gecko-dev/layout/generic/nsViewportFrame.cpp

308 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 "nsCOMPtr.h"
#include "nsViewportFrame.h"
#include "nsHTMLParts.h"
#include "nsGkAtoms.h"
#include "nsIScrollableFrame.h"
#include "nsDisplayList.h"
#include "FrameLayerBuilder.h"
#include "nsSubDocumentFrame.h"
#include "nsAbsoluteContainingBlock.h"
#include "sampler.h"
using namespace mozilla;
nsIFrame*
NS_NewViewportFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) ViewportFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(ViewportFrame)
NS_IMETHODIMP
ViewportFrame::Init(nsIContent* aContent,
nsIFrame* aParent,
nsIFrame* aPrevInFlow)
{
nsresult rv = Super::Init(aContent, aParent, aPrevInFlow);
nsIFrame* parent = nsLayoutUtils::GetCrossDocParentFrame(this);
if (parent) {
nsFrameState state = parent->GetStateBits();
mState |= state & (NS_FRAME_IN_POPUP);
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::SetInitialChildList(ChildListID aListID,
nsFrameList& aChildList)
{
// See which child list to add the frames to
#ifdef DEBUG
nsFrame::VerifyDirtyBitSet(aChildList);
#endif
return nsContainerFrame::SetInitialChildList(aListID, aChildList);
}
NS_IMETHODIMP
ViewportFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
SAMPLE_LABEL("ViewportFrame", "BuildDisplayList");
nsIFrame* kid = mFrames.FirstChild();
if (!kid)
return NS_OK;
// 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.
return BuildDisplayListForChild(aBuilder, kid, aDirtyRect, aLists);
}
NS_IMETHODIMP
ViewportFrame::AppendFrames(ChildListID aListID,
nsFrameList& aFrameList)
{
NS_ASSERTION(aListID == kPrincipalList ||
aListID == GetAbsoluteListID(), "unexpected child list");
NS_ASSERTION(aListID != GetAbsoluteListID() ||
GetChildList(aListID).IsEmpty(), "Shouldn't have any kids!");
return nsContainerFrame::AppendFrames(aListID, aFrameList);
}
NS_IMETHODIMP
ViewportFrame::InsertFrames(ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList)
{
NS_ASSERTION(aListID == kPrincipalList ||
aListID == GetAbsoluteListID(), "unexpected child list");
NS_ASSERTION(aListID != GetAbsoluteListID() ||
GetChildList(aListID).IsEmpty(), "Shouldn't have any kids!");
return nsContainerFrame::InsertFrames(aListID, aPrevFrame, aFrameList);
}
NS_IMETHODIMP
ViewportFrame::RemoveFrame(ChildListID aListID,
nsIFrame* aOldFrame)
{
NS_ASSERTION(aListID == kPrincipalList ||
aListID == GetAbsoluteListID(), "unexpected child list");
return nsContainerFrame::RemoveFrame(aListID, aOldFrame);
}
/* virtual */ nscoord
ViewportFrame::GetMinWidth(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_MIN_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetMinWidth(aRenderingContext);
return result;
}
/* virtual */ nscoord
ViewportFrame::GetPrefWidth(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_PREF_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetPrefWidth(aRenderingContext);
return result;
}
nsPoint
ViewportFrame::AdjustReflowStateForScrollbars(nsHTMLReflowState* aReflowState) const
{
// 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
// 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);
}
NS_IMETHODIMP
ViewportFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
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 mComputedHeight on the child to
// availableHeight.
AddStateBits(NS_FRAME_CONTAINS_RELATIVE_HEIGHT);
// 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 kidHeight = 0;
nsresult rv = NS_OK;
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.mFlags.mVResize ||
NS_SUBTREE_DIRTY(mFrames.FirstChild())) {
// Reflow our one-and-only principal child frame
nsIFrame* kidFrame = mFrames.FirstChild();
nsHTMLReflowMetrics kidDesiredSize;
nsSize availableSpace(aReflowState.availableWidth,
aReflowState.availableHeight);
nsHTMLReflowState kidReflowState(aPresContext, aReflowState,
kidFrame, availableSpace);
// Reflow the frame
kidReflowState.SetComputedHeight(aReflowState.ComputedHeight());
rv = ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
0, 0, 0, aStatus);
kidHeight = kidDesiredSize.height;
FinishReflowChild(kidFrame, aPresContext, nullptr, kidDesiredSize, 0, 0, 0);
} else {
kidHeight = mFrames.FirstChild()->GetSize().height;
}
}
NS_ASSERTION(aReflowState.availableWidth != NS_UNCONSTRAINEDSIZE,
"shouldn't happen anymore");
// Return the max size as our desired size
aDesiredSize.width = aReflowState.availableWidth;
// Being flowed initially at an unconstrained height means we should
// return our child's intrinsic size.
aDesiredSize.height = aReflowState.ComputedHeight() != NS_UNCONSTRAINEDSIZE
? aReflowState.ComputedHeight()
: kidHeight;
aDesiredSize.SetOverflowAreasToDesiredBounds();
if (mFrames.NotEmpty()) {
ConsiderChildOverflow(aDesiredSize.mOverflowAreas, mFrames.FirstChild());
}
if (IsAbsoluteContainer()) {
// 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.availableHeight == 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.availableHeight = aDesiredSize.height;
// Not having border/padding simplifies things
NS_ASSERTION(reflowState.mComputedBorderPadding == nsMargin(0,0,0,0),
"Viewports can't have border/padding");
reflowState.SetComputedHeight(aDesiredSize.height);
}
#ifdef DEBUG
nsPoint offset =
#endif
AdjustReflowStateForScrollbars(&reflowState);
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.
nscoord width = reflowState.ComputedWidth();
nscoord height = reflowState.ComputedHeight();
if (aPresContext->PresShell()->IsScrollPositionClampingScrollPortSizeSet()) {
nsSize size = aPresContext->PresShell()->
GetScrollPositionClampingScrollPortSize();
width = size.width;
height = size.height;
}
// Just reflow all the fixed-pos frames.
rv = GetAbsoluteContainingBlock()->Reflow(this, aPresContext, reflowState, aStatus,
width, height,
false, true, true, // XXX could be optimized
&aDesiredSize.mOverflowAreas);
}
// 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);
return rv;
}
nsIAtom*
ViewportFrame::GetType() const
{
return nsGkAtoms::viewportFrame;
}
#ifdef DEBUG
NS_IMETHODIMP
ViewportFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Viewport"), aResult);
}
#endif