477

This must come up very often.

When the user is editing preferences in an Android app, I'd like them to be able to see the currently set value of the preference in the Preference summary.

Example: if I have a Preference setting for "Discard old messages" that specifies the number of days after which messages need to be cleaned up. In the PreferenceActivity I'd like the user to see:

"Discard old messages" <- title

"Clean up messages after x days" <- summary where x is the current Preference value

Extra credit: make this reusable, so I can easily apply it to all my preferences regardless of their type (so that it work with EditTextPreference, ListPreference etc. with minimal amount of coding).

0

36 Answers 36

154

There are ways to make this a more generic solution, if that suits your needs.

For example, if you want to generically have all list preferences show their choice as summary, you could have this for your onSharedPreferenceChanged implementation:

public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { Preference pref = findPreference(key); if (pref instanceof ListPreference) { ListPreference listPref = (ListPreference) pref; pref.setSummary(listPref.getEntry()); } } 

This is easily extensible to other preference classes.

And by using the getPreferenceCount and getPreference functionality in PreferenceScreen and PreferenceCategory, you could easily write a generic function to walk the preference tree setting the summaries of all preferences of the types you desire to their toString representation

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5 Comments

nice solution indeed. only lacks an initialization
@njzk2 all you have to do is make sure the activity implements OnSharedPreferenceChangeListener
NB: There is a simpler way, see @Robertas's answer.
Actually, you can set summary to "%s" for ListPreference, and ListPreference.getSummary() will format the summary with the current selected entry (or "" if none selected).
findPreference(key) is deprecated, is there another way of accessing this?
144

Here is my solution... FWIW

package com.example.PrefTest; import android.content.SharedPreferences; import android.content.SharedPreferences.OnSharedPreferenceChangeListener; import android.os.Bundle; import android.preference.EditTextPreference; import android.preference.ListPreference; import android.preference.Preference; import android.preference.PreferenceActivity; import android.preference.PreferenceGroup; import android.preference.PreferenceManager; public class Preferences extends PreferenceActivity implements OnSharedPreferenceChangeListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); PreferenceManager.setDefaultValues(Preferences.this, R.xml.preferences, false); initSummary(getPreferenceScreen()); } @Override protected void onResume() { super.onResume(); // Set up a listener whenever a key changes getPreferenceScreen().getSharedPreferences() .registerOnSharedPreferenceChangeListener(this); } @Override protected void onPause() { super.onPause(); // Unregister the listener whenever a key changes getPreferenceScreen().getSharedPreferences() .unregisterOnSharedPreferenceChangeListener(this); } public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { updatePrefSummary(findPreference(key)); } private void initSummary(Preference p) { if (p instanceof PreferenceGroup) { PreferenceGroup pGrp = (PreferenceGroup) p; for (int i = 0; i < pGrp.getPreferenceCount(); i++) { initSummary(pGrp.getPreference(i)); } } else { updatePrefSummary(p); } } private void updatePrefSummary(Preference p) { if (p instanceof ListPreference) { ListPreference listPref = (ListPreference) p; p.setSummary(listPref.getEntry()); } if (p instanceof EditTextPreference) { EditTextPreference editTextPref = (EditTextPreference) p; if (p.getTitle().toString().toLowerCase().contains("password")) { p.setSummary("******"); } else { p.setSummary(editTextPref.getText()); } } if (p instanceof MultiSelectListPreference) { EditTextPreference editTextPref = (EditTextPreference) p; p.setSummary(editTextPref.getText()); } } } 

10 Comments

This does work great @EddieB...except that I have a preference screen within a preference screen. Any idea how to reach the inner preference screen and populate those with summary?
@taraloca - change if (p instanceof PreferenceCategory) { PreferenceCategory pCat = (PreferenceCategory) p; to if (p instanceof PreferenceGroup) { final PreferenceGroup pCat = (PreferenceGroup) p;
this is working great what if EditTextPreference is android:password="true" it shows the value
How should I modify the code to display summary from the resource (xml) file if no value is defined (i.e. if editTextPref.getText() == "")? How to get summary value at updatePrefSummary? p.getSummary() and editTextPref.getSummary() return already modified values.
Since both PreferenceCategory and PreferenceScreen inherit from PreferenceGroup, I've changed initSummary to handle a PreferenceGroup instead. This avoids the need of another loop in onCreate(). Change in behavior: nested PreferenceScreens now also ge handled recursively.
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104

Android documentation says one can use a String formatting marker in getSummary():

If the summary has a String formatting marker in it (i.e. "%s" or "%1$s"), then the current entry value will be substituted in its place.

