Prevent back button from closing a dialog box

Question

I am trying to prevent an AlertDialog box from closing when pressing the back button in Android. I have followed both of the popular methods in this thread, and with System.out.

Answer 1

Simply use the setCancelable() feature:

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setCancelable(false);

This prevents the back button from closing the dialog, but leaves the "negative" button intact if you chose to use it.

---

While any user that does not want to accept your terms of service can push the home button, in light of Squonk's comment, here two more ways to prevent them from "backing out" of the user agreement. One is a simple "Refuse" button and the other overrides the back button in the dialog:

builder.setNegativeButton("Refuse", new OnClickListener() {
           @Override
           public void onClick(DialogInterface dialog, int which) {
               finish();
           }
       })
       .setOnKeyListener(new OnKeyListener() {
           @Override
           public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
               if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_UP)
                   finish();
               return false;
           }
       });

Answer 2

When using DialogFragment you will need to call setCancelable() on the fragment, not the dialog:

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    dialog = new ProgressDialog(getActivity());
    dialog.setIndeterminate(true);
    dialog.setMessage(...);
    setCancelable(false);

    return dialog;
}

Calling dialog.setCancelable() seem to have no effect. It seems that DialogFragment does not takes notice of the dialog's setting for cancelability.

Answer 3

To prevent the back button closes a Dialog (without depending on Activity), just the following code:

alertDialog.setOnKeyListener(new DialogInterface.OnKeyListener() {
    @Override
    public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
        // Prevent dialog close on back press button
        return keyCode == KeyEvent.KEYCODE_BACK;
    }
});

Answer 4

Use setCancelable(false)

SampleDialog sampleDialog = SampleDialog.newInstance();
sampleDialog.setCancelable(false);
sampleDialog.show(getSupportFragmentManager(), SampleDialog.class.getSimpleName());

Answer 5

In JQuery Mobile a popup adds a hash to the url, the following code allows the back to dismiss the popup when open and return to the app when closed. You could use the same logic for a custom ui framework.

@Override
public void onBackPressed() {

    // check if modal is open #&ui-state=dialog

    if (webView.getVisibility() == View.VISIBLE && webView.getUrl().contains("#&ui-state=dialog")) {
        // don't pass back button action
        if (webView.canGoBack()) {
            webView.goBack();
        }
    } else {
        // pass back button action
        super.onBackPressed();
    }
}

Answer 6

AlertDialog.Builder builder = AlertDialog.Builder(this)
Dialog dialog = builder.create()
dialog.setCancelable(false)
dialog.setCanceledOnTouchOutside(false)

This will prevent the user on canceling the dialog when they press the back button or touch outside the dialog window