PreferenceActivity: save value as integer

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Using a simple EditTextPreference in my preferences activity:

<EditTextPreference
    android:key="SomeKey"
    android:title="@string/some_title"
    android:summary="..."
    android:numeric="integer"
    android:maxLength="2"
/>

Is there a way that this configuration value would be saved as integer? Seems now it just allows to enter numbers, but the value is still saved as string:

Calling:

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
int value = preferences.getInt("SomeKey", -1);

throws me java.lang.ClassCastException: java.lang.String, and:

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
String value = preferences.getString("SomeKey", "-1");

retrieves the value successfully.

How to make PreferenceActivity to save value as integer by default?

6 Answers

I know this is an old question with an already accepted answer but I think my solution can be helpful for someone searching for a more complete answer. I have just improved @broot answer a litte and there goes my solution:

Override the EditTextPreference to provide text to int conversion:

public class IntEditTextPreference extends EditTextPreference implements EditTextPreference.OnBindEditTextListener {
    private String mText;
    
    public IntEditTextPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        setOnBindEditTextListener(this);
    }

    public IntEditTextPreference(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        setOnBindEditTextListener(this);
    }

    public IntEditTextPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
        setOnBindEditTextListener(this);
    }

    public IntEditTextPreference(Context context) {
        super(context);
        setOnBindEditTextListener(this);
    }

    /**
     * Saves the text to the current data storage.
     *
     * @param text The text to save
     */
    public void setText(String text) {
        final boolean wasBlocking = shouldDisableDependents();

        mText = text;

        int value = Integer.parseInt(text);

        persistInt(value);

        final boolean isBlocking = shouldDisableDependents();
        if (isBlocking != wasBlocking) {
            notifyDependencyChange(isBlocking);
        }

        notifyChanged();
    }

    /**
     * Gets the text from the current data storage.
     *
     * @return The current preference value
     */
    public String getText() {
        return mText;
    }

    @Override
    protected void onSetInitialValue(Object defaultValue) {
        int value;
        if (defaultValue != null) {
            String strDefaultValue = (String) defaultValue;

            int defaultIntValue = Integer.parseInt(strDefaultValue);
            value = getPersistedInt(defaultIntValue);
        } else {
            value = getPersistedInt(0);
        }

        setText(Integer.toString(value));
    }

    @Override
    public boolean shouldDisableDependents() {
        return TextUtils.isEmpty(mText) || super.shouldDisableDependents();
    }

    @Override
    public void onBindEditText(@NonNull EditText editText) {
        editText.setInputType(InputType.TYPE_CLASS_NUMBER);
    }
}

In the preferences xml:

<your.package.here.IntEditTextPreference
            android:key="some_key"
            android:title="@string/some_title"
            android:defaultValue="5"
            app:useSimpleSummaryProvider="true"/>

Note: Don't use android:numeric nor android:inputType. Since EditTextPreference is not an EditText itself setting those attributes will do nothing. In order to achieve the desired effect on the EditText from the Dialog opened by the EditTextPreference, just set the input type in your custom EditTextPreference by implementing EditTextPreference.OnBindEditTextListener as you can see in the code above.

That's what worked for me.

I think this is the shortest one I could come up with:

int CheckInterval = Integer.parseInt(sharedPreferences.getString("check_frequency","60"));
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