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

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

 /*
  * Copyright (C) 2005, 2006, 2007, 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 169 matching lines @@
   UndoStep::trace(visitor);
 }
 
 CompositeEditCommand::CompositeEditCommand(Document& document)
     : EditCommand(document) {}
 
 CompositeEditCommand::~CompositeEditCommand() {
   DCHECK(isTopLevelCommand() || !m_composition);
 }
 
-// TODO(chongz): Fire 'beforeinput' based on |EditCommandSource|.
-bool CompositeEditCommand::apply(EditCommandSource) {
+bool CompositeEditCommand::apply(EditCommandSource source) {
   DCHECK(!isCommandGroupWrapper());
   if (!endingSelection().isContentRichlyEditable()) {
     switch (inputType()) {
       case InputEvent::InputType::InsertText:
       case InputEvent::InputType::InsertLineBreak:
       case InputEvent::InputType::InsertParagraph:
       case InputEvent::InputType::InsertFromPaste:
       case InputEvent::InputType::InsertFromDrop:
       case InputEvent::InputType::InsertReplacementText:
       case InputEvent::InputType::DeleteComposedCharacterForward:
@@ skipping 15 matching lines @@
   }
   ensureComposition();
 
   // Changes to the document may have been made since the last editing operation
   // that require a layout, as in <rdar://problem/5658603>. Low level
   // operations, like RemoveNodeCommand, don't require a layout because the high
   // level operations that use them perform one if one is necessary (like for
   // the creation of VisiblePositions).
   document().updateStyleAndLayoutIgnorePendingStylesheets();
 
+  if (!willApply(source))
+    return false;
+
   LocalFrame* frame = document().frame();
   DCHECK(frame);
   EditingState editingState;
   {
     EventQueueScope eventQueueScope;
     doApply(&editingState);
   }
 
   // Only need to call appliedEditing for top-level commands, and TypingCommands
   // do it on their own (see TypingCommand::typingAddedToOpenCommand).
   if (!isTypingCommand())
     frame->editor().appliedEditing(this);
   setShouldRetainAutocorrectionIndicator(false);
   return !editingState.isAborted();
 }
 
 EditCommandComposition* CompositeEditCommand::ensureComposition() {
   CompositeEditCommand* command = this;
   while (command && command->parent())
     command = command->parent();
   if (!command->m_composition)
     command->m_composition = EditCommandComposition::create(
         &document(), startingSelection(), endingSelection(), inputType());
   return command->m_composition.get();
 }
 
+bool CompositeEditCommand::willApply(EditCommandSource source) {
+  return willApplyEditing(source);

[tkent, 2016/12/19 03:43:24]

What's the difference between willApply() and willApplyEditing()?

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

The reason is both |TypingCommand::willAddTypingToOpenCommand()| and
|CompositeEditCommand::willApply()| should fire 'beforeinput', and these code
could be shared.

Having |CompositeEditCommand::willApplyEditing()| and put 'beforeinput' logic
here could make the logic cleaner. Also later we could move
|Editor::appliedEditing()| to |CompositeEditCommand::appliedEditing()|, so it
would be consistent with |willApplyEditing()|.

Also see comments in "CompositeEditCommand.h".

[tkent, 2016/12/19 08:22:18]

It didn't convince me.

Why CompositeEditCommand::apply() doesn't call willApplyEditing() directly? 
Will you add more code to willApply()?

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

Oh I got what you mean. Yeah we don't need |willApply()| for now and we should
only add it later if we really need it.
Removed |willApply()| and uses |willApplyEditing()| directly.

+}
+
+bool CompositeEditCommand::willApplyEditing(EditCommandSource) {
+  // TODO(chongz): Move all the 'beforeinput' dispatching logic here.
+  return true;
+}
+
 bool CompositeEditCommand::preservesTypingStyle() const {
   return false;
 }
 
 bool CompositeEditCommand::isTypingCommand() const {
   return false;
 }
 
 bool CompositeEditCommand::isCommandGroupWrapper() const {
   return false;
@@ skipping 1767 matching lines @@
   return node;
 }
 
 DEFINE_TRACE(CompositeEditCommand) {
   visitor->trace(m_commands);
   visitor->trace(m_composition);
   EditCommand::trace(visitor);
 }
 
 }  // namespace blink