Handler : Runnable

handlers_runnable

package course.examples.Threading.ThreadingHandlerRunnable;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.Toast;

public class HandlerRunnableActivity extends Activity {
	
	private ImageView mImageView;
	private ProgressBar mProgressBar;
	private Bitmap mBitmap;
	private int mDelay = 500;
//1. Creating a new handler by the main UI thread.  
	private final Handler handler = new Handler();

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		mImageView = (ImageView) findViewById(R.id.imageView);
		mProgressBar = (ProgressBar) findViewById(R.id.progressBar);

		final Button button = (Button) findViewById(R.id.loadButton);
		button.setOnClickListener(new OnClickListener() {
			public void onClick(View v) {
				new Thread(new LoadIconTask(R.drawable.painter)).start();
			}
		});

		final Button otherButton = (Button) findViewById(R.id.otherButton);
		otherButton.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				Toast.makeText(HandlerRunnableActivity.this, "I'm Working",
						Toast.LENGTH_SHORT).show();
			}
		});

	}

	private class LoadIconTask implements Runnable {
		int resId;

		LoadIconTask(int resId) {
			this.resId = resId;
		}

		public void run() {
	//2.handler post new runnable and set viz to visible.  
			handler.post(new Runnable() {
				@Override
				public void run() {
					mProgressBar.setVisibility(ProgressBar.VISIBLE);
				}
			});
	// Load the bitmap
			mBitmap = BitmapFactory.decodeResource(getResources(), resId);
			
	// Simulating long-running operation
	//3. Periodic posting of progress by calling setProgress().  		
			for (int i = 1; i < 11; i++) {
				sleep();
				final int step = i;
				handler.post(new Runnable() {
					@Override
					public void run() {
						mProgressBar.setProgress(step * 10);
					}
				});
			}
	//4.  Posting of a runnable that sets to new bitmap on display.  
			handler.post(new Runnable() {
				@Override
				public void run() {
					mImageView.setImageBitmap(mBitmap);
				}
			});
	//5.  Finish by posting another runnable that makes the progress bar visible.  
			handler.post(new Runnable() {
				@Override
				public void run() {
					mProgressBar.setVisibility(ProgressBar.INVISIBLE);
				}
			});
		}
	}

	private void sleep() {
		try {
			Thread.sleep(mDelay);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

}