Another exercise of SurfaceView, in a FrameLaout inside another LinearLayout

It's another exercise of using FurfaceView in Android.

In the previous exercises "Android SurfaceView" and "Android SurfaceView, run in Thread with sleep()", the layout was simple a FrameLayout composed of a SurfaceView only, setup using programming code setContentView(R.layout.main).

In this exercise, it's a FrameLayout inside a LinearLayout, together with two buttons. The FrameLayout is composed of a SurfaceView. And the layout is defined in main.xml. Both the MySurfaceView(extends SurfaceView) and the MySurfaceThread(extends Thread) are implemented as separated class. When the application is running, there are two buttons over the FrameLayout with SurfaceView, a dot bounce inside the SurfaceView. User can click the first button to make the another button invisible, to change the dimension of the FrameLayout in run-time, and the SurfaceView change also accordingly.



main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent">
<Button
 android:id="@+id/showhide"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="Toggle The Another Button Show/Hide" />
<Button
 android:id="@+id/dummy"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="a Button" />
<FrameLayout
 android:layout_width="fill_parent"
 android:layout_height="fill_parent">
<com.exercise.AndroidMergeSurfaceView.MySurfaceView
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"/>
</FrameLayout>
</LinearLayout>

MySurfaceView.java

package com.exercise.AndroidMergeSurfaceView;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback{
 
 private MySurfaceThread thread;
 private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
 int cx, cy, offx, offy;

 public MySurfaceView(Context context) {
  super(context);
  // TODO Auto-generated constructor stub
  init();
 }

 public MySurfaceView(Context context, AttributeSet attrs) {
  super(context, attrs);
  // TODO Auto-generated constructor stub
  init();
 }

 public MySurfaceView(Context context, AttributeSet attrs, int defStyle) {
  super(context, attrs, defStyle);
  // TODO Auto-generated constructor stub
  init();
 }

  private void init(){
    getHolder().addCallback(this);
    thread = new MySurfaceThread(getHolder(), this);
  
    setFocusable(true); // make sure we get key events
  
    paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeWidth(3);
    paint.setColor(Color.WHITE);
  
    cx = 0;
    cy = 0;
    offx = 10;
    offy = 10;
  
   }
 
 @Override
 public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
  // TODO Auto-generated method stub
  
 }

 @Override
 public void surfaceCreated(SurfaceHolder holder) {
  // TODO Auto-generated method stub
  thread.setRunning(true);
  thread.start();
  
 }

 @Override
 public void surfaceDestroyed(SurfaceHolder holder) {
  // TODO Auto-generated method stub
  boolean retry = true;
  thread.setRunning(false);
  while (retry) {
   try {
    thread.join();
    retry = false;
   }
   catch (InterruptedException e) {
   }
  }
 }

 @Override
 protected void onDraw(Canvas canvas) {
  // TODO Auto-generated method stub
  canvas.drawRGB(0, 0, 0);
  canvas.drawCircle(cx, cy, 3, paint);
  cx += offx;
  if (cx > getWidth() || (cx < 0)){
   offx *= -1;
   cx += offx;
  }
  
  cy += offy;
  if (cy > getHeight() || (cy < 0)){
   offy *= -1;
   cy += offy;
  }
 }
}

MySurfaceThread.java

package com.exercise.AndroidMergeSurfaceView;

import android.graphics.Canvas;
import android.view.SurfaceHolder;

public class MySurfaceThread extends Thread {
 private SurfaceHolder myThreadSurfaceHolder;
 private MySurfaceView myThreadSurfaceView;
 private boolean myThreadRun = false;
 
 public MySurfaceThread(SurfaceHolder surfaceHolder, MySurfaceView surfaceView) {
  myThreadSurfaceHolder = surfaceHolder;
  myThreadSurfaceView = surfaceView;
 }
 
 public void setRunning(boolean b) {
  myThreadRun = b;
 }

 @Override
 public void run() {
  // TODO Auto-generated method stub
  while(myThreadRun){
   Canvas c = null;

   try{
    c = myThreadSurfaceHolder.lockCanvas(null);
    synchronized (myThreadSurfaceHolder){
     myThreadSurfaceView.onDraw(c);
    }
    sleep(100);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
   finally{
    // do this in a finally so that if an exception is thrown
    // during the above, we don't leave the Surface in an
    // inconsistent state
    if (c != null) {
     myThreadSurfaceHolder.unlockCanvasAndPost(c);
    }
   }
  }
 }
}

AndroidMergeSurfaceView.java

package com.exercise.AndroidMergeSurfaceView;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class AndroidMergeSurfaceView extends Activity {
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
      
       Button buttonShowHide = (Button)findViewById(R.id.showhide);
       final Button buttonDummy = (Button)findViewById(R.id.dummy);
      
       buttonShowHide.setOnClickListener(
         new Button.OnClickListener(){

     @Override
     public void onClick(View arg0) {
      // TODO Auto-generated method stub
      if(buttonDummy.getVisibility()==View.VISIBLE){
       buttonDummy.setVisibility(View.GONE);
      }
      else{
       buttonDummy.setVisibility(View.VISIBLE);
      }
     }
          
         }
       );
      
   }
}

Download the files.

Further exercise on SurfaceView: SurfaceView overlap with a LinearLayout

It's a bug here!


Pls. refer to the article
"IllegalThreadStateException in LunarLander"
for details.


I'm Sorry about that! (Android Er@2010-06-04)