Android ImageView Zoom-in and Zoom-Out

Question

I want to Zoom-in and Zoom-out an Android ImageView. I tried most of the samples but in all of them the image in the ImageView itself is getting Zoomed-in and Zoomed-out, wh

Answer 1

I am Using this one it is working perfectly.

My a MyZoomableImageViewTouch class is below:

public class MyZoomableImageViewTouch extends ImageViewTouch
{

    static final float SCROLL_DELTA_THRESHOLD = 1.0f;

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

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

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

    private void init() {
        View.OnTouchListener listener = new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                if (getScale() > 1f) {
                    getParent().requestDisallowInterceptTouchEvent(true);
                } else {
                    getParent().requestDisallowInterceptTouchEvent(false);
                }
                return false;
            }
        };
        setOnTouchListener(listener);
        setDisplayType(DisplayType.FIT_TO_SCREEN);
    }

    @Override
    protected float onDoubleTapPost(float scale, float maxZoom) {
        if (scale != 1f) {
            mDoubleTapDirection = 1;
            return 1f;
        }
        if (mDoubleTapDirection == 1) {
            mDoubleTapDirection = -1;
            if ((scale + (mScaleFactor * 2)) <= maxZoom) {
                return scale + mScaleFactor;
            } else {
                mDoubleTapDirection = -1;
                return maxZoom;
            }
        } else {
            mDoubleTapDirection = 1;
            return 1f;
        }
    }

    @Override
    public boolean canScroll(int direction) {
        RectF bitmapRect = getBitmapRect();
        updateRect(bitmapRect, mScrollRect);
        Rect imageViewRect = new Rect();
        getGlobalVisibleRect(imageViewRect);

        if (null == bitmapRect) {
            return false;
        }

        if (Math.abs(bitmapRect.right - imageViewRect.right) < SCROLL_DELTA_THRESHOLD) {
            if (direction < 0) {
                return false;
            }
        }

        if (Math.abs(bitmapRect.left - mScrollRect.left) < SCROLL_DELTA_THRESHOLD) {
            if (direction > 0) {
                return false;
            }
        }
        return true;
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
    {
        if (getScale() == 1f) return false;
        if (distanceX != 0 && !canScroll((int) -distanceX)) {
            getParent().requestDisallowInterceptTouchEvent(false);
            return false;
        } else {
            getParent().requestDisallowInterceptTouchEvent(true);
            mUserScaled = true;
            scrollBy(-distanceX, -distanceY);
            invalidate();
            return true;
        }
    }
}