Sometimes you may need to display short animations in your applications like funny GIFs. The problem with GIFs is that they have only 256 colors and poor transparency. You can consider using PNGs, but basically that type of image doesn't support animations. So what can you do to push the advantage of PNGs (great lossless compression, alpha channels, various coloring schemes, etc.)?
This is a tutorial about using the e3roid 2D OpenGL framework for Android platform that has easy to use, simple API. The example will shown how to use textures, sprites and how to handle UI events.
This animations can be highly customized and combined, for example we can set the speed, delay, acceleration, duration of animations, then group them together in an AnimationSet.
Animations can be applyed as Layout animations to ViewGroups, to be triggered when the ViewGroup is created/displayed or applied to any view and be triggered by us any time.
The animations can be definex in XMl or by code. Defining in xml is mutch more clear, but you can not set animation parameters dinamically.
The animation XML files should be created in the res/anim folder and can be accessed using the R class, like R.anim.animation_name.
An animation defined in hyperspace_jump.xml can look like this:
I part 3 of the MusicDroid tutorial we create a simple controls interface that will be launched by our playlist when you play a song. The controls interface is a translucent Activity that simply has 4 images, one for each direction on the D-Pad. When you hit a direction on the pad it will send a command to the service and play a small animation.
This tutorial utilizes the work done in parts 1 and 2, though you do not have to be familiar with those parts if you just want some examples of animation or transparency.
