[InputEvent] Fire 'beforeinput' during typing, pressing hot keys and IME composition

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 16 matching lines @@
 #include "core/editing/InputMethodController.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/Text.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/Editor.h"
 #include "core/editing/commands/TypingCommand.h"
 #include "core/editing/markers/DocumentMarkerController.h"
 #include "core/events/CompositionEvent.h"
+#include "core/events/InputEvent.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLTextAreaElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutObject.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/page/ChromeClient.h"
 
 namespace blink {
 
 InputMethodController::SelectionOffsetsScope::SelectionOffsetsScope(InputMethodController* inputMethodController)
@@ skipping 102 matching lines @@
         clear();
         return true;
     }
 
     // Select the text that will be deleted or replaced.
     selectComposition();
 
     if (frame().selection().isNone())
         return false;
 
+    if (RuntimeEnabledFeatures::inputEventEnabled()) {

[dtapuska, 2016/03/01 21:49:51]

This seems to be a repeated pattern in this class. Can we use an anonymous
function?

+        if (Element* target = frame().document()->focusedElement()) {
+            // Dispatch 'beforeinput' before CompositionEvent
+            RefPtrWillBeRawPtr<InputEvent> beforeInputEvent = InputEvent::createBeforeInput("insertText", text);

[chongz, 2016/03/01 20:41:10]

https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand#Commands
doesn't have something like 'replaceText', or should it just be 'insertText'
with a range?

+            DispatchEventResult dispatchResult = target->dispatchEvent(beforeInputEvent);
+            if (dispatchResult != DispatchEventResult::NotCanceled)
+                return false;
+        }
+    }
+
     dispatchCompositionEndEvent(frame(), text);
 
     if (!frame().document())
         return false;
 
     // If text is empty, then delete the old composition here. If text is
     // non-empty, InsertTextCommand::input will delete the old composition with
     // an optimized replace operation.
     if (text.isEmpty())
         TypingCommand::deleteSelection(*frame().document(), 0);
 
     clear();
 
     insertTextForConfirmedComposition(text);
 
     return true;
 }
 
 bool InputMethodController::confirmCompositionOrInsertText(const String& text, ConfirmCompositionBehavior confirmBehavior)
 {
     if (!hasComposition()) {
         if (!text.length())
             return false;
+
+        if (RuntimeEnabledFeatures::inputEventEnabled()) {
+            if (Element* target = frame().document()->focusedElement()) {
+                // Dispatch 'beforeinput' before insertText
+                RefPtrWillBeRawPtr<InputEvent> beforeInputEvent = InputEvent::createBeforeInput("insertText", text);
+                DispatchEventResult dispatchResult = target->dispatchEvent(beforeInputEvent);
+                if (dispatchResult != DispatchEventResult::NotCanceled)
+                    return false;
+            }
+        }
         editor().insertText(text, 0);
         return true;
     }
 
     if (text.length()) {
         confirmComposition(text);
         return true;
     }
 
     if (confirmBehavior != KeepSelection)
@@ skipping 47 matching lines @@
     // inserting the previous composition text into text nodes oddly.
     // See https://bugs.webkit.org/show_bug.cgi?id=46868
     frame().document()->updateLayoutTree();
 
     selectComposition();
 
     if (frame().selection().isNone())
         return;
 
     if (Element* target = frame().document()->focusedElement()) {
+        if (RuntimeEnabledFeatures::inputEventEnabled()) {
+            // Dispatch 'beforeinput' before CompositionEvent
+            RefPtrWillBeRawPtr<InputEvent> beforeInputEvent = InputEvent::createBeforeInput("replaceContent", text);

[chongz, 2016/03/01 20:41:10]

'replaceContent' is mentioned here
http://w3c.github.io/editing/input-events.html#widl-InputEvent-inputType
Not sure which one I should use.

[dtapuska, 2016/03/01 21:49:51]

Let us leave it with replace text for now and see what the spec comes up as.

+            DispatchEventResult dispatchResult = target->dispatchEvent(beforeInputEvent);
+            if (dispatchResult != DispatchEventResult::NotCanceled)
+                return;
+        }
+
         // Dispatch an appropriate composition event to the focused node.
         // We check the composition status and choose an appropriate composition event since this
         // function is used for three purposes:
         // 1. Starting a new composition.
         //    Send a compositionstart and a compositionupdate event when this function creates
         //    a new composition node, i.e.
         //    !hasComposition() && !text.isEmpty().
         //    Sending a compositionupdate event at this time ensures that at least one
         //    compositionupdate event is dispatched.
         // 2. Updating the existing composition node.
@@ skipping 194 matching lines @@
     TypingCommand::deleteSelection(*frame().document());
 }
 
 DEFINE_TRACE(InputMethodController)
 {
     visitor->trace(m_frame);
     visitor->trace(m_compositionRange);
 }
 
 } // namespace blink