How do I add a preferences / setting screen to my android app?
Thankfully it is very easy to create a preferences screen, much like those you'd find within the Settings on your handset. A preference screen requires a special XML definition, you cannot use standard layouts and views, however this can still be placed within your
layout folder.
The
PreferenceScreen layout can be separated into sections with a
PreferenceCategory which has a title and is displayed as a dividing bar o the screen. There are several preference type views:
EditTextPreference - text box entry (text string)
CheckBoxPreference - tickable check box (true/false boolean)
ListPreference - Selection from array of options (text string)
RingtonePreference - Selection of Uri of ring tones stored on device
A simple example of a preferences screen layout is shown below:
/res/layout/prefs.xml
 |
| Preferences screen |
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
android:title="Preferences">
<PreferenceCategory
android:title="Options">
<CheckBoxPreference
android:key="pref_opt1"
android:title="Option 1"
android:summary="Tick to set this option"
android:defaultValue="true"
/>
<CheckBoxPreference
android:key="pref_opt2"
android:title="Option 2"
android:summary="Tick to set this option"
android:defaultValue="true"
/>
</PreferenceCategory>
<PreferenceCategory
android:title="Selection">
<ListPreference
android:key="pref_type"
android:title="Type"
android:summary="Select item from array"
android:entries="@array/types"
android:entryValues="@array/types_values"
android:defaultValue="1"
/>
<EditTextPreference
android:key="pref_text"
android:title="Input text"
android:summary="Tap to enter some text"
android:dialogTitle="Enter text"
/>
</PreferenceCategory>
<Preference
android:title="Intent"
android:summary="Open a webpage">
<intent
android:action="android.intent.action.VIEW"
android:data="http://android-elements.blogspot.com/" />
</Preference>
</PreferenceScreen>
The
ListPreference in the XML above references two arrays; one for the option text and one for the option values. These should be defined in your strings resource file:
/res/values/strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="types">
<item>Type 1</item>
<item>Type 2</item>
<item>Type 3</item>
</string-array>
<string-array name="types_values">
<item>1</item>
<item>2</item>
<item>3</item>
</string-array>
</resources>
Your activity must extend the
PreferenceActivity rather than a standard activity. This should be defined as below:
src/your.package.name/Prefs.java
package com.example.com;
import android.os.Bundle;
import android.preference.PreferenceActivity;
public class Prefs extends PreferenceActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.layout.prefs);
}
}
Don't forget to add this activity to your manifest!
You can read and write the prefence values in code with the following method examples...
// String
public static String Read(Context context, final String key) {
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(context);
return pref.getString(key, "");
}
public static void Write(Context context, final String key, final String value) {
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, value);
editor.commit();
}
// Boolean
public static boolean ReadBoolean(Context context, final String key, final boolean defaultValue) {
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);
return settings.getBoolean(key, defaultValue);
}
public static void WriteBoolean(Context context, final String key, final boolean value) {
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = settings.edit();
editor.putBoolean(key, value);
editor.commit();
}
Just as an aside, many apps I have build have been based upon a white theme rather than the default android dark. It is easy to set your preferences screen to use the built in Light
theme so that it looks more consistent within your app, simply set the theme for the activity within your manifest as follows:
<activity android:name=".Prefs" android:theme="@android:style/Theme.Light">
Then your preferences screen will look something like this:
 |
| Preferences Screen (Light theme) |
Posts
