Android: TimePicker in PreferenceScreen: send data to the TimePicker

Question

I have a PreferenceScreen where 3 of its preferences are TimePreferences. TimePreference is a custom class extending DialogPreference, and it contains a TimePicker. I created it following THIS CODE.

Now I want to limit the TimePicker input. Each TimePreference needs to have a specific time limit (this limit will be different in each TimePreference), and I'm going to use this limit to check the input values. I.e., I may want the first TimePreference to be inferior to 1 hour, the 2nd to 5 hours and the last one without limits.

Since I wanted to avoid having 3 different classes I was looking for a way to send some data to the preference. I tried to use defaultValue, but it's null when the user has already selected any value.

My PreferenceActivity uses a PreferenceFragment. This is their code:

public class PrefsActivity extends Activity {

@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    getFragmentManager().beginTransaction().replace(android.R.id.content,
            new PrefsFragment()).commit();
}

}

public class PrefsFragment extends PreferenceFragment {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.prefs_tod);
}

}

Can I send this data to the preference? Or should I have 3 different classes?

Thanks!

Answer 1

You can create custom preference with additional attributes, in your case with limit attribute.

res/values/attrs.xml

<declare-styleable name="CustomPreference">
    <attr name="limit" format="integer"/>
</declare-styleable>

CustomPreference.java

public class CustomPreference extends DialogPreference {
private int limit;

public CustomPreference(Context context, AttributeSet attrs) {
    super(context, attrs);

    TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CustomPreference, 0, 0);
    limit = a.getInteger(R.styleable.CustomPreference_limit, 0);

    a.recycle();
}

In preference layout:

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" 
   xmlns:app="http://schemas.android.com/apk/res/com.example.package">
    <PreferenceCategory>
        <com.example.package.CustomPreference
        android:key="@string/pref_key"
            android:title="@string/pref_title"
            app:limit="6" />
    </PreferenceCategory>
</PreferenceScreen>

Also you can set an attribute value programmatically