Change return value of FrameSelection::modify() to prevent unnecessary window scrolling

third_party/WebKit/Source/core/editing/FrameSelectionTest.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 "core/editing/FrameSelection.h"
 
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/Text.h"
@@ skipping 160 matching lines @@
     // Select "two" for selection in DOM tree
     // Select "twoone" for selection in Flat tree
     selection().setSelection(VisibleSelectionInFlatTree(PositionInFlatTree(host, 0), PositionInFlatTree(document().body(), 2)));
     selection().modify(FrameSelection::AlterationExtend, DirectionForward, WordGranularity);
     EXPECT_EQ(Position(two, 0), visibleSelectionInDOMTree().start());
     EXPECT_EQ(Position(two, 3), visibleSelectionInDOMTree().end());
     EXPECT_EQ(PositionInFlatTree(two, 0), visibleSelectionInFlatTree().start());
     EXPECT_EQ(PositionInFlatTree(two, 3), visibleSelectionInFlatTree().end());
 }
 
+TEST_F(FrameSelectionTest, ModifyWithUserTriggered)
+{
+    setBodyContent("<div id=sample>abc</div>");
+    Element* sample = document().getElementById("sample");
+    const Position endOfText(sample->firstChild(), 3);
+    selection().setSelection(VisibleSelection(endOfText));
+
+    EXPECT_FALSE(selection().modify(FrameSelection::AlterationMove, DirectionForward, CharacterGranularity, NotUserTriggered))
+        << "Selection.modify() returns false for non-user-triggered call when selection isn't modified.";
+    EXPECT_EQ(endOfText, selection().start())
+        << "Selection isn't modified";
+
+    EXPECT_TRUE(selection().modify(FrameSelection::AlterationMove, DirectionForward, CharacterGranularity, UserTriggered))
+        << "Selection.modify() returns true for user-triggered call";
+    EXPECT_EQ(endOfText, selection().start())
+        << "Selection isn't modified";
+}
+
 TEST_F(FrameSelectionTest, MoveRangeSelectionTest)
 {
     // "Foo Bar Baz,"
     Text* text = appendTextNode("Foo Bar Baz,");
     // Itinitializes with "Foo B|a>r Baz," (| means start and > means end).
     selection().setSelection(VisibleSelection(Position(text, 5), Position(text, 6)));
     EXPECT_EQ_SELECTED_TEXT("a");
 
     // "Foo B|ar B>az," with the Character granularity.
     selection().moveRangeSelection(createVisiblePosition(Position(text, 5)), createVisiblePosition(Position(text, 9)), CharacterGranularity);
@@ skipping 69 matching lines @@
     selection().updateIfNeeded();
 
     // TODO(yosin): Once lazy canonicalization implemented, selection.start
     // should be Position(HTML, 0).
     EXPECT_EQ(Position(), selection().start())
         << "updateIfNeeded() makes selection to null.";
     EXPECT_EQ(selection().start(), caretPosition().position());
 }
 
 } // namespace blink