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TangoAgency / material-intro-screen

Inspired by Heinrich Reimer Material Intro and developed with love from scratch
MIT License
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NPE when MaterialIntroActivity restoring state #142

Open gitanuj opened 6 years ago

gitanuj commented 6 years ago

Steps:

  1. Enable "Don't keep activities" option in Developer Options
  2. Add a SlideFragment with hasNeededPermissionsToGrant() & hasAnyPermissionsToGrant() set to false
  3. Open the MaterialActivity with this fragment selected
  4. Send Activity to background
  5. Use recents menu to open the activity back

Looks like getActivity() is null at the moment. A simple fix could be to just ignore the call if it's null.

Exception java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tanuj.nowplayinghistory/com.tanuj.nowplayinghistory.activities.IntroActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.support.v4.app.FragmentActivity.getString(int)' on a null object reference android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2778) android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2856) android.app.ActivityThread.-wrap11 () android.app.ActivityThread$H.handleMessage (ActivityThread.java:1589) android.os.Handler.dispatchMessage (Handler.java:106) android.os.Looper.loop (Looper.java:164) android.app.ActivityThread.main (ActivityThread.java:6494) java.lang.reflect.Method.invoke (Method.java) com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:438) com.android.internal.os.ZygoteInit.main (ZygoteInit.java:807) Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.support.v4.app.FragmentActivity.getString(int)' on a null object reference agency.tango.materialintroscreen.listeners.MessageButtonBehaviourOnPageSelected.pageSelected (MessageButtonBehaviourOnPageSelected.java:32) agency.tango.materialintroscreen.listeners.ViewBehavioursOnPageChangeListener.onPageSelected (ViewBehavioursOnPageChangeListener.java:61) android.support.v4.view.CustomViewPager.dispatchOnPageSelected (CustomViewPager.java:1939) android.support.v4.view.CustomViewPager.setCurrentItemInternal (CustomViewPager.java:666) android.support.v4.view.CustomViewPager.setCurrentItemInternal (CustomViewPager.java:632) android.support.v4.view.CustomViewPager.onRestoreInstanceState (CustomViewPager.java:1454) android.view.View.dispatchRestoreInstanceState (View.java:17706) android.view.ViewGroup.dispatchRestoreInstanceState (ViewGroup.java:3745) android.view.ViewGroup.dispatchRestoreInstanceState (ViewGroup.java:3751) android.view.ViewGroup.dispatchRestoreInstanceState (ViewGroup.java:3751) android.view.ViewGroup.dispatchRestoreInstanceState (ViewGroup.java:3751) android.view.ViewGroup.dispatchRestoreInstanceState (ViewGroup.java:3751) android.view.ViewGroup.dispatchRestoreInstanceState (ViewGroup.java:3751) android.view.View.restoreHierarchyState (View.java:17684) com.android.internal.policy.PhoneWindow.restoreHierarchyState (PhoneWindow.java:2131) android.app.Activity.onRestoreInstanceState (Activity.java:1102) android.app.Activity.performRestoreInstanceState (Activity.java:1057) android.app.Instrumentation.callActivityOnRestoreInstanceState (Instrumentation.java:1260) android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2751) android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2856) android.app.ActivityThread.-wrap11 () android.app.ActivityThread$H.handleMessage (ActivityThread.java:1589) android.os.Handler.dispatchMessage (Handler.java:106) android.os.Looper.loop (Looper.java:164) android.app.ActivityThread.main (ActivityThread.java:6494) java.lang.reflect.Method.invoke (Method.java) com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:438) com.android.internal.os.ZygoteInit.main (ZygoteInit.java:807)

gitanuj commented 6 years ago

For example it happens on the following fragment when user taps button to enable "Notification Access" which opens the Settings app. Then for some reason my app's Activity is removed from memory and user comes back to the Activity without enabling the permission.

https://github.com/gitanuj/nowplayinghistory/blob/master/app/src/main/java/com/tanuj/nowplayinghistory/fragments/NotificationAccessSlide.java