How Do You Create A Progress Bar Class That Loads Different Types Of Files From Both The /res And /assets Folder In Android?

Here's the core of my ProgressBar class: package nttu.edu.activities; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.uti

Solution 1:

Here's how to create a ProgressBar for arbitary files.

package nttu.edu.activities;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.LinkedList;
import java.util.Queue;

import nttu.edu.R;
import nttu.edu.graphics.Art;
import android.app.Activity;
import android.content.Intent;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.widget.ProgressBar;

public class NewLoadingActivity extends Activity {
    public ProgressBar bar;
    private AssetManager assetManager;
    public Handler handler;
    public ProgressTask task;

    private final String[] list = {
    // Art.sprites
    "art/sprites.png" };

    private class ProgressTask extends AsyncTask<Void, Void, Void> {
        public int totalByteSize;
        public int currentByteSize;
        public Queue<Bitmap> bitmapQueue;
        public Queue<byte[]> byteQueue;

        public ProgressTask() {
            totalByteSize = 0;
            currentByteSize = 0;
            bitmapQueue = new LinkedList<Bitmap>();
            byteQueue = new LinkedList<byte[]>();
        }

        public void onPostExecute(Void params) {
            Art.sprites = bitmapQueue.remove();
            finish();
        }

        public void onPreExecute() {
            try {
                for (int i = 0; i < list.length; i++) {
                    byte[] bytes = readFromStream(list[i]);
                    totalByteSize += bytes.length;
                    byteQueue.add(bytes);
                }
                bar.setMax(totalByteSize);
            }
            catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        public void onProgressUpdate(Void... params) {
            bar.setProgress(currentByteSize);
        }

        @Override
        protected Void doInBackground(Void... params) {
            while (currentByteSize < totalByteSize) {
                try {
                    Thread.sleep(1000);
                    if (byteQueue.size() > 0) {
                        byte[] bytes = byteQueue.remove();
                        Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
                        bitmapQueue.add(bitmap);
                        currentByteSize += bytes.length;
                        this.publishProgress();
                    }
                }
                catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            return null;
        }

        private byte[] readFromStream(String path) throws IOException {
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int length = 0;
            InputStream input = assetManager.open(path);
            while (input.available() > 0 && (length = input.read(buffer)) != -1)
                output.write(buffer, 0, length);
            return output.toByteArray();
        }

    }

    public void onCreate(Bundle b) {
        super.onCreate(b);
        this.setContentView(R.layout.progressbar);
        assetManager = this.getAssets();
        handler = new Handler();
        task = new ProgressTask();
        bar = (ProgressBar) this.findViewById(R.id.loadingBar);
        if (bar == null) throw new RuntimeException("Failed to load the progress bar.");
        task.execute();
    }

    public void finish() {
        Intent intent = new Intent(this, MenuActivity.class);
        intent.putExtra("Success Flag", Art.sprites != null);
        this.setResult(RESULT_OK, intent);
        super.finish();
    }
}