Request to send notifications

Starting with Android 8.0, users can manage the permissions of the app to show notifications. This permission is enabled by default.

We should check if the app has permission to show notifications at the right time, if not, the user should be directed to open the permission to show notifications for our app:

AndPermission.with(this)
    .notification()
    .permission()
    .rationale(new Rationale<Void>() {
        @Override
        public void showRationale(Context c, Void d, RequestExecutor e) {
            // Startup settings: e.execute();
            // Cancel: e.cancel();
        }
    })
    .onGranted(new Action<Void>() {
        @Override
        public void onAction(Void data) {
            // App can show notifications.
        }
     })
    .onDenied(new Action<Void>() {
        @Override
        public void onAction(Void data) {
            // App cann't show notifications.
        }
     })
     .start();

When showRationale() is called back without the Show Notifications permission, the developer must call RequestExecutor#execute() to initiate the setting or RequestExecutor#cancel() to cancel the startup setting, ortherwise AndPermission will have no response.

When showRationale() is called back it is a good idea to display a Dialog to solicit the user's comments, whether to launch the setup page authorization Show Notifications permissions, call RequestExecutor#execute() or RequestExecutor#cancel() depending on the user's choice.