[New Multicolumn] Add RenderMultiColumnFlowThread::findSetRendering().

Source/core/rendering/RenderMultiColumnFlowThreadTest.cpp

 // Copyright 2014 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 "config.h"
 
 #include "core/rendering/RenderMultiColumnFlowThread.h"
 
 #include "core/rendering/RenderMultiColumnSet.h"
 #include "core/rendering/RenderMultiColumnSpannerPlaceholder.h"
@@ skipping 89 matching lines @@
 {
     // If there's no column content, there should be no column set.
     setMulticolHTML("<div id='mc'></div>");
     EXPECT_EQ(columnSetSignature("mc"), "");
 }
 
 TEST_F(MultiColumnRenderingTest, OneBlock)
 {
     // There is some content, so we should create a column set.
     setMulticolHTML("<div id='mc'><div id='block'></div></div>");
-    ASSERT_EQ(columnSetSignature("mc"), "c");
+    RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
+    ASSERT_EQ(columnSetSignature(flowThread), "c");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("block")->renderer()), columnSet);

[Julien - ping for review, 2015/01/22 10:23:08]

Unfortunately by piggy-backing on these tests, you're making them more fragile
as they can break due to several reasons.

Usually it's better to follow a single responsibility approach for testing so
that there is only one reason for the test to break (and thus it's obvious what
went wrong).

 }
 
 TEST_F(MultiColumnRenderingTest, TwoBlocks)
 {
     // No matter how much content, we should only create one column set (unless there are spanners).
     setMulticolHTML("<div id='mc'><div id='block1'></div><div id='block2'></div></div>");
-    ASSERT_EQ(columnSetSignature("mc"), "c");
+    RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
+    ASSERT_EQ(columnSetSignature(flowThread), "c");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("block1")->renderer()), columnSet);
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("block2")->renderer()), columnSet);
 }
 
 TEST_F(MultiColumnRenderingTest, Spanner)
 {
     // With one spanner and no column content, we should create a spanner set.
     setMulticolHTML("<div id='mc'><div id='spanner'></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     ASSERT_EQ(columnSetSignature(flowThread), "s");
     RenderBox* columnBox = flowThread->firstMultiColumnBox();
     EXPECT_EQ(flowThread->firstMultiColumnSet(), nullptr);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner")->renderer()), columnBox);
     EXPECT_EQ(document().getElementById("spanner")->renderer()->spannerPlaceholder(), columnBox);
 }
 
 TEST_F(MultiColumnRenderingTest, ContentThenSpanner)
 {
     // With some column content followed by a spanner, we need a column set followed by a spanner set.
     setMulticolHTML("<div id='mc'><div id='columnContent'></div><div id='spanner'></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     ASSERT_EQ(columnSetSignature(flowThread), "cs");
-    RenderBox* columnBox = flowThread->lastMultiColumnBox();
+    RenderBox* columnBox = flowThread->firstMultiColumnBox();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("columnContent")->renderer()), columnBox);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner")->renderer()), columnBox);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("columnContent")->renderer()), nullptr);
 }
 
 TEST_F(MultiColumnRenderingTest, SpannerThenContent)
 {
     // With a spanner followed by some column content, we need a spanner set followed by a column set.
     setMulticolHTML("<div id='mc'><div id='spanner'></div><div id='columnContent'></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     ASSERT_EQ(columnSetSignature(flowThread), "sc");
     RenderBox* columnBox = flowThread->firstMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner")->renderer()), columnBox);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("columnContent")->renderer()), columnBox);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("columnContent")->renderer()), nullptr);
 }
 
 TEST_F(MultiColumnRenderingTest, ContentThenSpannerThenContent)
 {
     // With column content followed by a spanner followed by some column content, we need a column
     // set followed by a spanner set followed by a column set.
     setMulticolHTML("<div id='mc'><div id='columnContentBefore'></div><div id='spanner'></div><div id='columnContentAfter'></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     ASSERT_EQ(columnSetSignature(flowThread), "csc");
-    RenderBox* columnBox = flowThread->firstMultiColumnSet()->nextSiblingMultiColumnBox();
+    RenderBox* columnBox = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("columnContentBefore")->renderer()), columnBox);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("columnContentBefore")->renderer()), nullptr);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner")->renderer()), columnBox);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("columnContentAfter")->renderer()), columnBox);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("columnContentAfter")->renderer()), nullptr);
 }
 
 TEST_F(MultiColumnRenderingTest, TwoSpanners)
 {
     // With two spanners and no column content, we need two spanner sets.
     setMulticolHTML("<div id='mc'><div id='spanner1'></div><div id='spanner2'></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     ASSERT_EQ(columnSetSignature(flowThread), "ss");
     RenderBox* columnBox = flowThread->firstMultiColumnBox();
@@ skipping 10 matching lines @@
     // With two spanners and some column content in-between, we need a spanner set, a column set and another spanner set.
     setMulticolHTML("<div id='mc'><div id='spanner1'></div><div id='columnContent'></div><div id='spanner2'></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     ASSERT_EQ(columnSetSignature(flowThread), "scs");
     RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
     EXPECT_EQ(columnSet->nextSiblingMultiColumnSet(), nullptr);
     RenderBox* columnBox = flowThread->firstMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner1")->renderer()), columnBox);
     columnBox = columnBox->nextSiblingMultiColumnBox();
     EXPECT_EQ(columnBox, columnSet);
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("columnContent")->renderer()), columnSet);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("columnContent")->renderer()), nullptr);
     columnBox = columnBox->nextSiblingMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner2")->renderer()), columnBox);
 }
 
