How to expand view smoothly in Android?

Question

I met an issue when I expanded a 320*50 view to full-screen.

If I expand it directly, it works but the action is very abrupt and I think is not a good user experience. So I hide the view first, then expand it, and after two second, show the view again.

TextView.setVisibility(VIEW.INVISIBLE);
ViewGroup.LayoutParams lp = TextView.getLayoutParams();
lp.width = ViewGroup.LayoutParams.FILL_PARENT;
lp.height = ViewGroup.LayoutParams.FILL_PARENT;

//after two seconds
handler.postDelay(new Show(),2000);

class Show implements Runnable{
   @Override
public void run(){
       TextView.setVisibility(VIEW.VISIBLE);
   }
}

So l left two seconds for the application to expand the view. Then after two seconds the view will show again. I am expected that the view is expanded to full-screen when it shows. But actually, it doesn't. The view do the expand action after it shows instead of during the two seconds it is hiding.

Answer 1

1. Add android:animateLayoutChanges="true" to your ViewGroup.
2. Use setVisibility() to control the visibility of your target View.

3. If there is other View below you target View, add android:animateLayoutChanges="true" to your outer ViewGroup and following code before setVisibility():

   LayoutTransition layoutTransition = rootLinearLayout.getLayoutTransition();
   layoutTransition.enableTransitionType(LayoutTransition.CHANGING);