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

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

Index: third_party/WebKit/Source/core/editing/InputMethodController.cpp
diff --git a/third_party/WebKit/Source/core/editing/InputMethodController.cpp b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
index e1d2f0fe18572803afa15c40bfe7af59a60e36ee..32cf130b55d1852dec8a93f32b5ec8b539db4006 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
@@ -172,6 +172,12 @@ bool InputMethodController::confirmComposition(const String& text, ConfirmCompos
 
     clear();
 
+    // According to spec 'beforeinput' should not be sent along with  CompositionEnd, so
+    // dispatch after CompositionEnd if there is any update.
+    // https://w3c.github.io/uievents/#h-events-composition-event-input-events
+    if (dispatchBeforeInputInsertText(frame().document()->focusedElement(), text) != DispatchEventResult::NotCanceled)
+        return false;
+
     insertTextForConfirmedComposition(text);
 
     return true;
@@ -182,6 +188,10 @@ bool InputMethodController::confirmCompositionOrInsertText(const String& text, C
     if (!hasComposition()) {
         if (!text.length())
             return false;
+
+        if (dispatchBeforeInputInsertText(frame().document()->focusedElement(), text) != DispatchEventResult::NotCanceled)
+            return false;
+
         editor().insertText(text, 0);
         return true;
     }
@@ -278,8 +288,12 @@ void InputMethodController::setComposition(const String& text, const Vector<Comp
             else
                 event = CompositionEvent::create(EventTypeNames::compositionend, frame().domWindow(), text);
         }
-        if (event)
+        if (event) {
+            // TODO(chongz): Support canceling IME composition.
+            if (event->type() == EventTypeNames::compositionupdate)
+                dispatchBeforeInputFromComposition(target, InputEvent::InputType::ReplaceContent, text);
             target->dispatchEvent(event);
+        }
     }
 
     // If text is empty, then delete the old composition here. If text is non-empty, InsertTextCommand::input
@@ -453,6 +467,8 @@ void InputMethodController::extendSelectionAndDelete(int before, int after)
             break;
         ++before;
     } while (frame().selection().start() == frame().selection().end() && before <= static_cast<int>(selectionOffsets.start()));
+    // TODO(chongz): According to spec |data| should be "forward" or "backward".
+    dispatchBeforeInputFromComposition(frame().document()->focusedElement(), InputEvent::InputType::DeleteComposedCharacter, "backward");

[chongz, 2016/04/13 00:34:28]

Not sure when will this code path get called...?

[yosin_UTC9, 2016/04/13 06:13:09]

Backspace emulation? Or, Thai keyboard?
I remember that do-while loop introduced for deleting character in complex
script.

[chongz, 2016/04/13 23:53:08]

Actually it will always go into here by pressing backspace on Android's soft
keyboard (outside composition), so I think the event should be 'deleteContent'.

     TypingCommand::deleteSelection(*frame().document());
 }