Use Position instead of VisiblePosition for SurroundingText.

Using VisiblePosition has some not required performance implications.

BUG=None

Review URL: https://codereview.chromium.org/307353002

git-svn-id: svn://svn.chromium.org/blink/trunk@175788 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/core.gypi

@@ -3387,6 +3387,7 @@
             'dom/MainThreadTaskRunnerTest.cpp',
             'dom/RangeTest.cpp',
             'dom/TreeScopeTest.cpp',
+            'editing/SurroundingTextTest.cpp',
             'editing/TextIteratorTest.cpp',
             'editing/VisibleSelectionTest.cpp',
             'fetch/CachingCorrectnessTest.cpp',

third_party/WebKit/Source/core/editing/SurroundingText.cpp

@@ -32,38 +32,46 @@
 #include "core/editing/SurroundingText.h"
 
 #include "core/dom/Document.h"
+#include "core/dom/Element.h"
+#include "core/dom/Position.h"
 #include "core/dom/Range.h"
 #include "core/editing/TextIterator.h"
-#include "core/editing/VisiblePosition.h"
-#include "core/editing/VisibleUnits.h"
 
 namespace WebCore {
 
-SurroundingText::SurroundingText(const VisiblePosition& visiblePosition, unsigned maxLength)
+SurroundingText::SurroundingText(const Position& position, unsigned maxLength)
     : m_positionOffsetInContent(0)
 {
-    if (visiblePosition.isNull())
+    const unsigned halfMaxLength = maxLength / 2;
+
+    Document* document = position.document();
+    // The |position| will have no document if it is null (as in no position).
+    if (!document)
         return;
 
-    const unsigned halfMaxLength = maxLength / 2;
-    CharacterIterator forwardIterator(makeRange(visiblePosition, endOfDocument(visiblePosition)).get(), TextIteratorStopsOnFormControls);
+    // The forward range starts at the selection end and ends at the document's
+    // end. It will then be updated to only contain the text in the text in the
+    // right range around the selection.
+    RefPtrWillBeRawPtr<Range> forwardRange = Range::create(*document, position, lastPositionInNode(document->documentElement()).parentAnchoredEquivalent());
+    CharacterIterator forwardIterator(forwardRange.get(), TextIteratorStopsOnFormControls);
     if (!forwardIterator.atEnd())
         forwardIterator.advance(maxLength - halfMaxLength);
 
-    Position position = visiblePosition.deepEquivalent().parentAnchoredEquivalent();
-    Document* document = position.document();
-    ASSERT(document);
-    RefPtrWillBeRawPtr<Range> forwardRange = forwardIterator.range();
+    forwardRange = forwardIterator.range();
     if (!forwardRange || !Range::create(*document, position, forwardRange->startPosition())->text().length()) {
         ASSERT(forwardRange);
         return;
     }
 
-    BackwardsCharacterIterator backwardsIterator(makeRange(startOfDocument(visiblePosition), visiblePosition).get(), TextIteratorStopsOnFormControls);
+    // Same as with the forward range but with the backward range. The range
+    // starts at the document's start and ends at the selection start and will
+    // be updated.
+    RefPtrWillBeRawPtr<Range> backwardsRange = Range::create(*document, firstPositionInNode(document->documentElement()).parentAnchoredEquivalent(), position);
+    BackwardsCharacterIterator backwardsIterator(backwardsRange.get(), TextIteratorStopsOnFormControls);
     if (!backwardsIterator.atEnd())
         backwardsIterator.advance(halfMaxLength);
 
-    RefPtrWillBeRawPtr<Range> backwardsRange = backwardsIterator.range();
+    backwardsRange = backwardsIterator.range();
     if (!backwardsRange) {
         ASSERT(backwardsRange);
         return;

third_party/WebKit/Source/core/editing/SurroundingText.h

@@ -36,13 +36,13 @@
 
 namespace WebCore {
 
+class Position;
 class Range;
-class VisiblePosition;
 
 class SurroundingText {
     WTF_MAKE_NONCOPYABLE(SurroundingText);
 public:
-    SurroundingText(const VisiblePosition&, unsigned maxLength);
+    SurroundingText(const Position&, unsigned maxLength);
 
