Changeset 238401 in webkit

Timestamp:

Nov 20, 2018 7:52:28 AM (5 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Introduce InlineItem::nonBreakableStart/End
​https://bugs.webkit.org/show_bug.cgi?id=191839

Reviewed by Antti Koivisto.

Non-breakable start/end marks margin/padding/border space (even when it does not directly come from the associated layout box)

<span style="padding: 5px"><span>nested content with padding parent</span</span>
<nested content with padding parent> <- inline run has 5px non-breakable start/end.

<span style="border: 5px solid green"><span style="padding-right: 10px; margin-right: 1px">1</span>2</span><span> 3</span>
<1> <- inline run has 5px non-breakable start and 11px non-breakable end.
<2> <- inline run has 0px non-breakable start and 5px non-breakable end.
<3> <- no non-breakable values.

This is what the runs look like (input to line breaking)
< 1 2 >
< > (whitespace)
<3>
The line breaking treats the paddding/border etc space as part of the run and as non-breaking opportunity.
With the given runs the first position where we can break the line is at the whitespace.

• layout/inlineformatting/InlineFormattingContext.cpp:

(WebCore::Layout::InlineFormattingContext::collectInlineContentForSubtree const):

• layout/inlineformatting/InlineItem.h:

(WebCore::Layout::InlineItem::nonBreakableStart const):
(WebCore::Layout::InlineItem::nonBreakableEnd const):
(WebCore::Layout::InlineItem::addNonBreakableStart):
(WebCore::Layout::InlineItem::addNonBreakableEnd):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/inlineformatting/InlineFormattingContext.cpp (modified) (4 diffs)
• layout/inlineformatting/InlineItem.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2018-11-20  Zalan Butjas  <zalan@apple.com>
+
+        [LFC][IFC] Introduce InlineItem::nonBreakableStart/End
+        https://bugs.webkit.org/show_bug.cgi?id=191839
+
+        Reviewed by Antti Koivisto.
+
+        Non-breakable start/end marks margin/padding/border space (even when it does not directly come from the associated layout box)
+
+        <span style="padding: 5px"><span>nested content with padding parent</span</span>
+        <nested content with padding parent> <- inline run has 5px non-breakable start/end.
+
+        <span style="border: 5px solid green"><span style="padding-right: 10px; margin-right: 1px">1</span>2</span><span>    3</span>
+        <1> <- inline run has 5px non-breakable start and 11px non-breakable end.
+        <2> <- inline run has 0px non-breakable start and 5px non-breakable end.
+        <3> <- no non-breakable values.
+
+        This is what the runs look like (input to line breaking)
+        <     1           2     >
+        < > (whitespace)
+        <3>
+        The line breaking treats the paddding/border etc space as part of the run and as non-breaking opportunity.
+        With the given runs the first position where we can break the line is at the whitespace.
+
+        * layout/inlineformatting/InlineFormattingContext.cpp:
+        (WebCore::Layout::InlineFormattingContext::collectInlineContentForSubtree const):
+        * layout/inlineformatting/InlineItem.h:
+        (WebCore::Layout::InlineItem::nonBreakableStart const):
+        (WebCore::Layout::InlineItem::nonBreakableEnd const):
+        (WebCore::Layout::InlineItem::addNonBreakableStart):
+        (WebCore::Layout::InlineItem::addNonBreakableEnd):
+
 2018-11-20  Zalan Bujtas  <zalan@apple.com>
 

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

@@ -478 +478 @@
     }
 
+    // FIXME: Revisit this when we figured out how inline boxes fit the display tree.
+    auto padding = Geometry::computedPadding(layoutState(), root);
     // Setup breaking boundaries for this subtree.
     auto* lastDescendantInlineBox = inlineFormattingState.lastInlineItem();
@@ -486 +488 @@
     auto rootBreaksAtStart = [&] {
         // FIXME: add padding-inline-start, margin-inline-start etc.
+        if (padding && padding->horizontal.left)
+            return true;
         return root.isPositioned();
     };
@@ -491 +495 @@
     auto rootBreaksAtEnd = [&] {
         // FIXME: add padding-inline-end, margin-inline-end etc.
+        if (padding && padding->horizontal.right)
+            return true;
         return root.isPositioned();
     };
@@ -506 +512 @@
         ASSERT(firstDescendantInlineBox);
         firstDescendantInlineBox->addDetachingRule(InlineItem::DetachingRule::BreakAtStart);
-    }
-
-    if (rootBreaksAtEnd())
+        if (padding && padding->horizontal.left)
+            firstDescendantInlineBox->addNonBreakableStart(padding->horizontal.left);
+    }
+
+    if (rootBreaksAtEnd()) {
         lastDescendantInlineBox->addDetachingRule(InlineItem::DetachingRule::BreakAtEnd);
+        if (padding && padding->horizontal.right)
+            lastDescendantInlineBox->addNonBreakableEnd(padding->horizontal.right);
+    }
 }
 

trunk/Source/WebCore/layout/inlineformatting/InlineItem.h

@@ -69 +69 @@
     OptionSet<DetachingRule> detachingRules() const { return m_detachingRules; }
 
+    // Non-breakable start/end marks margin/padding/border space (even when it does not directly come from the associated layout box)
+    // <span style="padding: 5px"><span>nested content with padding parent</span</span>
+    // <nested content with padding parent> inline run has 5px non-breakable start/end.
+    LayoutUnit nonBreakableStart() const { return m_nonBreakableStart; }
+    LayoutUnit nonBreakableEnd() const { return m_nonBreakableEnd; }
+    void addNonBreakableStart(LayoutUnit value) { m_nonBreakableStart += value; }
+    void addNonBreakableEnd(LayoutUnit value) { m_nonBreakableEnd += value; }
+
 private:
     const Box& m_layoutBox;
     OptionSet<DetachingRule> m_detachingRules;
+    LayoutUnit m_nonBreakableStart;
+    LayoutUnit m_nonBreakableEnd;
 };