Android examples for Animation:Expand Animation
expand a View Vertical with AnimationListener
//package com.java2s; import android.view.View; import android.view.ViewGroup; import android.view.animation.AlphaAnimation; import android.view.animation.Animation; import android.view.animation.Transformation; public class Main { public static void expandVertical(final View v, int duration, Animation.AnimationListener listener) { v.measure(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); final int targetHeight = v.getMeasuredHeight(); v.getLayoutParams().height = 0;// ww w . j a v a2 s . com v.setVisibility(View.VISIBLE); Animation a = new AlphaAnimation((float) 0.0, (float) 1.0) { @Override protected void applyTransformation(float interpolatedTime, Transformation t) { super.applyTransformation(interpolatedTime, t); v.getLayoutParams().height = interpolatedTime == 1 ? ViewGroup.LayoutParams.WRAP_CONTENT : (int) (targetHeight * interpolatedTime); v.requestLayout(); } @Override public boolean willChangeBounds() { return true; } }; if (listener != null) { a.setAnimationListener(listener); } // 1dp/ms a.setDuration(duration); v.startAnimation(a); } }