Android scale animation on view

android, animation

Solution

Here is a code snip to do exactly that.

public void scaleView(View v, float startScale, float endScale) {
    Animation anim = new ScaleAnimation(
            1f, 1f, // Start and end values for the X axis scaling
            startScale, endScale, // Start and end values for the Y axis scaling
            Animation.RELATIVE_TO_SELF, 0f, // Pivot point of X scaling
            Animation.RELATIVE_TO_SELF, 1f); // Pivot point of Y scaling
    anim.setFillAfter(true); // Needed to keep the result of the animation
    anim.setDuration(1000);
    v.startAnimation(anim);
}

The ScaleAnimation constructor used here takes 8 args, 4 related to handling the X-scale which we don't care about `(1f, 1f, ... Animation.RELATIVE_TO_SELF, 0f, ...)`.

The other 4 args are for the Y-scaling we do care about.

`startScale, endScale` - In your case, you'd use `0f, 0.6f`.

`Animation.RELATIVE_TO_SELF, 1f` - This specifies where the shrinking of the view collapses to (referred to as the pivot in the documentation). Here, we set the float value to `1f` because we want the animation to start growing the bar from the bottom. If we wanted it to grow downward from the top, we'd use `0f`.

Finally, and equally important, is the call to `anim.setFillAfter(true)`. If you want the result of the animation to stick around after the animation completes, you must run this on the animator before executing the animation.

So in your case, you can do something like this:

View v = findViewById(R.id.viewContainer);
scaleView(v, 0f, .6f);

Problem

Original source