rijinrv rijinrv - 1 year ago 110
Android Question

Android: Rotate image in imageview by an angle

I am using the following code to rotate a image in ImageView by an angle. Is there any simpler and less complex method available.

ImageView iv = (ImageView)findViewById(imageviewid);
TextView tv = (TextView)findViewById(txtViewsid);
Matrix mat = new Matrix();
Bitmap bMap = BitmapFactory.decodeResource(getResources(),imageid);
mat.postRotate(Integer.parseInt(degree));===>angle to be rotated
Bitmap bMapRotate = Bitmap.createBitmap(bMap, 0, 0,bMap.getWidth(),bMap.getHeight(), mat, true);

Aks Aks
Answer Source

Another simple way to rotate an ImageView:
Required imports:

import android.graphics.Matrix;
import android.widget.ImageView;

Code: (Assuming imageView, angle, pivotX & pivotY are already defined)

Matrix matrix = new Matrix();
imageView.setScaleType(ImageView.ScaleType.MATRIX);   //required
matrix.postRotate((float) angle, pivotX, pivotY);

This method does not require creating a new bitmap each time.

NOTE: To rotate an ImageView on ontouch at runtime you can set onTouchListener on ImageView & rotate it by adding last two lines(i.e. postRotate matrix & set it on imageView) in above code section in your touch listener ACTION_MOVE part.