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Moving an imageview - different behavior in programmatic and xml implementation

开发者 https://www.devze.com 2023-03-08 01:43 出处:网络
My purpose is to move an imageview free on the ground and therefore i followed this tutorial: http://www.zdnet.com/blog/burnette/how-to-use-multi-touch-in-android-2-part-5-implementing-the-drag-gestu

My purpose is to move an imageview free on the ground and therefore i followed this tutorial: http://www.zdnet.com/blog/burnette/how-to-use-multi-touch-in-android-2-part-5-implementing-the-drag-gesture/1789

If I use it the same way declared there - Getting the view component by id and adding my touchlistener - it works good. On the other side when I create the view programmatic it doesn't move.

in my activity:

addProductToView(iterator.next());

in my viewclass:

public class ProductView extends ImageView{
public ProductView(Context context, Product product) {
        super(context);
        this.setBackgroundResource(R.drawable.bamboo);
        this.setScaleType(ScaleType.MATRIX);
                this.setOnTouchListener(new TouchListener());
...

the touchlistener:

public class TouchListener implements OnTouchListener{

    private static final String TAG = "Touch";
       // These matrices will be used to move and zoom image
       Matrix matrix = new Matrix();
       Matrix savedMatrix = new Matrix();

       // We can be in one of these 3 states
       static final int NONE = 0;
       static final int DRAG = 1;
       static final int ZOOM = 2;
       int mode = NONE;

       // Remember some things for zooming
       PointF start = new PointF();
       PointF mid = new PointF();
       float oldDist = 1f;

//     @Override
//     public void onCreate(Bundle savedInstanceState) {
//        super.onCreate(savedInstanceState);
//        setContentView(R.layout.main);
//        ImageView view = (ImageView) findViewById(R.id.imageView);
//        view.setOnTouchListener(this);
//     }

       @Override
       public boolean onTouch(View v, MotionEvent event) {
          ImageView view = (ImageView) v;

          // Dump touch event to log
          dumpEvent(event);

//        // Handle touch events here...
          switch (event.getAction() & MotionEvent.ACTION_MASK) {
          case MotionEvent.ACTION_DOWN:
             savedMatrix.set(matrix);
             start.set(event.getX(), event.getY());
             Log.d(TAG, "mode=DRAG");
             mode = DRAG;
             break;
          case MotionEvent.ACTION_POINTER_DOWN:
             oldDist = spacing(event);
             Log.d(TAG, "oldDist=" + oldDist);
             if (oldDist > 10f) {
                savedMatrix.set(matrix);
                midPoint(mid, event);
                mode = ZOOM;
                Log.d(TAG, "mode=ZOOM");
             }
             break;
          case MotionEvent.ACTION_UP:
          case MotionEvent.ACTION_POINTER_UP:
             mode = NONE;
             Log.d(TAG, "mode=NONE");
             break;
          case MotionEvent.ACTION_MOVE:
             if (mode == DRAG) {
                // ...
                matrix.set(savedMatrix);
                matrix.postTranslate(event.getX() - start.x,
                      event.getY() - start.y);
             }
             else if (mode == ZOOM) {
                float newDist = spacing(event);
                Log.d(TAG, "newDist=" + newDist);
                if (newDist > 10f) {
                   matrix.set(savedMatrix);
                   float scale = newDist / oldDist;
                   matrix.postScale(scale, scale, mid.x, mid.y);
                }
             }
             break;
          }

          view.setImageMatrix(matrix);
          return true; // indicate event was handled
       }

       /** Show an event in the LogCat view, for debugging */
       private void dumpEvent(MotionEvent event) {
          String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
                "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
          StringBuilder sb = new StringBuilder();
          int action = event.getAction();
          int actionCode = action & MotionEvent.ACTION_MASK;
          sb.append("event ACTION_").append(names[actionCode]);
          if (actionCode == MotionEvent.ACTION_POINTER_DOWN
                || actionCode == MotionEvent.ACTION_POINTER_UP) {
             sb.append("(pid ").append(
                   action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
             sb.append(")");
          }
          sb.append("[");
          for (int i = 0; i < event.getPointerCount(); i++) {
             sb.append("#").append(i);
             sb.append("(pid ").append(event.getPointerId(i));
             sb.append(")=").append((int) event.getX(i));
             sb.append(",").append((int) event.getY(i));
             if (i + 1 < event.getPointerCount())
                sb.append(";");
          }
          sb.append("]");
          Log.d(TAG, sb.toString());
       }

       /** Determine the space between the first two fingers */
       private float spacing(MotionEvent event) {
          float x = event.getX(0) - event.getX(1);
       开发者_JAVA百科   float y = event.getY(0) - event.getY(1);
          return FloatMath.sqrt(x * x + y * y);
       }

       /** Calculate the mid point of the first two fingers */
       private void midPoint(PointF point, MotionEvent event) {
          float x = event.getX(0) + event.getX(1);
          float y = event.getY(0) + event.getY(1);
          point.set(x / 2, y / 2);
       }
}

I receive the log info's that a drag is detected but I can't see any change. What did I wrong with the declaration of my image view component? I need to declare it programmatic.


I am guessing you are missing the clickable property of the imageview. When we define imageview, we have to specified the clickable property for clicking, moving, touch. Did you have implement it on programatic loading?

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