public void createAlertWaiter() {
mAlertsActive = true;
// All mupdf library calls are performed on asynchronous tasks to avoid stalling
// the UI. Some calls can lead to javascript-invoked requests to display an
// alert dialog and collect a reply from the user. The task has to be blocked
// until the user's reply is received. This method creates an asynchronous task,
// the purpose of which is to wait of these requests and produce the dialog
// in response, while leaving the core blocked. When the dialog receives the
// user's response, it is sent to the core via replyToAlert, unblocking it.
// Another alert-waiting task is then created to pick up the next alert.
if (mAlertTask != null) {
mAlertTask.cancel(true);
mAlertTask = null;
}
if (mAlertDialog != null) {
mAlertDialog.cancel();
mAlertDialog = null;
}
mAlertTask =
new AsyncTask<Void, Void, MuPDFAlert>() {
@Override
protected MuPDFAlert doInBackground(Void... arg0) {
if (!mAlertsActive) return null;
return core.waitForAlert();
}
@Override
protected void onPostExecute(final MuPDFAlert result) {
// core.waitForAlert may return null when shutting down
if (result == null) return;
final MuPDFAlert.ButtonPressed pressed[] = new MuPDFAlert.ButtonPressed[3];
for (int i = 0; i < 3; i++) pressed[i] = MuPDFAlert.ButtonPressed.None;
DialogInterface.OnClickListener listener =
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
mAlertDialog = null;
if (mAlertsActive) {
int index = 0;
switch (which) {
case AlertDialog.BUTTON1:
index = 0;
break;
case AlertDialog.BUTTON2:
index = 1;
break;
case AlertDialog.BUTTON3:
index = 2;
break;
}
result.buttonPressed = pressed[index];
// Send the user's response to the core, so that it can
// continue processing.
core.replyToAlert(result);
// Create another alert-waiter to pick up the next alert.
createAlertWaiter();
}
}
};
mAlertDialog = mAlertBuilder.create();
mAlertDialog.setTitle(result.title);
mAlertDialog.setMessage(result.message);
switch (result.iconType) {
case Error:
break;
case Warning:
break;
case Question:
break;
case Status:
break;
}
switch (result.buttonGroupType) {
case OkCancel:
mAlertDialog.setButton(AlertDialog.BUTTON2, getString(R.string.cancel), listener);
pressed[1] = MuPDFAlert.ButtonPressed.Cancel;
case Ok:
mAlertDialog.setButton(AlertDialog.BUTTON1, getString(R.string.okay), listener);
pressed[0] = MuPDFAlert.ButtonPressed.Ok;
break;
case YesNoCancel:
mAlertDialog.setButton(AlertDialog.BUTTON3, getString(R.string.cancel), listener);
pressed[2] = MuPDFAlert.ButtonPressed.Cancel;
case YesNo:
mAlertDialog.setButton(AlertDialog.BUTTON1, getString(R.string.yes), listener);
pressed[0] = MuPDFAlert.ButtonPressed.Yes;
mAlertDialog.setButton(AlertDialog.BUTTON2, getString(R.string.no), listener);
pressed[1] = MuPDFAlert.ButtonPressed.No;
break;
}
mAlertDialog.setOnCancelListener(
new DialogInterface.OnCancelListener() {
public void onCancel(DialogInterface dialog) {
mAlertDialog = null;
if (mAlertsActive) {
result.buttonPressed = MuPDFAlert.ButtonPressed.None;
core.replyToAlert(result);
createAlertWaiter();
}
}
});
mAlertDialog.show();
}
};
mAlertTask.executeOnExecutor(new ThreadPerTaskExecutor());
}
