Building Android UIs with Custom Views

ObjectAnimator

If we want to animate objects directly instead of properties, we could use the ObjectAnimator class. ObjectAnimator is a subclass of ValueAnimator and uses the same functionality and features, but adds the ability to animate objects properties by name.

For instance, to show how it works, we could animate a property of our own View this way. Let's add a small rotation to the whole canvas, controlled by the canvasAngle variable:

float canvasAngle; 
 
@Override 
protected void onDraw(Canvas canvas) { 
    canvas.save(); 
    canvas.rotate(canvasAngle, getWidth() / 2, getHeight() / 2); 
 
    ... 
 
    canvas.restore(); 
} 

We've got to create a setter and a getter with the right name: set<VariableName>and get<VariableName> in camel case, and in our specific ...