setOnPasteFromMenu method
Sets the callback to be invoked when the Paste menu item is selected.
The callback should return a Future that completes with true if the
operation was handled, or false to allow the default system behavior.
Parameters:
callback: The callback to invoke, ornullto clear the handler.
Implementation
@override
void setOnPasteFromMenu(Future<bool> Function()? callback) {
_onPaste = callback;
}