nsFrameList
nsFrameList::ExtractHead(FrameLinkEnumerator& aLink)
{
NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.PrevFrame()->GetNextSibling() ==
aLink.NextFrame(),
"Unexpected PrevFrame()");
NS_PRECONDITION(aLink.PrevFrame() ||
aLink.NextFrame() == FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.NextFrame() != FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(aLink.mEnd == nullptr,
"Unexpected mEnd for frame link enumerator");
nsIFrame* prev = aLink.PrevFrame();
nsIFrame* newFirstFrame = nullptr;
if (prev) {
// Truncate the list after |prev| and hand the first part to our new list.
prev->SetNextSibling(nullptr);
newFirstFrame = mFirstChild;
mFirstChild = aLink.NextFrame();
if (!mFirstChild) { // we handed over the whole list
mLastChild = nullptr;
}
// Now make sure aLink doesn't point to a frame we no longer have.
aLink.mPrev = nullptr;
}
// else aLink is pointing to before our first frame. Nothing to do.
return nsFrameList(newFirstFrame, prev);
}
// The following methods are all overridden to ensure that the menupopup frame
// is placed in the appropriate list.
nsFrameList
nsMenuFrame::GetChildList(nsIAtom* aListName) const
{
if (nsGkAtoms::popupList == aListName) {
return nsFrameList(mPopupFrame, mPopupFrame);
}
return nsBoxFrame::GetChildList(aListName);
}
nsFrameList
nsFrameList::RemoveFramesAfter(nsIFrame* aAfterFrame)
{
if (!aAfterFrame) {
nsFrameList result;
result.InsertFrames(nullptr, nullptr, *this);
return result;
}
NS_PRECONDITION(NotEmpty(), "illegal operation on empty list");
#ifdef DEBUG_FRAME_LIST
NS_PRECONDITION(ContainsFrame(aAfterFrame), "wrong list");
#endif
nsIFrame* tail = aAfterFrame->GetNextSibling();
// if (!tail) return EmptyList(); -- worth optimizing this case?
nsIFrame* oldLastChild = mLastChild;
mLastChild = aAfterFrame;
aAfterFrame->SetNextSibling(nullptr);
return nsFrameList(tail, tail ? oldLastChild : nullptr);
}
nsFrameList
nsFrameList::ExtractTail(FrameLinkEnumerator& aLink)
{
NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.PrevFrame()->GetNextSibling() ==
aLink.NextFrame(),
"Unexpected PrevFrame()");
NS_PRECONDITION(aLink.PrevFrame() ||
aLink.NextFrame() == FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.NextFrame() != FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(aLink.mEnd == nullptr,
"Unexpected mEnd for frame link enumerator");
nsIFrame* prev = aLink.PrevFrame();
nsIFrame* newFirstFrame;
nsIFrame* newLastFrame;
if (prev) {
// Truncate the list after |prev| and hand the second part to our new list
prev->SetNextSibling(nullptr);
newFirstFrame = aLink.NextFrame();
newLastFrame = newFirstFrame ? mLastChild : nullptr;
mLastChild = prev;
} else {
// Hand the whole list over to our new list
newFirstFrame = mFirstChild;
newLastFrame = mLastChild;
Clear();
}
// Now make sure aLink doesn't point to a frame we no longer have.
aLink.mFrame = nullptr;
NS_POSTCONDITION(aLink.AtEnd(), "What's going on here?");
return nsFrameList(newFirstFrame, newLastFrame);
}
NS_IMETHODIMP
nsCanvasFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("nsCanvasFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
NS_FRAME_TRACE_REFLOW_IN("nsCanvasFrame::Reflow");
// Initialize OUT parameter
aStatus = NS_FRAME_COMPLETE;
nsCanvasFrame* prevCanvasFrame = static_cast<nsCanvasFrame*>
(GetPrevInFlow());
if (prevCanvasFrame) {
nsAutoPtr<nsFrameList> overflow(prevCanvasFrame->StealOverflowFrames());
if (overflow) {
NS_ASSERTION(overflow->OnlyChild(),
"must have doc root as canvas frame's only child");
nsContainerFrame::ReparentFrameViewList(aPresContext, *overflow,
prevCanvasFrame, this);
// Prepend overflow to the our child list. There may already be
// children placeholders for fixed-pos elements, which don't get
// reflowed but must not be lost until the canvas frame is destroyed.
