2

I'm having problems with RadioGroups clearCheck method and rotating my app. I think it might be a Google issue?

I have a three button radio group that when launched has the first item selected by default in xml.

My problem is, I have a button that calls radio groups clearCheck(). If you rotate the app, and then try to press the first radio group item, it will not select it. It tries, it shows the animation, but it remains unselected.

I thought I was going crazy and it was something wrong in my code, but I've broken it down to the most simplistic app possible by just making a new app.

If I don't preselect Button A (via XML or code) then it works correctly, but I need this button pre-selected.

Any idea how I can work around this problem and have A selected by default?

Repo steps

  1. Launch app
  2. Select Radio Button B
  3. Press Clear Check
  4. Rotate App
  5. Press Radio Button A

Result: Radio A won't select. If you then press B or C you can once again press A, but not until then.

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radioGroup);

    Button clearButton = (Button) findViewById(R.id.clearButton);

    clearButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            radioGroup.clearCheck();
        }
    });
}
}


<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

 <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="10dp"
        android:gravity="center"
        android:checkedButton="@+id/radioButtonA"
        android:orientation="horizontal">

        <RadioButton
            android:id="@+id/radioButtonA"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="A" />

        <RadioButton
            android:id="@+id/radioButtonB"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="B" />

        <RadioButton
            android:id="@+id/radioButtonC"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="C" />

    </RadioGroup>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Clear"
        android:id="@+id/clearButton"
        android:layout_below="@+id/searchRadioGroup"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="114dp" />

</RelativeLayout>
Ben987654
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2 Answers2

1

Upon rotation, the checked id is reset due to android:checkedButton="@+id/radioButtonA".

If there was a button checked, CompoundButton's onRestoreInstanceState resets the checked button again to the correct checked button.

Contrarily, if there was no button checked, buttonA's onRestoreInstanceState will reset it to unchecked. RadioGroup is not handling this scenario because it is not designed to handle unchecks.

So, we end up with RadioGroup tracking buttonA as checked and buttonA tracking itself as unchecked. When you click on buttonA, the check is processed, however the UI does not update due to shortcircuit logic in the check() method because it assumes that since the id already matches the mCheckedId it has on hand, the button should already be checked:

// don't even bother
if (id != -1 && (id == mCheckedId)) {
    return;
}

I guess this could be considered a bug, but it ultimately comes down to some strange design choices on your part. You are setting it to default to buttonA, which means that the user cannot uncheck any button under normal circumstances and then you provide a clear button to get them to a non-default state that they could not reach under normal circumstances. So, there are two possible solutions that would bring your UI design choices in to focus:

1) If you want there to always be a checked button, have the reset button reset to default state.

clearButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        mRadioGroup.check(R.id.radioButtonA);
    }
});

2) If you want there to possibly be no checked button, don't default to anything.

tachyonflux
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  • That's really interesting! This problem still exists though even if I don't use the default setting and use radioGroup.check(R.id.radioButtonA); in the onCreate(). The reason for this design decision is it's for a search, and the default search is selected. If you change the search values manually, I no longer want the radio group selected as it doesn't represent the search anymore. I need a way to initially select A somehow without causing this issue. – Ben987654 Jul 31 '15 at 19:52
  • Looks like I found a way around it, don't use the default in the XML as per what you described, and in the onCreate() I can set it the first time it loads, but don't check it if savedInstanceState isn't null. The behavior still seems incorrect if you always check it in onCreate() but that's not the behavior I want, so the conditional check works for me. – Ben987654 Jul 31 '15 at 21:00
0

I had this problem in my App . I cheated . I created a new radio buttom and I selected gone its visibility . after that , I put setcheked=(true).

Hadi1986
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