BlurView drawing above another BlurView causes crash

[slavzilla]

1. 1.6.3
2. Pixel 4 Api 29 Emulator
3. I have a RecyclerView that has BlurView inside of it. That works fine. The problem is I have a fragment that hosts this RecyclerView and on one particular click on a button, I open DialogFragment which is completely custom. This DialogFragment is blurred. The problem is, when this dialog shows above the RecyclerView I get an error. I guess it is because one BlurView shows above another BlurView. I've seen in closed issues that someone already asked about this but in my case it is incidental and I really can't avoid it. Could you help me somehow?
4. I can provide XML layout if you need it but the issue is not in it I guess
5. 2020-11-05 15:21:22.753 17031-17031/lu.thebiggame E/AndroidRuntime: FATAL EXCEPTION: main Process: lu.thebiggame, PID: 17031 java.lang.IndexOutOfBoundsException: Index: 3, Size: 0 at java.util.ArrayList.get(ArrayList.java:437) at android.view.ViewGroup.getAndVerifyPreorderedView(ViewGroup.java:3659) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4147) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1975) at android.view.View.draw(View.java:21293) at android.view.ViewGroup.drawChild(ViewGroup.java:4388) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149) at android.view.View.draw(View.java:21424) at android.view.View.draw(View.java:21295) at android.view.ViewGroup.drawChild(ViewGroup.java:4388) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1975) at android.view.View.draw(View.java:21293) at android.view.ViewGroup.drawChild(ViewGroup.java:4388) at androidx.recyclerview.widget.RecyclerView.drawChild(RecyclerView.java:5125) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149) at android.view.View.draw(View.java:21424) at androidx.recyclerview.widget.RecyclerView.draw(RecyclerView.java:4524) at android.view.View.draw(View.java:21295) at android.view.ViewGroup.drawChild(ViewGroup.java:4388) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1975) at android.view.View.draw(View.java:21293) at android.view.ViewGroup.drawChild(ViewGroup.java:4388) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149) at android.view.View.draw(View.java:21424) at androidx.core.widget.NestedScrollView.draw(NestedScrollView.java:1998) at android.view.View.draw(View.java:21295) at android.view.ViewGroup.drawChild(ViewGroup.java:4388) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1975) at android.view.View.draw(View.java:21424) at eightbitlab.com.blurview.BlockingBlurController.updateBlur(BlockingBlurController.java:149) at eightbitlab.com.blurview.BlockingBlurController$1.onPreDraw(BlockingBlurController.java:61) at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1088) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2745) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1721) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7598) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:966) at android.view.Choreographer.doCallbacks(Choreographer.java:790) at android.view.Choreographer.doFrame(Choreographer.java:725) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:951) at android.os.Handler.handleCallback(Handler.java:883) at android.os.Handler.dispatchMessage(Handler.java:100) at android.os.Looper.loop(Looper.java:214) at android.app.ActivityThread.main(ActivityThread.java:7356) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

[Dimezis]

Thanks for the report, I have couple of similar ones for a while already, and most of them have ConstraintLayout in the trace, so I thought maybe it is its fault.
But I have no clue how it's happening or how to reproduce it, so unless you can make an example project with a reliable way to replicate the issue, I can not help unfortunately.

[slavzilla]

I can't give you my code as it is a corporate code I am not the owner. Could I help you in any other way? I can ask around and try to get approval to share parts of the project with you.

[Dimezis]

You don't have to share the company code, you can just create a small new app that contains the minimum required setup to reproduce this issue, and publish it on Github

[LonLove]

另一个BlurView上方绘制的BlurView，上方的不生效没崩溃，都是包含在ConstraintLayout里面，我尝试把上方的从ConstraintLayout拿出来，然后在上方绘制，结果ok了。

[jayshreeSK]

I am also getting a crash.
Below are the logs.

2021-01-12 16:33:39.954 17678-17678/com.example.example D/AndroidRuntime: Shutting down VM
2021-01-12 16:33:39.955 17678-17678/com.example.example E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.example , PID: 17678
java.lang.IndexOutOfBoundsException: Index: 3, Size: 0
at java.util.ArrayList.get(ArrayList.java:437)
at android.view.ViewGroup.getAndVerifyPreorderedView(ViewGroup.java:3659)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4147)
at android.view.View.draw(View.java:21428)
at android.view.View.draw(View.java:21299)
at android.view.ViewGroup.drawChild(ViewGroup.java:4388)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149)
at android.view.View.draw(View.java:21428)
at eightbitlab.com.blurview.BlockingBlurController.updateBlur(BlockingBlurController.java:117)
at eightbitlab.com.blurview.BlockingBlurController$1.onPreDraw(BlockingBlurController.java:55)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1088)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2746)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1722)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7605)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1041)
at android.view.Choreographer.doCallbacks(Choreographer.java:864)
at android.view.Choreographer.doFrame(Choreographer.java:799)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1026)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7397)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:935)

[Dimezis]

Closing this one as a duplicate of #110
Please post your repos/code samples/steps to reproduce there.