Question

I am using MotionEvent and Matrix to drag my bitmap but instead the bitmap gets “translated” to a nearby region (most of the times in the opposite direction of press). I want to be able to drag it using Matrix translations. Here’s my code.

switch(action){
        case MotionEvent.ACTION_DOWN: {
            final float touchX = event.getX();
            final float  touchY = event.getY();
          //check to see if the user is pressing  at most 80 pixels far from the bitmap 
            if(((Math.abs(touchX - player.prevX)<=80) && ((Math.abs(touchY - player.prevY)<=80)))){
                 //if so then proceed to drag it to a new location
                player.isDraggable = true;
            }
            break;
        }
        case MotionEvent.ACTION_MOVE: {
            if(player.isDraggable){
                player.x = event.getX();
                player.y = event.getY();                    
                float dx = player.x - player.prevX, dy = player.y - player.prevY;
                player.matrix.postTranslate(dx, dy);
                player.prevX = player.x;
                player.prevY = player.y;
                player.isDraggable = false; 
        }
            break;
        }
    }
public void draw(Canvas canvas) {       
        canvas.drawBitmap(background, 0, 0, null);
        canvas.drawBitmap(player.bmp, player.matrix, null);
       for(int i=0;i<particles.size();i++){
           particles.get(i).drawShower(canvas);
        }    

}

Answer 1

1. Your onTouch() method should return true to be able to get
   continuously values from the MotionEvent.
2. You set the isDraggable attribute of your player immediately to
   false, when an attempt to drag the image appears. After that, you check each time, if it is true, but it wont be. I don’t know, what is the logic behind that, but try something else!