forked from mirrors/gecko-dev
e02d078c12
These functions work fine as static functions, and `nsIFrame` is pretty overloaded. Differential Revision: https://phabricator.services.mozilla.com/D167991
89 lines
4 KiB
C++
89 lines
4 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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#include "Baseline.h"
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#include "nsIFrame.h"
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namespace mozilla {
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nscoord Baseline::SynthesizeBOffsetFromMarginBox(const nsIFrame* aFrame,
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WritingMode aWM,
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BaselineSharingGroup aGroup) {
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MOZ_ASSERT(!aWM.IsOrthogonalTo(aFrame->GetWritingMode()));
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auto margin = aFrame->GetLogicalUsedMargin(aWM);
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if (aGroup == BaselineSharingGroup::First) {
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if (aWM.IsAlphabeticalBaseline()) {
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// First baseline for inverted-line content is the block-start margin
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// edge, as the frame is in effect "flipped" for alignment purposes.
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return MOZ_UNLIKELY(aWM.IsLineInverted())
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? -margin.BStart(aWM)
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: aFrame->BSize(aWM) + margin.BEnd(aWM);
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}
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nscoord marginBoxCenter = (aFrame->BSize(aWM) + margin.BStartEnd(aWM)) / 2;
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return marginBoxCenter - margin.BStart(aWM);
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}
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MOZ_ASSERT(aGroup == BaselineSharingGroup::Last);
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if (aWM.IsAlphabeticalBaseline()) {
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// Last baseline for inverted-line content is the block-start margin edge,
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// as the frame is in effect "flipped" for alignment purposes.
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return MOZ_UNLIKELY(aWM.IsLineInverted())
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? aFrame->BSize(aWM) + margin.BStart(aWM)
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: -margin.BEnd(aWM);
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}
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// Round up for central baseline offset, to be consistent with ::First.
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nscoord marginBoxSize = aFrame->BSize(aWM) + margin.BStartEnd(aWM);
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nscoord marginBoxCenter = (marginBoxSize / 2) + (marginBoxSize % 2);
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return marginBoxCenter - margin.BEnd(aWM);
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}
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nscoord Baseline::SynthesizeBOffsetFromBorderBox(const nsIFrame* aFrame,
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WritingMode aWM,
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BaselineSharingGroup aGroup) {
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nscoord borderBoxSize =
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MOZ_UNLIKELY(aWM.IsOrthogonalTo(aFrame->GetWritingMode()))
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? aFrame->ISize(aWM)
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: aFrame->BSize(aWM);
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if (aGroup == BaselineSharingGroup::First) {
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return MOZ_LIKELY(aWM.IsAlphabeticalBaseline()) ? borderBoxSize
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: borderBoxSize / 2;
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}
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MOZ_ASSERT(aGroup == BaselineSharingGroup::Last);
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// Round up for central baseline offset, to be consistent with ::First.
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auto borderBoxCenter = (borderBoxSize / 2) + (borderBoxSize % 2);
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return MOZ_LIKELY(aWM.IsAlphabeticalBaseline()) ? 0 : borderBoxCenter;
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}
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nscoord Baseline::SynthesizeBOffsetFromContentBox(const nsIFrame* aFrame,
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WritingMode aWM,
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BaselineSharingGroup aGroup) {
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WritingMode wm = aFrame->GetWritingMode();
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MOZ_ASSERT(!aWM.IsOrthogonalTo(wm));
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const auto bp = aFrame->GetLogicalUsedBorderAndPadding(wm)
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.ApplySkipSides(aFrame->GetLogicalSkipSides())
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.ConvertTo(aWM, wm);
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if (MOZ_UNLIKELY(aWM.IsCentralBaseline())) {
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nscoord contentBoxBSize = aFrame->BSize(aWM) - bp.BStartEnd(aWM);
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if (aGroup == BaselineSharingGroup::First) {
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return contentBoxBSize / 2 + bp.BStart(aWM);
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}
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// Return the same center position as for ::First, but as offset from end:
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nscoord halfContentBoxBSize = (contentBoxBSize / 2) + (contentBoxBSize % 2);
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return halfContentBoxBSize + bp.BEnd(aWM);
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}
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if (aGroup == BaselineSharingGroup::First) {
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// First baseline for inverted-line content is the block-start content
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// edge, as the frame is in effect "flipped" for alignment purposes.
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return MOZ_UNLIKELY(aWM.IsLineInverted())
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? bp.BStart(aWM)
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: aFrame->BSize(aWM) - bp.BEnd(aWM);
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}
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// Last baseline for inverted-line content is the block-start content edge,
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// as the frame is in effect "flipped" for alignment purposes.
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return MOZ_UNLIKELY(aWM.IsLineInverted())
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? aFrame->BSize(aWM) - bp.BStart(aWM)
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: bp.BEnd(aWM);
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}
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} // namespace mozilla
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