Android: Using ObjectAnimator to translate a View with fractional values of the View’s dimension

Actually object animators accept fractional values. But maybe you didn’t understand the underlying concept of an objectAnimator or more generally a value animator. A value animator will animate a value related to a property (such as a color, a position on screen (X,Y), an alpha parameter or whatever you want). To create such a property (in your case xFraction and yFraction) you need to build your own getters and setters associated to this property name. Lets say you want to translate a FrameLayout from 0% to 25% of the size of your whole screen. Then you need to build a custom View that wraps the FrameLayout objects and write your getters and setters.

public class SlidingFrameLayout extends FrameLayout
{
    private static final String TAG = SlidingFrameLayout.class.getName();

    public SlidingFrameLayout(Context context) {
        super(context);
    }

    public SlidingFrameLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public float getXFraction()
    {
        int width = getWindowManager().getDefaultDisplay().getWidth();
        return (width == 0) ? 0 : getX() / (float) width;
    }

    public void setXFraction(float xFraction) {
        int width = getWindowManager().getDefaultDisplay().getWidth();
        setX((width > 0) ? (xFraction * width) : 0);
    }
}

Then You can use the xml way to declare the object animator putting xFraction under the property xml attribute and inflate it with a AnimatorInflater

<?xml version="1.0" encoding="utf-8"?>
<objectAnimator 
xmlns:android="http://schemas.android.com/apk/res/android"
android:propertyName="xFraction" 
android:valueType="floatType"
android:valueFrom="0"
android:valueTo="0.25" 
android:duration="500"/>

or you can just use the java line code

ObjectAnimator oa = ObjectAnimator.ofFloat(menuFragmentContainer, "xFraction", 0, 0.25f);

Hope it helps you!

Olivier,