Simply specifying android:summary="Clean up messages after %s days" in ListPreference xml declaration worked for me.

Note: This only works for ListPreference.

9 Comments

Someone correct me if I'm wrong, but the documentation for getSummary() states that it was added in API level 1. Are you implying that the behavior was different when first released?
Unfortunately, this only works for ListPreference. I want the same behavior for EditTextPreference. It's surprising that Google hasn't added this for all DialogPreferences.
Plus, I does not work as long as the value has not been set - on the first ever call of the Preference activity, it displays just %s which is really dumb.
@Zordid That can be fixed by specifying the default value in your xml like android:defaultValue="0" in your ListPreference. This is the most sensible answer and works for me.
@Mohit Singh / @Zordid, on Lollipop API 22, the defaultValue and the %s do not work. On other versions, generally, it works though. Any solution please? I sure do not want to write a custom class for this. Unbelievable that Google makes the most trivial of tasks such a pain.
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85

If you use PreferenceFragment, this is how I solved it. It's self explanatory.

public static class SettingsFragment extends PreferenceFragment implements OnSharedPreferenceChangeListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.settings); getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this); } @Override public void onResume() { super.onResume(); for (int i = 0; i < getPreferenceScreen().getPreferenceCount(); ++i) { Preference preference = getPreferenceScreen().getPreference(i); if (preference instanceof PreferenceGroup) { PreferenceGroup preferenceGroup = (PreferenceGroup) preference; for (int j = 0; j < preferenceGroup.getPreferenceCount(); ++j) { Preference singlePref = preferenceGroup.getPreference(j); updatePreference(singlePref, singlePref.getKey()); } } else { updatePreference(preference, preference.getKey()); } } } @Override public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { updatePreference(findPreference(key), key); } private void updatePreference(Preference preference, String key) { if (preference == null) return; if (preference instanceof ListPreference) { ListPreference listPreference = (ListPreference) preference; listPreference.setSummary(listPreference.getEntry()); return; } SharedPreferences sharedPrefs = getPreferenceManager().getSharedPreferences(); preference.setSummary(sharedPrefs.getString(key, "Default")); } } 

11 Comments

This solution needs more votes... It bugs me that the examples on the developer site SHOW this being done, but omit it completely.
To get EditTextPreferences also updated add this to updatePreference CODE if (preference instanceof EditTextPreference) { EditTextPreference editTextPref = (EditTextPreference) preference; preference.setSummary(editTextPref.getText()); } thanks @EddieB
Where you call unregisterOnSharedPreferenceChangeListener ?
findPreference(CharSequence key) This method was deprecated in API level 11. This function is not relevant for a modern fragment-based PreferenceActivity.
@DSlomer64 I'm well aware of what you're quoting. It's telling you not to use PreferenceActivity.findPreference (and several other methods), because Google wants you to switch to the technique shown in this answer, which uses PreferenceFragment.findPreference instead.
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33

My option is to extend ListPreference and it's clean:

public class ListPreferenceShowSummary extends ListPreference { private final static String TAG = ListPreferenceShowSummary.class.getName(); public ListPreferenceShowSummary(Context context, AttributeSet attrs) { super(context, attrs); init(); } public ListPreferenceShowSummary(Context context) { super(context); init(); } private void init() { setOnPreferenceChangeListener(new OnPreferenceChangeListener() { @Override public boolean onPreferenceChange(Preference arg0, Object arg1) { arg0.setSummary(getEntry()); return true; } }); } @Override public CharSequence getSummary() { return super.getEntry(); } } 

Then you add in your settings.xml:

<yourpackage.ListPreferenceShowSummary android:key="key" android:title="title" android:entries="@array/entries" android:entryValues="@array/values" android:defaultValue="first value"/> 

