Changeset 246458 in webkit

Timestamp:

Jun 15, 2019, 7:05:44 AM (7 years ago)

Author:

Alan Bujtas

Message:

[LFC] Convert both the absolutely and statically positioned out-of-flow block level boxes positions relative to the containing block's padding box
​https://bugs.webkit.org/show_bug.cgi?id=198878
<rdar://problem/51772882>

Reviewed by Antti Koivisto.

This patch ensures that while we compute the vertical/horizontal geometry for an out-of-flow block level box,
the static and the absolute positioned values are in the same coordinate system (relative to the containing block's padding box).

• layout/FormattingContextGeometry.cpp:

(WebCore::Layout::staticVerticalPositionForOutOfFlowPositioned):
(WebCore::Layout::staticHorizontalPositionForOutOfFlowPositioned):
(WebCore::Layout::FormattingContext::Geometry::outOfFlowNonReplacedVerticalGeometry):
(WebCore::Layout::FormattingContext::Geometry::outOfFlowNonReplacedHorizontalGeometry):
(WebCore::Layout::FormattingContext::Geometry::outOfFlowReplacedVerticalGeometry):
(WebCore::Layout::FormattingContext::Geometry::outOfFlowReplacedHorizontalGeometry):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/FormattingContextGeometry.cpp (modified) (12 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-06-15  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC] Convert both the absolutely and statically positioned out-of-flow block level boxes positions relative to the containing block's padding box
+        https://bugs.webkit.org/show_bug.cgi?id=198878
+        <rdar://problem/51772882>
+
+        Reviewed by Antti Koivisto.
+
+        This patch ensures that while we compute the vertical/horizontal geometry for an out-of-flow block level box,
+        the static and the absolute positioned values are in the same coordinate system (relative to the containing block's padding box).
+
+        * layout/FormattingContextGeometry.cpp:
+        (WebCore::Layout::staticVerticalPositionForOutOfFlowPositioned):
+        (WebCore::Layout::staticHorizontalPositionForOutOfFlowPositioned):
+        (WebCore::Layout::FormattingContext::Geometry::outOfFlowNonReplacedVerticalGeometry):
+        (WebCore::Layout::FormattingContext::Geometry::outOfFlowNonReplacedHorizontalGeometry):
+        (WebCore::Layout::FormattingContext::Geometry::outOfFlowReplacedVerticalGeometry):
+        (WebCore::Layout::FormattingContext::Geometry::outOfFlowReplacedHorizontalGeometry):
+
 2019-06-15  Zalan Bujtas  <zalan@apple.com>
 

trunk/Source/WebCore/layout/FormattingContextGeometry.cpp

@@ -202 +202 @@
 
     // Resolve top all the way up to the containing block.
-    auto* containingBlock = layoutBox.containingBlock();
+    auto& containingBlock = *layoutBox.containingBlock();
     // Start with the parent since we pretend that this box is normal flow.
-    for (auto* container = layoutBox.parent(); container != containingBlock; container = container->containingBlock()) {
+    for (auto* container = layoutBox.parent(); container != &containingBlock; container = container->containingBlock()) {
         auto& displayBox = layoutState.displayBoxForLayoutBox(*container);
         // Display::Box::top is the border box top position in its containing block's coordinate system.
@@ -210 +210 @@
         ASSERT(!container->isPositioned() || layoutBox.isFixedPositioned());
     }
-    return top;
+    // Move the static position relative to the padding box. This is very specific to abolutely positioned boxes.
+    auto paddingBoxTop = layoutState.displayBoxForLayoutBox(containingBlock).paddingBoxTop();
+    return top - paddingBoxTop;
 }
 
@@ -223 +225 @@
 
     // Resolve left all the way up to the containing block.
-    auto* containingBlock = layoutBox.containingBlock();
+    auto& containingBlock = *layoutBox.containingBlock();
     // Start with the parent since we pretend that this box is normal flow.
-    for (auto* container = layoutBox.parent(); container != containingBlock; container = container->containingBlock()) {
+    for (auto* container = layoutBox.parent(); container != &containingBlock; container = container->containingBlock()) {
         auto& displayBox = layoutState.displayBoxForLayoutBox(*container);
         // Display::Box::left is the border box left position in its containing block's coordinate system.
@@ -231 +233 @@
         ASSERT(!container->isPositioned() || layoutBox.isFixedPositioned());
     }
-    return left;
+    // Move the static position relative to the padding box. This is very specific to abolutely positioned boxes.
+    auto paddingBoxLeft = layoutState.displayBoxForLayoutBox(containingBlock).paddingBoxTop();
+    return left - paddingBoxLeft;
 }
 
@@ -293 +297 @@
     auto top = computedValueIfNotAuto(style.logicalTop(), containingBlockWidth);
     auto bottom = computedValueIfNotAuto(style.logicalBottom(), containingBlockWidth);
-    auto isStaticallyPositioned = !top && !bottom;
     auto height = usedValues.height ? usedValues.height.value() : computedHeightValue(layoutState, layoutBox, HeightType::Normal);
     auto computedVerticalMargin = Geometry::computedVerticalMargin(layoutBox, UsedHorizontalValues { containingBlockWidth });
@@ -371 +374 @@
 
