I improved the link provided by Macarse, so that the value is saved only on ok button click, and so that you can use @string/... values in the XML file.
Here is the code:
/* The following code was written by Matthew Wiggins
* and is released under the APACHE 2.0 license
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Improvements :
* - save the value on positive button click, not on seekbar change
* - handle @string/... values in xml file
*/
package fr.atcm.carpooling.views.utils;
import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.preference.DialogPreference;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.TextView;
public class SeekBarPreference extends DialogPreference implements SeekBar.OnSeekBarChangeListener, OnClickListener
{
// ------------------------------------------------------------------------------------------
// Private attributes :
private static final String androidns="http://schemas.android.com/apk/res/android";
private SeekBar mSeekBar;
private TextView mSplashText,mValueText;
private Context mContext;
private String mDialogMessage, mSuffix;
private int mDefault, mMax, mValue = 0;
// ------------------------------------------------------------------------------------------
// ------------------------------------------------------------------------------------------
// Constructor :
public SeekBarPreference(Context context, AttributeSet attrs) {
super(context,attrs);
mContext = context;
// Get string value for dialogMessage :
int mDialogMessageId = attrs.getAttributeResourceValue(androidns, "dialogMessage", 0);
if(mDialogMessageId == 0) mDialogMessage = attrs.getAttributeValue(androidns, "dialogMessage");
else mDialogMessage = mContext.getString(mDialogMessageId);
// Get string value for suffix (text attribute in xml file) :
int mSuffixId = attrs.getAttributeResourceValue(androidns, "text", 0);
if(mSuffixId == 0) mSuffix = attrs.getAttributeValue(androidns, "text");
else mSuffix = mContext.getString(mSuffixId);
// Get default and max seekbar values :
mDefault = attrs.getAttributeIntValue(androidns, "defaultValue", 0);
mMax = attrs.getAttributeIntValue(androidns, "max", 100);
}
// ------------------------------------------------------------------------------------------
// ------------------------------------------------------------------------------------------
// DialogPreference methods :
@Override
protected View onCreateDialogView() {
LinearLayout.LayoutParams params;
LinearLayout layout = new LinearLayout(mContext);
layout.setOrientation(LinearLayout.VERTICAL);
layout.setPadding(6,6,6,6);
mSplashText = new TextView(mContext);
mSplashText.setPadding(30, 10, 30, 10);
if (mDialogMessage != null)
mSplashText.setText(mDialogMessage);
layout.addView(mSplashText);
mValueText = new TextView(mContext);
mValueText.setGravity(Gravity.CENTER_HORIZONTAL);
mValueText.setTextSize(32);
params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layout.addView(mValueText, params);
mSeekBar = new SeekBar(mContext);
mSeekBar.setOnSeekBarChangeListener(this);
layout.addView(mSeekBar, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
if (shouldPersist())
mValue = getPersistedInt(mDefault);
mSeekBar.setMax(mMax);
mSeekBar.setProgress(mValue);
return layout;
}
@Override
protected void onBindDialogView(View v) {
super.onBindDialogView(v);
mSeekBar.setMax(mMax);
mSeekBar.setProgress(mValue);
}
@Override
protected void onSetInitialValue(boolean restore, Object defaultValue)
{
super.onSetInitialValue(restore, defaultValue);
if (restore)
mValue = shouldPersist() ? getPersistedInt(mDefault) : 0;
else
mValue = (Integer)defaultValue;
}
// ------------------------------------------------------------------------------------------
// ------------------------------------------------------------------------------------------
// OnSeekBarChangeListener methods :
@Override
public void onProgressChanged(SeekBar seek, int value, boolean fromTouch)
{
String t = String.valueOf(value);
mValueText.setText(mSuffix == null ? t : t.concat(" " + mSuffix));
}
@Override
public void onStartTrackingTouch(SeekBar seek) {}
@Override
public void onStopTrackingTouch(SeekBar seek) {}
public void setMax(int max) { mMax = max; }
public int getMax() { return mMax; }
public void setProgress(int progress) {
mValue = progress;
if (mSeekBar != null)
mSeekBar.setProgress(progress);
}
public int getProgress() { return mValue; }
// ------------------------------------------------------------------------------------------
// ------------------------------------------------------------------------------------------
// Set the positive button listener and onClick action :
@Override
public void showDialog(Bundle state) {
super.showDialog(state);
Button positiveButton = ((AlertDialog) getDialog()).getButton(AlertDialog.BUTTON_POSITIVE);
positiveButton.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if (shouldPersist()) {
mValue = mSeekBar.getProgress();
persistInt(mSeekBar.getProgress());
callChangeListener(Integer.valueOf(mSeekBar.getProgress()));
}
((AlertDialog) getDialog()).dismiss();
}
// ------------------------------------------------------------------------------------------
}
EDIT :
Here is a screenshot :
EDIT : on arlomedia’s demand, here are all the needed pieces of code (I just recreated a new projet, it is perfectly working. I corrected some bugs in SeekBarPreference class, so don’t forget to re-copy/paste it) :
MainActivity :
package fr.at.testsliderpref;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
switch(item.getItemId()) {
case R.id.menu_settings : {
startActivity(new Intent(this, SettingsActivity.class));
break;
}
}
return true;
}
}
SettingsActivity :
package fr.at.testsliderpref;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import fr.at.testsliderpref.utils.SeekBarPreference;
public class SettingsActivity extends PreferenceActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// Call super :
super.onCreate(savedInstanceState);
// Set the activity's fragment :
getFragmentManager().beginTransaction().replace(android.R.id.content, new SettingsFragment()).commit();
}
public static class SettingsFragment extends PreferenceFragment implements OnSharedPreferenceChangeListener {
private SeekBarPreference _seekBarPref;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load the preferences from an XML resource
addPreferencesFromResource(R.xml.activity_settings);
// Get widgets :
_seekBarPref = (SeekBarPreference) this.findPreference("SEEKBAR_VALUE");
// Set listener :
getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
// Set seekbar summary :
int radius = PreferenceManager.getDefaultSharedPreferences(this.getActivity()).getInt("SEEKBAR_VALUE", 50);
_seekBarPref.setSummary(this.getString(R.string.settings_summary).replace("$1", ""+radius));
}
@Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
// Set seekbar summary :
int radius = PreferenceManager.getDefaultSharedPreferences(this.getActivity()).getInt("SEEKBAR_VALUE", 50);
_seekBarPref.setSummary(this.getString(R.string.settings_summary).replace("$1", ""+radius));
}
}
}
layout > activity_main.xml :
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/textview_text" />
</RelativeLayout>
menu > main.xml :
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:id="@+id/menu_settings"
android:title="@string/menu_settings"
android:icon="@android:drawable/ic_menu_preferences"/>
</menu>
xml > activity_settings.xml :
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<fr.at.testsliderpref.utils.SeekBarPreference
android:defaultValue="50"
android:dialogMessage="@string/settings_dialog_message"
android:key="SEEKBAR_VALUE"
android:max="100"
android:summary="@string/settings_summary"
android:text="@string/settings_unit"
android:title="@string/settings_title" />
</PreferenceScreen>
values > strings.xml :
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">TestSliderPref</string>
<string name="textview_text">SeekBarPreference test</string>
<string name="menu_settings">Settings</string>
<string name="settings_dialog_message">Here comes a message</string>
<string name="settings_summary">Current value is $1</string>
<string name="settings_unit">Km</string>
<string name="settings_title">Here comes the title</string>
</resources>
Don’t forget to add your SettingsActivity to the manifest, and it should be OK.