0

I'm attempting to implement a Marquee HorizontalScrollView however I'm getting an error message stating FATAL EXCEPTION: main Unable to start activity java.lang.NullPointerException at line 55: 

s.fullScroll(HorizontalScrollView.FOCUS_LEFT);

I'm not sure exactly why this is happening. I've created/declared the HorizontalScrollView in XML: 

 <HorizontalScrollView
        android:id="@+id/sc"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentBottom="true"
        android:gravity="bottom"
        android:ellipsize="marquee"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:marqueeRepeatLimit="marquee_forever"
        android:scrollHorizontally="true"
        android:scrollbars="none" >

and attempted to start the scrolling process using: 

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        HorizontalScrollView s =(HorizontalScrollView) findViewById(R.id.sc);
        s.fullScroll(HorizontalScrollView.FOCUS_LEFT);

I got this far using this example:

HorizontalScrollView: auto-scroll to end when new Views are added?

However I am unsure why I am getting this fatal exception / NPE.

Suggestions/input is appreciated!

Logcat:

04-07 15:11:23.931: D/AndroidRuntime(11307): Shutting down VM
04-07 15:11:23.931: W/dalvikvm(11307): threadid=1: thread exiting with uncaught exception (group=0x41968ba8)
04-07 15:11:23.931: E/AndroidRuntime(11307): FATAL EXCEPTION: main
04-07 15:11:23.931: E/AndroidRuntime(11307): Process: com.test.app, PID: 11307
04-07 15:11:23.931: E/AndroidRuntime(11307): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.app/com.test.app.Cast}: java.lang.NullPointerException
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.os.Handler.dispatchMessage(Handler.java:102)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.os.Looper.loop(Looper.java:136)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.ActivityThread.main(ActivityThread.java:5017)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at java.lang.reflect.Method.invokeNative(Native Method)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at java.lang.reflect.Method.invoke(Method.java:515)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at dalvik.system.NativeStart.main(Native Method)
04-07 15:11:23.931: E/AndroidRuntime(11307): Caused by: java.lang.NullPointerException
04-07 15:11:23.931: E/AndroidRuntime(11307):    at com.test.app.Cast.onCreate(Cast.java:55)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.Activity.performCreate(Activity.java:5231)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-07 15:11:23.931: E/AndroidRuntime(11307):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-07 15:11:23.931: E/AndroidRuntime(11307):    ... 11 more
Community
  • 1
  • 1
Jane Cosack
  • 9
  • 1
  • 5

1 Answers1

0

You're trying to find the view before setting the content view. Add this line before finding the view.

setContentView(R.layout.your_xml_name);
Benjamin S
  • 575
  • 1
  • 7
  • 21
  • Thanks! That solved the NPE - but it still isn't automatically scrolling / performing a marquis - any idea what I may have overlooked? – Jane Cosack Apr 07 '15 at 19:46
  • Hate to say it, but that's where my knowledge on this ends. I've only ever implemented the native Android (non-scrolling) marquees. Good luck though! – Benjamin S Apr 07 '15 at 20:04