Introduce enum class SetSelectionBy as replacement of enum EUserTriggered

This patch introduces enum class |SetSelectionBy| as replacement of
|EUserTriggered| to allow forward declaration for preparation of the patch[1].

It is done by almost mechanical changes:
 - s/kUserTriggered/SetSelectionBy::kUser/
 - s/kNotUserTriggered/SetSelectionBy::kSystem/

This patch also introduces
 - ConvertSelectionOptionsToSetSelectionBy()
 - ConvertSetSelectionByToSetSelectionOptions()
as |constexpr| instead of |static inline| to utilize C++11 feature and
to avoid |static_cast<>| for improving readability.

[1] http://crrev.com/c/569662: Introduce SetSelectionData for

FrameSelection: :SetSelection()
Change-Id: Ib2f5a1dd942f820cd74ea90c37f9243b93336904
Reviewed-on: https://chromium-review.googlesource.com/579027Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488575}

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

@@ -270,9 +270,10 @@ void FrameSelection::DidSetSelectionDeprecated(SetSelectionOptions options,
     }
   }
 
-  EUserTriggered user_triggered = SelectionOptionsToUserTriggered(options);
-  NotifyTextControlOfSelectionChange(user_triggered);
-  if (user_triggered == kUserTriggered) {
+  SetSelectionBy set_selection_by =
+      ConvertSelectionOptionsToSetSelectionBy(options);
+  NotifyTextControlOfSelectionChange(set_selection_by);
+  if (set_selection_by == SetSelectionBy::kUser) {
     ScrollAlignment alignment;
 
     if (frame_->GetEditor()
@@ -343,13 +344,13 @@ static DispatchEventResult DispatchSelectStart(
 bool FrameSelection::Modify(SelectionModifyAlteration alter,
                             SelectionDirection direction,
                             TextGranularity granularity,
-                            EUserTriggered user_triggered) {
+                            SetSelectionBy set_selection_by) {
   SelectionModifier selection_modifier(*GetFrame(),
                                        ComputeVisibleSelectionInDOMTree(),
                                        x_pos_for_vertical_arrow_navigation_);
   const bool modified =
       selection_modifier.Modify(alter, direction, granularity);
-  if (user_triggered == kUserTriggered &&
+  if (set_selection_by == SetSelectionBy::kUser &&
       selection_modifier.Selection().IsRange() &&
       ComputeVisibleSelectionInDOMTree().IsCaret() &&
       DispatchSelectStart(ComputeVisibleSelectionInDOMTree()) !=
@@ -357,7 +358,7 @@ bool FrameSelection::Modify(SelectionModifyAlteration alter,
     return false;
   }
   if (!modified) {
-    if (user_triggered == kNotUserTriggered)
+    if (set_selection_by == SetSelectionBy::kSystem)
       return false;
     // If spatial navigation enabled, focus navigator will move focus to
     // another element. See snav-input.html and snav-textarea.html
@@ -369,7 +370,8 @@ bool FrameSelection::Modify(SelectionModifyAlteration alter,
   }
 
   const SetSelectionOptions options =
-      kCloseTyping | kClearTypingStyle | user_triggered;
+      kCloseTyping | kClearTypingStyle |
+      ConvertSetSelectionByToSetSelectionOptions(set_selection_by);
   SetSelection(selection_modifier.Selection().AsSelection(), options);
 
   if (granularity == TextGranularity::kLine ||
@@ -377,7 +379,7 @@ bool FrameSelection::Modify(SelectionModifyAlteration alter,
     x_pos_for_vertical_arrow_navigation_ =
         selection_modifier.XPosForVerticalArrowNavigation();
 
-  if (user_triggered == kUserTriggered)
+  if (set_selection_by == SetSelectionBy::kUser)
     granularity_ = TextGranularity::kCharacter;
 
   ScheduleVisualUpdateForPaintInvalidationIfNeeded();
@@ -631,7 +633,7 @@ static Node* NonBoundaryShadowTreeRootNode(const Position& position) {
              : nullptr;
 }
 
