CODEWITHSUNDEEP
androidimage-rotationtouch-event
Saurabh
Saurabh

Reputation: 457

rotate image on every touch event

In my application, I have some images and when I tap on that image, it should be rotated by 90 degree. I am able to rotate image once but can't rotate on second tap. Can anyone help me to solve this problem? How can I rotate image on every touch event?

if (event.getAction() == MotionEvent.ACTION_DOWN) {
    Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.quartercircle1);
        Matrix m = new Matrix();
        imgvwQrtr1.setScaleType(ScaleType.MATRIX);

        m.setRotate(90f, imgvwQrtr1.getDrawable().getBounds().width()/2, imgvwQrtr1.getDrawable().getBounds().height()/2);
        bm = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), m, true);
        imgvwQrtr1.setImageBitmap(bm);


        ClipData data = ClipData.newPlainText("", "");
        DragShadowBuilder shadowBuilder = new DragShadowBuilder(v);
        v.startDrag(data, shadowBuilder, v, 0);
        return true;
    }

Upvotes: 1

Views: 1285

Answers (2)

Krishna Prasad
Krishna Prasad

Reputation: 691

you need to create global variable like:

int degree = 0;

and in the code

.....
//shortest way
degree = degree + 90;
if(degree % 360 == 0) {
   degree = 0;
}
//if(degree >= 270) {
   //degree = 0;
//} else {
   //degree+=90;
//}
m.setRotate(degree, imgvwQrtr1.getDrawable().getBounds().width()/2,
imgvwQrtr1.getDrawable().getBounds().height()/2);
....

Upvotes: 1

Rachel Gallen
Rachel Gallen

Reputation: 28563

try this

    public static float getRotationAngle(final float x1, final float y1, final float x2, final float y2) {
                final float CLOCK_WISE = 1.0f;
                final float ANTI_CLOCK_WISE = -1.0f;

                final float deltaX = Math.abs(x2 - x1);
                final float deltaY = Math.abs(y2 - y1);

                if (deltaX == 0) {
                        return 0.0f;
                }

                final float angle = (float) Math.toDegrees(Math.atan(deltaY / deltaX));

                if (x1 <= x2 && y2 <= y1) {
                        return CLOCK_WISE * (90.0f - angle);
                } else if (x2 <= x1 && y2 <= y1) {
                        return ANTI_CLOCK_WISE * (90.0f - angle);
                } else if (x2 <= x1 && y1 <= y2) {
                        return ANTI_CLOCK_WISE * (90.0f + angle);
                } else if (x1 <= x2 && y1 <= y2) {
                        return CLOCK_WISE * (90.0f + angle);
                } else {
                        return 0.0f;
                }
        }

Upvotes: 0

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