Update text field 'change' event logic to match to Firefox.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 56 matching lines @@
               doc.frame()
                   ->editor()
                   .behavior()
                   .shouldConsiderSelectionAsDirectional()
           ? SelectionHasForwardDirection
           : SelectionHasNoDirection;
 }
 
 TextControlElement::~TextControlElement() {}
 
-Node::InsertionNotificationRequest TextControlElement::insertedInto(
-    ContainerNode* insertionPoint) {
-  HTMLFormControlElementWithState::insertedInto(insertionPoint);
-  if (!insertionPoint->isConnected())
-    return InsertionDone;
-  String initialValue = value();
-  setTextAsOfLastFormControlChangeEvent(initialValue.isNull() ? emptyString
-                                                              : initialValue);
-  return InsertionDone;
-}
-
 void TextControlElement::dispatchFocusEvent(
     Element* oldFocusedElement,
     WebFocusType type,
     InputDeviceCapabilities* sourceCapabilities) {
   if (supportsPlaceholder())
     updatePlaceholderVisibility();
   handleFocusEvent(oldFocusedElement, type);
   HTMLFormControlElementWithState::dispatchFocusEvent(oldFocusedElement, type,
                                                       sourceCapabilities);
 }
@@ skipping 99 matching lines @@
 }
 
 void TextControlElement::select() {
   setSelectionRangeForBinding(0, std::numeric_limits<unsigned>::max());
   // Avoid SelectionBehaviorOnFocus::Restore, which scrolls containers to show
   // the selection.
   focus(FocusParams(SelectionBehaviorOnFocus::None, WebFocusTypeNone, nullptr));
   restoreCachedSelection();
 }
 
-void TextControlElement::setChangedSinceLastFormControlChangeEvent(
-    bool changed) {
-  m_wasChangedSinceLastFormControlChangeEvent = changed;
+void TextControlElement::setValueBeforeFirstUserEditIfNotSet() {
+  if (!m_valueBeforeFirstUserEdit.isNull())
+    return;
+  String value = this->value();
+  m_valueBeforeFirstUserEdit = value.isNull() ? emptyString : value;
+}
+
+void TextControlElement::checkIfValueWasReverted(const String& value) {
+  DCHECK(!m_valueBeforeFirstUserEdit.isNull())
+      << "setValueBeforeFirstUserEditIfNotSet should be called beforehand.";
+  String nonNullValue = value.isNull() ? emptyString : value;
+  if (m_valueBeforeFirstUserEdit == nonNullValue)
+    clearValueBeforeFirstUserEdit();
+}
+
+void TextControlElement::clearValueBeforeFirstUserEdit() {
+  m_valueBeforeFirstUserEdit = String();
 }
 
 void TextControlElement::setFocused(bool flag) {
   HTMLFormControlElementWithState::setFocused(flag);
 
-  if (!flag) {
-    if (wasChangedSinceLastFormControlChangeEvent()) {
-      dispatchFormControlChangeEvent();
-    } else {
-      // |value| IDL attribute setter haven't updated
-      // textAsOfLastFormControlChangeEvent while this is focused. So we
-      // synchronize now.
-      setTextAsOfLastFormControlChangeEvent(value());
-    }
-  }
+  if (!flag)
+    dispatchFormControlChangeEvent();
 }
 
 bool TextControlElement::shouldDispatchFormControlChangeEvent(
     String& oldValue,
     String& newValue) {
   return !equalIgnoringNullity(oldValue, newValue);
 }
 
 void TextControlElement::dispatchFormControlChangeEvent() {
   String newValue = value();
-  if (shouldDispatchFormControlChangeEvent(m_textAsOfLastFormControlChangeEvent,
+  if (!m_valueBeforeFirstUserEdit.isNull() &&
+      shouldDispatchFormControlChangeEvent(m_valueBeforeFirstUserEdit,
                                            newValue)) {
-    setTextAsOfLastFormControlChangeEvent(newValue);
+    clearValueBeforeFirstUserEdit();
     dispatchChangeEvent();
+  } else {
+    clearValueBeforeFirstUserEdit();
   }
-  setChangedSinceLastFormControlChangeEvent(false);
 }
 
 void TextControlElement::enqueueChangeEvent() {
   String newValue = value();
-  if (shouldDispatchFormControlChangeEvent(m_textAsOfLastFormControlChangeEvent,
+  if (!m_valueBeforeFirstUserEdit.isNull() &&
+      shouldDispatchFormControlChangeEvent(m_valueBeforeFirstUserEdit,
                                            newValue)) {
-    setTextAsOfLastFormControlChangeEvent(newValue);
     Event* event = Event::createBubble(EventTypeNames::change);
     event->setTarget(this);
     document().enqueueAnimationFrameEvent(event);
   }
-  setChangedSinceLastFormControlChangeEvent(false);
+  clearValueBeforeFirstUserEdit();
 }
 
+// TODO(tkent): Remove this function.
 void TextControlElement::dispatchFormControlInputEvent() {
-  setChangedSinceLastFormControlChangeEvent(true);
   HTMLFormControlElementWithState::dispatchInputEvent();
 }
 
 void TextControlElement::setRangeText(const String& replacement,
                                       ExceptionState& exceptionState) {
   setRangeText(replacement, selectionStart(), selectionEnd(), "preserve",
                exceptionState);
 }
 
 void TextControlElement::setRangeText(const String& replacement,
@@ skipping 704 matching lines @@
 
 void TextControlElement::copyNonAttributePropertiesFromElement(
     const Element& source) {
   const TextControlElement& sourceElement =
       static_cast<const TextControlElement&>(source);
   m_lastChangeWasUserEdit = sourceElement.m_lastChangeWasUserEdit;
   HTMLFormControlElement::copyNonAttributePropertiesFromElement(source);
 }
 
 }  // namespace blink