Question

My android app needs to run through a sequence of events as in a state machine

Event 1: play video # 1

Event 2: load an image and wait for a button press

Event 3: play video #2

etc…

One way of doing would be to generate a separate activity for each event, but with over 20 events, I thought there’s an easier way of doing it.

So I coded a state machine like this:

    int mState = 0;     
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //
    switch(mState) {
    case 0:
        Boolean flag = videoIntent(url0); 
        break;
    case 1:
        flag = loadImage(img1);
    }
    }


public Boolean videoIntent(String video) {
     mBundle.putString("url",video ); 
     Intent myIntent = new Intent();
     myIntent.putExtras(mBundle);
         myIntent.setClass(mySM.this, SM_vPlayer.class);
         startActivity(myIntent);
             mState ++;
    return true;     
 }

public Boolean loadImage(String image) {
    //load image
            mState ++;
    return true;
}

Questions: After starting the intent to play the video (that activity has a listener to wait for the completion) and then finish() is called.

1. Where will finish() come back to onCreate, onResume or another method?

2. How do I get back to the switch statement?

3. Any better ways of doing this?

Answer 1

The startActivity() method is non-blocking, so your loop (assuming you’re considering a loop in your onCreate() method) would cycle through before the video completed. You could instead perform startActivityForResult(), which would cause a callback in your (current) activity to be called when the started activity finish()’d. You could also load your image without waiting since the new activity will cause yours to be hidden.