-void FrameSelection::SelectAll(EUserTriggered user_triggered) {
+void FrameSelection::SelectAll(SetSelectionBy set_selection_by) {
   if (isHTMLSelectElement(GetDocument().FocusedElement())) {
     HTMLSelectElement* select_element =
         toHTMLSelectElement(GetDocument().FocusedElement());
@@ -643,7 +645,7 @@ void FrameSelection::SelectAll(EUserTriggered user_triggered) {
 
   Node* root = nullptr;
   Node* select_start_target = nullptr;
-  if (user_triggered == kUserTriggered && IsHidden()) {
+  if (set_selection_by == SetSelectionBy::kUser && IsHidden()) {
     // Hidden selection appears as no selection to user, in which case user-
     // triggered SelectAll should act as if there is no selection.
     root = GetDocument().documentElement();
@@ -683,14 +685,14 @@ void FrameSelection::SelectAll(EUserTriggered user_triggered) {
       return;
   }
 
-  // TODO(editing-dev): Should we pass in user_triggered?
+  // TODO(editing-dev): Should we pass in set_selection_by?
   SetSelection(SelectionInDOMTree::Builder()
                    .SelectAllChildren(*root)
                    .SetIsHandleVisible(IsHandleVisible())
                    .Build());
   SelectFrameElementInParentIfFullySelected();
-  // TODO(editing-dev): Should we pass in user_triggered?
-  NotifyTextControlOfSelectionChange(kUserTriggered);
+  // TODO(editing-dev): Should we pass in set_selection_by?
+  NotifyTextControlOfSelectionChange(SetSelectionBy::kUser);
   if (IsHandleVisible()) {
     ContextMenuAllowedScope scope;
     frame_->GetEventHandler().ShowNonLocatedContextMenu(nullptr,
@@ -811,12 +813,12 @@ void FrameSelection::UpdateAppearance() {
 }
 
 void FrameSelection::NotifyTextControlOfSelectionChange(
-    EUserTriggered user_triggered) {
+    SetSelectionBy set_selection_by) {
   TextControlElement* text_control =
       EnclosingTextControl(GetSelectionInDOMTree().Base());
   if (!text_control)
     return;
-  text_control->SelectionChanged(user_triggered == kUserTriggered);
+  text_control->SelectionChanged(set_selection_by == SetSelectionBy::kUser);
 }
 
 // Helper function that tells whether a particular node is an element that has

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

@@ -56,7 +56,7 @@ struct PaintInvalidatorContext;
 
 enum class CursorAlignOnScroll { kIfNeeded, kAlways };
 
-enum EUserTriggered { kNotUserTriggered = 0, kUserTriggered = 1 };
+enum class SetSelectionBy { kSystem = 0, kUser = 1 };
 
 enum RevealExtentOption { kRevealExtent, kDoNotRevealExtent };
 
@@ -77,17 +77,25 @@ class CORE_EXPORT FrameSelection final
   ~FrameSelection();
 
   enum SetSelectionOption {
-    // 1 << 0 is reserved for EUserTriggered
+    kUserTriggered = 1,
     kCloseTyping = 1 << 1,
     kClearTypingStyle = 1 << 2,
     kDoNotSetFocus = 1 << 3,
     kDoNotClearStrategy = 1 << 4,
   };
-  // Union of values in SetSelectionOption and EUserTriggered
+  static_assert(kUserTriggered == static_cast<int>(SetSelectionBy::kUser),
+                "|kUserTriggered| should equal to |SetSelectionBy::kUser|");
+
+  // Union of values in SetSelectionOption and SetSelectionBy
   typedef unsigned SetSelectionOptions;
-  static inline EUserTriggered SelectionOptionsToUserTriggered(
+  static constexpr SetSelectionBy ConvertSelectionOptionsToSetSelectionBy(
       SetSelectionOptions options) {
-    return static_cast<EUserTriggered>(options & kUserTriggered);
+    return static_cast<SetSelectionBy>(options &
+                                       static_cast<int>(SetSelectionBy::kUser));
+  }
+  static constexpr SetSelectionOptions
+  ConvertSetSelectionByToSetSelectionOptions(SetSelectionBy set_selection_by) {
+    return static_cast<SetSelectionOptions>(set_selection_by);
   }
 
