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

third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Igalia S.L.
  *
  * 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.
@@ skipping 86 matching lines @@
         std::begin(kCommandNameEntries), std::end(kCommandNameEntries), commandName,
         [](const CommandNameEntry& entry, const String& needle)
         {
             return codePointCompareIgnoringASCIICase(needle, entry.name) > 0;
         });
     if (result != std::end(kCommandNameEntries) && codePointCompareIgnoringASCIICase(commandName, result->name) == 0)
         return result->type;
     return WebEditingCommandType::Invalid;
 }
 
+InputEvent::InputType InputTypeFromCommandType(WebEditingCommandType commandType)
+{
+    switch (commandType) {
+    case WebEditingCommandType::Delete:
+    case WebEditingCommandType::DeleteBackward:
+    case WebEditingCommandType::DeleteBackwardByDecomposingPreviousCharacter:
+    case WebEditingCommandType::DeleteForward:
+    case WebEditingCommandType::DeleteToBeginningOfLine:
+    case WebEditingCommandType::DeleteToBeginningOfParagraph:
+    case WebEditingCommandType::DeleteToEndOfLine:
+    case WebEditingCommandType::DeleteToEndOfParagraph:
+    case WebEditingCommandType::DeleteToMark:
+    case WebEditingCommandType::DeleteWordBackward:
+    case WebEditingCommandType::DeleteWordForward:
+        return InputEvent::InputType::DeleteContent;
+    case WebEditingCommandType::Redo:
+        return InputEvent::InputType::Redo;
+    case WebEditingCommandType::Undo:
+        return InputEvent::InputType::Undo;
+    case WebEditingCommandType::InsertBacktab:
+    case WebEditingCommandType::InsertHTML:
+    case WebEditingCommandType::InsertHorizontalRule:
+    case WebEditingCommandType::InsertImage:
+    case WebEditingCommandType::InsertLineBreak:
+    case WebEditingCommandType::InsertNewline:
+    case WebEditingCommandType::InsertNewlineInQuotedContent:
+    case WebEditingCommandType::InsertOrderedList:
+    case WebEditingCommandType::InsertParagraph:
+    case WebEditingCommandType::InsertTab:
+    case WebEditingCommandType::InsertText:
+    case WebEditingCommandType::InsertUnorderedList:
+        return InputEvent::InputType::InsertText;

[ojan, 2016/04/16 00:11:45]

I think InsertText and InsertHTML should be two separate values. All of the
above are InserHTML except InsertBacktab and InsertText. Although, I'm not sure
exactly what InsertLineBreak, InsertNewline and InsertNewlineInQuotedContent
(i.e. whether they insert HTML or just raw text).

[chongz, 2016/04/18 22:54:47]

The spec (http://w3c.github.io/editing/input-events.html) haven't mentioned
|InsertHTML| yet... Will only support |InsertText| in this patch and doing some
research about |InsertHTML|. 

[chongz, 2016/04/19 21:17:01]

Actually according to https://github.com/w3c/editing/issues/124 |replaceContent|
(or probably better rename to |insertContent|?) looks very similar to
|insertHTML|, if they are the same thing I will add support in another CL. 

+    default:
+        return InputEvent::InputType::None;
+    }
+}
+
 } // anonymous namespace
 
 class EditorInternalCommand {
 public:
     WebEditingCommandType commandType;
     bool (*execute)(LocalFrame&, Event*, EditorCommandSource, const String&);
     bool (*isSupportedFromDOM)(LocalFrame*);
     bool (*isEnabled)(LocalFrame&, Event*, EditorCommandSource);
     TriState (*state)(LocalFrame&, Event*);
     String (*value)(LocalFrame&, Event*);
@@ skipping 1627 matching lines @@
 {
     // TODO(yosin) We should move this logic into |canExecute()| member function
     // in |EditorInternalCommand| to replace |allowExecutionWhenDisabled|.
     // |allowExecutionWhenDisabled| is for "Copy", "Cut" and "Paste" commands
     // only.
     if (!isEnabled(triggeringEvent)) {
         // Let certain commands be executed when performed explicitly even if they are disabled.
         if (!isSupported() || !m_frame || !m_command->allowExecutionWhenDisabled)
             return false;
     }
+
+    if (m_source == CommandFromMenuOrKeyBinding) {
+        InputEvent::InputType inputType = InputTypeFromCommandType(m_command->commandType);
+        if (inputType != InputEvent::InputType::None) {
+            if (dispatchBeforeInputEditorCommand(eventTargetNodeForDocument(m_frame->document()), inputType) != DispatchEventResult::NotCanceled)
+                return true;
+        }
+    }
+
+    // 'beforeinput' event handler may destroy |frame()|.
+    if (!m_frame || !frame().document())
+        return false;
+
     frame().document()->updateLayoutIgnorePendingStylesheets();
     DEFINE_STATIC_LOCAL(SparseHistogram, commandHistogram, ("WebCore.Editing.Commands"));
     commandHistogram.sample(static_cast<int>(m_command->commandType));
     return m_command->execute(*m_frame, triggeringEvent, m_source, parameter);
 }
 
 bool Editor::Command::execute(Event* triggeringEvent) const
 {
     return execute(String(), triggeringEvent);
 }
@@ skipping 39 matching lines @@
 {
     return m_command && m_command->isTextInsertion;
 }
 
 int Editor::Command::idForHistogram() const
 {
     return isSupported() ? static_cast<int>(m_command->commandType) : 0;
 }
 
 } // namespace blink