From e86f8777aecad717dbd50346b6ba44bd3d2f81af Mon Sep 17 00:00:00 2001
From: Ojan Vafai <ojan@chromium.org>
Date: Fri, 20 Feb 2015 20:26:59 -0800
Subject: [PATCH] Remove the concept of staticly positioned absolutes.

On the web, if you set position:absolute, but not
top/right/bottom/left, then the absolute goes where it
would have gone if it wasn't positioned. The use-cases for
this are slim and it introduces a lot of complexity to the
engine.

Also changes behavior in the presence of direction:rtl.
On the web, direction:rtl and top/left:auto would
sometimes set right:0. Instead we always position at
0,0 if the opposing values are auto.

This removes the code for this positioning and allows
simplifying a bunch of dirty bit handling code since
we don't need to setNeedsLayout if lines move around
or wrap differently.

The test cases did change their output, but the new
positioning all looks correct to me.

Review URL: https://codereview.chromium.org/944073006
---
 .../tests/layout/position-absolute-expected.txt      | 12 ++++++------
 .../layout/position-absolute-pixels-expected.sky     |  2 +-
 .../src/flutter/tests/lowlevel/layers-expected.sky   |  2 +-
 engine/src/flutter/tests/lowlevel/layers.sky         |  6 +++---
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/engine/src/flutter/tests/layout/position-absolute-expected.txt b/engine/src/flutter/tests/layout/position-absolute-expected.txt
index 58658574d3f..8021bc56ca5 100644
--- a/engine/src/flutter/tests/layout/position-absolute-expected.txt
+++ b/engine/src/flutter/tests/layout/position-absolute-expected.txt
@@ -4,18 +4,18 @@ layer at (0,0) size 100x100
   RenderBlock {block} at (0,0) size 100x100 [bgcolor=#FFC0CB]
     RenderBlock {spacer} at (0,0) size 40x40 [bgcolor=#FFEFD5] [border: (5px solid #800080)]
     RenderBlock {spacer} at (0,40) size 40x40 [bgcolor=#FFEFD5] [border: (5px solid #800080)]
-layer at (0,40) size 20x20
-  RenderBlock (positioned) {absolute} at (0,40) size 20x20 [bgcolor=#008000]
+layer at (0,0) size 20x20
+  RenderBlock (positioned) {absolute} at (0,0) size 20x20 [bgcolor=#008000]
 layer at (0,150) size 100x100
   RenderParagraph {paragraph} at (0,150) size 100x100 [bgcolor=#FFA500]
     RenderBlock (inline-block) {spacer} at (0,0) size 40x40 [bgcolor=#FFEFD5] [border: (5px solid #800080)]
     RenderBlock (inline-block) {spacer} at (40,0) size 40x40 [bgcolor=#FFEFD5] [border: (5px solid #800080)]
-layer at (0,194) size 20x20
-  RenderBlock (positioned) {absolute} at (0,44) size 20x20 [bgcolor=#008000]
+layer at (0,150) size 20x20
+  RenderBlock (positioned) {absolute} at (0,0) size 20x20 [bgcolor=#008000]
 layer at (0,300) size 100x100
   RenderFlexibleBox {flex} at (0,300) size 100x100 [bgcolor=#FA8072]
     RenderBlock {spacer} at (0,0) size 40x40 [bgcolor=#FFEFD5] [border: (5px solid #800080)]
     RenderBlock {spacer} at (40,0) size 40x40 [bgcolor=#FFEFD5] [border: (5px solid #800080)]
-layer at (40,300) size 20x20
-  RenderBlock (positioned) {absolute} at (40,0) size 20x20 [bgcolor=#008000]
+layer at (0,300) size 20x20
+  RenderBlock (positioned) {absolute} at (0,0) size 20x20 [bgcolor=#008000]
 
diff --git a/engine/src/flutter/tests/layout/position-absolute-pixels-expected.sky b/engine/src/flutter/tests/layout/position-absolute-pixels-expected.sky
index 5a7585e2edb..27a2db61342 100644
--- a/engine/src/flutter/tests/layout/position-absolute-pixels-expected.sky
+++ b/engine/src/flutter/tests/layout/position-absolute-pixels-expected.sky
@@ -1,7 +1,7 @@
 <sky>
   <import src="../resources/run-after-display.sky"/>
 
-  <img src="http://storage.googleapis.com/mojo/sky-pngs/df9f2bee2247645ae83ed672858ee47fb239f70a" />
+  <img src="http://storage.googleapis.com/mojo/sky-pngs/0e49314437b063e76c28511c34a6c6da72c17956" />
 
   <script>
   import "dart:sky";
diff --git a/engine/src/flutter/tests/lowlevel/layers-expected.sky b/engine/src/flutter/tests/lowlevel/layers-expected.sky
index 877ef5c9a77..b923a4cec33 100644
--- a/engine/src/flutter/tests/lowlevel/layers-expected.sky
+++ b/engine/src/flutter/tests/lowlevel/layers-expected.sky
@@ -1,7 +1,7 @@
 <foo>
 <import src="../resources/run-after-display.sky" />
 
-<img src="http://storage.googleapis.com/mojo/sky-pngs/ed3514fd579dbaa8c18594cf99f3b60bf4b6ee75" />
+<img src="http://storage.googleapis.com/mojo/sky-pngs/8ce0b808d5248b9e7ed051046def933f6ffaa889" />
 
 <script>
 import "dart:sky";
diff --git a/engine/src/flutter/tests/lowlevel/layers.sky b/engine/src/flutter/tests/lowlevel/layers.sky
index 10f1a46774b..f15ff018dae 100644
--- a/engine/src/flutter/tests/lowlevel/layers.sky
+++ b/engine/src/flutter/tests/lowlevel/layers.sky
@@ -24,11 +24,11 @@ Transforms
 
 <div style="position: absolute; top: 250px;">
   Opacity
-  <div style="opacity: 0.8; background-color: pink;">
+  <div style="opacity: 0.8; background-color: pink; transform: translate3d(0, 0, 0)">
     One
-    <div style="opacity: 0.7; position: absolute; left: 10px; background-color: salmon;">
+    <div style="opacity: 0.7; position: absolute; left: 15px; top: 10px; background-color: salmon;">
       Two
-      <div style="opacity: 0.6; position: absolute; left: 20px; background-color: papayawhip;">
+      <div style="opacity: 0.6; position: absolute; left: 15px; top: 10px; background-color: papayawhip;">
         Three
         <div style="opacity: 0; transform: translate3d(0, 10px, 0); background-color: papayawhip;">
           Clear