   bool IsAvailable() const { return LifecycleContext(); }
@@ -112,7 +120,7 @@ class CORE_EXPORT FrameSelection final
                     SetSelectionOptions = kCloseTyping | kClearTypingStyle,
                     CursorAlignOnScroll = CursorAlignOnScroll::kIfNeeded,
                     TextGranularity = TextGranularity::kCharacter);
-  void SelectAll(EUserTriggered = kNotUserTriggered);
+  void SelectAll(SetSelectionBy = SetSelectionBy::kSystem);
   void Clear();
   bool IsHidden() const;
 
@@ -138,7 +146,7 @@ class CORE_EXPORT FrameSelection final
   bool Modify(SelectionModifyAlteration,
               SelectionDirection,
               TextGranularity,
-              EUserTriggered = kNotUserTriggered);
+              SetSelectionBy = SetSelectionBy::kSystem);
 
   // Moves the selection extent based on the selection granularity strategy.
   // This function does not allow the selection to collapse. If the new
@@ -205,7 +213,7 @@ class CORE_EXPORT FrameSelection final
 #endif
 
   void SetFocusedNodeIfNeeded();
-  void NotifyTextControlOfSelectionChange(EUserTriggered);
+  void NotifyTextControlOfSelectionChange(SetSelectionBy);
 
   String SelectedHTMLForClipboard() const;
   String SelectedText(const TextIteratorBehavior&) const;

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

@@ -190,7 +190,7 @@ TEST_F(FrameSelectionTest, ModifyWithUserTriggered) {
 
   EXPECT_FALSE(
       Selection().Modify(SelectionModifyAlteration::kMove, kDirectionForward,
-                         TextGranularity::kCharacter, kNotUserTriggered))
+                         TextGranularity::kCharacter, SetSelectionBy::kSystem))
       << "Selection.modify() returns false for non-user-triggered call when "
          "selection isn't modified.";
   EXPECT_EQ(end_of_text,
@@ -199,7 +199,7 @@ TEST_F(FrameSelectionTest, ModifyWithUserTriggered) {
 
   EXPECT_TRUE(Selection().Modify(SelectionModifyAlteration::kMove,
                                  kDirectionForward, TextGranularity::kCharacter,
-                                 kUserTriggered))
+                                 SetSelectionBy::kUser))
       << "Selection.modify() returns true for user-triggered call";
   EXPECT_EQ(end_of_text,
             Selection().ComputeVisibleSelectionInDOMTreeDeprecated().Start())

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

@@ -1023,7 +1023,7 @@ bool SelectionController::HandleMouseReleaseEvent(
     handled = true;
   }
 
-  Selection().NotifyTextControlOfSelectionChange(kUserTriggered);
+  Selection().NotifyTextControlOfSelectionChange(SetSelectionBy::kUser);
 
   Selection().SelectFrameElementInParentIfFullySelected();
 

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

@@ -1209,13 +1209,15 @@ void WebLocalFrameImpl::SelectRange(
       handle_visibility_behavior == kShowSelectionHandle ||
       (handle_visibility_behavior == kPreserveHandleVisibility &&
        selection.IsHandleVisible());
-  selection.SetSelection(SelectionInDOMTree::Builder()
+  selection.SetSelection(
+      SelectionInDOMTree::Builder()
           .SetBaseAndExtent(range)
           .SetAffinity(VP_DEFAULT_AFFINITY)
           .SetIsHandleVisible(show_handles)
           .SetIsDirectional(false)
           .Build(),
-                         kNotUserTriggered);
+      FrameSelection::ConvertSetSelectionByToSetSelectionOptions(
+          SetSelectionBy::kSystem));
 }
 
 WebString WebLocalFrameImpl::RangeAsText(const WebRange& web_range) {