Android save state for dialog

Question

How do you save the state of a dialog in android? I have the following dialog with radio buttons but can't figure out how to save the state of the dialog. Thanks for any help

final CharSequence[] items = {"Item 1", "Item 2", "Item 3"};
AlertDialog.Builder builder = new AlertDialog.Builder(Tweaks.this);
builder.setTitle("Pick an item");
builder.setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int item) {
        Toast.makeText(getApplicationContext(), items[item], Toast.LENGTH_SHORT).show();
    }
}).show();

Answer 1

You should store the position of the selected item when the user clicks. Then you look for a previously stored index when you display the list. If there is no previously stored value you return -1.

I have an app Preferences helper class ...

public class AppPreferences {
     private static final String APP_SHARED_PREFS = "myApp_preferences"; //  Name of the file -.xml
     private SharedPreferences appSharedPrefs;
     private Editor prefsEditor;

     public AppPreferences(Context context)
     {
         this.appSharedPrefs = context.getSharedPreferences(APP_SHARED_PREFS, Activity.MODE_PRIVATE);
         this.prefsEditor = appSharedPrefs.edit();
     }

     public int getItemIndex() {
         return appSharedPrefs.getInt("itemIndex", -1);
     }

     public void saveItemIndex(int i) {
         prefsEditor.putInt("itemIndex", i);
         prefsEditor.commit();
     }
}

Then, in my code I create a field variable ...

protected AppPreferences appPrefs;

And instantiate an instance of it inside the Activity onCreate() ...

appPrefs = new AppPreferences(getApplicationContext());

Then replace your "-1" with ...

builder.setSingleChoiceItems(items, appPrefs.getItemIndex(), new DialogInterface.OnClickListener() {

And in your onClick() make sure you ...

appPrefs.saveItemIndex(item);