commit d8930777738b3364429c15d6c289cda9463e4d76
parent e09fd0f1ac0b4069f44575f2c952049fcc15b8a0
Author: Ting-Yu Lin <tlin@mozilla.com>
Date: Mon, 13 Oct 2025 21:36:13 +0000
Bug 1983345 Part 3 - Improve the helper for getting containing block of a hypothetical box. r=layout-reviewers,emilio
The helper now returns the block container's border+padding, which will be used
in a later part.
Differential Revision: https://phabricator.services.mozilla.com/D268299
Diffstat:
2 files changed, 38 insertions(+), 57 deletions(-)
diff --git a/layout/generic/ReflowInput.cpp b/layout/generic/ReflowInput.cpp
@@ -1188,47 +1188,31 @@ void ReflowInput::ApplyRelativePositioning(
*aPosition = LogicalPoint(aWritingMode, pos, aContainerSize - frameSize);
}
-nsIFrame* ReflowInput::GetHypotheticalBoxContainer(nsIFrame* aFrame,
- nscoord& aCBIStartEdge,
- LogicalSize& aCBSize) const {
- aFrame = aFrame->GetContainingBlock();
- NS_ASSERTION(aFrame != mFrame, "How did that happen?");
-
- /* Now aFrame is the containing block we want */
-
- /* Check whether the containing block is currently being reflowed.
- If so, use the info from the reflow input. */
- const ReflowInput* reflowInput;
- if (aFrame->HasAnyStateBits(NS_FRAME_IN_REFLOW)) {
- for (reflowInput = mParentReflowInput;
- reflowInput && reflowInput->mFrame != aFrame;
- reflowInput = reflowInput->mParentReflowInput) {
- /* do nothing */
+ReflowInput::HypotheticalBoxContainerInfo
+ReflowInput::GetHypotheticalBoxContainer(const nsIFrame* aFrame) const {
+ nsIFrame* cb = aFrame->GetContainingBlock();
+ NS_ASSERTION(cb != mFrame, "How did that happen?");
+
+ // If cb is currently being reflowed, find its ReflowInput.
+ const ReflowInput* ri = nullptr;
+ if (cb->HasAnyStateBits(NS_FRAME_IN_REFLOW)) {
+ ri = mParentReflowInput;
+ while (ri && ri->mFrame != cb) {
+ ri = ri->mParentReflowInput;
}
- } else {
- reflowInput = nullptr;
}
- if (reflowInput) {
- WritingMode wm = reflowInput->GetWritingMode();
- NS_ASSERTION(wm == aFrame->GetWritingMode(), "unexpected writing mode");
- aCBIStartEdge = reflowInput->ComputedLogicalBorderPadding(wm).IStart(wm);
- aCBSize = reflowInput->ComputedSize(wm);
- } else {
- /* Didn't find a reflow reflowInput for aFrame. Just compute the
- information we want, on the assumption that aFrame already knows its
- size. This really ought to be true by now. */
- NS_ASSERTION(!aFrame->HasAnyStateBits(NS_FRAME_IN_REFLOW),
- "aFrame shouldn't be in reflow; we'll lie if it is");
- WritingMode wm = aFrame->GetWritingMode();
- // Compute CB's offset & content-box size by subtracting borderpadding from
- // frame size.
- const auto& bp = aFrame->GetLogicalUsedBorderAndPadding(wm);
- aCBIStartEdge = bp.IStart(wm);
- aCBSize = aFrame->GetLogicalSize(wm) - bp.Size(wm);
- }
-
- return aFrame;
+ const WritingMode wm = cb->GetWritingMode();
+ if (ri) {
+ return {cb, ri->ComputedLogicalBorderPadding(wm), ri->ComputedSize(wm)};
+ }
+
+ // Didn't find a ReflowInput for cb. Just compute the information we want, on
+ // the assumption that cb already knows its size. This really ought to be true
+ // by now.
+ NS_ASSERTION(!cb->HasAnyStateBits(NS_FRAME_IN_REFLOW),
+ "cb shouldn't be in reflow; we'll lie if it is");
+ return {cb, cb->GetLogicalUsedBorderAndPadding(wm), cb->ContentSize(wm)};
}
struct nsHypotheticalPosition {
@@ -1364,22 +1348,15 @@ void ReflowInput::CalculateHypotheticalPosition(
NS_ASSERTION(mStyleDisplay->mOriginalDisplay != StyleDisplay::None,
"mOriginalDisplay has not been properly initialized");
- // Find the nearest containing block frame to the placeholder frame,
- // and its inline-start edge and width.
- nscoord blockIStartContentEdge;
- // Dummy writing mode for blockContentSize, will be changed as needed by
- // GetHypotheticalBoxContainer.
WritingMode cbwm = aCBReflowInput->GetWritingMode();
- LogicalSize blockContentSize(cbwm);
- nsIFrame* containingBlock = GetHypotheticalBoxContainer(
- aPlaceholderFrame, blockIStartContentEdge, blockContentSize);
- // Now blockContentSize is in containingBlock's writing mode.
+ const auto [containingBlock, blockContainerBP, blockContentSize] =
+ GetHypotheticalBoxContainer(aPlaceholderFrame);
+ WritingMode wm = containingBlock->GetWritingMode();
+ const nscoord blockIStartContentEdge = blockContainerBP.IStart(wm);
// If it's a replaced element and it has a 'auto' value for
//'inline size', see if we can get the intrinsic size. This will allow
// us to exactly determine both the inline edges
- WritingMode wm = containingBlock->GetWritingMode();
-
const auto anchorResolutionParams = AnchorPosResolutionParams::From(this);
const auto styleISize = mStylePosition->ISize(wm, anchorResolutionParams);
bool isAutoISize = styleISize->IsAuto();
diff --git a/layout/generic/ReflowInput.h b/layout/generic/ReflowInput.h
@@ -859,14 +859,18 @@ struct ReflowInput : public SizeComputationInput {
LogicalSize ComputeContainingBlockRectangle(
nsPresContext* aPresContext, const ReflowInput* aContainingBlockRI) const;
- // Returns the nearest containing block or block frame (whether or not
- // it is a containing block) for the specified frame. Also returns
- // the inline-start edge and logical size of the containing block's
- // content area.
- // These are returned in the coordinate space of the containing block.
- nsIFrame* GetHypotheticalBoxContainer(nsIFrame* aFrame,
- nscoord& aCBIStartEdge,
- LogicalSize& aCBSize) const;
+ // mBorderPadding and mFrame are both in mBoxContainer's writing-mode.
+ struct HypotheticalBoxContainerInfo {
+ nsIFrame* mBoxContainer;
+ LogicalMargin mBorderPadding;
+ LogicalSize mContentBoxSize;
+ };
+
+ // Returns the nearest containing block for aFrame. Also returns its border &
+ // padding and content-box size. These are returned in the coordinate space of
+ // the containing block.
+ HypotheticalBoxContainerInfo GetHypotheticalBoxContainer(
+ const nsIFrame* aFrame) const;
// Calculate the position of the hypothetical box that the placeholder frame
// (for a position:fixed/absolute element) would have if it were in the flow