mFrames.InsertFrames(this, nullptr, *overflow);
}
}
// 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 our one and only normal child frame. It's either the root
// element's frame or a placeholder for that frame, if the root element
// is abs-pos or fixed-pos. We may have additional children which
// are placeholders for continuations of fixed-pos content, but those
// don't need to be reflowed. The normal child is always comes before
// the fixed-pos placeholders, because we insert it at the start
// of the child list, above.
nsHTMLReflowMetrics kidDesiredSize;
if (mFrames.IsEmpty()) {
// We have no child frame, so return an empty size
aDesiredSize.width = aDesiredSize.height = 0;
} else {
nsIFrame* kidFrame = mFrames.FirstChild();
bool kidDirty = (kidFrame->GetStateBits() & NS_FRAME_IS_DIRTY) != 0;
nsHTMLReflowState kidReflowState(aPresContext, aReflowState, kidFrame,
nsSize(aReflowState.availableWidth,
aReflowState.availableHeight));
if (aReflowState.mFlags.mVResize &&
(kidFrame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)) {
// Tell our kid it's being vertically resized too. Bit of a
// hack for framesets.
kidReflowState.mFlags.mVResize = true;
}
nsPoint kidPt(kidReflowState.mComputedMargin.left,
kidReflowState.mComputedMargin.top);
// Apply CSS relative positioning
const nsStyleDisplay* styleDisp = kidFrame->GetStyleDisplay();
if (NS_STYLE_POSITION_RELATIVE == styleDisp->mPosition) {
kidPt += nsPoint(kidReflowState.mComputedOffsets.left,
kidReflowState.mComputedOffsets.top);
}
// Reflow the frame
ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
kidPt.x, kidPt.y, 0, aStatus);
// Complete the reflow and position and size the child frame
FinishReflowChild(kidFrame, aPresContext, &kidReflowState, kidDesiredSize,
kidPt.x, kidPt.y, 0);
if (!NS_FRAME_IS_FULLY_COMPLETE(aStatus)) {
nsIFrame* nextFrame = kidFrame->GetNextInFlow();
NS_ASSERTION(nextFrame || aStatus & NS_FRAME_REFLOW_NEXTINFLOW,
"If it's incomplete and has no nif yet, it must flag a nif reflow.");
if (!nextFrame) {
nsresult rv = aPresContext->PresShell()->FrameConstructor()->
CreateContinuingFrame(aPresContext, kidFrame, this, &nextFrame);
NS_ENSURE_SUCCESS(rv, rv);
SetOverflowFrames(aPresContext, nsFrameList(nextFrame, nextFrame));
// Root overflow containers will be normal children of
// the canvas frame, but that's ok because there
// aren't any other frames we need to isolate them from
// during reflow.
}
if (NS_FRAME_OVERFLOW_IS_INCOMPLETE(aStatus)) {
nextFrame->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
}
}
// If the child frame was just inserted, then we're responsible for making sure
// it repaints
if (kidDirty) {
// But we have a new child, which will affect our background, so
// invalidate our whole rect.
// Note: Even though we request to be sized to our child's size, our
// scroll frame ensures that we are always the size of the viewport.
// Also note: GetPosition() on a CanvasFrame is always going to return
// (0, 0). We only want to invalidate GetRect() since Get*OverflowRect()
// could also include overflow to our top and left (out of the viewport)
// which doesn't need to be painted.
nsIFrame* viewport = PresContext()->GetPresShell()->GetRootFrame();
viewport->InvalidateFrame();
}
// Return our desired size. Normally it's what we're told, but
// sometimes we can be given an unconstrained height (when a window
// is sizing-to-content), and we should compute our desired height.
aDesiredSize.width = aReflowState.ComputedWidth();
if (aReflowState.ComputedHeight() == NS_UNCONSTRAINEDSIZE) {
aDesiredSize.height = kidFrame->GetRect().height +
kidReflowState.mComputedMargin.TopBottom();
} else {
aDesiredSize.height = aReflowState.ComputedHeight();
}
aDesiredSize.SetOverflowAreasToDesiredBounds();
aDesiredSize.mOverflowAreas.UnionWith(
kidDesiredSize.mOverflowAreas + kidPt);
}
if (prevCanvasFrame) {
ReflowOverflowContainerChildren(aPresContext, aReflowState,
aDesiredSize.mOverflowAreas, 0,
aStatus);
}
FinishReflowWithAbsoluteFrames(aPresContext, aDesiredSize, aReflowState, aStatus);
NS_FRAME_TRACE_REFLOW_OUT("nsCanvasFrame::Reflow", aStatus);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
