IndexOutOfBoundsException causing a lot of crashes

[mohakapt]

I'm using this library in my application, recently i started to receive a large amount of crash reports from my users. I cannot reproduce the issue while debugging.
I'm using the latest version of the library.

com.kizitonwose.calendarview.ui.CalendarAdapter.notifyMonthScrollListenerIfNeeded (CalendarAdapter.kt:197)
com.kizitonwose.calendarview.ui.CalendarAdapter$notifyMonthScrollListenerIfNeeded$1.onAnimationsFinished (CalendarAdapter.kt:191)
androidx.recyclerview.widget.RecyclerView$ItemAnimator.dispatchAnimationsFinished (RecyclerView.java:13751)
androidx.recyclerview.widget.DefaultItemAnimator.dispatchFinishedWhenDone (DefaultItemAnimator.java:551)
androidx.recyclerview.widget.DefaultItemAnimator$5.onAnimationEnd (DefaultItemAnimator.java:249)
android.view.ViewPropertyAnimator$AnimatorEventListener.onAnimationEnd (ViewPropertyAnimator.java:1111)
android.animation.Animator$AnimatorListener.onAnimationEnd (Animator.java:554)
android.animation.ValueAnimator.endAnimation (ValueAnimator.java:1242)
android.animation.ValueAnimator.cancel (ValueAnimator.java:1127)
android.view.ViewPropertyAnimator.cancel (ViewPropertyAnimator.java:424)
androidx.recyclerview.widget.DefaultItemAnimator.cancelAll (DefaultItemAnimator.java:642)
androidx.recyclerview.widget.DefaultItemAnimator.endAnimations (DefaultItemAnimator.java:634)
androidx.recyclerview.widget.RecyclerView.removeAndRecycleViews (RecyclerView.java:1205)
androidx.recyclerview.widget.RecyclerView.setAdapterInternal (RecyclerView.java:1236)
androidx.recyclerview.widget.RecyclerView.setAdapter (RecyclerView.java:1194)
com.kizitonwose.calendarview.CalendarView.invalidateViewHolders (CalendarView.kt:411)
com.kizitonwose.calendarview.CalendarView.onMeasure (CalendarView.kt:300)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
android.widget.LinearLayout.measureChildBeforeLayout (LinearLayout.java:1552)
android.widget.LinearLayout.measureVertical (LinearLayout.java:842)
android.widget.LinearLayout.onMeasure (LinearLayout.java:721)
android.view.View.measure (View.java:26415)
androidx.constraintlayout.widget.ConstraintLayout$Measurer.measure (ConstraintLayout.java:811)
androidx.constraintlayout.core.widgets.analyzer.BasicMeasure.measure (BasicMeasure.java:466)
androidx.constraintlayout.core.widgets.analyzer.BasicMeasure.measureChildren (BasicMeasure.java:134)
androidx.constraintlayout.core.widgets.analyzer.BasicMeasure.solverMeasure (BasicMeasure.java:278)
androidx.constraintlayout.core.widgets.ConstraintWidgetContainer.measure (ConstraintWidgetContainer.java:120)
androidx.constraintlayout.widget.ConstraintLayout.resolveSystem (ConstraintLayout.java:1593)
androidx.constraintlayout.widget.ConstraintLayout.onMeasure (ConstraintLayout.java:1700)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
android.widget.FrameLayout.onMeasure (FrameLayout.java:194)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
androidx.coordinatorlayout.widget.CoordinatorLayout.onMeasureChild (CoordinatorLayout.java:760)
com.google.android.material.appbar.HeaderScrollingViewBehavior.onMeasureChild (HeaderScrollingViewBehavior.java:99)
com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior.onMeasureChild (AppBarLayout.java:2003)
androidx.coordinatorlayout.widget.CoordinatorLayout.onMeasure (CoordinatorLayout.java:831)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
android.widget.FrameLayout.onMeasure (FrameLayout.java:194)
androidx.appcompat.widget.ContentFrameLayout.onMeasure (ContentFrameLayout.java:145)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
android.widget.LinearLayout.measureChildBeforeLayout (LinearLayout.java:1552)
android.widget.LinearLayout.measureVertical (LinearLayout.java:842)
android.widget.LinearLayout.onMeasure (LinearLayout.java:721)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
android.widget.FrameLayout.onMeasure (FrameLayout.java:194)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
android.widget.LinearLayout.measureChildBeforeLayout (LinearLayout.java:1552)
android.widget.LinearLayout.measureVertical (LinearLayout.java:842)
android.widget.LinearLayout.onMeasure (LinearLayout.java:721)
android.view.View.measure (View.java:26415)
android.view.ViewGroup.measureChildWithMargins (ViewGroup.java:7845)
android.widget.FrameLayout.onMeasure (FrameLayout.java:194)
com.android.internal.policy.DecorView.onMeasure (DecorView.java:1013)
android.view.View.measure (View.java:26415)
android.view.ViewRootImpl.performMeasure (ViewRootImpl.java:3606)
android.view.ViewRootImpl.measureHierarchy (ViewRootImpl.java:2349)
android.view.ViewRootImpl.performTraversals (ViewRootImpl.java:2641)
android.view.ViewRootImpl.doTraversal (ViewRootImpl.java:2201)
android.view.ViewRootImpl$TraversalRunnable.run (ViewRootImpl.java:9000)
android.view.Choreographer$CallbackRecord.run (Choreographer.java:996)
android.view.Choreographer.doCallbacks (Choreographer.java:794)
android.view.Choreographer.doFrame (Choreographer.java:729)
android.view.Choreographer$FrameDisplayEventReceiver.run (Choreographer.java:981)
android.os.Handler.handleCallback (Handler.java:883)
android.os.Handler.dispatchMessage (Handler.java:100)
android.os.Looper.loop (Looper.java:237)
android.app.ActivityThread.main (ActivityThread.java:7948)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:493)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1075) 

