Changeset 246680 in webkit

Timestamp:

Jun 21, 2019 8:49:21 AM (5 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Adjust baseline top when the baseline moves.
​https://bugs.webkit.org/show_bug.cgi?id=199091
<rdar://problem/51966257>

Reviewed by Antti Koivisto.

Currently only "text-align: bottom" adjusts the baseline top. This patch fixes the "text-align: baseline" case when
the growing ascent pushes the baseline top closer to the line top.

• layout/inlineformatting/InlineLine.cpp:

(WebCore::Layout::Line::adjustBaselineAndLineHeight):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/inlineformatting/InlineLine.cpp (modified) (4 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-06-21  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Adjust baseline top when the baseline moves.
+        https://bugs.webkit.org/show_bug.cgi?id=199091
+        <rdar://problem/51966257>
+
+        Reviewed by Antti Koivisto.
+
+        Currently only "text-align: bottom" adjusts the baseline top. This patch fixes the "text-align: baseline" case when
+        the growing ascent pushes the baseline top closer to the line top.
+
+        * layout/inlineformatting/InlineLine.cpp:
+        (WebCore::Layout::Line::adjustBaselineAndLineHeight):
+
 2019-06-21  Zalan Bujtas  <zalan@apple.com>
 

trunk/Source/WebCore/layout/inlineformatting/InlineLine.cpp

@@ -314 +314 @@
 
     if (inlineItem.isContainerStart()) {
+        // FIXME: This implies baseline vertical aligment for the inline container.
         auto& fontMetrics = style.fontMetrics();
         auto halfLeading = halfLeadingMetrics(fontMetrics, style.computedLineHeight());
@@ -335 +336 @@
     // Replaced and non-replaced inline level box.
     switch (inlineItem.style().verticalAlign()) {
-    case VerticalAlign::Baseline:
+     case VerticalAlign::Baseline: {
+        auto newBaselineCandidate = LineBox::Baseline { runHeight, 0 };
         if (layoutBox.isInlineBlockBox() && layoutBox.establishesInlineFormattingContext()) {
             // Inline-blocks with inline content always have baselines.
@@ -341 +343 @@
             // Spec makes us generate at least one line -even if it is empty.
             ASSERT(!formattingState.lineBoxes().isEmpty());
-            auto inlineBlockBaseline = formattingState.lineBoxes().last().baseline();
-            m_baseline.descent = std::max(inlineBlockBaseline.descent, m_baseline.descent);
-            m_baseline.ascent = std::max(inlineBlockBaseline.ascent, m_baseline.ascent);
-            m_lineLogicalHeight = std::max(std::max(m_lineLogicalHeight, runHeight), m_baseline.height());
-            break;
-        }
-        m_baseline.descent = std::max<LayoutUnit>(0, m_baseline.descent);
-        m_baseline.ascent = std::max(runHeight, m_baseline.ascent);
-        m_lineLogicalHeight = std::max(m_lineLogicalHeight, m_baseline.height());
+            newBaselineCandidate = formattingState.lineBoxes().last().baseline();
+        }
+        m_baseline.ascent = std::max(newBaselineCandidate.ascent, m_baseline.ascent);
+        m_baseline.descent = std::max(newBaselineCandidate.descent, m_baseline.descent);
+        m_lineLogicalHeight = std::max(std::max(m_lineLogicalHeight, runHeight), m_baseline.height());
+        // Baseline ascent/descent never shrink -> max.
+        m_baselineTop = std::max(m_baselineTop, m_lineLogicalHeight - m_baseline.height());
         break;
+    }
     case VerticalAlign::Top:
         // Top align content never changes the baseline offset, it only pushes the bottom of the line further down.
@@ -356 +357 @@
         break;
     case VerticalAlign::Bottom:
-        if (m_lineLogicalHeight < runHeight) {
-            m_baselineTop += runHeight - m_lineLogicalHeight;
+        // Bottom aligned, tall content pushes the baseline further down from the line top.
+        if (runHeight > m_lineLogicalHeight) {
+            m_baselineTop += (runHeight - m_lineLogicalHeight);
             m_lineLogicalHeight = runHeight;
         }