[New Multicolumn] Add RenderMultiColumnSpannerSet.

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/RenderMultiColumnSpannerSet.h"
+#include "core/rendering/RenderingTestHelper.h"
+
+#include <gtest/gtest.h>
+
+namespace blink {
+
+namespace {
+
+class MultiColumnRenderingTest : public RenderingTest {
+public:
+    RenderMultiColumnFlowThread* findFlowThread(const char* id) const;
+
+    // Generate a signature string based on what kind of column sets the flow thread has
+    // established. There will be one character for each column set. 'c' is used for regular column
+    // content sets, while 's' is used for spanner sets.
+    String columnSetSignature(RenderMultiColumnFlowThread*);
+    String columnSetSignature(const char* multicolId);

[Julien - ping for review, 2014/11/05 16:52:39]

The signature based check saves quite some code but there is a pattern in your
test cases: whenever you have a spanner (not other renderers btw), you want to
check the containing column set.

[mstensho (USE GERRIT), 2014/11/05 21:43:06]

For some of the tests that we currently have, columnSetSignature() is kind of
redundant, but I don't plan to call containingColumnSpannerSet() and stuff in
all future tests.

(But good point, anyway, I should call containingColumnSpannerSet() for some
other renderers as well, and see that I get nullptr).

+
+    void setMulticolHTML(const String&);
+};
+
+RenderMultiColumnFlowThread* MultiColumnRenderingTest::findFlowThread(const char* id) const
+{
+    Node* multicol = document().getElementById(id);
+    if (!multicol)
+        return 0;
+    RenderBlockFlow* multicolContainer = toRenderBlockFlow(multicol->renderer());
+    if (!multicolContainer)
+        return 0;
+    return multicolContainer->multiColumnFlowThread();
+}
+
+String MultiColumnRenderingTest::columnSetSignature(RenderMultiColumnFlowThread* flowThread)
+{
+    String signature = "";
+    for (RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet(); columnSet; columnSet = columnSet->nextSiblingMultiColumnSet()) {
+        if (columnSet->isRenderMultiColumnSpannerSet())
+            signature.append('s');
+        else
+            signature.append('c');
+    }
+    return signature;
+}
+
+String MultiColumnRenderingTest::columnSetSignature(const char* multicolId)
+{
+    return columnSetSignature(findFlowThread(multicolId));
+}
+
+void MultiColumnRenderingTest::setMulticolHTML(const String& html)
+{
+    const char* style =
+        "<style>"
+        "  #mc { -webkit-columns:2; }"
+        "  .s, #spanner, #spanner1, #spanner2 { -webkit-column-span:all; }"
+        "</style>";
+    setBodyInnerHTML(style + html);
+}
+
+TEST_F(MultiColumnRenderingTest, BasicSanityTest)

[Julien - ping for review, 2014/11/05 16:52:39]

There is quite some overlap with the other tests, like OneBlock (as the column
set has a single child which is a block renderer).

When reading the name, I thought this was a sanity check where we would check
some very simple characteristics of the tree that is required for other tests to
pass.

I think this test is valuable but we should rename it to e.g.
OneBlockWithInDepthTreeStructureCheck

[mstensho (USE GERRIT), 2014/11/05 21:43:06]

Done.

