Databases
StackOverflow2013
Postsdbo
POAndroid SurfaceView canvas drawing with a thread
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POAndroid SurfaceView canvas drawing with a thread
    primarykey
    data
    text
    <p>I am experimenting with drawing on a canvas using a thread to create a simple game engine but I'm having some weird issues I cannot explain. The purpose of this "game" is to draw a circle every second on the canvas. This works, but not the way I want it to work, it seems the app is switching between two canvasses and adding a circle to each canvas so you get a switch between two canvasses every second with the same number of circles but in a different place on the canvas.</p> <p>I don't know what I'm doing wrong, but I'm not that familiar with Treadding, has it something to do with how many cores my android device has or something like that?</p> <p>My code is shown below, so I just use a launchthread which uses a layoutfile that links to the animationthread which starts a thread and draws a circle on the canvas every second. (You can ignore the touchevent, it isn't uses yet).</p> <p>The project exists out of a main launchthread:</p> <pre><code>public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); } } </code></pre> <p>which uses this layout file:</p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent"&gt; &lt;com.androidtesting.AnimationView android:id="@+id/aview" android:layout_width="fill_parent" android:layout_height="fill_parent"/&gt; &lt;/FrameLayout&gt; </code></pre> <p>And my Surfaceview class with an inner Thread class:</p> <pre><code>class AnimationView extends SurfaceView implements SurfaceHolder.Callback { private boolean touched = false; private float touched_x, touched_y = 0; private Paint paint; private Canvas c; private Random random; private AnimationThread thread; public AnimationView(Context context, AttributeSet attrs) { super(context, attrs); SurfaceHolder holder = getHolder(); holder.addCallback(this); thread = new AnimationThread(holder); } class AnimationThread extends Thread { private boolean mRun; private SurfaceHolder mSurfaceHolder; public AnimationThread(SurfaceHolder surfaceHolder) { mSurfaceHolder = surfaceHolder; paint = new Paint(); paint.setARGB(255,255,255,255); paint.setTextSize(32); } @Override public void run() { while (mRun) { c = null; try { c = mSurfaceHolder.lockCanvas(null); synchronized (mSurfaceHolder) { doDraw(c); sleep(1000); } } catch (Exception e) { e.printStackTrace(); }finally { if (c != null) { mSurfaceHolder.unlockCanvasAndPost(c); } } } } private void doDraw(Canvas canvas) { //clear the canvas //canvas.drawColor(Color.BLACK); random = new Random(); int w = canvas.getWidth(); int h = canvas.getHeight(); int x = random.nextInt(w-50); int y = random.nextInt(h-50); int r = random.nextInt(255); int g = random.nextInt(255); int b = random.nextInt(255); int size = 20; canvas.drawCircle(x,y,size,paint); canvas.restore(); } public void setRunning(boolean b) { mRun = b; } } public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public boolean onTouchEvent(MotionEvent event) { touched_x = event.getX(); touched_y = event.getY(); int action = event.getAction(); switch(action){ case MotionEvent.ACTION_DOWN: touched = true; break; case MotionEvent.ACTION_MOVE: touched = true; break; default: touched = false; break; } return true; } public void surfaceCreated(SurfaceHolder holder) { thread.setRunning(true); thread.start(); } public void surfaceDestroyed(SurfaceHolder holder) { boolean retry = true; thread.setRunning(false); while (retry) { try { thread.join(); retry = false; } catch (InterruptedException e) { } } } } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USrandomizer
    1. USrandomizer
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POAndroid SurfaceView canvas drawing with a thread
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POAndroid SurfaceView canvas drawing with a thread
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload