android - Custom PreferenceCategory Headings

Question

I have a simple preference screen defined like this

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <PreferenceCategory android:title="Security">
        <CheckBoxPreference 
            android:title="Require Pin on Start"
            android:summary="Require pin to run the application"
            android:key="@string/pref_require_pin"
            android:defaultValue="false" />
    </PreferenceCategory>

    <PreferenceCategory android:title="Settings">
        <ListPreference
           android:title="History Age (in days)"
           android:summary="Display items up to 30 days old"
           android:key="@string/pref_history_days"
           android:defaultValue="30"
           android:entries="@array/days_list"
           android:entryValues="@array/days_list"
           android:dialogTitle="Select History Age"/>
    </PreferenceCategory>
</PreferenceScreen>

I have a style setup already and used elsewhere in my app.

<style name="ListHeader">
    <item name="android:textColor">#000000</item>
    <item name="android:textStyle">bold</item>
    <item name="android:textSize">12sp</item>
    <item name="android:background">#cccccc</item>
    <item name="android:paddingTop">6px</item>
    <item name="android:paddingBottom">6px</item>
    <item name="android:paddingLeft">12px</item>
</style>

and here is my activity

public class PreferencesActivity extends PreferenceActivity implements OnSharedPreferenceChangeListener {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        addPreferencesFromResource(R.layout.preferences);
    }
}

How do I apply my custom style to the PreferenceCategory heading?

Answer 1

You should take a look at Preference.Category style:

<style name="Preference.Category">
    <item name="android:layout">@android:layout/preference_category</item>
   <item name="android:shouldDisableView">false</item>
   <item name="android:selectable">false</item>
</style>

Let's take a look at preference_category.xml file:

<!-- Layout used for PreferenceCategory in a PreferenceActivity. -->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    style="?android:attr/listSeparatorTextViewStyle"
    android:id="@+android:id/title"
/>

So you need to create custom theme that extends default android Theme and override listSeparatorTextViewStyle value with ListHeader style. And then apply this theme to Activity that extends PreferenceActivity .

---

Here is how you can do it.

First, in your styles.xml add next code:

<style name="PreferenceListHeader" 
       parent="@android:style/Widget.TextView.ListSeparator">

    <item name="android:textColor">#000000</item>
    <item name="android:textStyle">bold</item>
    <item name="android:textSize">12sp</item>
    <item name="android:background">#cccccc</item>
    <item name="android:paddingTop">6px</item>
    <item name="android:paddingBottom">6px</item>
    <item name="android:paddingLeft">12px</item>
</style>

<style name="Theme.Custom" parent="@android:style/Theme">
    <item name="android:listSeparatorTextViewStyle">@style/PreferenceListHeader</item>               
</style>

Then in your AndroidManifest.xml add theme to your preference acitivity:

 <activity android:name=".MyPreferencesActivity" 
           android:theme="@style/Theme.Custom" 
           ... >
 ...
 </activity>

Here is a screenshot: