In Android there is a method setRotation(float), which you can use it
textview.setRotation(float);
NOTE: this method was added in API 11
so if you want to support it you can use this
if (Build.VERSION.SDK_INT < 11) {
RotateAnimation animation = new RotateAnimation(oldAngel, newAngel);
animation.setDuration(100);
animation.setFillAfter(true);
watermarkText.startAnimation(animation);
} else {
watermarkText.setRotation(progress);
}
EDIT: Here's my solution:

Here's my full activity_main.xml
:
For creating triangle, create triangle.xml
file in this directory:
your_app_name/app/src/main/res/drawable
and as content put this code:
-
In your Java MainActivity
class put:
TextView oldPrice = (TextView) findViewById(R.id.old_price);
oldPrice.setPaintFlags(oldPrice.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
to add to your old price text strike-through effect.
If you have a question, please free to ask.
Hope it help