This document discusses code review and the Android framework source code. It provides instructions on how to access and view the framework source code in Eclipse, as well as an alternate online source viewer. It gives examples of modifying framework classes like SeekBar and AsyncTask. Finally, it asks if there are any questions.

1. Know thy code Framework

2. Know thy code ???.* What we wont know after this talk Code review secrets Know my code What we will learn from it ( Hopefully ) How to make better use of framework source How to make new components from the framework Framework

3. Android – Open Source Android has been available under a free software/open source license since October, 21 2008 Google published the entire source code (including network and telephony stacks) under an Apache License.

4. Android – Open Source Source available at source.android.com. Source is a bunch of git projects. Google built repo on top of git. Souce is ~3GB , needs ~10GB to build. Currently only builds on Linux and Mac

5. What code will we be seeing

6. Framework source in eclipse Source code from major release-specific branches can be downloaded like this: http://android.git.kernel.org/?p=platform/frameworks/base.git;a=snapshot;h=refs/heads/froyo;sf=tgz You can get other versions by changing the branch name (froyo) in the link above (to donut, gingerbread, etc.) Links : https://bitly.com/bundles/rvyas/1

7. Framework source in eclipse Extract the android folder from <tarball>/core/java/ into android-sdk/platforms/<platform version>/sources/ Make sure the platform-version is the same as the android version of the tarball. Refresh project in eclipse To test press Alt + Shift + T to check if you can view the activity class Source : http://kmansoft.wordpress.com/2011/01/27/android-sources-for-debugging/

9. Alternate “cloud” source viewer Chrome extension : bit.ly/andsrcchrome Adds an 'ad' command to the Chrome Omnibox

10. Alternate “cloud” source viewer

11. Getting hands dirty

12. Getting hands dirty publicclassSeekBarextendsAbsSeekBar publicabstractclassAbsSeekBarextendsProgressBar mThumbOffset= thumb.getIntrinsicWidth() / 2; setThumbPos(getWidth(), thumb, scale, Integer.MIN_VALUE); setThumbPos(w, thumb, scale, 0); Modified code : http://bit.ly/andvsb

13. Getting hands dirty Story : HTTP Requests

14. Getting hands dirty publicabstractclassAsyncTask<Params, Progress, Result> { privatestaticfinal String LOG_TAG = "AsyncTask"; privatestaticfinalintCORE_POOL_SIZE = 5; privatestaticfinalintMAXIMUM_POOL_SIZE = 128; privatestaticfinalintKEEP_ALIVE = 10; privatestaticfinalBlockingQueue<Runnable> sWorkQueue = newLinkedBlockingQueue<Runnable>(10); privatestaticfinalThreadFactorysThreadFactory = newThreadFactory() { privatefinalAtomicIntegermCount = newAtomicInteger(1); public Thread newThread(Runnable r) { returnnew Thread(r, "AsyncTask #" + mCount.getAndIncrement()); } };

15. Performance examples publicclassSQLiteDatabaseextendsSQLiteClosable Android implements locking in SQLiteDatabase - No point trying to hit the database from multiple threads - On the positive you don’t need to synchronize your requests.

16. Questions? Thank you.