Pausing loop to wait for response of actionListener

[Joanne Quinn]

Hello everyone, I'm fairly new to Java and programming in general, and it often makes my head spin. I have been trying to write a program that I can use to conduct a survey. The program will play a short video clip and then the user will select the emotion that they hear/see in the clip. When the "submit" button is pressed, the clip name and emotion are then stored in a .csv file for me to examine later. I have been trying for ages to get the submit button to control the for loop so that the program waits in between each iteration; I keep seeing that the way to do this is with the actionListener, but it doesn't seem to work for me. The for loop just continues to execute, and the only video that is ever actually seen is the last one. Any help would be appreciated. Thank you.

Just to not claim that all this code is mine, I got some of it from random tutorials over the course of many weeks trying to get different parts to work.
Also, I do realize how disgusting this code is, but when I try to break it down into methods, it stops working all together...

Thanks again,
Joanne

import com.sun.jna.Native;
import com.sun.jna.NativeLibrary;
import uk.co.caprica.vlcj.binding.LibVlc;
import uk.co.caprica.vlcj.player.MediaPlayerEventAdapter;
import uk.co.caprica.vlcj.player.MediaPlayerFactory;
import uk.co.caprica.vlcj.player.embedded.EmbeddedMediaPlayer;
import uk.co.caprica.vlcj.player.embedded.windows.Win32FullScreenStrategy;
import uk.co.caprica.vlcj.runtime.RuntimeUtil;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;


public class WDPlayer {

        public static void main(String[] args) {

            JFrame f = new JFrame("Name That Emotion!");
            f.setLocation(90, 40);
            f.setSize(1200, 600);
            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            JPanel replay = new JPanel();
            replay.setBackground(Color.black);
            JButton replayButton = new JButton("Replay");
            replay.add(replayButton);

            JPanel controls = new JPanel();
            ButtonGroup choices = new ButtonGroup();
            JRadioButton happy = new JRadioButton("Happy/Playful");
            JRadioButton neut = new JRadioButton("Neutral");
            JRadioButton sad = new JRadioButton("Sad");
            JRadioButton angry = new JRadioButton("Angry");
            choices.add(happy);
            choices.add(neut);
            choices.add(sad);
            choices.add(angry);
            controls.add(happy);
            controls.add(neut);
            controls.add(sad);
            controls.add(angry);


            JButton submitButton = new JButton("Submit");
            controls.add(submitButton);
            f.add(replay, BorderLayout.NORTH);
            controls.setBackground(Color.CYAN);
            f.add(controls, BorderLayout.SOUTH);

            Canvas c = new Canvas();
            c.setBackground(Color.black);
            JPanel p = new JPanel();
            p.setLayout(new BorderLayout());
            p.add(c, BorderLayout.CENTER);
            f.add(p, BorderLayout.CENTER);
            f.setVisible(true); //This MUST come after all components are set.  Dummy!


            NativeLibrary.addSearchPath(RuntimeUtil.getLibVlcLibraryName(), "C:/Program Files (x86)/VideoLAN/VLC");
            Native.loadLibrary(RuntimeUtil.getLibVlcLibraryName(), LibVlc.class);


            MediaPlayerFactory mpf = new MediaPlayerFactory();
            EmbeddedMediaPlayer emp = mpf.newEmbeddedMediaPlayer(new Win32FullScreenStrategy(f));


            for (int i = 1; i <= 11; i++) {
                int filename = i;
                String file = "" + filename;
                String fullname = "clip" + file + ".avi";
                emp.setVideoSurface(mpf.newVideoSurface(c));
                emp.prepareMedia(fullname);
                emp.play();


                replayButton.addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent evt) {
                        emp.play();
                    }
                });

                submitButton.addActionListener(new ActionListener() {
                    String response = "";

                    @Override
                    public void actionPerformed(ActionEvent e) {
                        if (happy.isSelected()) {
                            response += fullname + ",1,0,0,0\n";
                        } else if (neut.isSelected()) {
                            response += fullname + ",0,1,0,0\n";
                        } else if (sad.isSelected()) {
                            response += fullname + ",0,0,1,0\n";
                        } else if (angry.isSelected()) {
                            response += fullname + ",0,0,0,1\n";
                        }

                        String results = "sample.csv";
                        try {
                            FileWriter fileWriter =
                                    new FileWriter(results, true);

                            // Wrap FileWriter in BufferedWriter.
                            BufferedWriter bufferedWriter =
                                    new BufferedWriter(fileWriter);

                            //Enter response in spreadsheet
                            bufferedWriter.write(response);
                            bufferedWriter.close();
                        } catch (IOException ex) {
                            System.out.println(
                                    "Error writing to file '"
                                            + results + "'");
                        }

                    }
                });
            }
        }
    }

[Knute Snortum]

Welcome to the Ranch! Sounds like an interesting project.

I'm going to correct you code tags (you can read about it here: UseCodeTags) and move this to the Swing forum.

[Piet Souris]

hi Joanne,

there is no need to wait for some action in the first place. Just let the actionListeners
do all th hard work,

What about a structure like this?

private ActionListener getActionListenerForReplayButton() {
   ActionListener temp = new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
         boolean canPlay = true;
         if (emp.isPlaying() {   // assumed to exist
            emp.reWind();
         }
         if (currentVideo == 0) {
             canPlay = loadNextVideo();
         }
         if (canPlay()) emp.play();
    }
    return temp;
}

private ActionListener getActionListenerForSubmit() {
    ActionListener temp = new ActionLstener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            if (currentVideo < 1) {
                // no videos yet, nothing to submit
                return;
            }
            saveAssessment();
        }
   }
    return temp;
}

Currently you have all your code in the 'main' method. However, this
makes it necessary to make all the extra methods static as well, and it
is generally considered bad coding style. So, let's change that structure
a little.

First, change 'main' to the following:

public static void main(String... args) {
    SwingUtilities.invokeLater( new Runnable() {
       @Override
        public void run() {
            new WDPlayer();
        }
    });
}

That's all for the main method! It creates an instance of your
class, so that we can dispose of the word 'static'.
And secondly, it forces your code to be run on what is called
the EDT. That is important for programs using a Swing GUI.

Now, we need a constructor that actually creates an instance
of WDPlayer.

So here goes:

public WDPlayer() {
   // put all your initialization code here), for instance
   currentVideo = 0;
   // put the two ActionListeners to the two buttons
   // show the frame
   // do we need a button to load the next video as well?
}

And in theory, that's it! No for-next loops, no complicated things,
just implement the methods 'loadVideo' and the 'saveAssessment'.

Mybe you need some code to decide what to do when a video
is finished.

I hope I made clear what structure I have in mind. Give it a
thought, and let us know what you think of it.

[Joanne Quinn]

Thank you, I will give it a try! Usually when I use methods, I wind up breaking the whole thing, but your suggestions are very good, so hopefully this time will be different. I am going to try and implement the changes now (though it will most likely take me a while...) I will let you know how it works out. Thanks again!

Joanne

[Joanne Quinn]

Hi Piet,

I was not able to get it working with separate methods like I know I was supposed to, but I was able to get it functional (but very, very ugly) by incrementing the global variable currentVideo from within the submitButton actionListener. Hopefully it will work for my experiment (and hopefully I will one day understand how to get methods to work together!!).

Thanks for your help!

Joanne