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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /layout/generic/nsILineIterator.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'layout/generic/nsILineIterator.h')
-rw-r--r-- | layout/generic/nsILineIterator.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/layout/generic/nsILineIterator.h b/layout/generic/nsILineIterator.h new file mode 100644 index 0000000000..bef4b28cc1 --- /dev/null +++ b/layout/generic/nsILineIterator.h @@ -0,0 +1,133 @@ +/* -*- 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 http://mozilla.org/MPL/2.0/. */ +#ifndef nsILineIterator_h___ +#define nsILineIterator_h___ + +#include "nscore.h" +#include "nsINode.h" +#include "nsRect.h" +#include "mozilla/Attributes.h" +#include "mozilla/Result.h" +#include "mozilla/WritingModes.h" + +class nsIFrame; + +/** + * Line iterator API. + * + * Lines are numbered from 0 to N, where 0 is the top line and N is + * the bottom line. + * + * Obtain this interface from frames via nsIFrame::GetLineIterator. + * This iterator belongs to the frame from which it was obtained, and should + * not be deleted by the caller. + * Note that any modification of the frame will invalidate the iterator! + * Users must get a new iterator any time the target may have been touched. + */ +class nsILineIterator { + protected: + ~nsILineIterator() = default; + + public: + /** + * The number of lines in the block + */ + virtual int32_t GetNumLines() const = 0; + + /** + * Returns whether our lines are rtl. + */ + virtual bool IsLineIteratorFlowRTL() = 0; + + struct LineInfo { + /** The first frame on the line. */ + nsIFrame* mFirstFrameOnLine = nullptr; + /** The numbers of frames on the line. */ + int32_t mNumFramesOnLine = 0; + /** + * The bounding box of the line (which is based on the in-flow position of + * the frames on the line; if a frame was moved because of relative + * positioning then its coordinates may be outside the line bounds) + */ + nsRect mLineBounds; + /** Whether the line is wrapped at the end */ + bool mIsWrapped = false; + }; + + // Return miscellaneous information about a line. + virtual mozilla::Result<LineInfo, nsresult> GetLine(int32_t aLineNumber) = 0; + + /** + * Given a frame that's a child of the block, find which line its on + * and return that line index, as long as it's at least as big as + * aStartLine. Returns -1 if the frame cannot be found on lines + * starting with aStartLine. + */ + virtual int32_t FindLineContaining(nsIFrame* aFrame, + int32_t aStartLine = 0) = 0; + + // Given a line number and a coordinate, find the frame on the line + // that is nearest to aPos along the inline axis. (The block-axis coord + // of aPos is irrelevant.) + // The aPosIsBeforeFirstFrame and aPosIsAfterLastFrame flags are updated + // appropriately. + NS_IMETHOD FindFrameAt(int32_t aLineNumber, nsPoint aPos, + nsIFrame** aFrameFound, bool* aPosIsBeforeFirstFrame, + bool* aPosIsAfterLastFrame) = 0; + + // Check whether visual and logical order of frames within a line are + // identical. + // If not, return the first and last visual frames + NS_IMETHOD CheckLineOrder(int32_t aLine, bool* aIsReordered, + nsIFrame** aFirstVisual, + nsIFrame** aLastVisual) = 0; +}; + +namespace mozilla { + +// Helper struct for FindFrameAt. +struct LineFrameFinder { + LineFrameFinder(const nsPoint& aPos, const nsSize& aContainerSize, + WritingMode aWM, bool aIsReversed) + : mPos(aWM, aPos, aContainerSize), + mContainerSize(aContainerSize), + mWM(aWM), + mIsReversed(aIsReversed) {} + + void Scan(nsIFrame*); + void Finish(nsIFrame**, bool* aPosIsBeforeFirstFrame, + bool* aPosIsAfterLastFrame); + + const LogicalPoint mPos; + const nsSize mContainerSize; + const WritingMode mWM; + const bool mIsReversed; + + bool IsDone() const { return mDone; } + + private: + bool mDone = false; + nsIFrame* mFirstFrame = nullptr; + nsIFrame* mClosestFromStart = nullptr; + nsIFrame* mClosestFromEnd = nullptr; +}; + +} // namespace mozilla + +/** + * Helper intended to be used in a scope where we're using an nsILineIterator + * and want to verify that no DOM mutations (which would invalidate the + * iterator) occur while we're using it. + */ +class MOZ_STACK_CLASS AutoAssertNoDomMutations final { +#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED + nsMutationGuard mGuard; +#endif + public: + ~AutoAssertNoDomMutations() { MOZ_DIAGNOSTIC_ASSERT(!mGuard.Mutated(0)); } +}; + +#endif /* nsILineIterator_h___ */ |