3 Comments

I made a solution based on this. In my solution I have a method to set an array of entrySummaries instead of using the entries strings in both the menu and the summaries. There is one problem here: getEntry() returns the previous value not the new one.
Actually is init() even nescessary? I have just overidden getSummary() and it seems to work prefectly!
The init() function is necessary to update the summary when the user changes that preference. Without it, it will just stay whatever the entry was initially.
23

You can override default Preference classes and implement the feature.

public class MyListPreference extends ListPreference { public MyListPreference(Context context) { super(context); } public MyListPreference(Context context, AttributeSet attrs) { super(context, attrs); } @Override public void setValue(String value) { super.setValue(value); setSummary(getEntry()); } } 

Later in you xml you can use custom preference like

<your.package.name.MyListPreference android:key="noteInterval" android:defaultValue="60" android:title="Notification Interval" android:entries="@array/noteInterval" android:entryValues="@array/noteIntervalValues" /> 

1 Comment

Excellent simple method. Just watch out for things like % in the getEntry string as they might cause issues (or they did for me)
21

After several hours I've been spent to solve such problem I've implemented this code:

[UPDATE: the final version listing]

public class MyPreferencesActivity extends PreferenceActivity { ... ListPreference m_updateList; ... @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); m_updateList = (ListPreference) findPreference(getString(R.string.pref_update_interval_key)); String currentValue = m_updateList.getValue(); if (currentValue == null) { m_updateList.setValue((String)m_updateList.getEntryValues()[DEFAULT_UPDATE_TIME_INDEX]); currentValue = m_updateList.getValue(); } updateListSummary(currentValue); m_updateList.setOnPreferenceChangeListener(new OnPreferenceChangeListener() { @Override public boolean onPreferenceChange(Preference preference, Object newValue) { updateListSummary(newValue.toString()); return true; } }); } private void updateListSummary(String newValue) { int index = m_updateList.findIndexOfValue(newValue); CharSequence entry = m_updateList.getEntries()[index]; m_updateList.setSummary(entry); } } 

That was the only solution that worked for me fine. Before I've tried to subclass from ListPreferences and to implement android:summary="bla bla bla %s". Neither worked.

3 Comments

Your way is more clear and uses less code then others. The top answers works using "proxy" - preferences manager. It's not so clear as listening for direct changes in list.
@Subtle Fox, Neat solution. just curious if you did 'setDefaultValue()' then why check for (ss==null)
Because setDefaultValue() shouldn't be there :) I've put this code before refactoring
21

Maybe like ListPreference: Modify getSummary to get what you want:

package your.package.preference; import android.content.Context; import android.util.AttributeSet; public class EditTextPreference extends android.preference.EditTextPreference{ public EditTextPreference(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public EditTextPreference(Context context, AttributeSet attrs) { super(context, attrs); } public EditTextPreference(Context context) { super(context); } @Override public CharSequence getSummary() { if(super.getSummary() == null) return null; String summary = super.getSummary().toString(); return String.format(summary, getText()); } } 

And use this in your xml:

<your.package.EditTextPreference android:key="pref_alpha" android:summary="Actual value: %s" android:title="Title" android:defaultValue="default" /> 

So you are able to write a summary with %s instead of the actual value.

2 Comments

@Eruvanos @serv-inc At least with a subclass of android.support.v7.preference.EditTextPreference, this does not update the summary when the preference is changed, only when the preferences activity is created. A way around this without implementing OnSharedPreferenceChangeListener.onSharedPreferenceChanged in the preferences fragment class is to also override android.support.v7.preference.EditTextPreference.setText(String text): @Override public void setText(String text) { super.setText(text); this.setSummary(this.getText()); }
@PointedEars: done. But this also seems to be a copy of stackoverflow.com/a/21906829/1587329
18

This is the code you need to set the summary to the chosen value. It also sets the values on startup and respects the default values, not only on change. Just change "R.layout.prefs" to your xml-file and extend the setSummary-method to your needs. It actually is only handling ListPreferences, but it is easy to customize to respect other Preferences.

