JumpingBeans

The JumpingBeans make your test jump to the eye. Literally!

What are the JumpingBeans

Have you ever used Hangouts? If not, do it and then come back here. Go. Go, I said!

Good. With that under our belt, we can be confident you've seen at least once those fancy, nice jumping suspension dots that Hangouts uses to indicate that someone is typing, or some other kind of ongoing activity (e.g., connecting to a video hangout).

Well, since there's no official naming for them, and since they remind me of the jumping Mexican beans, the name for a library that emulates their behaviour has come to be exactly that: JumpingBeans.

See them in action

Please come closer, ladies and gentlemen! Here you have, for your own amusement, the amazing JumpingBeans:

What you can do

The library supports two main operation modes: appending three jumping dots, Hangouts-style, or making any arbitrary subsection of a CharSequence jump, either as a wave or as a single block.

Append jumping dots

This method takes the trailing ... (or appends them, if the given TextView's text doesn't end in three dots), and makes them jump like it was -the 70s- Hangouts.

The defaults emulate the Hangouts L&F as closely as possible, but you can easily change the animation properties to suit your needs.

Make text jumping

This method takes the specified subsection a the TextView text and animates it as to make it jump.

Usage

Just create a JumpingBeans by using its Builder and call the method you want:

// Append jumping dots
final TextView textView1 = (TextView) findViewById(R.id.jumping_text_1);
jumpingBeans1 = new JumpingBeans.Builder()
        .appendJumpingDots(textView1)
        .build();
        
// Make the first word's letters jump
final TextView textView2 = (TextView) findViewById(R.id.jumping_text_2);
jumpingBeans2 = new JumpingBeans.Builder()
        .makeTextJump(textView2, 0, textView2.getText().toString().indexOf(' '))
        .build();

Customising the jumpin' beans

Just act on the Builder. Don't want the dots to jump in a wave? Call setIsWave(false). Don't like the default loop duration? setLoopDuration(int) is here to help. Fancy different per-char delays in waves? Well, ya know that setWavePerCharDelay(int) is the one you want. Maybe you wanted to have a shorter pause between jumping cycles? BAM, setAnimatedDutyCycle(float) and you're all set.

Being a responsible citizen

Since Spans were not really designed to be animated, there's some trickery going on behind the scenes to make this happen. You needn't be concerned with it, but make sure you call the stopJumping() method on your JumpingBeans object whenever you stop using the TextView (it's detaching from the view tree, or the container Activity or Fragment is going in paused state, ...).

This allows a deeper cleanup than what the JumpingBeans library is trying to perform if you forget to. Don't leave stuff lying around if you can!

Also, a few caveats

Please note that you:

Must not try to change a jumping beans text in a textview before calling stopJumping() as to avoid unnecessary invalidation calls; the JumpingBeans class cannot know when this happens and will keep animating the textview (well, try to, anyway), wasting resources
Must not try to use a jumping beans text in another view; it will not animate. Just create another jumping beans animation for each new view
Must not use more than one JumpingBeans instance on a single TextView, as the first cleanup operation called on any of these JumpingBeans will also cleanup all other JumpingBeans' stuff. This is most likely not what you want to happen in some cases.
Should not use JumpingBeans on large chunks of text. Ideally this should be done on small views with just a few words. We've strived to make it as inexpensive as possible to use JumpingBeans but invalidating and possibly relayouting a large TextView can be pretty expensive.

Demo app

You can find the JumpingBeans demo app on the Google Play Store.

License

This library was written by Sebastiano Poggi and released by Frakbot under the Apache 2.0 License.

Please see the NOTICE file for details.

aikun/JumpingBeans