Class not found when unmarshalling: android.support.v7.widget.Toolbar$SavedState

Question

i am using Maps API to create a simple android app and i get a wierd error i can\'t solve. It usually happens when i rotate my device. I\'m using google services 8.4.0

Answer 1

I had a similar problem with my custom view and found this solution. I noticed that this crash occurred when I extended RecyclerView or AppCompatSpinner and needed to save the state. The crash will probably happen for other views as well.

Basically the crash is caused by a bug in AbsSavedState as mentioned here. And the crash only occurs when the constructor of the SavedState is called without a class loader. It seemed like this was an old issue however I started getting crash reports for Android 9 and 10.

So the fix was to change:

public SavedState(Parcel source) {
  super(source);
  //... 
}

to:

public SavedState(Parcel source) {
  super(source, LinearLayoutManager.class.getClassLoader());
  //... 
}

Edit I was on the right track, but then I was looking at some Android code and found out that there was actually a constructor missing that caused the crash. So I had the following constructor for the SavedState:

SavedState(Parcel in)
{
    super(in);
    //...
}

And I needed to add the following:

@RequiresApi(Build.VERSION_CODES.N)
SavedState(Parcel in, ClassLoader loader)
{
    super(in, loader);
    //...
}

And then I needed to change the creator:

public static final Creator CREATOR = new ClassLoaderCreator()
{
    @Override
    public SavedState createFromParcel(Parcel source, ClassLoader loader)
    {
        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.N ? new SavedState(source, loader) : new SavedState(source);
    }

    @Override
    public SavedState createFromParcel(Parcel source)
    {
        return createFromParcel(source, null);
    }

    public SavedState[] newArray(int size)
    {
        return new SavedState[size];
    }
};