androidダブル指スケーリング

img_round.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                // return ArtFilterActivity.this.mGestureDetector.onTouchEvent(event);
                if (event.getAction() == MotionEvent.ACTION_DOWN) {
                    baseValue = 0;
                    float x = last_x = event.getRawX();
                    float y = last_y = event.getRawY();
                } else if (event.getAction() == MotionEvent.ACTION_MOVE) {
                    if (event.getPointerCount() == 2) {
                        float x = event.getX(0) - event.getX(1);
                        float y = event.getY(0) - event.getY(1);
//                        float value = (float) Math.sqrt(x * x + y * y);//        
                        float value = (float) x;//   x   
                        if (baseValue == 0) {
                            baseValue = value;
                        } else {
                            if (value - baseValue >= 10 || value - baseValue <= -10) {
                                float scale = value / baseValue;//                               。
                                Log.e("ddddddd",scale+"");  //    
                            }
                        }
                    } else if (event.getPointerCount() == 1) {
                        float x = event.getRawX();
                        float y = event.getRawY();
                        x -= last_x;
                        y -= last_y;
                        if (x >= 10 || y >= 10 || x <= -10 || y <= -10)
                            Log.e("      ", "      "); //      
                        last_x = event.getRawX();
                        last_y = event.getRawY();
                    }
                } else if (event.getAction() == MotionEvent.ACTION_UP) {

                }
                return true;
            }
        });