Changeset 246479 in webkit

Timestamp:

Jun 16, 2019, 12:33:18 PM (7 years ago)

Author:

Alan Bujtas

Message:

[LFC] Add Layout::Box::isContainingBlockDescendantOf
​https://bugs.webkit.org/show_bug.cgi?id=198888
<rdar://problem/51776466>

Reviewed by Antti Koivisto.

Box::isDescendantOf indicates simple ancestor - descendant relationship, while
isContainingBlockDescendantOf checks the containing block chain.

• layout/FormattingContext.cpp:

(WebCore::Layout::mapHorizontalPositionToAncestor):
(WebCore::Layout::FormattingContext::mapBoxToAncestor):
(WebCore::Layout::FormattingContext::mapTopToAncestor):
(WebCore::Layout::FormattingContext::mapPointToAncestor):

• layout/floats/FloatingState.h:

(WebCore::Layout::FloatingState::FloatItem::isDescendantOfFormattingRoot const):

• layout/layouttree/LayoutBox.cpp:

(WebCore::Layout::Box::isDescendantOf const):
(WebCore::Layout::Box::isContainingBlockDescendantOf const):

• layout/layouttree/LayoutBox.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/FormattingContext.cpp (modified) (4 diffs)
• layout/floats/FloatingState.h (modified) (1 diff)
• layout/layouttree/LayoutBox.cpp (modified) (1 diff)
• layout/layouttree/LayoutBox.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-06-16  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC] Add Layout::Box::isContainingBlockDescendantOf
+        https://bugs.webkit.org/show_bug.cgi?id=198888
+        <rdar://problem/51776466>
+
+        Reviewed by Antti Koivisto.
+
+        Box::isDescendantOf indicates simple ancestor - descendant relationship, while
+        isContainingBlockDescendantOf checks the containing block chain.
+
+        * layout/FormattingContext.cpp:
+        (WebCore::Layout::mapHorizontalPositionToAncestor):
+        (WebCore::Layout::FormattingContext::mapBoxToAncestor):
+        (WebCore::Layout::FormattingContext::mapTopToAncestor):
+        (WebCore::Layout::FormattingContext::mapPointToAncestor):
+        * layout/floats/FloatingState.h:
+        (WebCore::Layout::FloatingState::FloatItem::isDescendantOfFormattingRoot const):
+        * layout/layouttree/LayoutBox.cpp:
+        (WebCore::Layout::Box::isDescendantOf const):
+        (WebCore::Layout::Box::isContainingBlockDescendantOf const):
+        * layout/layouttree/LayoutBox.h:
+
 2019-06-16  Zalan Bujtas  <zalan@apple.com>
 

trunk/Source/WebCore/layout/FormattingContext.cpp

@@ -171 +171 @@
     if (&containingBlock == &ancestor)
         return horizontalPosition;
-    ASSERT(containingBlock.isDescendantOf(ancestor));
+    ASSERT(containingBlock.isContainingBlockDescendantOf(ancestor));
     for (auto* container = &containingBlock; container && container != &ancestor; container = container->containingBlock())
         horizontalPosition += layoutState.displayBoxForLayoutBox(*container).left();
@@ -192 +192 @@
 Display::Box FormattingContext::mapBoxToAncestor(const LayoutState& layoutState, const Box& layoutBox, const Container& ancestor)
 {
-    ASSERT(layoutBox.isDescendantOf(ancestor));
-
+    ASSERT(layoutBox.isContainingBlockDescendantOf(ancestor));
     auto& displayBox = layoutState.displayBoxForLayoutBox(layoutBox);
     auto topLeft = displayBox.topLeft();
-
-    auto* containingBlock = layoutBox.containingBlock();
-    for (; containingBlock && containingBlock != &ancestor; containingBlock = containingBlock->containingBlock())
+    for (auto* containingBlock = layoutBox.containingBlock(); containingBlock && containingBlock != &ancestor; containingBlock = containingBlock->containingBlock())
         topLeft.moveBy(layoutState.displayBoxForLayoutBox(*containingBlock).topLeft());
-
-    if (!containingBlock) {
-        ASSERT_NOT_REACHED();
-        return Display::Box(displayBox);
-    }
 
     auto mappedDisplayBox = Display::Box(displayBox);
@@ -213 +205 @@
 LayoutUnit FormattingContext::mapTopToAncestor(const LayoutState& layoutState, const Box& layoutBox, const Container& ancestor)
 {
-    ASSERT(layoutBox.isDescendantOf(ancestor));
+    ASSERT(layoutBox.isContainingBlockDescendantOf(ancestor));
     auto top = layoutState.displayBoxForLayoutBox(layoutBox).top();
-    auto* container = layoutBox.containingBlock();
-    for (; container && container != &ancestor; container = container->containingBlock())
+    for (auto* container = layoutBox.containingBlock(); container && container != &ancestor; container = container->containingBlock())
         top += layoutState.displayBoxForLayoutBox(*container).top();
     return top;
@@ -223 +214 @@
 Point FormattingContext::mapPointToAncestor(const LayoutState& layoutState, Point position, const Container& containingBlock, const Container& ancestor)
 {
+    if (&containingBlock == &ancestor)
+        return position;
+    ASSERT(containingBlock.isContainingBlockDescendantOf(ancestor));
     auto mappedPosition = position;
-    auto* container = &containingBlock;
-    for (; container && container != &ancestor; container = container->containingBlock())
+    for (auto* container = &containingBlock; container && container != &ancestor; container = container->containingBlock())
         mappedPosition.moveBy(layoutState.displayBoxForLayoutBox(*container).topLeft());
-
-    if (!container) {
-        ASSERT_NOT_REACHED();
-        return position;
-    }
-
     return mappedPosition;
 }

trunk/Source/WebCore/layout/floats/FloatingState.h

@@ -122 +122 @@
     if (!is<Container>(formattingContextRoot))
         return false;
-    return m_layoutBox->isDescendantOf(downcast<Container>(formattingContextRoot));
+    return m_layoutBox->isContainingBlockDescendantOf(downcast<Container>(formattingContextRoot));
 }
 

trunk/Source/WebCore/layout/layouttree/LayoutBox.cpp

@@ -198 +198 @@
 }
 
-bool Box::isDescendantOf(const Container& container) const
+bool Box::isDescendantOf(const Container& ancestorCandidate) const
+{
+    for (auto* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
+        if (ancestor == &ancestorCandidate)
+            return true;
+    }
+    return false;
+}
+
+bool Box::isContainingBlockDescendantOf(const Container& ancestorCandidate) const
 { 
     for (auto* ancestor = containingBlock(); ancestor; ancestor = ancestor->containingBlock()) {
-        if (ancestor == &container)
+        if (ancestor == &ancestorCandidate)
             return true;
     }

trunk/Source/WebCore/layout/layouttree/LayoutBox.h

@@ -102 +102 @@
 
     bool isDescendantOf(const Container&) const;
+    bool isContainingBlockDescendantOf(const Container&) const;
 
     bool isAnonymous() const { return !m_elementAttributes; }