| /* |
| * Copyright (C) 2020 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
| * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
| * THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #pragma once |
| |
| #if ENABLE(LAYOUT_FORMATTING_CONTEXT) |
| |
| #include "DisplayBox.h" |
| #include "DisplayInlineRect.h" |
| |
| namespace WebCore { |
| namespace Layout { |
| |
| class LineBoxBuilder { |
| WTF_MAKE_FAST_ALLOCATED; |
| public: |
| struct Baseline { |
| Baseline(InlineLayoutUnit ascent, InlineLayoutUnit descent); |
| Baseline() = default; |
| |
| void setAscent(InlineLayoutUnit); |
| void setDescent(InlineLayoutUnit); |
| |
| void reset(); |
| |
| InlineLayoutUnit height() const { return ascent() + descent(); } |
| InlineLayoutUnit ascent() const; |
| InlineLayoutUnit descent() const; |
| |
| private: |
| #if ASSERT_ENABLED |
| bool m_hasValidAscent { false }; |
| bool m_hasValidDescent { false }; |
| #endif |
| InlineLayoutUnit m_ascent { 0 }; |
| InlineLayoutUnit m_descent { 0 }; |
| }; |
| |
| LineBoxBuilder(const Display::InlineRect&, const Baseline&, InlineLayoutUnit baselineOffset); |
| LineBoxBuilder() = default; |
| |
| const Display::InlineRect& logicalRect() const { return m_rect; } |
| const Display::InlineRect& scrollableOverflow() const { return m_scrollableOverflow; } |
| |
| InlineLayoutUnit logicalLeft() const { return m_rect.left(); } |
| InlineLayoutUnit logicalRight() const { return m_rect.right(); } |
| InlineLayoutUnit logicalTop() const { return m_rect.top(); } |
| InlineLayoutUnit logicalBottom() const { return m_rect.bottom(); } |
| |
| InlineLayoutUnit logicalWidth() const { return m_rect.width(); } |
| InlineLayoutUnit logicalHeight() const { return m_rect.height(); } |
| |
| const Baseline& baseline() const; |
| // Baseline offset from line logical top. Note that offset does not necessarily equal to ascent. |
| // |
| // ------------------- line logical top ------------------- (top align) |
| // ^ ^ |
| // | ^ | |
| // ^ | baseline offset | | baseline offset |
| // | | | | |
| // | ascent | | ascent | |
| // | | v v |
| // v v ------------------- baseline |
| // ----------------- baseline ^ |
| // ^ | descent |
| // | descent v |
| // v |
| // ------------------- line logical bottom ------------------- |
| InlineLayoutUnit baselineOffset() const; |
| void setBaselineOffsetIfGreater(InlineLayoutUnit); |
| void setAscentIfGreater(InlineLayoutUnit); |
| void setDescentIfGreater(InlineLayoutUnit); |
| |
| void resetBaseline(); |
| void resetDescent() { m_baseline.setDescent(0_lu); } |
| |
| void setLogicalHeight(InlineLayoutUnit logicalHeight) { m_rect.setHeight(logicalHeight); } |
| |
| void setLogicalHeightIfGreater(InlineLayoutUnit); |
| void setLogicalWidth(InlineLayoutUnit logicalWidth) { m_rect.setWidth(logicalWidth); } |
| |
| void setScrollableOverflow(const Display::InlineRect& rect) { m_scrollableOverflow = rect; } |
| |
| void moveHorizontally(InlineLayoutUnit delta) { m_rect.moveHorizontally(delta); } |
| |
| void expandHorizontally(InlineLayoutUnit delta) { m_rect.expandHorizontally(delta); } |
| void shrinkHorizontally(InlineLayoutUnit delta) { expandHorizontally(-delta); } |
| |
| void expandVertically(InlineLayoutUnit delta) { m_rect.expandVertically(delta); } |
| void shrinkVertically(InlineLayoutUnit delta) { expandVertically(-delta); } |
| |
| // https://www.w3.org/TR/CSS22/visuren.html#inline-formatting |
| // Line boxes that contain no text, no preserved white space, no inline elements with non-zero margins, padding, or borders, |
| // and no other in-flow content (such as images, inline blocks or inline tables), and do not end with a preserved newline |
