Question

I am working on an app were I am going to open other apps. The only problem is that I do not know how to refer to third party apps. I am planing to use an intent. Can you refer to it useing only the packagename, or do you need the Main Activity intent. Are there any simple ways of finding the right intent, and then refer to it.

Answer 1

I am working on an app were I am going to open other apps.

I am interpreting this as meaning that you are creating a launcher, akin to the ones found on home screens.

Can you refer to it useing only the packagename, or do you need the Main Activity intent.

Launchers use an ACTION_MAIN/CATEGORY_LAUNCHER Intent.

Are there any simple ways of finding the right intent, and then refer to it.

Use PackageManager to find all the possible ACTION_MAIN/CATEGORY_LAUNCHER activities on the device, and then display those to the user to choose from. You can then construct a suitable Intent for starting up their specific choice.

Here is a sample project that implements a launcher.

To come up with the list of things that could be launched, that sample app uses:

PackageManager pm=getPackageManager();
Intent main=new Intent(Intent.ACTION_MAIN, null);

main.addCategory(Intent.CATEGORY_LAUNCHER);

List<ResolveInfo> launchables=pm.queryIntentActivities(main, 0);

And here is the actual launching logic, based upon the user clicking on one of those “launchables” in a ListActivity:

  @Override
  protected void onListItemClick(ListView l, View v,
                                 int position, long id) {
    ResolveInfo launchable=adapter.getItem(position);
    ActivityInfo activity=launchable.activityInfo;
    ComponentName name=new ComponentName(activity.applicationInfo.packageName,
                                         activity.name);
    Intent i=new Intent(Intent.ACTION_MAIN);

    i.addCategory(Intent.CATEGORY_LAUNCHER);
    i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
                Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
    i.setComponent(name);

    startActivity(i);    
  }