package de.koem.timetunnel; import android.content.SharedPreferences; import android.content.SharedPreferences.OnSharedPreferenceChangeListener; import android.os.Bundle; import android.preference.ListPreference; import android.preference.Preference; import android.preference.PreferenceActivity; import android.preference.PreferenceGroup; public class Prefs extends PreferenceActivity implements OnSharedPreferenceChangeListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.addPreferencesFromResource(R.layout.prefs); this.initSummaries(this.getPreferenceScreen()); this.getPreferenceScreen().getSharedPreferences() .registerOnSharedPreferenceChangeListener(this); } /** * Set the summaries of all preferences */ private void initSummaries(PreferenceGroup pg) { for (int i = 0; i < pg.getPreferenceCount(); ++i) { Preference p = pg.getPreference(i); if (p instanceof PreferenceGroup) this.initSummaries((PreferenceGroup) p); // recursion else this.setSummary(p); } } /** * Set the summaries of the given preference */ private void setSummary(Preference pref) { // react on type or key if (pref instanceof ListPreference) { ListPreference listPref = (ListPreference) pref; pref.setSummary(listPref.getEntry()); } } /** * used to change the summary of a preference */ public void onSharedPreferenceChanged(SharedPreferences sp, String key) { Preference pref = findPreference(key); this.setSummary(pref); } // private static final String LOGTAG = "Prefs"; } 

koem

2 Comments

Thanks a lot! I created a class from this, giving the resource id as an argument to the onCreate() -- that way it was a one line change to my settings screens to have them show the values in summary.
BTW: Note that non-persistent preferences will not get updated using this system. Changes to them must be listened using the setOnPreferenceChangeListener(Preference.OnPreferenceChangeListener onPreferenceChangeListener)-method of individual Preferences.
14

According to Android docs you can use app:useSimpleSummaryProvider="true" in ListPreference and EditTextPreference components.

2 Comments

This should actually be the accepted answer, if you use androidx.preference.EditTextPreference
Actually this makes me wonder why this isn't enabled by default.
12

For EditTextPreference:

public class MyEditTextPreference extends EditTextPreference { public MyEditTextPreference(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public MyEditTextPreference(Context context, AttributeSet attrs) { super(context, attrs); } @Override public void setText(String text) { super.setText(text); setSummary(text); } } 

Comments

11

Actually, CheckBoxPreference does have the ability to specify a different summary based on the checkbox value. See the android:summaryOff and android:summaryOn attributes (as well as the corresponding CheckBoxPreference methods).

Comments

11

If someone is still looking for answers to this, you should check out thirtythreefortys answer.

<ListPreference android:key="pref_list" android:title="A list of preferences" android:summary="%s" android:entries="@array/pref_list_entries" android:entryValues="@array/pref_list_entries_values" android:defaultValue="0" /> 

Android will replace %s with the current string value of the preference, as displayed by the ListPreference's picker.

2 Comments

Works. This is the easiest and best solution today.
Note that the "%s" can be placed anywhere in your summary string. And yes, that includes resource strings!
7

Thanks for this tip!

I have one preference screen and want to show the value for each list preference as the summary.

This is my way now:

public class Preferences extends PreferenceActivity implements OnSharedPreferenceChangeListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); } @Override protected void onResume() { super.onResume(); // Set up initial values for all list preferences Map<String, ?> sharedPreferencesMap = getPreferenceScreen().getSharedPreferences().getAll(); Preference pref; ListPreference listPref; for (Map.Entry<String, ?> entry : sharedPreferencesMap.entrySet()) { pref = findPreference(entry.getKey()); if (pref instanceof ListPreference) { listPref = (ListPreference) pref; pref.setSummary(listPref.getEntry()); } } // Set up a listener whenever a key changes getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this); } @Override protected void onPause() { super.onPause(); // Unregister the listener whenever a key changes getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this); } public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { Preference pref = findPreference(key); if (pref instanceof ListPreference) { ListPreference listPref = (ListPreference) pref; pref.setSummary(listPref.getEntry()); } } 

This works for me, but I'm wondering what is the best solution (performance, stability, scalibility): the one Koem is showing or this one?

