pjs/layout/generic/nsViewportFrame.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
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*
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/*
* 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"
nsIFrame*
NS_NewViewportFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) ViewportFrame(aContext);
}
NS_IMETHODIMP
ViewportFrame::Init(nsIContent* aContent,
nsIFrame* aParent,
nsIFrame* aPrevInFlow)
{
return Super::Init(aContent, aParent, aPrevInFlow);
}
void
ViewportFrame::Destroy()
{
mFixedContainer.DestroyFrames(this);
nsContainerFrame::Destroy();
}
NS_IMETHODIMP
ViewportFrame::SetInitialChildList(nsIAtom* aListName,
nsIFrame* aChildList)
{
nsresult rv = NS_OK;
// See which child list to add the frames to
#ifdef NS_DEBUG
nsFrame::VerifyDirtyBitSet(aChildList);
#endif
if (nsGkAtoms::fixedList == aListName) {
rv = mFixedContainer.SetInitialChildList(this, aListName, aChildList);
}
else {
rv = nsContainerFrame::SetInitialChildList(aListName, aChildList);
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
// We don't need any special painting or event handling. We just need to
// mark our visible out-of-flow frames (i.e., the fixed position frames) so
// that display list construction is guaranteed to recurse into their
// ancestors.
aBuilder->MarkFramesForDisplayList(this, mFixedContainer.GetFirstChild(), aDirtyRect);
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(nsIAtom* aListName,
nsIFrame* aFrameList)
{
nsresult rv = NS_OK;
if (nsGkAtoms::fixedList == aListName) {
rv = mFixedContainer.AppendFrames(this, aListName, aFrameList);
}
else {
// We only expect incremental changes for our fixed frames
NS_ERROR("unexpected child list");
rv = NS_ERROR_INVALID_ARG;
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::InsertFrames(nsIAtom* aListName,
nsIFrame* aPrevFrame,
nsIFrame* aFrameList)
{
nsresult rv = NS_OK;
if (nsGkAtoms::fixedList == aListName) {
rv = mFixedContainer.InsertFrames(this, aListName, aPrevFrame, aFrameList);
}
else {
// We only expect incremental changes for our fixed frames
NS_ERROR("unexpected child list");
rv = NS_ERROR_INVALID_ARG;
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::RemoveFrame(nsIAtom* aListName,
nsIFrame* aOldFrame)
{
nsresult rv = NS_OK;
if (nsGkAtoms::fixedList == aListName) {
rv = mFixedContainer.RemoveFrame(this, aListName, aOldFrame);
}
else {
// We only expect incremental changes for our fixed frames
NS_ERROR("unexpected child list");
rv = NS_ERROR_INVALID_ARG;
}
return rv;
}
nsIAtom*
ViewportFrame::GetAdditionalChildListName(PRInt32 aIndex) const
{
NS_PRECONDITION(aIndex >= 0, "illegal index");
if (0 == aIndex) {
return nsGkAtoms::fixedList;
}
return nsnull;
}
nsIFrame*
ViewportFrame::GetFirstChild(nsIAtom* aListName) const
{
if (nsGkAtoms::fixedList == aListName) {
nsIFrame* result = nsnull;
mFixedContainer.FirstChild(this, aListName, &result);
return result;
}
return nsContainerFrame::GetFirstChild(aListName);
}
/* virtual */ nscoord
ViewportFrame::GetMinWidth(nsIRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_MIN_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetMinWidth(aRenderingContext);
// XXXldb Deal with mFixedContainer (matters for SizeToContent)!
return result;
}
/* virtual */ nscoord
ViewportFrame::GetPrefWidth(nsIRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_PREF_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetPrefWidth(aRenderingContext);
// XXXldb Deal with mFixedContainer (matters for SizeToContent)!
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();
nsCOMPtr<nsIScrollableFrame> scrollingFrame(do_QueryInterface(kidFrame));
if (scrollingFrame) {
nsMargin scrollbars = scrollingFrame->GetActualScrollbarSizes();
aReflowState->SetComputedWidth(aReflowState->ComputedWidth() -
scrollbars.LeftRight());
aReflowState->availableWidth -= scrollbars.LeftRight();
aReflowState->SetComputedHeight(aReflowState->ComputedHeight() -
scrollbars.TopBottom());
// XXX why don't we also adjust "aReflowState->availableHeight"?
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);
// Reflow the main content first so that the placeholders of the
// fixed-position frames will be in the right places on an initial
// reflow.
nsRect kidRect(0,0,aReflowState.availableWidth,aReflowState.availableHeight);
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.availableHeight);
rv = ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
0, 0, 0, aStatus);
kidRect.width = kidDesiredSize.width;
kidRect.height = kidDesiredSize.height;
FinishReflowChild(kidFrame, aPresContext, nsnull, kidDesiredSize, 0, 0, 0);
}
}
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.availableHeight != NS_UNCONSTRAINEDSIZE
? aReflowState.availableHeight
: kidRect.height;
// 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);
nsPoint offset = AdjustReflowStateForScrollbars(&reflowState);
#ifdef DEBUG
nsIFrame* f;
mFixedContainer.FirstChild(this, nsGkAtoms::fixedList, &f);
NS_ASSERTION(!f || (offset.x == 0 && offset.y == 0),
"We don't handle correct positioning of fixed frames with "
"scrollbars in odd positions");
#endif
// Just reflow all the fixed-pos frames.
rv = mFixedContainer.Reflow(this, aPresContext, reflowState,
reflowState.ComputedWidth(),
reflowState.ComputedHeight(),
PR_TRUE, PR_TRUE); // XXX could be optimized
// If we were dirty then do a repaint
if (GetStateBits() & NS_FRAME_IS_DIRTY) {
nsRect damageRect(0, 0, aDesiredSize.width, aDesiredSize.height);
Invalidate(damageRect, PR_FALSE);
}
// XXX Should we do something to clip our children to this?
aDesiredSize.mOverflowArea =
nsRect(nsPoint(0, 0), nsSize(aDesiredSize.width, aDesiredSize.height));
NS_FRAME_TRACE_REFLOW_OUT("ViewportFrame::Reflow", aStatus);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return rv;
}
nsIAtom*
ViewportFrame::GetType() const
{
return nsGkAtoms::viewportFrame;
}
/* virtual */ PRBool
ViewportFrame::IsContainingBlock() const
{
return PR_TRUE;
}
void
ViewportFrame::InvalidateInternal(const nsRect& aDamageRect,
nscoord aX, nscoord aY, nsIFrame* aForChild,
PRBool aImmediate)
{
nsIFrame* parent = nsLayoutUtils::GetCrossDocParentFrame(this);
if (parent) {
nsPoint pt = GetOffsetTo(parent);
parent->InvalidateInternal(aDamageRect, aX + pt.x, aY + pt.y, this, aImmediate);
return;
}
InvalidateRoot(aDamageRect, aX, aY, aImmediate);
}
#ifdef DEBUG
NS_IMETHODIMP
ViewportFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Viewport"), aResult);
}
#endif