IAccessibleText::get_text must support special text offsets.

BUG=82224
TEST=unit_tests:BrowserAccessibilityTest.TestTextBoundaries

Review URL: http://codereview.chromium.org/6995040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@84948 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 22 insertions, 5 deletions

diff --git a/chrome/browser/accessibility/browser_accessibility_win.cc b/chrome/browser/accessibility/browser_accessibility_win.cc
index 80e4e48..a217f05 100644
--- a/chrome/browser/accessibility/browser_accessibility_win.cc
+++ b/chrome/browser/accessibility/browser_accessibility_win.cc
@@ -640,6 +640,10 @@ STDMETHODIMP BrowserAccessibilityWin::get_text(
 
   const string16& text_str = TextForIAccessibleText();
 
+  // Handle special text offsets.
+  HandleSpecialTextOffset(text_str, &start_offset);
+  HandleSpecialTextOffset(text_str, &end_offset);
+
   // The spec allows the arguments to be reversed.
   if (start_offset > end_offset) {
     LONG tmp = start_offset;
@@ -1205,6 +1209,15 @@ const string16& BrowserAccessibilityWin::TextForIAccessibleText() {
   }
 }
 
+void BrowserAccessibilityWin::HandleSpecialTextOffset(
+    const string16& text, LONG* offset) {
+  if (*offset == IA2_TEXT_OFFSET_LENGTH) {
+    *offset = static_cast<LONG>(text.size());
+  } else if (*offset == IA2_TEXT_OFFSET_CARET) {
+    get_caretOffset(offset);
+  }
+}
+
 LONG BrowserAccessibilityWin::FindBoundary(
     const string16& text,
     IA2TextBoundaryType boundary,
@@ -1216,11 +1229,7 @@ LONG BrowserAccessibilityWin::FindBoundary(
          start_offset == IA2_TEXT_OFFSET_CARET);
   DCHECK(direction == 1 || direction == -1);
 
-  if (start_offset == IA2_TEXT_OFFSET_LENGTH) {
-    start_offset = text_size;
-  } else if (start_offset == IA2_TEXT_OFFSET_CARET) {
-    get_caretOffset(&start_offset);
-  }
+  HandleSpecialTextOffset(text, &start_offset);
 
   if (boundary == IA2_TEXT_BOUNDARY_CHAR) {
     if (direction == 1 && start_offset < text_size)
diff --git a/chrome/browser/accessibility/browser_accessibility_win.h b/chrome/browser/accessibility/browser_accessibility_win.h
index 879a7dc..78d0ecd 100644
--- a/chrome/browser/accessibility/browser_accessibility_win.h
+++ b/chrome/browser/accessibility/browser_accessibility_win.h
@@ -470,6 +470,10 @@ class BrowserAccessibilityWin
   // be the name, it may be the value, etc. depending on the role.
   const string16& TextForIAccessibleText();
 
+  // If offset is a member of IA2TextSpecialOffsets this function updates the
+  // value of offset and returns, otherwise offset remains unchanged.
+  void HandleSpecialTextOffset(const string16& text, LONG* offset);
+
   // Search forwards (direction == 1) or backwards (direction == -1) from
   // the given offset until the given IAccessible2 boundary (like word,
   // sentence) is found, and return its offset.
diff --git a/chrome/browser/accessibility/browser_accessibility_win_unittest.cc b/chrome/browser/accessibility/browser_accessibility_win_unittest.cc
index 4875130..e40d505 100644
--- a/chrome/browser/accessibility/browser_accessibility_win_unittest.cc
+++ b/chrome/browser/accessibility/browser_accessibility_win_unittest.cc
@@ -358,6 +358,10 @@ TEST_F(BrowserAccessibilityTest, TestTextBoundaries) {
   ASSERT_EQ(text, string16(L"One two three"));
   SysFreeString(text);
 
+  ASSERT_EQ(S_OK, text1_obj->get_text(0, IA2_TEXT_OFFSET_LENGTH, &text));
+  ASSERT_EQ(text, string16(L"One two three.\nFour five six."));
+  SysFreeString(text);
+
   // Delete the manager and test that all BrowserAccessibility instances are
   // deleted.
   delete manager;