How to make text fade in and out in Android?

I have a paragraph of text and when a button is clicked I want that text to fade out, change to some other text, then fade back in. I have some code but it doesn't do the fade out animation just the fade in.

    final TextView mSwitcher = (TextView) findViewById(R.id.bookContent);
    mSwitcher.setText("old text");

    final Animation in = new AlphaAnimation(0.0f, 1.0f);
    in.setDuration(3000);

    final Animation out = new AlphaAnimation(1.0f, 0.0f);
    out.setDuration(3000);

    Button moveOn = (Button) findViewById(R.id.moveOn);
    moveOn.setOnClickListener( new OnClickListener() {
        public void onClick(View v) {

            mSwitcher.startAnimation(out);
            mSwitcher.setText("new text");
            mSwitcher.startAnimation(in);

        }
    });

Solution 1:

You seem to be setting the animation to in right after you had set it to out. This makes only the "in" animation work.

To make the second animation start right after the first, you can add a listener to your first animation:

out.setAnimationListener(new AnimationListener() {

    @Override
    public void onAnimationEnd(Animation animation) {
        mSwitcher.setText("New Text");
        mSwitcher.startAnimation(in);

    }
});

Then, in your onClick() method:

public void onClick(View v) {

    mSwitcher.startAnimation(out);

}

That should do the trick.

Another approach is to use AnimationSet.

final Animation in = new AlphaAnimation(0.0f, 1.0f);
in.setDuration(3000);

final Animation out = new AlphaAnimation(1.0f, 0.0f);
out.setDuration(3000);

AnimationSet as = new AnimationSet(true);
as.addAnimation(out);
in.setStartOffset(3000);
as.addAnimation(in);

Then, instead of starting out, start as.

I hope this helps!

Solution 2:

You should consider using something like a TextSwitcher. There is a brief document on TextSwitcher in the Android documentation. What I would recommend best though is to look at the API Demos, there is a great and simple to use one of TextSwitchers. Download the API Demos and check them out for yourself, or see here.