ImageView限制拖放和縮小屏幕

Question

我想限制imageView的拖放不熄滅屏幕，我不知道怎麼做，特別是當imageView放大時，我如何保持imageView在放大或縮小時的屏幕？

這裏是我的代碼：

/** 
* Apply drag zoom to image 
* 
* @param imageToEdit 
* @param mActivity 
*/ 
      public static void setOntoucheListner(ImageView imageToEdit, Activity mActivity, final ImageView imageMask) { 

    // Calcul pourcentage du min image 
    float ratio1 = imageToEdit.getWidth()/imageMask.getWidth(); 
    float ratio2 = imageToEdit.getHeight()/imageMask.getHeight(); 
    if (ratio1 < 1 && ratio2 < 1) 
     ZOOM_MIN = 1; 
    else 
     ZOOM_MIN = Math.min(ratio1, ratio2); 

    Display display = mActivity.getWindowManager().getDefaultDisplay(); 
    Point size = new Point(); 
    display.getSize(size); 
    screenWidth = size.x; 
    screenHeight = size.y; 
    matrix = new Matrix(); 
    savedMatrix = new Matrix(); 
    startPoint = new PointF(); 
    midPoint = new PointF(); 

    // imageToEdit.setImageMatrix(new Matrix()); 
    /** * set on touch listner on image */ 
    imageToEdit.setOnTouchListener(new View.OnTouchListener() { 
     private float savedTranslateX = 0; 
     private float savedTranslateY = 0; 

     @Override 
     public boolean onTouch(View v, MotionEvent event) { 
      ImageView view = (ImageView) v; 
      System.out.println("matrix=" + savedMatrix.toString()); 
      switch (event.getAction() & MotionEvent.ACTION_MASK) { 
      case MotionEvent.ACTION_DOWN: 
       savedMatrix.set(matrix); 
       startPoint.set(event.getX(), event.getY()); 
       mode = DRAG; 
       break; 
      case MotionEvent.ACTION_POINTER_DOWN: 
       oldDist = spacing(event); 
       if (oldDist > 10f) { 
        savedMatrix.set(matrix); 
        midPoint(midPoint, event); 
        mode = ZOOM; 
       } 
       break; 
      case MotionEvent.ACTION_UP: 
      case MotionEvent.ACTION_POINTER_UP: 
       mode = NONE; 
       break; 
      case MotionEvent.ACTION_MOVE: 
       if (mode == DRAG) { 

        imageMask.getTop(); 
        imageMask.getTop(); 
        matrix.set(savedMatrix); 
        matrix.postTranslate(event.getX() - startPoint.x, event.getY() - startPoint.y); 
        mode = DRAG; 
       } else if (mode == ZOOM) {                                                                                                             
        float newDist = spacing(event); 
        if (newDist > 10f) { 
         matrix.set(savedMatrix); 
         float scale = newDist/oldDist; 
         matrix.postScale(scale, scale, midPoint.x, midPoint.y); 
        } 
       } 
       break; 
      } 

      float[] f = new float[9]; 
      matrix.getValues(f); 
      float scaleX = f[Matrix.MSCALE_X]; 
      float scaleY = f[Matrix.MSCALE_Y]; 
      if (mode == ZOOM) { 
       if (scaleX <= ZOOM_MIN) 
        matrix.postScale((ZOOM_MIN)/scaleX, (ZOOM_MIN)/scaleY, midPoint.x, midPoint.y); 
       else if (scaleX >= ZOOM_MAX) 
        matrix.postScale((ZOOM_MAX)/scaleX, (ZOOM_MAX)/scaleY, midPoint.x, midPoint.y); 
       else { 

        view.setImageMatrix(matrix); 
       } 
      } else { 
       view.setImageMatrix(matrix); 
      } 

      return true; 
     } 

     @SuppressLint("FloatMath") 
     private float spacing(MotionEvent event) { 
      float x = event.getX(0) - event.getX(1); 
      float y = event.getY(0) - event.getY(1); 
      return FloatMath.sqrt(x * x + y * y); 
     } 

     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); 
     } 
    }); 
} 

}

感謝的很多您的答覆

Answer 1

我解決我的問題，當用戶DRAP ImageView的出界和釋放他的手指，我更換imageView上的最後有效的地方，所以我完成這種情況MotionEvent.ACTION_POINTER_UP像這樣：我的限制這裏不是屏幕，但另一個ImageView，

  case MotionEvent.ACTION_POINTER_UP: 
       matrix.getValues(values); 
       translateX = values[Matrix.MTRANS_X]; 
       translateY = values[Matrix.MTRANS_Y]; 

       Log.d("####### actualWidthImageToEdit" 
         + actualWidthImageToEdit); 
       Log.d("####### translateX" + translateX); 
       Log.d("####### imageMask.getRight()" + imageMask.getRight()); 
       // After User release fingers from screen we test if image 
       // is on a valid position if not we replace it in the last 
       // valid position 
       if (mode == DRAG || mode == DEZOOM) { 
        if (
        // Limit Left, Move left to right 
        translateX > imageMask.getLeft() 
        // Limit Button, from top to buttom 
          || translateY > imageMask.getTop() 
          // left to right 
          || actualWidthImageToEdit 
            - imageMask.getRight() + translateX < 0 
          // Limit Top, from buttom to top 
          || actualHeightImageToEdit 
            - imageMask.getBottom() + translateY < 0 

        ) { 

         matrix = new Matrix(savedMatrix); 
         view.setImageMatrix(matrix); 
         view.invalidate(); 
        } 
       }