Fixed bugs with finding line boundaries using IA2 get_textAtOffset and AXPosition::AtStartOfLine.

ui/accessibility/ax_node_position_unittest.cc

 // Copyright 2016 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 <stdint.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 135 matching lines @@
   text_field_.AddIntListAttribute(AX_ATTR_CACHED_LINE_STARTS,
                                   std::vector<int32_t>{0, 7});
   text_field_.child_ids.push_back(static_text1_.id);
   text_field_.child_ids.push_back(line_break_.id);
   text_field_.child_ids.push_back(static_text2_.id);
   root_.child_ids.push_back(text_field_.id);
 
   static_text1_.role = AX_ROLE_STATIC_TEXT;
   static_text1_.AddState(AX_STATE_EDITABLE);
   static_text1_.SetName("Line 1");
-  static_text1_.AddIntAttribute(AX_ATTR_NEXT_ON_LINE_ID, line_break_.id);
   static_text1_.child_ids.push_back(inline_box1_.id);
 
   inline_box1_.role = AX_ROLE_INLINE_TEXT_BOX;
   inline_box1_.AddState(AX_STATE_EDITABLE);
   inline_box1_.SetName("Line 1");
   inline_box1_.AddIntListAttribute(AX_ATTR_WORD_STARTS,
                                    std::vector<int32_t>{0, 5});
   inline_box1_.AddIntListAttribute(AX_ATTR_WORD_ENDS,
                                    std::vector<int32_t>{4, 6});
-  inline_box1_.AddIntAttribute(AX_ATTR_NEXT_ON_LINE_ID, line_break_.id);
 
   line_break_.role = AX_ROLE_LINE_BREAK;
   line_break_.AddState(AX_STATE_EDITABLE);
   line_break_.SetName("\n");
   line_break_.AddIntAttribute(AX_ATTR_PREVIOUS_ON_LINE_ID, inline_box1_.id);
 
   static_text2_.role = AX_ROLE_STATIC_TEXT;
   static_text2_.AddState(AX_STATE_EDITABLE);
   static_text2_.SetName("Line 2");
   static_text2_.child_ids.push_back(inline_box2_.id);
@@ skipping 180 matching lines @@
   ASSERT_NE(nullptr, text_position);
   EXPECT_FALSE(text_position->AtEndOfAnchor());
 
   text_position = AXNodePosition::CreateTextPosition(
       tree_.data().tree_id, inline_box1_.id, 0 /* text_offset */,
       AX_TEXT_AFFINITY_DOWNSTREAM);
   ASSERT_NE(nullptr, text_position);
   EXPECT_FALSE(text_position->AtEndOfAnchor());
 }
 
+TEST_F(AXPositionTest, AtStartOfLineWithTextPosition) {
+  // An upstream affinity should not affect the outcome since there is no soft
+  // line break.
+  TestPositionType text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box1_.id, 0 /* text_offset */,
+      AX_TEXT_AFFINITY_UPSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_TRUE(text_position->AtStartOfLine());
+
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box1_.id, 1 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_FALSE(text_position->AtStartOfLine());
+
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, line_break_.id, 0 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_FALSE(text_position->AtStartOfLine());
+
+  // An "after text" position anchored at the line break should visually be the
+  // same as a text position at the start of the next line.
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, line_break_.id, 1 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_TRUE(text_position->AtStartOfLine());
+
+  // An upstream affinity should not affect the outcome since there is no soft
+  // line break.
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box2_.id, 0 /* text_offset */,
+      AX_TEXT_AFFINITY_UPSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_TRUE(text_position->AtStartOfLine());
+
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box2_.id, 1 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_FALSE(text_position->AtStartOfLine());
+}
+
+TEST_F(AXPositionTest, AtEndOfLineWithTextPosition) {
+  TestPositionType text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box1_.id, 5 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_FALSE(text_position->AtEndOfLine());
+
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box1_.id, 6 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_TRUE(text_position->AtEndOfLine());
+
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, line_break_.id, 0 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_FALSE(text_position->AtEndOfLine());
+
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box2_.id, 5 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_FALSE(text_position->AtEndOfLine());
+
+  text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, inline_box2_.id, 6 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  ASSERT_NE(nullptr, text_position);
+  EXPECT_TRUE(text_position->AtEndOfLine());
+}
+
 TEST_F(AXPositionTest, LowestCommonAncestor) {
   TestPositionType null_position = AXNodePosition::CreateNullPosition();
   ASSERT_NE(nullptr, null_position);
   // An "after children" position.
   TestPositionType root_position = AXNodePosition::CreateTreePosition(
       tree_.data().tree_id, root_.id, 3 /* child_index */);
   ASSERT_NE(nullptr, root_position);
   // A "before text" position.
   TestPositionType button_position = AXNodePosition::CreateTreePosition(
       tree_.data().tree_id, button_.id, AXNodePosition::BEFORE_TEXT);
@@ skipping 1554 matching lines @@
       AX_TEXT_AFFINITY_DOWNSTREAM);
   AXRange<AXPosition<AXNodePosition, AXNode>> forward_range(start->Clone(),
                                                             end->Clone());
   EXPECT_EQ(most_text, forward_range.GetText());
   AXRange<AXPosition<AXNodePosition, AXNode>> backward_range(std::move(end),
                                                              std::move(start));
   EXPECT_EQ(most_text, backward_range.GetText());
 }
 
 }  // namespace ui