INPUT/TEXTAREA elements: Dispatch 'select' event only if text selection is changed.

third_party/WebKit/Source/core/html/TextControlElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2009, 2010, 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 29 matching lines @@
   SelectionHasNoDirection,
   SelectionHasForwardDirection,
   SelectionHasBackwardDirection
 };
 enum TextFieldEventBehavior {
   DispatchNoEvent,
   DispatchChangeEvent,
   DispatchInputAndChangeEvent
 };
 
+enum class TextControlSetValueSelection {
+  kSetSelectionToEnd,

[yoichio, 2017/03/07 09:00:56]

Why do you use another coding style to above enums?

[tkent, 2017/03/07 09:27:34]

kFooBar is the standard naming convention.  FooBar style will be disappear soon.

+  kDoNotSet,
+};
+
 class CORE_EXPORT TextControlElement : public HTMLFormControlElementWithState {
  public:
   // Common flag for HTMLInputElement::tooLong(),
   // HTMLTextAreaElement::tooLong(),
   // HTMLInputElement::tooShort() and HTMLTextAreaElement::tooShort().
   enum NeedsToCheckDirtyFlag { CheckDirtyFlag, IgnoreDirtyFlag };
 
   ~TextControlElement() override;
 
   void forwardEvent(Event*);
@@ skipping 57 matching lines @@
   void setTextAsOfLastFormControlChangeEvent(const String& text) {
     m_textAsOfLastFormControlChangeEvent = text;
   }
   // A user has changed the value since the last 'change' event.
   bool wasChangedSinceLastFormControlChangeEvent() const {
     return m_wasChangedSinceLastFormControlChangeEvent;
   }
   void setChangedSinceLastFormControlChangeEvent(bool);
 
   virtual String value() const = 0;
-  virtual void setValue(const String&,
-                        TextFieldEventBehavior = DispatchNoEvent) = 0;
+  virtual void setValue(
+      const String&,
+      TextFieldEventBehavior = DispatchNoEvent,
+      TextControlSetValueSelection =
+          TextControlSetValueSelection::kSetSelectionToEnd) = 0;
 
   HTMLElement* innerEditorElement() const;
 
   void selectionChanged(bool userTriggered);
   bool lastChangeWasUserEdit() const;
   virtual void setInnerEditorValue(const String&);
   String innerEditorValue() const;
   Node* createPlaceholderBreakElement() const;
 
   String directionForFormData() const;
@@ skipping 14 matching lines @@
   void addPlaceholderBreakElementIfNecessary();
   String valueWithHardLineBreaks() const;
 
   virtual bool shouldDispatchFormControlChangeEvent(String&, String&);
   void copyNonAttributePropertiesFromElement(const Element&) override;
 
  private:
   unsigned computeSelectionStart() const;
   unsigned computeSelectionEnd() const;
   TextFieldSelectionDirection computeSelectionDirection() const;
-  void cacheSelection(unsigned start,
+  // Returns true if cached values and arguments are not same.
+  bool cacheSelection(unsigned start,
                       unsigned end,
-                      TextFieldSelectionDirection direction) {
-    DCHECK_LE(start, end);
-    m_cachedSelectionStart = start;
-    m_cachedSelectionEnd = end;
-    m_cachedSelectionDirection = direction;
-  }
+                      TextFieldSelectionDirection);
   static unsigned indexForPosition(HTMLElement* innerEditor, const Position&);
 
   void dispatchFocusEvent(Element* oldFocusedElement,
                           WebFocusType,
                           InputDeviceCapabilities* sourceCapabilities) final;
   void dispatchBlurEvent(Element* newFocusedElement,
                          WebFocusType,
                          InputDeviceCapabilities* sourceCapabilities) final;
   void scheduleSelectEvent();
 
@@ skipping 28 matching lines @@
 }
 
 DEFINE_HTMLELEMENT_TYPE_CASTS_WITH_FUNCTION(TextControlElement);
 
 TextControlElement* enclosingTextControl(const Position&);
 TextControlElement* enclosingTextControl(const Node*);
 
 }  // namespace blink
 
 #endif