bluetooth: Bluetooth support
bluez: Bluetooth tools and daemons
bluez-alsa: Bluetooth ALSA support
bluez-audio: Transitional package
bluez-compat: BlueZ 3.x compatibility binaries
bluez-cups: Bluetooth printer driver for CUPS
bluez-dbg: Bluetooth tools and daemons (with debugging symbols)
bluez-gstreamer: Bluetooth GStreamer support
bluez-pcmcia-support: PCMCIA support files for BlueZ 2.0 Bluetooth tools
bluez-utils: Transitional package
libbluetooth-dev: Development files for using the BlueZ Linux Bluetooth library
libbluetooth3: Library to use the BlueZ Linux Bluetooth stack
libbluetooth3-dbg: Library to use the BlueZ Linux Bluetooth stack with debugging symbols

Maverick AFP with Ubuntu is having errors. Solution:
Edit /etc/netatalk/afpd.conf. At the end of the file are the default parameters:
-tcp -noddp -uamlist uams_dhx.so,uams_dhx2.so
Notice it is commented out. Uncomment the line and change it to:
-tcp -noddp -uamlist uams_dhx_passwd.so,uams_dhx2_passwd.so

Method A:

Compare three type of “Passing Method as Parameter":
+(int) get_mutual_friend:(NSString*) fb_id completion:(void(^)(int))handler;

Method B:

+(int) get_mutual_friend:(NSString*) fb_id completion:(SEL)handler;
IMP imp = [connection methodForSelector: handler];
void (*func)(id, SEL, int) = (void *)imp;
func(connection, handler, 1);

Method C:

id block = [^{NSLog(@"Hello, world");} copy];
[button addTarget:block
action:@selector(invoke)
forControlEvents:UIControlEventTouchUpInside];

Steps
1. Register/Create a new app on Facebook

2. Add Android section

3. Generate Key Hash with your keystore and put to Facebook Developer
keytool -exportcert -alias your.alias -keystore your.keystore > key.bin
openssl sha1 -binary key.bin > sha.bin
openssl base64 -in sha.bin -out output.txt


4. Import Facebook SDK into your Eclipse

5. Eclipse > Project > Properties > Android > Reference. Add Facebook SDK.

6. Follow Facebook tutorial at
https://developers.facebook.com/docs/android/login-with-facebook#config

7. Facebook tutorial missed out two part. First is the meta-data with appid.
< meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/app_id" />
Then put your app id in string.xml

8. Add the com.facebook.LoginActivity to your AndroidManifest.xml.

Done.

寫一篇Base64 Encoding Algorithm

= Base64, Why? =
有Base64的原因，是因為電腦內部(e.g. ASCII)是用8-bit 編碼的。但這些編碼大部份都不是 printable character，就是可以在螢幕上顯示的字。
將內部的8-bit，轉換成可以在螢幕上顯示的字，就是Base64最簡單的定義。

= Base64, How? =
== Base set ==
Base64之所以叫Base64，就是選用了64個printable的字作為編碼基組。
即是，任何Bit stream都可以以這64個字編碼後當printable的字來傳送。

64個字符選哪些，Base64 有多個不統一的implementation。一般最常用的是以A-Z, a-z, 0-9, +, /，這64個字符。
還有一個 = 作padding，下文再述。

== Algorithm ==
1. 將byte 變成8個bit 的1010，排成bitstream。
2. 每6個bit 一組（2^6 = 64）。不足的尾數，補上零(0)。
3. 每6個bit 編碼成base64。
4. 如此，必定會形成了「每3個byte就編成4個base64」(3*8=4*6)。
5. base64結果的長度必需為4的倍數。不足處補上等號(=)。完成。

== Check ==
1. 要檢查一個Base64是否正確，其長度必然是４的倍數。
2. 尾部只會有三個可能。一是沒有=（即應是一個Base64的字符），二是有一個=，三是有兩個=。不會有兩個=以上或其他。因為，Base64的原理，是將3個byte編成4個base64。
3. 分析。若byte除以三後：
– 剩１：兩個＝（1byte=8bit，補4個零12bit，編成兩個Base64，補上兩個＝，成為四個一組Base64）
– 剩２：一個＝（2byte=16bit，補2個零18bit，編成三個Base64，補上一個＝，成為四個一組Base64）
– 除盡：無＝

完。

= Supplementary =
留意有某些SDK implementation，會有在編碼中，插入了newline character的情況。只需要看Base64的總長是否４的倍數即可分辨。

http://strophe.im/strophejs/doc/1.0.2/files2/strophe-js.html

Good reference:
http://stackoverflow.com/questions/12454025/cannot-read-custom-attributes-from-message-tag-when-using-asmack-xmpp-library-fo

Optimisation tricks for engineers

NSArray Literals

Previously:

array = [NSArray arrayWithObjects:a, b, c, nil];

Now:

array = @[ a, b, c ];

NSDictionary Literals

Previously:

dict = [NSDictionary dictionaryWithObjects:@[o1, o2, o3]
                                   forKeys:@[k1, k2, k3]];

Now:

dict = @{ k1 : o1, k2 : o2, k3 : o3 };

http://stackoverflow.com/questions/9347722/what-are-the-details-of-objective-c-literals-mentioned-in-the-xcode-4-4-releas

For QM
https://testflightapp.com/m/login

1. Facebook
2. UILabel NumberOfLines
3. NSDateFormatter yyyy-MM-dd’T’hh:mm:ssZZZZ (don’t accept a colon in ZZZZ part)
4. sqlite INSERT statement – single row

常見IOS framework build error
1. _SCNNetwork*
Solution: SystemConfiguration.framework
2. _NSInMemoryStoreType
Solution: CoreData.framework
3. _SSL*
Solution: Security.Framework
4. _KCF* &nbsp&nbsp
Solution: CFNetwork.Framework
5. _xml* &nbsp&nbsp
Solution: libxml.dylib
6. _OBJC_CLASS_$_CLLocation
Solution:CoreLocation.Framework
7. _dns_parse_resource_record _dns_free_resource_record
Solution:libresolv.dylib
8. _SCNetworkReachability*
Solution: SystemConfiguration.framework
9. _UTType* , _kUTTagClass
Solution: MobileCoreServices.framework
10. _deflate*, _inflate*
Solution: libz.dylib
11. _SecTrust*
Solution: Security.framework
12. _kCA*
Solution: QuartzCore.framework

Reference:
http://nobody-diaries.blogspot.hk/2012/10/ios-framework-build-error.html