Question

I want to create an animation for an image that is loaded into a vertical linear layout dynamically. When triggered I would like the image to slide down with its alpha set to 0 (this will slide all content below it down I hope) then fade the image in. Being new to Android animations I am having some trouble. Right now I’m trying to get just the fade in to work, here is what I have:

fade_in.xml

<?xml version="1.0" encoding="utf-8"?>

<alpha
    xmlns:android="https://chemas.android.com/ap/res/android"
    android:interpolator="@android:anim/anticipate_interpolator"
    android:fromAlpha="0.0"
    android:toAlpha="1.0"
    android:duration="5000" >
</alpha>

In the Activity:

Animation animation = AnimationUtils.loadAnimation(context, R.anim.fade_in);

ImageView image = new ImageView(context);
image.setImageResource(R.drawable.my_image);
image.setLayoutParams(layoutParams);
image.setAlpha(0);

((ViewGroup) view).addView(image, 0);

image.startAnimation(animation);

The image is being loaded as all the context below it is shifted down, however if never fades in. I would like to get this working as well as having the image slide down so the dynamica add does not look so choppy.

Thanks in advance.

Answer 1

You have a typo in the xmlns:android tag.

It should be

xmlns:android = "http://schemas.android.com/apk/res/android"

With that being corrected, just remove the image.setAlpha(0); and it should animate. I am afraid I cannot give you a reason why it doesn’t work with the alpha attribute set to 0.

Regarding the slide down animation, you will have to subclass Animation. Have a look at this answer that I think can help you get what you want: https://stackoverflow.com/a/5122460/871102