[css-align] Don't resolve 'auto' values for computed style.

third_party/WebKit/Source/core/layout/LayoutGrid.cpp

Index: third_party/WebKit/Source/core/layout/LayoutGrid.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
index f955002399cbeb49112738b948ec1f5b00a557b2..263f3abae4db187de05857a3e181dc050c139f31 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -97,12 +97,78 @@ void LayoutGrid::RemoveChild(LayoutObject* child) {
   DirtyGrid();
 }
 
+bool LayoutGrid::SelfAlignmentChangedToStretchInRowAxis(
+    const ComputedStyle& old_style,
+    const ComputedStyle& new_style,
+    const LayoutBox& child) {
+  return child.StyleRef()
+                 .ResolvedJustifySelf(SelfAlignmentNormalBehavior(&child),
+                                      &old_style)
+                 .GetPosition() != kItemPositionStretch &&
+         child.StyleRef()
+                 .ResolvedJustifySelf(SelfAlignmentNormalBehavior(&child),
+                                      &new_style)
+                 .GetPosition() == kItemPositionStretch;
+}
+
+bool LayoutGrid::SelfAlignmentChangedFromStretchInRowAxis(
+    const ComputedStyle& old_style,
+    const ComputedStyle& new_style,
+    const LayoutBox& child) {
+  return child.StyleRef()
+                 .ResolvedJustifySelf(SelfAlignmentNormalBehavior(&child),
+                                      &old_style)
+                 .GetPosition() == kItemPositionStretch &&
+         child.StyleRef()
+                 .ResolvedJustifySelf(SelfAlignmentNormalBehavior(&child),
+                                      &new_style)
+                 .GetPosition() != kItemPositionStretch;
+}
+
+bool LayoutGrid::SelfAlignmentChangedFromStretchInColumnAxis(
+    const ComputedStyle& old_style,
+    const ComputedStyle& new_style,
+    const LayoutBox& child) {
+  return child.StyleRef()
+                 .ResolvedAlignSelf(SelfAlignmentNormalBehavior(&child),
+                                    &old_style)
+                 .GetPosition() == kItemPositionStretch &&
+         child.StyleRef()
+                 .ResolvedAlignSelf(SelfAlignmentNormalBehavior(&child),
+                                    &new_style)
+                 .GetPosition() != kItemPositionStretch;
+}

[svillar, 2017/05/25 08:13:09]

Very compact but impossible to read. Could we add some variable or do something
different. Also is it possible to refactor them?

[jfernandez, 2017/05/25 11:25:15]

Done.

+
 void LayoutGrid::StyleDidChange(StyleDifference diff,
                                 const ComputedStyle* old_style) {
   LayoutBlock::StyleDidChange(diff, old_style);
   if (!old_style)
     return;
 
+  const ComputedStyle& new_style = StyleRef();
+  if (old_style &&
+      old_style->ResolvedAlignItems(SelfAlignmentNormalBehavior(this))
+              .GetPosition() == kItemPositionStretch &&
+      diff.NeedsFullLayout()) {
+    // Grid items that were not previously stretched in row-axis need to be
+    // relayed out so we can compute new available space.
+    // Grid items that were previously stretching in column-axis need to be
+    // relayed out so we can compute new available space.
+    // This is only necessary for stretching since other alignment values don't
+    // change the size of the box.
+    for (LayoutBox* child = FirstInFlowChildBox(); child;
+         child = child->NextInFlowSiblingBox()) {
+      if (SelfAlignmentChangedToStretchInRowAxis(*old_style, new_style,
+                                                 *child) ||
+          SelfAlignmentChangedFromStretchInRowAxis(*old_style, new_style,
+                                                   *child) ||
+          SelfAlignmentChangedFromStretchInColumnAxis(*old_style, new_style,
+                                                      *child)) {
+        child->SetNeedsLayout(LayoutInvalidationReason::kGridChanged);

[svillar, 2017/05/25 08:13:09]

Shouldn't we clear the stretch overrides here?

[jfernandez, 2017/05/25 11:25:15]

Well, I'd rather let the Grid layout logic do it when consider it more
convenient. 

+      }
+    }
+  }
+
   // FIXME: The following checks could be narrowed down if we kept track of
   // which type of grid items we have:
   // - explicit grid size changes impact negative explicitely positioned and
@@ -1530,26 +1596,12 @@ LayoutUnit LayoutGrid::AvailableAlignmentSpaceForChildBeforeStretching(
 
 StyleSelfAlignmentData LayoutGrid::AlignSelfForChild(
     const LayoutBox& child) const {
-  if (!child.IsAnonymous()) {
-    return child.StyleRef().ResolvedAlignSelf(
-        SelfAlignmentNormalBehavior(&child));
-  }
-  // All the 'auto' values has been solved by the StyleAdjuster, but it's
-  // possible that some grid items generate Anonymous boxes, which need to be
-  // solved during layout.
   return child.StyleRef().ResolvedAlignSelf(SelfAlignmentNormalBehavior(&child),
                                             Style());
 }
 
 StyleSelfAlignmentData LayoutGrid::JustifySelfForChild(
     const LayoutBox& child) const {
-  if (!child.IsAnonymous()) {
-    return child.StyleRef().ResolvedJustifySelf(
-        SelfAlignmentNormalBehavior(&child));
-  }
-  // All the 'auto' values has been solved by the StyleAdjuster, but it's
-  // possible that some grid items generate Anonymous boxes, which need to be
-  // solved during layout.
   return child.StyleRef().ResolvedJustifySelf(
       SelfAlignmentNormalBehavior(&child), Style());
 }