+{
+    // Examine the render tree established by a simple multicol container with a block with some text inside.
+    setMulticolHTML("<div id='mc'><div>xxx</div></div>");
+    Node* multicol = document().getElementById("mc");
+    ASSERT_TRUE(multicol);
+    RenderBlockFlow* multicolContainer = toRenderBlockFlow(multicol->renderer());
+    ASSERT_TRUE(multicolContainer);
+    RenderMultiColumnFlowThread* flowThread = multicolContainer->multiColumnFlowThread();
+    ASSERT_TRUE(flowThread);
+    EXPECT_EQ(columnSetSignature(flowThread), "c");
+    EXPECT_EQ(flowThread->parent(), multicolContainer);
+    EXPECT_FALSE(flowThread->previousSibling());
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    ASSERT_TRUE(columnSet);
+    EXPECT_EQ(columnSet->previousSibling(), flowThread);
+    EXPECT_FALSE(columnSet->nextSibling());
+    RenderBlockFlow* block = toRenderBlockFlow(flowThread->firstChild());
+    ASSERT_TRUE(block);
+    EXPECT_FALSE(block->nextSibling());
+    ASSERT_TRUE(block->firstChild());
+    EXPECT_TRUE(block->firstChild()->isText());
+    EXPECT_FALSE(block->firstChild()->nextSibling());
+}
+
+TEST_F(MultiColumnRenderingTest, Empty)
+{
+    // 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");
+}
+
+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");
+}
+
+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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner")->renderer()), columnSet);
+}
+
+TEST_F(MultiColumnRenderingTest, ContentAndSpanner)

[Julien - ping for review, 2014/11/05 16:52:39]

Maybe better name ContentThenSpanner or SpannerFollowingContent (it's backwards
so really not great)?

[mstensho (USE GERRIT), 2014/11/05 21:43:06]

Done.

+{
+    // 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");
+    RenderMultiColumnSet* columnSet = flowThread->lastMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner")->renderer()), columnSet);
+}
+
+TEST_F(MultiColumnRenderingTest, SpannerAndContent)
+{
+    // 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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner")->renderer()), columnSet);
+}
+
+TEST_F(MultiColumnRenderingTest, ContentAndSpannerAndContent)
+{
+    // 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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet()->nextSiblingMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner")->renderer()), columnSet);
+}
+
+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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner1")->renderer()), columnSet);
+    columnSet = columnSet->nextSiblingMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner2")->renderer()), columnSet);
+}
+
+TEST_F(MultiColumnRenderingTest, SpannerAndContentAndSpanner)
+{
+    // 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(flowThread->containingColumnSpannerSet(document().getElementById("spanner1")->renderer()), columnSet);
+    columnSet = columnSet->nextSiblingMultiColumnSet()->nextSiblingMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner2")->renderer()), columnSet);
+}
+
+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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner")->renderer()), columnSet);
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("invalidSpanner")->renderer()), columnSet);
+    EXPECT_EQ(toRenderMultiColumnSpannerSet(columnSet)->rendererInFlowThread(), document().getElementById("spanner")->renderer());
+}
+
+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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet()->nextSiblingMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner")->renderer()), columnSet);
+    EXPECT_EQ(toRenderMultiColumnSpannerSet(columnSet)->rendererInFlowThread(), document().getElementById("spanner")->renderer());
+}
+
+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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner1")->renderer()), columnSet);
+    EXPECT_EQ(toRenderMultiColumnSpannerSet(columnSet)->rendererInFlowThread(), document().getElementById("spanner1")->renderer());
+    columnSet = columnSet->nextSiblingMultiColumnSet()->nextSiblingMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner2")->renderer()), columnSet);
+    EXPECT_EQ(toRenderMultiColumnSpannerSet(columnSet)->rendererInFlowThread(), document().getElementById("spanner2")->renderer());
+}
+
+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");
+    RenderMultiColumnSet* columnSet = flowThread->firstMultiColumnSet()->nextSiblingMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner1")->renderer()), columnSet);
+    EXPECT_EQ(toRenderMultiColumnSpannerSet(columnSet)->rendererInFlowThread(), document().getElementById("spanner1")->renderer());
+    columnSet = columnSet->nextSiblingMultiColumnSet()->nextSiblingMultiColumnSet();
+    EXPECT_EQ(flowThread->containingColumnSpannerSet(document().getElementById("spanner2")->renderer()), columnSet);
+    EXPECT_EQ(toRenderMultiColumnSpannerSet(columnSet)->rendererInFlowThread(), document().getElementById("spanner2")->renderer());
+}
+
+} // anonymous namespace
+
+} // namespace blink