From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- layout/generic/CSSAlignUtils.cpp | 129 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 layout/generic/CSSAlignUtils.cpp (limited to 'layout/generic/CSSAlignUtils.cpp') diff --git a/layout/generic/CSSAlignUtils.cpp b/layout/generic/CSSAlignUtils.cpp new file mode 100644 index 0000000000..b88ec8bfa4 --- /dev/null +++ b/layout/generic/CSSAlignUtils.cpp @@ -0,0 +1,129 @@ +/* -*- 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/. */ + +/* Utility code for performing CSS Box Alignment */ + +#include "CSSAlignUtils.h" +#include "ReflowInput.h" + +namespace mozilla { + +static nscoord SpaceToFill(WritingMode aWM, const LogicalSize& aSize, + nscoord aMargin, LogicalAxis aAxis, + nscoord aCBSize) { + nscoord size = aSize.Size(aAxis, aWM); + return aCBSize - (size + aMargin); +} + +nscoord CSSAlignUtils::AlignJustifySelf(const StyleAlignFlags& aAlignment, + LogicalAxis aAxis, + AlignJustifyFlags aFlags, + nscoord aBaselineAdjust, + nscoord aCBSize, const ReflowInput& aRI, + const LogicalSize& aChildSize) { + MOZ_ASSERT(aAlignment != StyleAlignFlags::AUTO, + "auto values should have resolved already"); + MOZ_ASSERT(aAlignment != StyleAlignFlags::LEFT && + aAlignment != StyleAlignFlags::RIGHT, + "caller should map that to the corresponding START/END"); + + // Promote aFlags to convenience bools: + const bool isOverflowSafe = !!(aFlags & AlignJustifyFlags::OverflowSafe); + const bool isSameSide = !!(aFlags & AlignJustifyFlags::SameSide); + + StyleAlignFlags alignment = aAlignment; + // Map some alignment values to 'start' / 'end'. + if (alignment == StyleAlignFlags::SELF_START) { + // align/justify-self: self-start + alignment = + MOZ_LIKELY(isSameSide) ? StyleAlignFlags::START : StyleAlignFlags::END; + } else if (alignment == StyleAlignFlags::SELF_END) { + alignment = + MOZ_LIKELY(isSameSide) ? StyleAlignFlags::END : StyleAlignFlags::START; + // flex-start/flex-end are the same as start/end, in most contexts. + // (They have special behavior in flex containers, so flex containers + // should map them to some other value before calling this method.) + } else if (alignment == StyleAlignFlags::FLEX_START) { + alignment = StyleAlignFlags::START; + } else if (alignment == StyleAlignFlags::FLEX_END) { + alignment = StyleAlignFlags::END; + } + + // Get the item's margin corresponding to the container's start/end side. + WritingMode wm = aRI.GetWritingMode(); + const LogicalMargin margin = aRI.ComputedLogicalMargin(wm); + const auto startSide = MakeLogicalSide( + aAxis, MOZ_LIKELY(isSameSide) ? eLogicalEdgeStart : eLogicalEdgeEnd); + const nscoord marginStart = margin.Side(startSide, wm); + const auto endSide = GetOppositeSide(startSide); + const nscoord marginEnd = margin.Side(endSide, wm); + + const auto& styleMargin = aRI.mStyleMargin->mMargin; + bool hasAutoMarginStart; + bool hasAutoMarginEnd; + if (aFlags & AlignJustifyFlags::IgnoreAutoMargins) { + // (Note: ReflowInput will have treated "auto" margins as 0, so we + // don't need to do anything special to avoid expanding them.) + hasAutoMarginStart = hasAutoMarginEnd = false; + } else if (aAxis == eLogicalAxisBlock) { + hasAutoMarginStart = styleMargin.GetBStart(wm).IsAuto(); + hasAutoMarginEnd = styleMargin.GetBEnd(wm).IsAuto(); + } else { /* aAxis == eLogicalAxisInline */ + hasAutoMarginStart = styleMargin.GetIStart(wm).IsAuto(); + hasAutoMarginEnd = styleMargin.GetIEnd(wm).IsAuto(); + } + + // https://drafts.csswg.org/css-align-3/#overflow-values + // This implements = 'safe'. + // And auto-margins: https://drafts.csswg.org/css-grid/#auto-margins + if ((MOZ_UNLIKELY(isOverflowSafe) && alignment != StyleAlignFlags::START) || + hasAutoMarginStart || hasAutoMarginEnd) { + nscoord space = + SpaceToFill(wm, aChildSize, marginStart + marginEnd, aAxis, aCBSize); + // XXX we might want to include == 0 here as an optimization - + // I need to see what the baseline/last baseline code looks like first. + if (space < 0) { + // "Overflowing elements ignore their auto margins and overflow + // in the end directions" + alignment = StyleAlignFlags::START; + } else if (hasAutoMarginEnd) { + alignment = hasAutoMarginStart ? StyleAlignFlags::CENTER + : (isSameSide ? StyleAlignFlags::START + : StyleAlignFlags::END); + } else if (hasAutoMarginStart) { + alignment = isSameSide ? StyleAlignFlags::END : StyleAlignFlags::START; + } + } + + // Determine the offset for the child frame (its border-box) which will + // achieve the requested alignment. + nscoord offset = 0; + if (alignment == StyleAlignFlags::BASELINE || + alignment == StyleAlignFlags::LAST_BASELINE) { + if (MOZ_LIKELY(isSameSide == (alignment == StyleAlignFlags::BASELINE))) { + offset = marginStart + aBaselineAdjust; + } else { + nscoord size = aChildSize.Size(aAxis, wm); + offset = aCBSize - (size + marginEnd) - aBaselineAdjust; + } + } else if (alignment == StyleAlignFlags::STRETCH || + alignment == StyleAlignFlags::START) { + // ComputeSize() deals with stretch + offset = marginStart; + } else if (alignment == StyleAlignFlags::END) { + nscoord size = aChildSize.Size(aAxis, wm); + offset = aCBSize - (size + marginEnd); + } else if (alignment == StyleAlignFlags::CENTER) { + nscoord size = aChildSize.Size(aAxis, wm); + offset = (aCBSize - size + marginStart - marginEnd) / 2; + } else { + MOZ_ASSERT_UNREACHABLE("unknown align-/justify-self value"); + } + + return offset; +} + +} // namespace mozilla -- cgit v1.2.3