RotateDrawable

RotateDrawable is a drawable in the Android SDK that allows for the rotation of another drawable. It is commonly used to create visual effects or to indicate the orientation of an object. The drawable to be rotated is specified, along with an angle of rotation. This angle can be static or dynamically updated at runtime.

When a RotateDrawable is drawn, it first rotates its child drawable by the specified angle around its center. The rotation is typically applied in a clockwise direction. The RotateDrawable itself can be configured to rotate around a specific pivot point. By default, it rotates around the center of the drawable.

A common use case for RotateDrawable is to display a rotating indicator, such as a loading spinner or an element that shows the current state of a device. Developers can animate the rotation angle over time to create smooth visual transitions. For example, a refresh button might use a RotateDrawable to indicate that a data refresh is in progress.

The rotation angle is usually specified in degrees. It can be set directly in XML layout files or programmatically in Java or Kotlin code. When setting it programmatically, you can obtain a reference to the RotateDrawable and then use methods like set and setPivotX/setPivotY to control its behavior. The rotation can be a full 360 degrees or a partial rotation.