Question

Thanks to this tutorial: http://mobile.tutsplus.com/tutorials/android/android-sdk-implement-a-share-intent/ I know how to simply share my message: I simply create the intent and start activity.
However, there’s a little latency between startActivity call and effective show of the share windows so I’d like to make a custom activity with, for example, a listview of suitable apps for that type of sharing.

I thus need:

edit:
1) A way to get a list of apps wich can handle the intent, in my case an ACTION.SEND intent with a text/plain mime type.

2)A way to start them with my message body and subject.

Answer 1

Get the list of installed application:

final PackageManager pm = getPackageManager();

List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);

for (ApplicationInfo packageInfo : packages) {

   Log.d(TAG, "Installed package :" + packageInfo.packageName);
   Log.d(TAG, "Launch Activity :" + pm.getLaunchIntentForPackage(packageInfo.packageName)); 

   }// the getLaunchIntentForPackage returns an intent that you can use with startActivity() 
}

and to launch that package:

protected void launchApp(String packageName) {
    Intent mIntent = getPackageManager().getLaunchIntentForPackage(packageName);
    if (mIntent != null) {
        try {
            startActivity(mIntent);
        } catch (ActivityNotFoundException err) {
            Toast t = Toast.makeText(getApplicationContext(),
            "Application not found", Toast.LENGTH_SHORT);
            t.show();
        }
    }
}

EDIT

This method queries the package manager for installed packages that can respond to an intent with the specified action:

public static boolean isIntentAvailable(Context context, String action) {
    final PackageManager packageManager = context.getPackageManager();
    final Intent intent = new Intent(action);
    List<ResolveInfo> list =
    packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
    return list.size() > 0;
}

and to share your text using a specific application (which can handle ACTION_SEND):

ResolveInfo info = list.get(index);
Intent intent = new Intent(android.content.Intent.ACTION_SEND);
intent.setClassName(info.activityInfo.packageName, info.activityInfo.name);
intent.setType("text/plain");
intent.putExtra(Intent.EXTRA_SUBJECT, subject);
intent.putExtra(Intent.EXTRA_TEXT, body);
((Activity)context).startActivity(intent);