How to rotate an image clockwise and anti-clockwise on multiple(2 and more) fingers touch in android?

Question

I have to rotate an image on touch of multiple finger(2 and more) in android device. If any one have a solution then please help me. I got a solution, But it is working very fine for the single finger Touch. Here is the link

Please help me, I am indeed. :( :(

Answer 1

Hello all i got a best solution to this.click Here to see. In this link you will get there functionality (a)Drag (b)Zoom (c)Rotation. You can use any one from them or every one from them in your code according to need by editing in code of this example. Best of luck :)

Answer 2

Try with below code its working for me.

float[] lastEvent = null;
float d = 0f;
float newRot = 0f;
private Matrix matrix = new Matrix();
private Matrix savedMatrix = new Matrix();
public static String fileNAME;
public static int framePos = 0;

private float scale = 0;
private float newDist = 0;

// Fields
private String TAG = this.getClass().getSimpleName();

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

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

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

            // Handle touch events here...
            switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                savedMatrix.set(matrix);
                start.set(event.getX(), event.getY());
                mode = DRAG;
                lastEvent = null;
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
                oldDist = spacing(event);
                if (oldDist > 10f) {
                    savedMatrix.set(matrix);
                    midPoint(mid, event);
                    mode = ZOOM;
                }
                lastEvent = new float[4];
                lastEvent[0] = event.getX(0);
                lastEvent[1] = event.getX(1);
                lastEvent[2] = event.getY(0);
                lastEvent[3] = event.getY(1);
                d = rotation(event);
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_POINTER_UP:
                mode = NONE;
                lastEvent = null;
                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 && event.getPointerCount() == 2) {
                    float newDist = spacing(event);
                    matrix.set(savedMatrix);
                    if (newDist > 10f) {
                        float scale = newDist / oldDist;
                        matrix.postScale(scale, scale, mid.x, mid.y);
                    }
                    if (lastEvent != null) {
                        newRot = rotation(event);
                        float r = newRot - d;
                        matrix.postRotate(r, view.getMeasuredWidth() / 2,
                                view.getMeasuredHeight() / 2);
                    }
                }
                break;
            }

            view.setImageMatrix(matrix);

            return true;
        }

//For rotate image on multi-touch.

private float rotation(MotionEvent event) {
        double delta_x = (event.getX(0) - event.getX(1));
        double delta_y = (event.getY(0) - event.getY(1));
        double radians = Math.atan2(delta_y, delta_x);

        return (float) Math.toDegrees(radians);
    }
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);
    }

Answer 3

Use matrix.postRotate(DEGREE)

bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),bitmap.getHeight(), matrix, true);

Then set this bitmap to your image view.