| // must be treated as zero-height line boxes for the purposes of determining the positions of any elements inside of them, |
| // and must be treated as not existing for any other purpose. |
| // Note that it does not necessarily mean visually non-empty line. <span style="font-size: 0px">this is still considered non-empty</span> |
| bool isConsideredEmpty() const { return m_isConsideredEmpty; } |
| void setIsConsideredEmpty() { m_isConsideredEmpty = true; } |
| void setIsConsideredNonEmpty() { m_isConsideredEmpty = false; } |
| |
| private: |
| #if ASSERT_ENABLED |
| bool m_hasValidBaseline { false }; |
| bool m_hasValidBaselineOffset { false }; |
| #endif |
| Display::InlineRect m_rect; |
| Display::InlineRect m_scrollableOverflow; |
| Baseline m_baseline; |
| InlineLayoutUnit m_baselineOffset { 0 }; |
| bool m_isConsideredEmpty { true }; |
| }; |
| |
| inline LineBoxBuilder::LineBoxBuilder(const Display::InlineRect& rect, const Baseline& baseline, InlineLayoutUnit baselineOffset) |
| : m_rect(rect) |
| , m_baseline(baseline) |
| , m_baselineOffset(baselineOffset) |
| { |
| #if ASSERT_ENABLED |
| m_hasValidBaseline = true; |
| m_hasValidBaselineOffset = true; |
| #endif |
| } |
| |
| inline void LineBoxBuilder::setLogicalHeightIfGreater(InlineLayoutUnit logicalHeight) |
| { |
| if (logicalHeight <= m_rect.height()) |
| return; |
| m_rect.setHeight(logicalHeight); |
| } |
| |
| inline const LineBoxBuilder::Baseline& LineBoxBuilder::baseline() const |
| { |
| ASSERT(m_hasValidBaseline); |
| return m_baseline; |
| } |
| |
| inline void LineBoxBuilder::setBaselineOffsetIfGreater(InlineLayoutUnit baselineOffset) |
| { |
| #if ASSERT_ENABLED |
| m_hasValidBaselineOffset = true; |
| #endif |
| m_baselineOffset = std::max(baselineOffset, m_baselineOffset); |
| } |
| |
| inline void LineBoxBuilder::setAscentIfGreater(InlineLayoutUnit ascent) |
| { |
| if (ascent < m_baseline.ascent()) |
| return; |
| setBaselineOffsetIfGreater(ascent); |
| m_baseline.setAscent(ascent); |
| } |
| |
| inline void LineBoxBuilder::setDescentIfGreater(InlineLayoutUnit descent) |
| { |
| if (descent < m_baseline.descent()) |
| return; |
| m_baseline.setDescent(descent); |
| } |
| |
| inline InlineLayoutUnit LineBoxBuilder::baselineOffset() const |
| { |
| ASSERT(m_hasValidBaselineOffset); |
| return m_baselineOffset; |
| } |
| |
| inline void LineBoxBuilder::resetBaseline() |
| { |
| #if ASSERT_ENABLED |
| m_hasValidBaselineOffset = true; |
| #endif |
| m_baselineOffset = 0_lu; |
| m_baseline.reset(); |
| } |
| |
| inline LineBoxBuilder::Baseline::Baseline(InlineLayoutUnit ascent, InlineLayoutUnit descent) |
| : m_ascent(ascent) |
| , m_descent(descent) |
| { |
| #if ASSERT_ENABLED |
| m_hasValidAscent = true; |
| m_hasValidDescent = true; |
| #endif |
| } |
| |
| inline void LineBoxBuilder::Baseline::setAscent(InlineLayoutUnit ascent) |
| { |
| #if ASSERT_ENABLED |
| m_hasValidAscent = true; |
| #endif |
| m_ascent = ascent; |
| } |
| |
| inline void LineBoxBuilder::Baseline::setDescent(InlineLayoutUnit descent) |
| { |
| #if ASSERT_ENABLED |
| m_hasValidDescent = true; |
| #endif |
| m_descent = descent; |
| } |
| |
| inline void LineBoxBuilder::Baseline::reset() |
| { |
| #if ASSERT_ENABLED |
| m_hasValidAscent = true; |
| m_hasValidDescent = true; |
| #endif |
| m_ascent = 0_lu; |
| m_descent = 0_lu; |
| } |
| |
| inline InlineLayoutUnit LineBoxBuilder::Baseline::ascent() const |
| { |
| ASSERT(m_hasValidAscent); |
| return m_ascent; |
| } |
| |
| inline InlineLayoutUnit LineBoxBuilder::Baseline::descent() const |
| { |
| ASSERT(m_hasValidDescent); |
| return m_descent; |
| } |
| |
| } |
| } |
| |
| #endif |