas* overflowAreas = &aDesiredSize.mOverflowAreas;
nsIScrollableFrame* rootScrollFrame =
aPresContext->PresShell()->GetRootScrollFrameAsScrollable();
if (rootScrollFrame && !rootScrollFrame->IsIgnoringViewportClipping()) {
overflowAreas = nullptr;
}
GetAbsoluteContainingBlock()->Reflow(this, aPresContext, reflowState, aStatus,
rect,
false, true, true, // XXX could be optimized
overflowAreas);
}
if (mFrames.NotEmpty()) {
ConsiderChildOverflow(aDesiredSize.mOverflowAreas, mFrames.FirstChild());
}
// If we were dirty then do a repaint
if (GetStateBits() & NS_FRAME_IS_DIRTY) {
InvalidateFrame();
}
// Clipping is handled by the document container (e.g., nsSubDocumentFrame),
// so we don't need to change our overflow areas.
bool overflowChanged = FinishAndStoreOverflow(&aDesiredSize);
if (overflowChanged) {
// We may need to alert our container to get it to pick up the
// overflow change.
nsSubDocumentFrame* container = static_cast<nsSubDocumentFrame*>
(nsLayoutUtils::GetCrossDocParentFrame(this));
if (container && !container->ShouldClipSubdocument()) {
container->PresContext()->PresShell()->
FrameNeedsReflow(container, nsIPresShell::eResize, NS_FRAME_IS_DIRTY);
}
}
NS_FRAME_TRACE_REFLOW_OUT("ViewportFrame::Reflow", aStatus);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
}
bool
ViewportFrame::UpdateOverflow()
{
nsIScrollableFrame* rootScrollFrame =
PresContext()->PresShell()->GetRootScrollFrameAsScrollable();
if (rootScrollFrame && !rootScrollFrame->IsIgnoringViewportClipping()) {
return false;
}
return nsFrame::UpdateOverflow();
}
nsIAtom*
ViewportFrame::GetType() const
{
return nsGkAtoms::viewportFrame;
}
#ifdef DEBUG_FRAME_DUMP
nsresult
ViewportFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Viewport"), aResult);
}
#endif