зеркало из https://github.com/mozilla/gecko-dev.git
81 строка
3.1 KiB
C++
81 строка
3.1 KiB
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef LAYOUT_BASE_BASELINE_H_
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#define LAYOUT_BASE_BASELINE_H_
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#include "nsCoord.h"
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#include "mozilla/WritingModes.h"
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class nsIFrame;
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namespace mozilla {
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// https://drafts.csswg.org/css-align-3/#baseline-sharing-group
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enum class BaselineSharingGroup : uint8_t {
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// NOTE Used as an array index so must be 0 and 1.
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First = 0,
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Last = 1,
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};
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class Baseline {
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public:
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/**
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* Synthesize a first(last) inline-axis baseline in aWM based on aFrame's
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* margin-box.
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*
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* An alphabetical baseline is at the end edge of aFrame's margin-box with
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* respect to aWM's block-axis, and a central baseline is halfway between the
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* start and end edges. (aWM tells which baseline to use.)
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* https://drafts.csswg.org/css-align-3/#synthesize-baseline
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*
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* @note This works only when aFrame's writing-mode is parallel to aWM.
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* @param aWM the writing-mode of the alignment context.
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* @return an offset from aFrame's border-box start(end) edge in aWM's
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* block-axis for a first(last) baseline, respectively.
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*/
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static nscoord SynthesizeBOffsetFromMarginBox(const nsIFrame* aFrame,
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WritingMode aWM,
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BaselineSharingGroup);
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/**
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* Synthesize a first(last) inline-axis baseline in aWM based on aFrame's
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* border-box.
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*
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* An alphabetical baseline is at the end edge of aFrame's border-box with
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* respect to aWM's block-axis, and a central baseline is halfway between the
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* start and end edges. (aWM tells which baseline to use.)
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* https://drafts.csswg.org/css-align-3/#synthesize-baseline
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*
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* @param aWM the writing-mode of the alignment context.
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* @return an offset from aFrame's border-box start(end) edge in aWM's
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* block-axis for a first(last) baseline, respectively.
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*/
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static nscoord SynthesizeBOffsetFromBorderBox(const nsIFrame* aFrame,
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WritingMode aWM,
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BaselineSharingGroup);
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/**
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* Synthesize a first(last) inline-axis baseline in aWM based on aFrame's
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* content-box.
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*
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* An alphabetical baseline is at the end edge of aFrame's content-box with
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* respect to aWM's block-axis, and a central baseline is halfway between the
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* start and end edges. (aWM tells which baseline to use.)
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* https://drafts.csswg.org/css-align-3/#synthesize-baseline
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*
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* @note This works only when aFrame's writing-mode is parallel to aWM.
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* @param aWM the writing-mode of the alignment context.
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* @return an offset from aFrame's border-box start(end) edge in aWM's
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* block-axis for a first(last) baseline, respectively.
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*/
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static nscoord SynthesizeBOffsetFromContentBox(const nsIFrame* aFrame,
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WritingMode aWM,
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BaselineSharingGroup);
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};
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} // namespace mozilla
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#endif // LAYOUT_BASE_BASELINE_H_
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