[Editing] Introduce |CompositeEditCommand::willApplyEditing()| in prepare for 'beforeinput' (1/3)

third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h

 /*
  * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 100 matching lines @@
   virtual bool isDragAndDropCommand() const;
   virtual bool preservesTypingStyle() const;
   virtual void setShouldRetainAutocorrectionIndicator(bool);
   virtual bool shouldStopCaretBlinking() const { return false; }
 
   DECLARE_VIRTUAL_TRACE();
 
  protected:
   explicit CompositeEditCommand(Document&);
 
+  // Fires "beforeinput", returns |false| to cancel applying editing if
+  //   * "beforeinput" was canceled, or
+  //   * |frame| was destroyed by event handlers.
+  // |willApplyEditing()| should be called from
+  //   * |CompositeEditCommand::willApply()|, and
+  //   * |TypingCommand::willAddTypingToOpenCommand()|.
+  bool willApplyEditing(EditCommandSource);

[Xiaocheng, 2016/12/19 03:33:57]

Please add a TODO: implementation note here since this function is not really
firing beforeinput for now.

[chongz, 2016/12/19 06:48:57]

Will do.

[chongz, 2016/12/19 20:55:22]

Done.

+
   //
   // sugary-sweet convenience functions to help create and apply edit commands
   // in composite commands
   //
   void appendNode(Node*, ContainerNode* parent, EditingState*);
   void applyCommandToComposite(EditCommand*, EditingState*);
   void applyCommandToComposite(CompositeEditCommand*,
                                const VisibleSelection&,
                                EditingState*);
   void applyStyle(const EditingStyle*, EditingState*);
@@ skipping 127 matching lines @@
   bool breakOutOfEmptyMailBlockquotedParagraph(EditingState*);
 
   Position positionAvoidingSpecialElementBoundary(const Position&,
                                                   EditingState*);
 
   Node* splitTreeToNode(Node*, Node*, bool splitAncestor = false);
 
   HeapVector<Member<EditCommand>> m_commands;
 
  private:
+  // Returns |false| to cancel applying command.
+  bool willApply(EditCommandSource);
+
   bool isCompositeEditCommand() const final { return true; }
 
   Member<EditCommandComposition> m_composition;
 };
 
 DEFINE_TYPE_CASTS(CompositeEditCommand,
                   EditCommand,
                   command,
                   command->isCompositeEditCommand(),
                   command.isCompositeEditCommand());
 
 }  // namespace blink
 
 #endif  // CompositeEditCommand_h