android: open a pdf from my app using the built in pdf viewer

This was my original question:

I want to be able to open a pdf file in my app using the android's built in pdf viewer app, but i dont know how to start other apps. I'm sure i have to call start activity, i just dont know how to identify the app im opening and how to pass the file to that specific app.

Anyone have a clue?

I just learned that the pdf viewer i have on my phone is actually made by HTC and that Adobe just barely released their android pdf viewer (which is great). So the new question is this: how do i verify that the user has installed adobe's viewer, and then how do i open the file in that app from my app?

You can programmatically determine whether a suitable application exists on the user's device, without catching exceptions.

Intent intent = new Intent(Intent.ACTION_VIEW,
        Uri.parse("path-to-document"));
intent.setType("application/pdf");
PackageManager pm = getPackageManager();
List<ResolveInfo> activities = pm.queryIntentActivities(intent, 0);
if (activities.size() > 0) {
    startActivity(intent);
} else {
    // Do something else here. Maybe pop up a Dialog or Toast
}

AFAIK, Adobe has not documented any public Intents it wants developers to use.

You can try an ACTION_VIEW Intent with a Uri pointing to the file (either on the SD card or MODE_WORLD_READABLE in your app-local file store) and a MIME type of "application/pdf".

private void loadDocInReader(String doc)
     throws ActivityNotFoundException, Exception {

    try {
                Intent intent = new Intent();

                intent.setPackage("com.adobe.reader");
                intent.setDataAndType(Uri.parse(doc), "application/pdf");

                startActivity(intent);

    } catch (ActivityNotFoundException activityNotFoundException) {
                activityNotFoundException.printStackTrace();

                throw activityNotFoundException;
    } catch (Exception otherException) {
                otherException.printStackTrace();

                throw otherException;
    }
}

            FileFinalpath = SdCardpath + "/" + Filepath + Filename;
            File file = new File(FileFinalpath);
            if (file.exists()) {
                Uri filepath = Uri.fromFile(file);
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setDataAndType(filepath, "application/pdf");
                intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

                try {
                    startActivity(intent);
                } catch (Exception e) {
                    alert.showAlertDialog(PDF_Activity.this, "File Not Started...","File Not Started From SdCard ", false);             
                    Log.e("error", "" + e);
                }

            } else {
                alert.showAlertDialog(PDF_Activity.this, "File Not Found...","File Not Found From SdCard ", false);             

            }