Question

i am trying to referencing a Main.class that extend SurfaceView to XML layout.
the XML is like this:

<AbsoluteLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
>
    <coba.gesture.Main
        android:id="@+id/LayoDalam"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
    />
</AbsoluteLayout>

but it comes to error when i running it.
here’s the errors:

05-29 11:57:05.713: ERROR/AndroidRuntime(806): FATAL EXCEPTION: main
05-29 11:57:05.713: ERROR/AndroidRuntime(806): java.lang.RuntimeException: Unable to start activity ComponentInfo{coba.gesture/coba.gesture.CobaGesture}: android.view.InflateException: Binary XML file line #47: Error inflating class coba.gesture.MainBaby
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1622)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1638)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:928)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.os.Looper.loop(Looper.java:123)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.ActivityThread.main(ActivityThread.java:3647)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at java.lang.reflect.Method.invokeNative(Native Method)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at java.lang.reflect.Method.invoke(Method.java:507)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at dalvik.system.NativeStart.main(Native Method)
05-29 11:57:05.713: ERROR/AndroidRuntime(806): Caused by: android.view.InflateException: Binary XML file line #47: Error inflating class coba.gesture.MainBaby
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.createView(LayoutInflater.java:508)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:570)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:626)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:207)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.Activity.setContentView(Activity.java:1657)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at coba.gesture.CobaGesture.onCreate(CobaGesture.java:19)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1586)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     ... 11 more
05-29 11:57:05.713: ERROR/AndroidRuntime(806): Caused by: java.lang.NoSuchMethodException: MainBaby(Context,AttributeSet)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at java.lang.Class.getMatchingConstructor(Class.java:643)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at java.lang.Class.getConstructor(Class.java:472)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     at android.view.LayoutInflater.createView(LayoutInflater.java:480)
05-29 11:57:05.713: ERROR/AndroidRuntime(806):     ... 22 more

My prediction is the errors come from MainBaby.java but i don’t know what is wrong.

UPDATE.

Here’s the source of MainBaby.java that u wanted.

public class MainBaby extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = MainBaby.class.getSimpleName();
private ObjBaby obaby;
private ThreadBaby thread;
private static final float TOUCH_TOLERANCE = 4;

static float static_x = 0;
static float static_y = 0;
float mX, mY;
Paint p;
Path mPath;
Canvas mCanvas;
Bitmap mBitmap;
Paint mBitmapPaint;


public MainBaby(Context context){
    super(context);


    // adding the callback (this) to the surface holder to intercept events

    getHolder().addCallback(this);

    obaby = new ObjBaby(BitmapFactory.decodeResource(getResources(), R.drawable.clue_btn), 50, 50);

    // create the game loop thread
    thread = new ThreadBaby(getHolder(), this);

    mPath = new Path();
    mBitmapPaint = new Paint(Paint.DITHER_FLAG);
    p = new Paint();
     p.setAntiAlias(true);
     p.setDither(true);
     p.setColor(Color.WHITE);
     p.setStyle(Paint.Style.STROKE);
     p.setStrokeJoin(Paint.Join.ROUND);
     p.setStrokeCap(Paint.Cap.ROUND);
     p.setStrokeWidth(12);



    setFocusable(true);

}



@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
}

@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;
    while (retry) {
        try {
            thread.join();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        retry = false;
    }
}

private void touch_start(float x, float y) {
    mPath.reset();
    mPath.moveTo(x, y);
    mX = x;
    mY = y;
}

private void touch_move(float x, float y) {
    float dx = Math.abs(x - mX);
    float dy = Math.abs(y - mY);
    if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
        mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
        mX = x;
        mY = y;
    }
}

private void touch_up() {
    mPath.lineTo(mX, mY);
    // commit the path to our offscreen
    mCanvas.drawPath(mPath, p);

    // kill this so we don't double draw
    mPath.reset();
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    static_x = event.getX();
    static_y = event.getY();

    if (event.getAction() == MotionEvent.ACTION_DOWN) {
        // delegating event handling to the droid
        obaby.handleActionDown((int)event.getX(), (int)event.getY());
        touch_start(static_x, static_y);



        if (event.getY() > getHeight() - 50) {
            thread.setRunning(false);
            ((Activity)getContext()).finish();
        } else {
            //Log.d(TAG, "Coords: x=" + event.getX() + ",y=" + event.getY());
        }
    } if (event.getAction() == MotionEvent.ACTION_MOVE) {
        // the gestures
        if (obaby.isTouched()) {
            // the droid was picked up and is being dragged
            obaby.setX((int)event.getX());
            obaby.setY((int)event.getY());
            touch_move(static_x, static_y);
        }
    } if (event.getAction() == MotionEvent.ACTION_UP) {
        // touch was released
        if (obaby.isTouched()) {
            touch_up();
            obaby.setTouched(false);


        }
    }
    return true;
}

@Override
protected void onDraw(Canvas canvas) {
    // fills the canvas with black
    canvas.drawColor(Color.BLACK);



    canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
    canvas.drawPath(mPath, p);
    obaby.draw(canvas);
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    //mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
    mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.background_number);
    mCanvas = new Canvas(mBitmap);

}
}

Answer 1

When you extend a view type and create an instance in an XML like this, behind the scenes Android calls MainBaby(Context context, AttributeSet attrs) where the AttributeSet is everything you defined in XML. But you only overrode the MainBaby(Context context), so to fix this error start here:

public MainBaby(Context context){
    super(context);
    ...

and cover all your bases by trying this:

public MainBaby(Context context) {
    super(context);
    init();
}

public MainBaby(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

public MainBaby(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init();
}

private void init() {
    // Original constructor code here
    ...

The new method init() should contain the initialization code from your first constructor.

Also, I might be missing something from the code not included but are you trying to reference your MainBaby view here?

<coba.gesture.Main
    android:id="@+id/LayoDalam"
    ...

If so, I think you meant this:

<coba.gesture.MainBaby
    android:id="@+id/LayoDalam"
    ...

Lastly, AbsoluteLayout are deprecated because they are not readily portable across screens of different densities. This is from the Developer’s Guide:

3. Do not use AbsoluteLayout

Unlike the other layouts widgets, AbsoluteLayout enforces the use of fixed positions to lay out its child views, which can easily lead to user interfaces that do not work well on different displays. Because of this, AbsoluteLayout was deprecated in Android 1.5 (API Level 3).

You should instead use RelativeLayout, which uses relative positioning to lay out its child views. For instance, you can specify that a button widget should appear "to the right of" a text widget.