Android: how to clip only top rounded corners
This is a Kotlin variation of @Jankers answer and answers to @Tony's question also. Explains how you can set only one rounded corner or two adjacent ones.
fun setCorners() {
val outlineProvider = object : ViewOutlineProvider() {
override fun getOutline(view: View, outline: Outline) {
val left = 0
val top = 0
val right = view.width
val bottom = view.height
val cornerRadiusDP = 16f
val cornerRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, cornerRadiusDP, resources.displayMetrics).toInt()
// all corners
outline.setRoundRect(left, top, right, bottom, cornerRadius.toFloat())
/* top corners
outline.setRoundRect(left, top, right, bottom+cornerRadius, cornerRadius.toFloat())*/
/* bottom corners
outline.setRoundRect(left, top - cornerRadius, right, bottom, cornerRadius.toFloat())*/
/* left corners
outline.setRoundRect(left, top, right + cornerRadius, bottom, cornerRadius.toFloat())*/
/* right corners
outline.setRoundRect(left - cornerRadius, top, right, bottom, cornerRadius.toFloat())*/
/* top left corner
outline.setRoundRect(left , top, right+ cornerRadius, bottom + cornerRadius, cornerRadius.toFloat())*/
/* top right corner
outline.setRoundRect(left - cornerRadius , top, right, bottom + cornerRadius, cornerRadius.toFloat())*/
/* bottom left corner
outline.setRoundRect(left, top - cornerRadius, right + cornerRadius, bottom, cornerRadius.toFloat())*/
/* bottom right corner
outline.setRoundRect(left - cornerRadius, top - cornerRadius, right, bottom, cornerRadius.toFloat())*/
}
}
myView.outlineProvider = outlineProvider
myView.clipToOutline = true
}
I've managed to get this working by creating a custom ViewOutlineProvider and using that instead of a background value
ViewOutlineProvider mViewOutlineProvider = new ViewOutlineProvider() {
@Override
public void getOutline(final View view, final Outline outline) {
float cornerRadiusDP = 16f;
float cornerRadius = TypedValue.applyDimension( TypedValue.COMPLEX_UNIT_DIP, cornerRadiusDP, getResources().getDisplayMetrics());
outline.setRoundRect(0, 0, view.getWidth(), (int)(view.getHeight() + cornerRadius), cornerRadius);
}
};
scrollView.setOutlineProvider(mViewOutlineProvider);
scrollView.setClipToOutline(true);