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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 https://mozilla.org/MPL/2.0/. */
// A frame for CSS multi-column layout that wraps nsColumnSetFrames and
// column-span frames.
#ifndef mozilla_ColumnSetWrapperFrame_h
#define mozilla_ColumnSetWrapperFrame_h
#include "nsBlockFrame.h"
namespace mozilla {
class PresShell;
// This class is a wrapper for nsColumnSetFrames and column-span frame.
// Essentially, we divide the *original* nsColumnSetFrame into multiple
// nsColumnSetFrames on the basis of the number and position of spanning
// elements.
//
// This wrapper is necessary for implementing column-span as it allows us to
// maintain each nsColumnSetFrame as an independent set of columns, and each
// column-span element then becomes just a block level element.
//
class ColumnSetWrapperFrame final : public nsBlockFrame {
public:
NS_DECL_FRAMEARENA_HELPERS(ColumnSetWrapperFrame)
NS_DECL_QUERYFRAME
friend nsBlockFrame* ::NS_NewColumnSetWrapperFrame(
mozilla::PresShell* aPresShell, ComputedStyle* aStyle,
nsFrameState aStateFlags);
void Init(nsIContent* aContent, nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) override;
nsContainerFrame* GetContentInsertionFrame() override;
void AppendDirectlyOwnedAnonBoxes(nsTArray<OwnedAnonBox>& aResult) override;
#ifdef DEBUG_FRAME_DUMP
nsresult GetFrameName(nsAString& aResult) const override;
#endif
void AppendFrames(ChildListID aListID, nsFrameList&& aFrameList) override;
void InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
const nsLineList::iterator* aPrevFrameLine,
nsFrameList&& aFrameList) override;
void RemoveFrame(DestroyContext&, ChildListID, nsIFrame*) override;
void MarkIntrinsicISizesDirty() override;
nscoord IntrinsicISize(const IntrinsicSizeInput& aInput,
IntrinsicISizeType aType) override;
Maybe<nscoord> GetNaturalBaselineBOffset(
WritingMode aWM, BaselineSharingGroup aBaselineGroup,
BaselineExportContext aExportContext) const override;
private:
explicit ColumnSetWrapperFrame(ComputedStyle* aStyle,
nsPresContext* aPresContext);
~ColumnSetWrapperFrame() override = default;
// MinISize() and PrefISize() are helpers to implement IntrinsicISize().
nscoord MinISize(const IntrinsicSizeInput& aInput);
nscoord PrefISize(const IntrinsicSizeInput& aInput);
#ifdef DEBUG
static void AssertColumnSpanWrapperSubtreeIsSane(const nsIFrame* aFrame);
// True if frame constructor has finished building this frame and all of
// its descendants.
bool mFinishedBuildingColumns = false;
#endif
template <typename Iterator>
Maybe<nscoord> GetBaselineBOffset(Iterator aStart, Iterator aEnd,
WritingMode aWM,
BaselineSharingGroup aBaselineGroup,
BaselineExportContext aExportContext) const;
};
} // namespace mozilla
#endif // mozilla_ColumnSetWrapperFrame_h
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