[css-align] New CSS Value 'normal' for Self Alignment

third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 255 matching lines @@
 
     // Force inline display (except for floating first-letters).
     style.setDisplay(style.isFloating() ? BLOCK : INLINE);
 
     // CSS2 says first-letter can't be positioned.
     style.setPosition(StaticPosition);
 }
 
 void StyleAdjuster::adjustStyleForAlignment(ComputedStyle& style, const ComputedStyle& parentStyle)
 {
-    bool isFlexOrGrid = style.isDisplayFlexibleOrGridBox();
-    bool absolutePositioned = style.position() == AbsolutePosition;
+    // To avoid needing to copy the RareNonInheritedData, we repurpose the 'auto' flag
+    // to not just mean 'auto' prior to running the StyleAdjuster but also mean 'normal'
+    // after running it.
 
-    // If the inherited value of justify-items includes the legacy keyword, 'auto'
+    // If the inherited value of justify-items includes the 'legacy' keyword, 'auto'
     // computes to the the inherited value.
-    // Otherwise, auto computes to:
-    //  - 'stretch' for flex containers and grid containers.
-    //  - 'start' for everything else.
+    // Otherwise, 'auto' computes to 'normal'.
     if (style.justifyItemsPosition() == ItemPositionAuto) {
         if (parentStyle.justifyItemsPositionType() == LegacyPosition)
             style.setJustifyItems(parentStyle.justifyItems());
-        else if (isFlexOrGrid)
-            style.setJustifyItemsPosition(ItemPositionStretch);
     }
 
-    // The 'auto' keyword computes to 'stretch' on absolutely-positioned elements,
-    // and to the computed value of justify-items on the parent (minus
-    // any legacy keywords) on all other boxes.
+    // The 'auto' keyword computes the computed value of justify-items on the parent (minus
+    // any legacy keywords), or 'normal' if the box has no parent.

[rune, 2016/05/30 07:55:10]

I haven't looked at the details here, but I noticed this part reading the spec,
and might be what's causing problems in fullscreen.

Does the first "parent" mean parent element, or parent box? Normally, computed
style works on the flattened dom tree, not the layout tree. The "if the box has
no parent" indicates this works on the layout tree.

     if (style.justifySelfPosition() == ItemPositionAuto) {
-        if (absolutePositioned)
-            style.setJustifySelfPosition(ItemPositionStretch);
-        else
+        if (parentStyle.justifyItemsPositionType() == LegacyPosition)
+            style.setJustifySelfPosition(parentStyle.justifyItemsPosition());
+        else if (parentStyle.justifyItemsPosition() != ItemPositionAuto)
             style.setJustifySelf(parentStyle.justifyItems());
     }
 
-    // The 'auto' keyword computes to:
-    //  - 'stretch' for flex containers and grid containers,
-    //  - 'start' for everything else.
-    if (style.alignItemsPosition() == ItemPositionAuto) {
-        if (isFlexOrGrid)
-            style.setAlignItemsPosition(ItemPositionStretch);
-    }
+    // The 'auto' keyword computes the computed value of align-items on the parent
+    // or 'normal' if the box has no parent.
+    if (style.alignSelfPosition() == ItemPositionAuto && parentStyle.alignItemsPosition() != ItemPositionNormal)
+        style.setAlignSelf(parentStyle.alignItems());
 }
 
 void StyleAdjuster::adjustStyleForHTMLElement(ComputedStyle& style, const ComputedStyle& parentStyle, HTMLElement& element)
 {
     // <div> and <span> are the most common elements on the web, we skip all the work for them.
     if (isHTMLDivElement(element) || isHTMLSpanElement(element))
         return;
 
     if (isHTMLTableCellElement(element)) {
         if (style.whiteSpace() == KHTML_NOWRAP) {
@@ skipping 139 matching lines @@
         // We want to count vertical percentage paddings/margins on flex items because our current
         // behavior is different from the spec and we want to gather compatibility data.
         if (style.paddingBefore().hasPercent() || style.paddingAfter().hasPercent())
             UseCounter::count(document, UseCounter::FlexboxPercentagePaddingVertical);
         if (style.marginBefore().hasPercent() || style.marginAfter().hasPercent())
             UseCounter::count(document, UseCounter::FlexboxPercentageMarginVertical);
     }
 }
 
 } // namespace blink