Universal Image Loader: Story, Architecture, FAQ

Presentation of Android library - Universal Image Loader.
Presented on:
- MobileOptimized 2014 conference in Minsk, Belarus (29.06.2014)
- Mobilization 4 conference in Lodz, Poland (18.10.2014)

1. Universal Image Loader Story, Architecture, FAQ Sergey Tarasevich @nostra13

2. Who’s this man? Sergey Tarasevich (@nostra13) Android developer at CactusSoft Author of Universal Image Loader Certified Java SE 7 Programmer

3. Story

4. Chronology 27.11.2011 – First commit on GitHub 08.12.2011 – Article on Habrahabr.ru 09.02.2012 – Versioning 19.01.2013 – Mavenizing 3 .2013 –  1000 07.2013 –  2000 10.2013 –  3000 03.2014 –  4000 06.2014 –  5000 10.2014 – 6 000

5. Statistics #1 Android image loading lib on GitHub #3 Android lib on GitHub #5 Java repo on GitHub #27 Android lib (appbrain.com) 3.09% of installs

6. Architecture

7. Modules Image Loader Image Downloader Image Decoder Memory Cache Disk Cache

8. API ImageLoaderConfiguration DisplayImageOptions ImageLoader displayImage ( … ) loadImage ( … ) loadImageSync ( … )

9. API ImageAware MemoryCache DiskCache FileNameGenerator ImageDownloader ImageDecoder BitmapProcessor BitmapDisplayer

10. ImageAware getId () : int getWidth () : int getHeight () : int getScaleType () : ViewScaleType getWrappedView () : View isCollected () : boolean setImageDrawable ( Drawable drawable ) : boolean setImageBitmap (Bitmap bitmap ) : boolean

11. Task flow

12. Disk cache

13. Memory cache Weak Strong Weak&Strong

14. ImageScaleType Source image size: 4000x3000 Target view size: 280x280 ImageScaleType Result bmp size NONE 4000x3000 NONE_SAFE 2000x1500 /2 IN_SAMPLE_POWER_OF_2 500x375 /8 (2 ³) IN_SAMPLE_INT 400x300 /10 EXACTLY 374x280 /10+ EXACTLY_STRETCHED 374x280 /10+

15. So…

16. Why so slow?

17. No tests?

18. Singleton?

19. OutOfMemoryError

20. OutOfMemoryError . bitmapConfig (Bitmap.Config.RGB_565 ) . imageScaleType ( ImageScaleType.EXACTLY ) . threadPoolSize (...) // 1 – 5 . diskCacheExtraOptions (480, 320, null) . cacheInMemory (false) MemoryAnalyzer Still OOM

21. « ImageAware is reused for another image. Task is cancelled [http://…] »

22. « …[http://v.ad/image.png_666x13] » _666x13 _666x13 _666x13

23. “How to display images from JSON!? Not Constants!”

24. Alternatives?

25. UIL vs Picasso

26. Questions?

27. Thanks!