Comments

7

I've seen all voted answers show how to set the summary with the exact current value, but the OP wanted also something like:

"Clean up messages after x days"* <- summary where x is the current Preference value

Here is my answer for achieving that

As per the documentation on ListPreference.getSummary():

Returns the summary of this ListPreference. If the summary has a String formatting marker in it (i.e. "%s" or "%1$s"), then the current entry value will be substituted in its place.

However, I tried this on several devices and it doesn't seem to work. With some research, I found a good solution in this answer. It simply consists of extending every Preference you use and override getSummary() to work as specified by Android documentation.

2 Comments

It does seem to work initially, but when you choose a new value it doesn't automatically update until you do something to invalidate the whole activity and cause it to redraw. I'm on Android 4.0.4.
Would be nice if Google could add a formatting string to the preference object.
6

Thanks, Reto, for the detailed explanation!

In case this is of any help to anyone, I had to change the code proposed by Reto Meier to make it work with the SDK for Android 1.5

@Override protected void onResume() { super.onResume(); // Setup the initial values mListPreference.setSummary("Current value is " + mListPreference.getEntry().toString()); // Set up a listener whenever a key changes ... } 

The same change applies for the callback function onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)

Cheers,

Chris

Comments

5

In Android Studio, open "root_preferences.xml", select Design mode. Select the desired EditTextPreference preference, and under "All attributes", look for the "useSimpleSummaryProvider" attribute and set it to true. It will then show the current value.

1 Comment

duplicate answer, but i like this solution
4

I solved the issue with the following descendant of ListPreference:

public class EnumPreference extends ListPreference { public EnumPreference(Context aContext, AttributeSet attrs) { super(aContext,attrs); } @Override protected View onCreateView(ViewGroup parent) { setSummary(getEntry()); return super.onCreateView(parent); } @Override protected boolean persistString(String aNewValue) { if (super.persistString(aNewValue)) { setSummary(getEntry()); notifyChanged(); return true; } else { return false; } } } 

Seems to work fine for me in 1.6 up through 4.0.4.

Comments

4
public class ProfileManagement extends PreferenceActivity implements OnPreferenceChangeListener { EditTextPreference screenName; ListPreference sex; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.layout.profile_management); screenName = (EditTextPreference) findPreference("editTextPref"); sex = (ListPreference) findPreference("sexSelector"); screenName.setOnPreferenceChangeListener(this); sex.setOnPreferenceChangeListener(this); } @Override public boolean onPreferenceChange(Preference preference, Object newValue) { preference.setSummary(newValue.toString()); return true; } } 

Comments

3

If you only want to display the plain text value of each field as its summary, the following code should be the easiest to maintain. It requires only two changes (lines 13 and 21, marked with "change here"):

package com.my.package; import android.content.SharedPreferences; import android.content.SharedPreferences.OnSharedPreferenceChangeListener; import android.os.Bundle; import android.preference.EditTextPreference; import android.preference.ListPreference; import android.preference.Preference; import android.preference.PreferenceActivity; public class PreferencesActivity extends PreferenceActivity implements OnSharedPreferenceChangeListener { private final String[] mAutoSummaryFields = { "pref_key1", "pref_key2", "pref_key3" }; // change here private final int mEntryCount = mAutoSummaryFields.length; private Preference[] mPreferenceEntries; @SuppressWarnings("deprecation") @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences_file); // change here mPreferenceEntries = new Preference[mEntryCount]; for (int i = 0; i < mEntryCount; i++) { mPreferenceEntries[i] = getPreferenceScreen().findPreference(mAutoSummaryFields[i]); } } @SuppressWarnings("deprecation") @Override protected void onResume() { super.onResume(); for (int i = 0; i < mEntryCount; i++) { updateSummary(mAutoSummaryFields[i]); // initialization } getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this); // register change listener } @SuppressWarnings("deprecation") @Override protected void onPause() { super.onPause(); getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this); // unregister change listener } private void updateSummary(String key) { for (int i = 0; i < mEntryCount; i++) { if (key.equals(mAutoSummaryFields[i])) { if (mPreferenceEntries[i] instanceof EditTextPreference) { final EditTextPreference currentPreference = (EditTextPreference) mPreferenceEntries[i]; mPreferenceEntries[i].setSummary(currentPreference.getText()); } else if (mPreferenceEntries[i] instanceof ListPreference) { final ListPreference currentPreference = (ListPreference) mPreferenceEntries[i]; mPreferenceEntries[i].setSummary(currentPreference.getEntry()); } break; } } } public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { updateSummary(key); } } 

