1. Android
App to the challenge
Udi Cohen

2. We'll talk about..
● Graphics:
– Over Draw
– Detect UI glitches
– Optimizing layouts with HierarchyViewer
● Profiling with Traceview
● Helping the GC with HPROF
● Playing tough with StrictMode
● Getting intimate with the OS using EventLog
● Hardware Accelerate your app
● Tips

3. whoami

4. Over Draw
● Draw something on top of
something else 4x
● Rule – aim overdraw to 2x 3x
● Could indicate a complex
2x
hierarchy
● “Show GPU overdraws” on
Developer options (4.2+)
1x

5. Over Draw – Solutions
● Remove default background
● getWindow().setBackgroundDrawable(null)
● <item name="android:windowBackground">@null
</item>
● Transparent regions in
9patches
● Use tools
● Tracer for OpenGL
● Hierarchy Viewer

6. Over Draw
Happens to the best of us

7. Tracer for OpenGL
● Layout tree step by step
● See redundant draw operations
● Heavy

8. Dumpsys gfxinfo
● Since Jelly Bean
● Last 128 frames
● Frame < 16ms
● 3 columns
– Draw
– Process 9
8
7
– Execute 6
5 Execute
4 Process
● 3 Draw
2
1
0
5 13 21 29 37 45 53 61 69 77 85 93 101 109 117 125
1 9 17 25 33 41 49 57 65 73 81 89 97 105 113 121

9. Hierarchy Viewer

10. Traceview Profiling
● Performance of each method
● Graphical interface
● Run from DDMS or code

11. Traceview Profiling

12. Traceview Profiling
Inclusive: Includes child functions
Exclusive: This function only

13. Traceview Profiling

14. Traceview Profiling
So...what's the problem here?

15. Helping out the GC
● Allocation Tracker (DDMS)
●

16. Helping out the GC
● Memory profiling → Dalvik HPROF file
Use code or DDMS
● Use hprof-conv to convert to standard
● Use any Java HPROF analyzer

17. Helping out the GC
● Eclipse MAT (Memory Analyzer Tool)

18. Helping out the GC
● Histogram & Dominator tree

19. Tips - Bitmaps
● InJustDecodeBounds – Load only
properties
● InBitmap – reuse other allocation
● InSampleSize – good for preview
● Resource folders

20. StrictMode
● Problems Detector
● Single thread or the entire VM
● Show dialog, write to Log and more..
● Usually used to detect slow operations on
UI thread
● Came with Gingerbread (2.3)

21. Log
● EventLog
– Adb logcat -b events
– Framework level logs
– DB and system operations

22. Hardware Acceleration
● android:hardwareAccelerated="true"
or
targetApi >= 14
● Efficient drawing model
● Compatibility issues
– Custom views
– Unsupported operations

23. Hardware Acceleration
● Good for animations
● View Layers

24. Tips
● Always Measure
● Lint
– Comes with the SDK
– Scan the project's for optimizations
– Great Eclipse/IntelliJ integration
● ListView – Easy on the getView()
● Alpha – Watch it...
● Storage Read/Write
● Direct access inside the class (!Get/Set)
● SQLite indexes

25. @udinic
http://www.udinic.com
udi@udinic.com
Thank you