Asynchronously check if it is possible to execute the given editing command.
When the operation is finished, callback will be called. You can then call webkit.web_view.WebView.canExecuteEditingCommandFinish to get the result of the operation.
the command to check
a #GCancellable or null to ignore
a #GAsyncReadyCallback to call when the request is satisfied
Asynchronously check if it is possible to execute the given editing command.
When the operation is finished, callback will be called. You can then call webkit.web_view.WebView.canExecuteEditingCommandFinish to get the result of the operation.