     // For out-of-flow elements the containing block is formed by the padding edge of the ancestor.
-    // At this point the non-statically positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
-    if (!isStaticallyPositioned) {
-        auto containingBlockPaddingVerticalEdge = containingBlockDisplayBox.paddingBoxTop();
-        *top += containingBlockPaddingVerticalEdge;
-        *bottom += containingBlockPaddingVerticalEdge;
-    }
+    // At this point the positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
+    auto containingBlockPaddingVerticalEdge = containingBlockDisplayBox.paddingBoxTop();
+    *top += containingBlockPaddingVerticalEdge;
+    *bottom += containingBlockPaddingVerticalEdge;
 
     LOG_WITH_STREAM(FormattingContextLayout, stream << "[Position][Height][Margin] -> out-of-flow non-replaced -> top(" << *top << "px) bottom("  << *bottom << "px) height(" << *height << "px) margin(" << usedVerticalMargin.before << "px, "  << usedVerticalMargin.after << "px) layoutBox(" << &layoutBox << ")");
@@ -421 +422 @@
     auto left = computedValueIfNotAuto(style.logicalLeft(), containingBlockWidth);
     auto right = computedValueIfNotAuto(style.logicalRight(), containingBlockWidth);
-    auto isStaticallyPositioned = !left && !right;
     auto width = computedValueIfNotAuto(usedValues.width ? Length { usedValues.width.value(), Fixed } : style.logicalWidth(), containingBlockWidth);
     auto computedHorizontalMargin = Geometry::computedHorizontalMargin(layoutBox, usedValues);
@@ -525 +525 @@
 
     // For out-of-flow elements the containing block is formed by the padding edge of the ancestor.
-    // At this point the non-statically positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
-    if (!isStaticallyPositioned) {
-        auto containingBlockPaddingVerticalEdge = containingBlockDisplayBox.paddingBoxLeft();
-        *left += containingBlockPaddingVerticalEdge;
-        *right += containingBlockPaddingVerticalEdge;
-    }
+    // At this point the positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
+    auto containingBlockPaddingVerticalEdge = containingBlockDisplayBox.paddingBoxLeft();
+    *left += containingBlockPaddingVerticalEdge;
+    *right += containingBlockPaddingVerticalEdge;
 
     LOG_WITH_STREAM(FormattingContextLayout, stream << "[Position][Width][Margin] -> out-of-flow non-replaced -> left(" << *left << "px) right("  << *right << "px) width(" << *width << "px) margin(" << usedHorizontalMargin.start << "px, "  << usedHorizontalMargin.end << "px) layoutBox(" << &layoutBox << ")");
@@ -558 +556 @@
     auto top = computedValueIfNotAuto(style.logicalTop(), containingBlockWidth);
     auto bottom = computedValueIfNotAuto(style.logicalBottom(), containingBlockWidth);
-    auto isStaticallyPositioned = !top && !bottom;
     auto height = inlineReplacedHeightAndMargin(layoutState, layoutBox, usedValues).height;
     auto computedVerticalMargin = Geometry::computedVerticalMargin(layoutBox, UsedHorizontalValues { containingBlockWidth });
@@ -605 +602 @@
 
     // For out-of-flow elements the containing block is formed by the padding edge of the ancestor.
-    // At this point the non-statically positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
-    if (!isStaticallyPositioned) {
-        auto containingBlockPaddingVerticalEdge = containingBlockDisplayBox.paddingBoxTop();
-        *top += containingBlockPaddingVerticalEdge;
-        *bottom += containingBlockPaddingVerticalEdge;
-    }
+    // At this point the positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
+    auto containingBlockPaddingVerticalEdge = containingBlockDisplayBox.paddingBoxTop();
+    *top += containingBlockPaddingVerticalEdge;
+    *bottom += containingBlockPaddingVerticalEdge;
 
     ASSERT(top);
@@ -646 +641 @@
     auto left = computedValueIfNotAuto(style.logicalLeft(), containingBlockWidth);
     auto right = computedValueIfNotAuto(style.logicalRight(), containingBlockWidth);
-    auto isStaticallyPositioned = !left && !right;
     auto computedHorizontalMargin = Geometry::computedHorizontalMargin(layoutBox, usedValues);
     Optional<LayoutUnit> usedMarginStart = computedHorizontalMargin.start;
@@ -716 +710 @@
 
     // For out-of-flow elements the containing block is formed by the padding edge of the ancestor.
-    // At this point the non-statically positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
-    if (!isStaticallyPositioned) {
-        auto containingBlockPaddingVerticalEdge = layoutState.displayBoxForLayoutBox(containingBlock).paddingBoxLeft();
-        *left += containingBlockPaddingVerticalEdge;
-        *right += containingBlockPaddingVerticalEdge;
-    }
+    // At this point the positioned value is in the coordinate system of the padding box. Let's convert it to border box coordinate system.
+    auto containingBlockPaddingVerticalEdge = layoutState.displayBoxForLayoutBox(containingBlock).paddingBoxLeft();
+    *left += containingBlockPaddingVerticalEdge;
+    *right += containingBlockPaddingVerticalEdge;
 
     LOG_WITH_STREAM(FormattingContextLayout, stream << "[Position][Width][Margin] -> out-of-flow replaced -> left(" << *left << "px) right("  << *right << "px) width(" << width << "px) margin(" << *usedMarginStart << "px, "  << *usedMarginEnd << "px) layoutBox(" << &layoutBox << ")");