Bug-98 Use preference to store the last visit card position.

[thomas771020]

@john-hu please help me review this patch.Thank you.

[john-hu]

Hi, you had broke a unit test: exec] org.vosie.wikicards.test.CardActivityTest:
[exec] Failure in testRemeberCardPosotion_get:
[exec] junit.framework.AssertionFailedError: expected:<1> but was:<0>
[exec] at org.vosie.wikicards.test.CardActivityTest.testRemeberCardPosotion_get(CardActivityTest.java:41)
[exec] at java.lang.reflect.Method.invokeNative(Native Method)
[exec] at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
[exec] at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
[exec] at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
[exec] at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
[exec] at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
[exec] at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:554)
[exec] at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)
[exec] .

[john-hu]

You forget to commit the editor. http://developer.android.com/reference/android/content/SharedPreferences.Editor.html

[john-hu]

Without commit(), the preferences only saved in memory instead of storage. So, this patch may not work correctly. BTW, I think this issue's priority is not high. You may take your time to fix it.