 TEST_F(MultiColumnRenderingTest, SpannerWithSpanner)
 {
     // column-span:all on something inside column-span:all has no effect.
     setMulticolHTML("<div id='mc'><div id='spanner'><div id='invalidSpanner' class='s'></div></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     ASSERT_EQ(columnSetSignature(flowThread), "s");
     RenderBox* columnBox = flowThread->firstMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner")->renderer()), columnBox);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("invalidSpanner")->renderer()), columnBox);
     EXPECT_EQ(toRenderMultiColumnSpannerPlaceholder(columnBox)->rendererInFlowThread(), document().getElementById("spanner")->renderer());
     EXPECT_EQ(document().getElementById("spanner")->renderer()->spannerPlaceholder(), columnBox);
     EXPECT_EQ(document().getElementById("invalidSpanner")->renderer()->spannerPlaceholder(), nullptr);
 }
 
 TEST_F(MultiColumnRenderingTest, SubtreeWithSpanner)
 {
     setMulticolHTML("<div id='mc'><div id='outer'><div id='block1'></div><div id='spanner'></div><div id='block2'></div></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     EXPECT_EQ(columnSetSignature(flowThread), "csc");
-    RenderBox* columnBox = flowThread->firstMultiColumnSet()->nextSiblingMultiColumnBox();
+    RenderBox* columnBox = flowThread->firstMultiColumnBox();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("outer")->renderer()), columnBox);
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("block1")->renderer()), columnBox);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner")->renderer()), columnBox);
     EXPECT_EQ(document().getElementById("spanner")->renderer()->spannerPlaceholder(), columnBox);
     EXPECT_EQ(toRenderMultiColumnSpannerPlaceholder(columnBox)->rendererInFlowThread(), document().getElementById("spanner")->renderer());
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("outer")->renderer()), nullptr);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("block1")->renderer()), nullptr);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("block2")->renderer()), nullptr);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("block2")->renderer()), columnBox);
 }
 
 TEST_F(MultiColumnRenderingTest, SubtreeWithSpannerAfterSpanner)
 {
     setMulticolHTML("<div id='mc'><div id='spanner1'></div><div id='outer'>text<div id='spanner2'></div><div id='after'></div></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     EXPECT_EQ(columnSetSignature(flowThread), "scsc");
     RenderBox* columnBox = flowThread->firstMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner1")->renderer()), columnBox);
     EXPECT_EQ(toRenderMultiColumnSpannerPlaceholder(columnBox)->rendererInFlowThread(), document().getElementById("spanner1")->renderer());
     EXPECT_EQ(document().getElementById("spanner1")->renderer()->spannerPlaceholder(), columnBox);
-    columnBox = columnBox->nextSiblingMultiColumnBox()->nextSiblingMultiColumnBox();
+    columnBox = columnBox->nextSiblingMultiColumnBox();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("outer")->renderer()), columnBox);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner2")->renderer()), columnBox);
     EXPECT_EQ(toRenderMultiColumnSpannerPlaceholder(columnBox)->rendererInFlowThread(), document().getElementById("spanner2")->renderer());
     EXPECT_EQ(document().getElementById("spanner2")->renderer()->spannerPlaceholder(), columnBox);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("outer")->renderer()), nullptr);
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("after")->renderer()), nullptr);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("after")->renderer()), columnBox);
 }
 
 TEST_F(MultiColumnRenderingTest, SubtreeWithSpannerBeforeSpanner)
 {
     setMulticolHTML("<div id='mc'><div id='outer'>text<div id='spanner1'></div>text</div><div id='spanner2'></div></div>");
     RenderMultiColumnFlowThread* flowThread = findFlowThread("mc");
     EXPECT_EQ(columnSetSignature(flowThread), "cscs");
-    RenderBox* columnBox = flowThread->firstMultiColumnSet()->nextSiblingMultiColumnBox();
+    RenderBox* columnBox = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->findSetRendering(document().getElementById("outer")->renderer()), columnBox);
+    columnBox = columnBox->nextSiblingMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner1")->renderer()), columnBox);
     EXPECT_EQ(document().getElementById("spanner1")->renderer()->spannerPlaceholder(), columnBox);
     EXPECT_EQ(toRenderMultiColumnSpannerPlaceholder(columnBox)->rendererInFlowThread(), document().getElementById("spanner1")->renderer());
     columnBox = columnBox->nextSiblingMultiColumnBox()->nextSiblingMultiColumnBox();
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("spanner2")->renderer()), columnBox);
     EXPECT_EQ(document().getElementById("spanner2")->renderer()->spannerPlaceholder(), columnBox);
     EXPECT_EQ(toRenderMultiColumnSpannerPlaceholder(columnBox)->rendererInFlowThread(), document().getElementById("spanner2")->renderer());
     EXPECT_EQ(flowThread->containingColumnSpannerPlaceholder(document().getElementById("outer")->renderer()), nullptr);
 }
 
@@ skipping 50 matching lines @@
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(799)), secondRow);
     RenderMultiColumnSet* thirdRow = secondRow->nextSiblingMultiColumnSet();
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(800)), thirdRow);
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(899)), thirdRow); // bottom of last row
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(10000)), thirdRow); // overflow
 }
 
 } // anonymous namespace
 
 } // namespace blink