Pass Events Between QML Objects

Question

I have a situation where I would like to pass a QML event to another QML item in the middle of the initial event handler. e.g.

Item {
   id: item1

   Keys.onPressed: {
      // Pre-process...

      passEventToObject(event, item2);

      // Post-process based on results of event passing...
   }
}

TextInput {
   id: item2
   // Expect key press event to be handled by text input
}

What can I do to acheive passEventToObject?

Notes:

• I don't have access to modify Keys.onPressed inside item2, it's a QML built-in (TextInput).
• The event passing must happen in the middle of item1.Keys.onPressed

Answer 1

One method to move events between Items is to create a C++ plugin and use QCoreApplication::sendEvent. Unfortunately, Qt doesn't map directly from the QML KeyEvent and the C++ QKeyEvent, so the interface to the plugin will need to expose the internals of the event:

bool EventRelay::relayKeyPressEvent(
   int key,
   Qt::KeyboardModifiers modifiers,
   const QString& text,
   bool autoRepeat,
   ushort count) const
{
   QKeyEvent event(QKeyEvent::KeyPress, key, modifiers, text, autoRepeat, count);
   return relayEventToObject(&event, mpTargetObject);
}

To use it:

EventRelay { id: relay }

Item {
   id: item1
   Keys.onPressed: {
      // Pre-process...

      relay.relayEventToObject(event, item2);

      // Post-process...
   }
}

TextInput {
   id: item2
}