     String content() const;
     unsigned positionOffsetInContent() const;

third_party/WebKit/Source/core/editing/SurroundingTextTest.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/editing/SurroundingText.h"
+
+#include "core/dom/Position.h"
+#include "core/dom/Range.h"
+#include "core/dom/Text.h"
+#include "core/editing/VisibleSelection.h"
+#include "core/html/HTMLElement.h"
+#include "core/testing/DummyPageHolder.h"
+#include <gtest/gtest.h>
+
+using namespace WebCore;
+
+namespace {
+
+class SurroundingTextTest : public ::testing::Test {
+protected:
+    Document& document() const { return m_dummyPageHolder->document(); }
+    void setHTML(const String&);
+    VisibleSelection select(int offset) { return select(offset, offset); }
+    VisibleSelection select(int start, int end);
+
+private:
+    virtual void SetUp() OVERRIDE;
+
+    OwnPtr<DummyPageHolder> m_dummyPageHolder;
+};
+
+void SurroundingTextTest::SetUp()
+{
+    m_dummyPageHolder = DummyPageHolder::create(IntSize(800, 600));
+}
+
+void SurroundingTextTest::setHTML(const String& content)
+{
+    document().body()->setInnerHTML(content, ASSERT_NO_EXCEPTION);
+}
+
+VisibleSelection SurroundingTextTest::select(int start, int end)
+{
+    Element* element = document().getElementById("selection");
+    VisibleSelection selection;
+    selection.setBase(Position(toText(element->firstChild()), start));
+    selection.setExtent(Position(toText(element->firstChild()), end));
+    return selection;
+}
+
+TEST_F(SurroundingTextTest, BasicCaretSelection)
+{
+    setHTML(String("<p id='selection'>foo bar</p>"));
+
+    {
+        VisibleSelection selection = select(0);
+        SurroundingText surroundingText(selection.start(), 1);
+
+        EXPECT_EQ("f", surroundingText.content());
+        EXPECT_EQ(0u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(0);
+        SurroundingText surroundingText(selection.start(), 5);
+
+        // maxlength/2 is used on the left and right.
+        EXPECT_EQ("foo", surroundingText.content().simplifyWhiteSpace());
+        EXPECT_EQ(1u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(0);
+        SurroundingText surroundingText(selection.start(), 42);
+
+        EXPECT_EQ("foo bar", surroundingText.content().simplifyWhiteSpace());
+        EXPECT_EQ(1u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        // FIXME: if the selection is at the end of the text, SurroundingText
+        // will return nothing.
+        VisibleSelection selection = select(7);
+        SurroundingText surroundingText(selection.start(), 42);
+
+        EXPECT_EQ(0u, surroundingText.content().length());
+        EXPECT_EQ(0u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(6);
+        SurroundingText surroundingText(selection.start(), 2);
+
+        EXPECT_EQ("ar", surroundingText.content());
+        EXPECT_EQ(1u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(6);
+        SurroundingText surroundingText(selection.start(), 42);
+
+        EXPECT_EQ("foo bar", surroundingText.content().simplifyWhiteSpace());
+        EXPECT_EQ(7u, surroundingText.positionOffsetInContent());
+    }
+}
+
+TEST_F(SurroundingTextTest, TreeCaretSelection)
+{
+    setHTML(String("<div>This is outside of <p id='selection'>foo bar</p> the selected node</div>"));
+
+    {
+        VisibleSelection selection = select(0);
+        SurroundingText surroundingText(selection.start(), 1);
+
+        EXPECT_EQ("f", surroundingText.content());
+        EXPECT_EQ(0u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(0);
+        SurroundingText surroundingText(selection.start(), 5);
+
+        EXPECT_EQ("foo", surroundingText.content().simplifyWhiteSpace());
+        EXPECT_EQ(1u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(0);
+        SurroundingText surroundingText(selection.start(), 1337);
+
+        EXPECT_EQ("This is outside of foo bar the selected node", surroundingText.content().simplifyWhiteSpace());
+        EXPECT_EQ(20u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(6);
+        SurroundingText surroundingText(selection.start(), 2);
+
+        EXPECT_EQ("ar", surroundingText.content());
+        EXPECT_EQ(1u, surroundingText.positionOffsetInContent());
+    }
+
+    {
+        VisibleSelection selection = select(6);
+        SurroundingText surroundingText(selection.start(), 1337);
+
+        EXPECT_EQ("This is outside of foo bar the selected node", surroundingText.content().simplifyWhiteSpace());
+        EXPECT_EQ(26u, surroundingText.positionOffsetInContent());
+    }
+}
+
+} // anonymous namespace

third_party/WebKit/Source/core/testing/Internals.cpp

@@ -2338,7 +2338,7 @@ String Internals::textSurroundingNode(Node* node, int x, int y, unsigned long ma
     if (!node)
         return String();
     blink::WebPoint point(x, y);
-    SurroundingText surroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(point))), maxLength);
+    SurroundingText surroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(point))).deepEquivalent().parentAnchoredEquivalent(), maxLength);
     return surroundingText.content();
 }
 

third_party/WebKit/Source/web/WebSurroundingText.cpp

@@ -45,7 +45,7 @@ void WebSurroundingText::initialize(const WebNode& webNode, const WebPoint& node
     if (!node || !node->renderer())
         return;
 
-    m_private.reset(new SurroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(nodePoint))), maxLength));
+    m_private.reset(new SurroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(nodePoint))).deepEquivalent().parentAnchoredEquivalent(), maxLength));
 }
 
 WebString WebSurroundingText::textContent() const