Thursday, January 31, 2013

DevBytes: BitmapAllocation

This example shows how to speed up bitmap loading and reduce garbage collection by reusing existing bitmaps.

Note that the reused bitmap must be mutable and of the same size and configuration as the bitmap you load into it. Not sure if this is clear from the video, although it is documented in the API.

Code: http://developer.android.com/shareables/devbytes/BitmapAllocation.zip

Video: http://www.youtube.com/watch?v=rsQet4nBVi8

DevBytes: BitmapScaling

This example shows how the use of BitmapOptions affects the resulting size of a loaded bitmap. Sub-sampling can speed up load times and reduce the need for large bitmaps in memory if your target bitmap size is much smaller, although it's good to understand that you can't get specific Bitmap sizes, but rather power-of-two reductions in sizes.

Code: http://developer.android.com/shareables/devbytes/BitmapScaling.zip

Video: http://www.youtube.com/watch?v=12cB7gnL6po

Wednesday, January 16, 2013

DevBytes: Short, Focused Android Tutorials

The Android team has just rolled out the first four shows in a new series called DevBytes, which is intended to be very short, focused tutorials on specific developer topics. A quick explanation, maybe a demo, and a few lines of code to walk through and it's done. Taking a break from work? Want to learn something new? Or just wonder how a specific piece of technology works on the platform? Tune into one of the DevBytes episodes to get a quick deep dive into that exact topic (well, assuming we've done a show on that topic. Maybe we could interest you in one of the shows that we've actually filmed yet instead?)

The first few of these feature ... me! (Surprise, surprise!) I'll be doing many of these tutorials over time, especially in the areas of animation, graphics, and UI development, starting with this first set:


ViewAnimations:
This show covers the basics of creating and running pre-3.0 Animations on View objects.

PropertyAnimations:
This show parallels the ViewAnimations demo, but uses the new Animator classes introduced in Android 3.0.

WindowAnimations:
Ever want to use a custom window animation to transition between sub activities? Watch this show.

CrossFading:
TransitionDrawable can be used for very simple cross-fade effects between two different Drawable objects.

There will be other shows coming online in the future as well; we're just starting with some of the ones that I did. I wouldn't mind if everything were about animation, but that's just me...

There are code links in the video descriptions if you want to see the code I cover in the videos. I'll also be posting individual blogs with the video and code links to make this easier, I just wanted to get this introduction/overview out there to get it rolling.

These are just a start: we have more videos on the way in the coming weeks. So tune in and geek out.