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Interesting Android Networking Libraries

Volley OKHttp SPDY Protobuf

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Android SQLite3 corruption

Stacktrace Caused by: android.database.sqlite.SQLiteCantOpenDatabaseException: unable to open database file at android.database.sqlite.SQLiteDatabase.dbopen(Native Method) at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:1048) at android.database.sqlite.SQLiteDatabase.openDatabaseEnc(SQLiteDatabase.java:1026) at android.database.sqlite.SQLiteDatabase.openOrCreateDatabaseEnc(SQLiteDatabase.java:1143) at android.app.ContextImpl.openOrCreateDatabaseEnc(ContextImpl.java:981) at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:966) at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:245) at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:187) Things that can go wrong http://www.sqlite.org/howtocorrupt.html Android deletes corrupt databases http://stackoverflow.com/questions/7764943/what-can-be-done-about-the-fact-that-android-automatically-deletes-corrupt-sqlit?lq=1 Best Practices http://stackoverflow.com/questions/2493331/what-are-the-best-practices-for-sqlite-on-android?rq=1

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Quadcopter

Good Sites http://diydrones.com http://aeroquad.com Thrust Calcs http://adamone.rchomepage.com/calc_motor.htm http://www.ecalc.ch/xcoptercalc_e.htm

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Plugins

Services Manifest can declare icons and description — android:icon=”@/drawable/XXXX” always set android:exported=”true” permissions are possible Plugins could also be Activities Also service could launch activity IntentSerivce is Asynchronous Metadata use self documenting names like OptionalCopyright get metadata with getPackageManager() with … Continue reading

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Open GL Notes

NIO Buffers (New I/O) Standard for Android Vertex Attributes Setup – Give expecations glEnableXXXX(GL10.XXXX); Draw Can have colors and/or textures(image) State Machine States stay active until next state is called or context is lost Blending Current Texture Right Hand Rule … Continue reading

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Creating Lightweight SDKs

Should Be Must be stable Don’t take features away Catch all exceptions only throw if in debug mode Should create a test app Easy to use Interacting with Users without Activity Use Toasts – customized Notifications launch browser Permissions Avoid … Continue reading

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App Marketing

Internet Marketing Funnel Target Prospect – app discovery, letting them know the product exsists Lead Purchase Loyal Customer — buy addons Advocate — good rating Conversion User completes a goal i.e. purchase Target Audience Find by looking at similar apps … Continue reading

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Android Touch Input

Notes from AnDevCon IV – Touch Input Start with dispatchTouchEvent() flow down until consumed by a view End back to Activity with onTouchEvent() <– only if not consumed, last in chain OnTouchListener optional always called first onInterceptTouchEvent() can grab touch … Continue reading

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Android Concurrency

Notes from AnDevCon IV Design for correctness upfront Don’t leak Activities Possible Solutions Use threads when needing full control – must handle lifecycle Non static inner class hold reference to activity Don’t lock orientation as a solution Use timeouts for … Continue reading

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AI Apps

Notes from AnDevCon IV Artificial Intelligence (AI) and Intelligent Apps Terms Metadata Feature Extraction What is AI? Representation of human like capabilities in software Systemic AI – Combining smaller AI systems that solve simple problems Practical AI Robot Control Personalized … Continue reading

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