Introduce AdjustSelectionWithTrailingWhitespace()

This patch introduces |AdjustSelectionWithTrailingWhitespace()| as replacement
of |VisibleSelectionInFlatTree::AppendTrailingWhitespace()| to simplify
|VisibleSelectionTemplate| for improving code health.

Bug: 657237
Change-Id: Iaf5e0157c42ac5a16647da9616fc3bc67c9420f9
Reviewed-on: https://chromium-review.googlesource.com/597557Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491619}

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

@@ -562,15 +562,14 @@ bool SelectionController::SelectClosestWordFromHitTestResult(
     visibility = HandleVisibility::kVisible;
   }
 
-  const VisibleSelectionInFlatTree& adjusted_selection =
+  const SelectionInFlatTree& adjusted_selection =
       append_trailing_whitespace == AppendTrailingWhitespace::kShouldAppend
-          ? new_selection.AppendTrailingWhitespace()
-          : new_selection;
+          ? AdjustSelectionWithTrailingWhitespace(new_selection.AsSelection())
+          : new_selection.AsSelection();
 
   return UpdateSelectionForMouseDownDispatchingSelectStart(
       inner_node,
-      ExpandSelectionToRespectUserSelectAll(inner_node,
-                                            adjusted_selection.AsSelection()),
+      ExpandSelectionToRespectUserSelectAll(inner_node, adjusted_selection),
       TextGranularity::kWord, visibility);
 }
 
@@ -608,14 +607,13 @@ void SelectionController::SelectClosestMisspellingFromHitTestResult(
   const PositionInFlatTree end(container_node, marker->EndOffset());
   const VisibleSelectionInFlatTree& new_selection = CreateVisibleSelection(
       SelectionInFlatTree::Builder().Collapse(start).Extend(end).Build());
-  const VisibleSelectionInFlatTree& adjusted_selection =
+  const SelectionInFlatTree& adjusted_selection =
       append_trailing_whitespace == AppendTrailingWhitespace::kShouldAppend
-          ? new_selection.AppendTrailingWhitespace()
-          : new_selection;
+          ? AdjustSelectionWithTrailingWhitespace(new_selection.AsSelection())
+          : new_selection.AsSelection();
   UpdateSelectionForMouseDownDispatchingSelectStart(
       inner_node,
-      ExpandSelectionToRespectUserSelectAll(inner_node,
-                                            adjusted_selection.AsSelection()),
+      ExpandSelectionToRespectUserSelectAll(inner_node, adjusted_selection),
       TextGranularity::kWord, HandleVisibility::kNotVisible);
 }
 

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

@@ -210,22 +210,30 @@ VisibleSelectionTemplate<Strategy>::ToNormalizedEphemeralRange() const {
   return NormalizeRange(EphemeralRangeTemplate<Strategy>(Start(), End()));
 }
 
-template <typename Strategy>
-VisibleSelectionTemplate<Strategy>
-VisibleSelectionTemplate<Strategy>::AppendTrailingWhitespace() const {
-  if (IsNone())
-    return *this;
-  if (!IsRange())
-    return *this;
-  const PositionTemplate<Strategy>& new_end = SkipWhitespace(End());
-  if (End() == new_end)
-    return *this;
-  VisibleSelectionTemplate<Strategy> result = *this;
-  if (base_is_first_)
-    result.extent_ = new_end;
-  else
-    result.base_ = new_end;
-  return result;
+// TODO(editing-dev): We should move |AdjustSelectionWithTrailingWhitespace()|
+// to "SelectionController.cpp" as file local function.
+SelectionInFlatTree AdjustSelectionWithTrailingWhitespace(
+    const SelectionInFlatTree& selection) {
+  if (selection.IsNone())
+    return selection;
+  if (!selection.IsRange())
+    return selection;
+  const bool base_is_first =
+      selection.Base() == selection.ComputeStartPosition();
+  const PositionInFlatTree& end =
+      base_is_first ? selection.Extent() : selection.Base();
+  DCHECK_EQ(end, selection.ComputeEndPosition());
+  const PositionInFlatTree& new_end = SkipWhitespace(end);
+  if (end == new_end)
+    return selection;
+  if (base_is_first) {
+    return SelectionInFlatTree::Builder(selection)
+        .SetBaseAndExtent(selection.Base(), new_end)
+        .Build();
+  }
+  return SelectionInFlatTree::Builder(selection)
+      .SetBaseAndExtent(new_end, selection.Extent())
+      .Build();
 }
 
 template <typename Strategy>

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

@@ -106,8 +106,6 @@ class CORE_TEMPLATE_CLASS_EXPORT VisibleSelectionTemplate {
   bool IsBaseFirst() const { return base_is_first_; }
   bool IsDirectional() const { return is_directional_; }
 
-  VisibleSelectionTemplate<Strategy> AppendTrailingWhitespace() const;
-
   // TODO(yosin) Most callers probably don't want these functions, but
   // are using them for historical reasons. |toNormalizedEphemeralRange()|
   // contracts the range around text, and moves the caret most backward
@@ -199,6 +197,11 @@ PositionInFlatTree ComputeEndRespectingGranularity(
     const PositionInFlatTreeWithAffinity&,
     TextGranularity);
 
+// TODO(editing-dev): We should move |AdjustSelectionWithTrailingWhitespace()|
+// to "SelectionController.cpp" as file local function.
+CORE_EXPORT SelectionInFlatTree
+AdjustSelectionWithTrailingWhitespace(const SelectionInFlatTree&);
+
 }  // namespace blink
 
 #ifndef NDEBUG

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

@@ -71,8 +71,9 @@ VisibleSelectionTemplate<Strategy> ExpandUsingGranularity(
       granularity);
 }
 
+// TODO(editing-dev): We should move this test to "SelectionControllerTest.cpp"
 // For http://crbug.com/700368
-TEST_F(VisibleSelectionTest, appendTrailingWhitespaceWithAfterAnchor) {
+TEST_F(VisibleSelectionTest, AdjustSelectionWithTrailingWhitespace) {
   SetBodyContent(
       "<input type=checkbox>"
       "<div style='user-select:none'>abc</div>");
@@ -82,16 +83,19 @@ TEST_F(VisibleSelectionTest, appendTrailingWhitespaceWithAfterAnchor) {
   // TODO(editing-dev): We should remove above comment once we fix [1].
   // [1] http://crbug.com/701657 double-click on user-select:none should not
   // compute selection.
-  const VisibleSelection selection = CreateVisibleSelectionWithGranularity(
-      SelectionInDOMTree::Builder()
-          .Collapse(Position::BeforeNode(*input))
-          .Extend(Position::AfterNode(*input))
+  const VisibleSelectionInFlatTree& selection =
+      CreateVisibleSelectionWithGranularity(
+          SelectionInFlatTree::Builder()
+              .Collapse(PositionInFlatTree::BeforeNode(*input))
+              .Extend(PositionInFlatTree::AfterNode(*input))
               .Build(),
           TextGranularity::kWord);
-  const VisibleSelection result = selection.AppendTrailingWhitespace();
+  const SelectionInFlatTree& result =
+      AdjustSelectionWithTrailingWhitespace(selection.AsSelection());
 
-  EXPECT_EQ(Position::BeforeNode(*input), result.Start());
-  EXPECT_EQ(Position::AfterNode(*input), result.End());
+  EXPECT_EQ(PositionInFlatTree::BeforeNode(*input),
+            result.ComputeStartPosition());
+  EXPECT_EQ(PositionInFlatTree::AfterNode(*input), result.ComputeEndPosition());
 }
 
 TEST_F(VisibleSelectionTest, expandUsingGranularity) {