Regular update, May 1st

Videos watched & notes taken + reading materials

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Androidology - Architecture Overview [ link ]

Decompose the app into application building blocks, which include

• Activities
• BroadcastReceivers (triggered by any event)
• Services
• ContentProviders

Androidology - Application Lifecycle [ link ]
Androidology - APIs [ link ]

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Google I/O 2009 - ...Make your Android UI Fast and Efficient [ link ] (good one!)

• reuse views with Recycler for higher fps
• prescale bitmaps with
  image = Bitmap.createPrescaledBitmap(image, view.getWidth(), view.getHeight(), true);
• remove backgrounds from views, which fill parents full width and height (eg if you have a map, you don't see the background, which is still rendered) [00:17:23]
• invalidate() to redraw a view is inefficient, use invalidate(rect) or invalidate(left, top, right, bottom)
• fewer (views) is better ;) (try to get rid of views that have only one child, too: HierarchyViewer)
• use compound drawables (eg TextView instead of ImageView+TextView)
• use ViewStub to inflate part of the UI on demand (eg for part of the UI that for majority of the time is invisible) [00:35:20]
• use merge tag to reuse UI hierarchy elements
• RelativeLayout instead of embedding linear layouts; hard to use, but it pays off
• use custom views, custom layouts instead of overusing numerous views
• garbage collection kicks in for 100~500ms, stops threads (so allocate little memory, or even none :d)
• do not allocate memory in those time-critical points:

onMeasure()
onLayout()
draw()
dispatchDraw()
onDraw()
dispatchTouchEvent()
onTouchEvent()
getView()
bindView()

• SoftReferences != WeakReferences [00:51:17]
• soft references are good for caching objects
• weak references help avoid mem leaks
• pool of objects (frameworks/base/core/java/android/util, find Pools.java)

Resources:
http://d.android.com
http://source.android.com (includes examples of relative layouts)
http://android.git.kernel.org
http://code.google.com/p/apps-for-android (about good quality UI)
http://code.google.com/p/shelves (about good quality UI)

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Google I/O 2009 -...Interaction & Visual Design with Android [ link ]

• ongoing notification (eg for downloading a file) vs event notification
• uninvasive notification - Toast ;D
• use Marquee to animate strings (eg for long filenames) [00:38:10]
• built-in scalable pixel units typography [00:38:38] for font scaling (eg on the files list)

Resources:
http://android-developers.blogspot.com

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Reading materials

http://developer.android.com/sdk/index.html
http://www.talkandroid.com/android-sdk-install-guide/

http://developer.android.com/guide/topics/fundamentals.html

http://developer.android.com/resources/tutorials/hello-world.html
http://developer.android.com/resources/tutorials/notepad/index.html