Translate flow thread coords to the nearest enclosing coord space when appropriate.

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
 #include "platform/geometry/TransformState.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 542 matching lines @@
     mappedPoint = mapLocalToAncestor(flowThread, container, mappedPoint);
     EXPECT_EQ(FloatPoint(125, 35), mappedPoint);
 
     mappedPoint = mapAncestorToLocal(flowThread, container, mappedPoint);
     EXPECT_EQ(FloatPoint(110, 20), mappedPoint);
 
     mappedPoint = mapAncestorToLocal(target, flowThread, mappedPoint);
     EXPECT_EQ(FloatPoint(), mappedPoint);
 }
 
+TEST_F(MapCoordinatesTest, NestedMulticolWithBlock)
+{
+    setBodyInnerHTML(
+        "<div id='outerMulticol' style='columns:2; column-gap:0; column-fill:auto; width:560px; height:215px; border:8px solid; padding:7px;'>"
+        "    <div style='height:10px;'></div>"
+        "    <div id='innerMulticol' style='columns:2; column-gap:0; border:8px solid; padding:7px;'>"
+        "        <div style='height:630px;'></div>"
+        "        <div id='target' style='width:50px; height:50px;'></div>"
+        "    </div>"
+        "</div>");
+
+    LayoutBox* target = toLayoutBox(getLayoutObjectByElementId("target"));
+    LayoutBox* outerMulticol = toLayoutBox(getLayoutObjectByElementId("outerMulticol"));
+    LayoutBox* innerMulticol = toLayoutBox(getLayoutObjectByElementId("innerMulticol"));
+    LayoutBox* innerFlowThread = target->parentBox();
+    ASSERT_TRUE(innerFlowThread->isLayoutFlowThread());
+    LayoutBox* outerFlowThread = innerMulticol->parentBox();
+    ASSERT_TRUE(outerFlowThread->isLayoutFlowThread());
+
+    FloatPoint mappedPoint = mapLocalToAncestor(target, outerMulticol, FloatPoint());
+    EXPECT_EQ(FloatPoint(435, 115), mappedPoint);
+
+    // TODO(mstensho): Add mapAncestorToLocal() tests when it starts working in nested multicol.
+
+    // Walk each ancestor in the chain separately, to verify each step on the way.
+    mappedPoint = mapLocalToAncestor(target, innerFlowThread, FloatPoint());
+    EXPECT_EQ(FloatPoint(0, 630), mappedPoint);
+
+    mappedPoint = mapLocalToAncestor(innerFlowThread, innerMulticol, mappedPoint);
+    EXPECT_EQ(FloatPoint(140, 305), mappedPoint);
+
+    mappedPoint = mapLocalToAncestor(innerMulticol, outerFlowThread, mappedPoint);
+    EXPECT_EQ(FloatPoint(140, 315), mappedPoint);
+
+    mappedPoint = mapLocalToAncestor(outerFlowThread, outerMulticol, mappedPoint);
+    EXPECT_EQ(FloatPoint(435, 115), mappedPoint);
+}
+
 TEST_F(MapCoordinatesTest, MulticolWithAbsPosInRelPos)
 {
     setBodyInnerHTML(
         "<div id='multicol' style='-webkit-columns:3; -webkit-column-gap:0; column-fill:auto; width:300px; height:100px; border:8px solid; padding:7px;'>"
         "    <div style='height:110px;'></div>"
         "    <div id='relpos' style='position:relative; left:4px; top:4px;'>"
         "        <div id='target' style='position:absolute; left:15px; top:15px; margin:10px; border:13px; padding:13px;'></div>"
         "    </div>"
         "</div>");
 
@@ skipping 558 matching lines @@
 
     // With child2, each rotation gets flattened and the end result is approximately a 90-degree rotation.
     matrix = child2->localToAbsoluteTransform();
     EXPECT_NEAR(50.0, matrix.projectPoint(FloatPoint(100.0, 50.0)).x(), LayoutUnit::epsilon());
     EXPECT_NEAR(50.0, matrix.projectPoint(FloatPoint(100.0, 50.0)).y(), LayoutUnit::epsilon());
     EXPECT_NEAR(25.0, matrix.projectPoint(FloatPoint(50.0, 100.0)).x(), LayoutUnit::epsilon());
     EXPECT_NEAR(100.0, matrix.projectPoint(FloatPoint(50.0, 100.0)).y(), LayoutUnit::epsilon());
 }
 
 } // namespace blink