[danieldcoded]

Do you have the source code available? Might be able to help you

[mohakapt]

Are you referring to my source code? or the library's?
The crash is happening here CalendarAdapter.kt

[danieldcoded]

Sorry I just got to see this, I was referring to your source code. Or are you working on a private project?

[mohakapt]

Sorry for the late reply, I'm working on a private project so unfortunately I cannot share the source code.
The main issue here is that the stack trace doesn't refer to any code in my project so I'm not able to pinpoint what's starting the stack that's causing the crash.

[kizitonwose]

Just curious, do you use the month-to-week collapsing feature?

[mohakapt]

Hello! Yes, I'm using that feature

[HoLuong1609]

I have a clue for this and raise a detail issue at #343

[olegsvs]

@kizitonwose This happens if you go to for example to another fragment during the expansion animation (initial STATE_COLLAPSED) CalendarView, and go back to the screen with CalendarView (for reproduce, you can set a longer animation duration in the developer settings). In my case onRestoreInstanceState setting up saved STATE(collapsed/etc)

2021-10-14 01:20:44.191 11292-11292/com.* I/System.out: expandInternal to 2021-10 NO ANIM
2021-10-14 01:20:44.193 11292-11292/com.* I/System.out: STATE_EXPANDED
2021-10-14 01:20:44.193 11292-11292/com.* D/AndroidRuntime: Shutting down VM
2021-10-14 01:20:44.194 11292-11292/com.* E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.*, PID: 11292
    java.lang.IndexOutOfBoundsException: Index: 93, Size: 28
        at java.util.ArrayList.get(ArrayList.java:437)
        at com.kizitonwose.calendarview.ui.CalendarAdapter.notifyMonthScrollListenerIfNeeded(CalendarAdapter.kt:197)
        at com.kizitonwose.calendarview.ui.CalendarAdapter$onAttachedToRecyclerView$1.run(CalendarAdapter.kt:59)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

[kizitonwose]

@olegsvs So to reproduce with the Sample app:

• Increase anim duration.
• Toggle expanded state.
• Navigate away from the page.

Is this correct?

[olegsvs]

@kizitonwose Correct, i will try to reproduce on a sample and provide a project

[kizitonwose]

@olegsvs Thanks, that would be very helpful.

[olegsvs]

@kizitonwose Sorry, I found a bug in my code, i used save and restore the status (week mode) of the calendar in onSaveState / onRestoreState, which entailed a double function call to expandCalendarView. I think the author of Issue also needs to give more details about the setup week mode in his project(wait for animation and block actions before anim has end). @mohakapt

[kizitonwose]

@olegsvs So the expand/collapse logic works fine otherwise?

[olegsvs]

@kizitonwose Yep, I no longer had problems with multiple state changes or changing screens during animation, as I said, in problematic projects need to check the animation code for a change in height at the end of which there is a change in the calendar state, if animation is used. I think the creators of such Issue need to attach a code for changing the state of the weekMode

[olegsvs]

@kizitonwose see my code(L 269) https://gist.github.com/olegsvs/d8e6e55e5d668c52bc4ce8b52ea5079a#file-cv-L269

[mohakapt]

Hello, I checked my code but couldn't find anything different from the sample in this project. I'm setting up the calendar view exactly like the example here Example1Fragment.kt.

Personally, I couldn't reproduce the issue myself, on my devices the component wouldn't crash no matter what I do. The issue is only appearing on my Crashlytics reports from real users.

As a workaround I'm calling the setup() function on the calendar view every time the user switches between week and month views. It seems to work since the crash reports stopped appearing.

[kizitonwose]

A temporary workaround that I see would be to use getOrNull() instead of just accessing the index. However, I am trying to see if we can first get to the root of the issue, otherwise, this only suppresses the real problem.

[kizitonwose]

This is now fixed in version 2.0.0