[Exposed Dropdown Menu] Filtering incorrectly applied after rotation

Description: It seems that in some cases filtering is incorrectly applied to AutocompleteTextView after rotating the device which causes that all options except for the selected one disappear from Dropdown Menu.

Steps to reproduce:

1. Open Material Catalog app
2. Go to TextField -> Exposed Dropdown Menu Demo
3. Tap on 4th TextField from the top and select any value from the dropdown menu.
4. Rotate the device to landscape and back to portrait
5. Try to select a value from any of the 4 TextFields

The result is that those Dropdowns are now showing only 1 value instead of all of them.

Expected behavior: All TextField Dropdown Menus should show all values after device rotations

Android API version: Tested on Android 10 and Android 11 Beta

Material Library version: Checked on 1.3.0-alpha01 and 1.2.0-beta01

Device: Google Pixel 3 and Emulator

[TepesLucian]

Stumbled upon this issue in our app when fragment view gets recreated from backstack or when a config change happens. We’re using inputType="none" so filtering is not needed. The above adapter filtering solution works for me but i’ve changed the filter slightly to basically do nothing:

class MyAdapter(context: Context, val items: List<Item>)
    : ArrayAdapter<Item>(context, R.layout.layout_item, items) {

    private val noOpFilter = object : Filter() {
        private val noOpResult = FilterResults()
        override fun performFiltering(constraint: CharSequence?) = noOpResult
        override fun publishResults(constraint: CharSequence?, results: FilterResults?) {}
    }

    override fun getFilter() = noOpFilter
}

[ar-arvind]

FIX: All the values will be visible after the device rotation and also the selected value will be displayed.

public class TextInputDropDownMenu extends AppCompatAutoCompleteTextView {

    public TextInputDropDownMenu(@NonNull Context context) {
        super(context);
    }

    public TextInputDropDownMenu(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public TextInputDropDownMenu(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    {
        setInputType(InputType.TYPE_NULL);
    }

    @Override
    public boolean getFreezesText() {
        return false;
    }

    @Override
    public Parcelable onSaveInstanceState() {
        Parcelable parcelable = super.onSaveInstanceState();
        if (TextUtils.isEmpty(getText())) {
            return parcelable;
        }

        CustomSavedState customSavedState = new CustomSavedState(parcelable);
        customSavedState.text = getText().toString();
        return customSavedState;
    }

    @Override
    public void onRestoreInstanceState(Parcelable state) {
        if (!(state instanceof CustomSavedState)) {
            super.onRestoreInstanceState(state);
            return;
        }

        CustomSavedState customSavedState = (CustomSavedState) state;
        setText(customSavedState.text, false);
        super.onRestoreInstanceState(customSavedState.getSuperState());
    }

    private static final class CustomSavedState extends BaseSavedState {

        private String text;

        public CustomSavedState(Parcelable superState) {
            super(superState);
        }

        public CustomSavedState(Parcel source) {
            super(source);
            text = source.readString();
        }

        @Override
        public void writeToParcel(Parcel out, int flags) {
            super.writeToParcel(out, flags);
            out.writeString(text);
        }

        private static final Creator<CustomSavedState> CREATOR = new Creator<CustomSavedState>() {
            @Override
            public CustomSavedState createFromParcel(Parcel source) {
                return new CustomSavedState(source);
            }

            @Override
            public CustomSavedState[] newArray(int size) {
                return new CustomSavedState[size];
            }
        };

    }

}