consp1racy
commented
6 years ago Do you have custom preferences that save state?
1)
If you overridePreference#onSaveInstanceState you have to override Preference#onRestoreInstanceState.
2)
You have to maintain the hierarchy of saved state. Your custom saved state must extend Preference.BaseSavedState.
Example from TwoStatePreference:
@Override
protected Parcelable onSaveInstanceState() {
final Parcelable superState = super.onSaveInstanceState();
if (isPersistent()) {
// No need to save instance state since it's persistent
return superState;
}
final TwoStatePreference.SavedState myState = new TwoStatePreference.SavedState(superState);
myState.checked = isChecked();
return myState;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state == null || !state.getClass().equals(TwoStatePreference.SavedState.class)) {
// Didn't save state for us in onSaveInstanceState
super.onRestoreInstanceState(state);
return;
}
SavedState myState = (TwoStatePreference.SavedState) state;
super.onRestoreInstanceState(myState.getSuperState());
setChecked(myState.checked);
}
static class SavedState extends BaseSavedState {
boolean checked;
public SavedState(Parcel source) {
super(source);
checked = source.readInt() == 1;
}
@Override
public void writeToParcel(@NonNull Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(checked ? 1 : 0);
}
public SavedState(Parcelable superState) {
super(superState);
}
public static final Parcelable.Creator<SavedState> CREATOR =
new Parcelable.Creator<SavedState>() {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}Here's what happens in Preference, the base class for all preferences:
protected Parcelable onSaveInstanceState() {
mBaseMethodCalled = true;
return BaseSavedState.EMPTY_STATE;
}
protected void onRestoreInstanceState(Parcelable state) {
mBaseMethodCalled = true;
if (state != BaseSavedState.EMPTY_STATE && state != null) {
throw new IllegalArgumentException("Wrong state class -- expecting Preference State");
}
}If you send wrong SavedState to super.onRestoreInstanceState it will crash. Each child class has its own saved state and you need to pass correct state to super class.
3)
Upgrade to Android Gradle Plugin 3.1.x or disable D8. The version of D8 bundled with AGP before 3.1.0 final is known to produce ~broken~ incompatible bytecode with some devices. It may or may not affect this case.
dirkam
michaeldiener
This might not be related to the library at all, but maybe you might have a clue on what's going on here.
Recently updated to support-preference 2.1.2 and support library 27.1.1 and started to get these crashes.
Your help is highly appreciated.