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How do I initiate xml-defined surface view via button press?

开发者 https://www.devze.com 2023-02-23 04:33 出处:网络
I\'ve patterned my initial code from another tutorial to create classes to handle drawing to a SurfaceView.This tutorial (and others I\'ve found) associate an xml-defined SurfaceView to a class which

I've patterned my initial code from another tutorial to create classes to handle drawing to a SurfaceView. This tutorial (and others I've found) associate an xml-defined SurfaceView to a class which intiates upon creation of the activity. My goal is to initiate animation in an xml-defined surface view upon pushing a button in my layout and terminating it when I push it again.

Furthermore, the animation must run inside the region I've specified in my xml (rather than the entire display).

For simplicity, I'm currently only drawing a circle in the surfaceview until I figure out how to get my layout working.

So, when I click the Go button (BattleActivity::onClick), my surface view is created and drawn, but it fills the entire display covering the other controls in my layout, including the button. I want the animation to take place only in the surface view defined as part of my layout (id=battleView).

Here's a sub-section of my XML layout code (tabBattle.xml).

<LinearLayout
    android:orientation="vertical"
    android:gravity="center"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <SurfaceView
        android:id="@+id/battleView"
        android:layout_weight="70"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:layout_gravity="center_horizontal"/>        

    <Button
        android:onClick="onClick"
        android:text=" Go "
        android:gravity="center"
        android:layout_weight="30"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

Here's my main activity class. This is created when I navigate to the tab view where its layout (tabBattle) resides. The onClick is called when I push the Go button. My intention in onClick is to get the surface view, create a new BattleView instance, and and pass the surface view context to the BattleView constructor. This clearly is not correct but I have no idea how else to do this.

public class BattleActivity extends Activity implements View.OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.tabbattle); }

@Override
public void onClick(View v)
{
    SurfaceView battleSurface = (SurfaceView)findViewById(R.id.battleView);
    setContentView(new BattleView( battleSurface.getContext() ));
}

}

SurfaceView subclass:

public class BattleView extends SurfaceView implements SurfaceHolder.Callback { private int circleRadius; private Paint circlePaint; UpdateThreadBattle updateThread;

private int width;
private int height;
private int xPos;
private int yPos;
private int xVel;
private int yVel;

pu开发者_JAVA百科blic BattleView(Context context)
{
    super(context);
    getHolder().addCallback(this);

    circleRadius = 10;
    circlePaint = new Paint();
    circlePaint.setColor(Color.BLUE);

    xVel = 2;
    yVel = 2;       
}

@Override
protected void onDraw(Canvas canvas) {
    canvas.drawColor(Color.WHITE);
    canvas.drawCircle(xPos, yPos, circleRadius, circlePaint);
}


@Override
public void surfaceCreated(SurfaceHolder holder)
{
    Rect surfaceFrame = holder.getSurfaceFrame();
    width = surfaceFrame.width();
    height = surfaceFrame.height();

    xPos = width / 2;
    yPos = circleRadius;

    updateThread = new UpdateThreadBattle(this);
    updateThread.setRunning(true);
    updateThread.start();
}

@Override
public void surfaceDestroyed(SurfaceHolder arg0)
{
    boolean retry = true;

    updateThread.setRunning(false);

    while (retry) {
        try {
            updateThread.join();
            retry = false;
        } catch (InterruptedException e) {

        }
    }
}

@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
    // TODO Auto-generated method stub

}

}

As you probably have suspected, I amm new to android and java in general. Any help is greatly appreciated!

Greg


The eventual solution I chose was to utilize a timer rather than implement a thread-based surface animation which was overkill for the simple animation I required in a view. At the time I wrote the question I didn't know about the timer. It works great, brw!

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