Comments

3

Here's my solution:

Build a preference type 'getter' method.

protected String getPreference(Preference x) { // http://stackoverflow.com/questions/3993982/how-to-check-type-of-variable-in-java if (x instanceof CheckBoxPreference) return "CheckBoxPreference"; else if (x instanceof EditTextPreference) return "EditTextPreference"; else if (x instanceof ListPreference) return "ListPreference"; else if (x instanceof MultiSelectListPreference) return "MultiSelectListPreference"; else if (x instanceof RingtonePreference) return "RingtonePreference"; else if (x instanceof SwitchPreference) return "SwitchPreference"; else if (x instanceof TwoStatePreference) return "TwoStatePreference"; else if (x instanceof DialogPreference) // Needs to be after ListPreference return "DialogPreference"; else return "undefined"; } 

Build a 'setSummaryInit' method.

public void onSharedPreferenceChanged(SharedPreferences prefs, String key) { Log.i(TAG, "+ onSharedPreferenceChanged(prefs:" + prefs + ", key:" + key + ")"); if( key != null ) { updatePreference(prefs, key); setSummary(key); } else { Log.e(TAG, "Preference without key!"); } Log.i(TAG, "- onSharedPreferenceChanged()"); } protected boolean setSummary() { return _setSummary(null); } protected boolean setSummary(String sKey) { return _setSummary(sKey); } private boolean _setSummary(String sKey) { if (sKey == null) Log.i(TAG, "Initializing"); else Log.i(TAG, sKey); // Get Preferences SharedPreferences sharedPrefs = PreferenceManager .getDefaultSharedPreferences(this); // Iterate through all Shared Preferences // http://stackoverflow.com/questions/9310479/how-to-iterate-through-all-keys-of-shared-preferences Map<String, ?> keys = sharedPrefs.getAll(); for (Map.Entry<String, ?> entry : keys.entrySet()) { String key = entry.getKey(); // Do work only if initializing (null) or updating specific preference key if ( (sKey == null) || (sKey.equals(key)) ) { String value = entry.getValue().toString(); Preference pref = findPreference(key); String preference = getPreference(pref); Log.d("map values", key + " | " + value + " | " + preference); pref.setSummary(key + " | " + value + " | " + preference); if (sKey != null) return true; } } return false; } private void updatePreference(SharedPreferences prefs, String key) { Log.i(TAG, "+ updatePreference(prefs:" + prefs + ", key:" + key + ")"); Preference pref = findPreference(key); String preferenceType = getPreference(pref); Log.i(TAG, "preferenceType = " + preferenceType); Log.i(TAG, "- updatePreference()"); } 

Initialize

Create public class that PreferenceActivity and implements OnSharedPreferenceChangeListener

protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); PreferenceManager.setDefaultValues(this, R.xml.global_preferences, false); this.addPreferencesFromResource(R.xml.global_preferences); this.getPreferenceScreen().getSharedPreferences() .registerOnSharedPreferenceChangeListener(this); } protected void onResume() { super.onResume(); setSummary(); } 

Comments

3

Simply:

listPreference.setSummary("%s"); 

Comments

3

FYI:

findPreference(CharSequence key) This method was deprecated in API level 11. This function is not relevant for a modern fragment-based PreferenceActivity. 

All the more reason to look at the very slick Answer of @ASD above (source found here) saying to use %s in android:summary for each field in preferences.xml. (Current value of preference is substituted for %s.)

enter image description here

<ListPreference ... android:summary="Length of longest word to return as match is %s" ... /> 

Comments

3

Since in androidx Preference class has the SummaryProvider interface, it can be done without OnSharedPreferenceChangeListener. Simple implementations are provided for EditTextPreference and ListPreference. Building on EddieB's answer it can look like this. Tested on androidx.preference:preference:1.1.0-alpha03.

package com.example.util.timereminder.ui.prefs; import android.os.Bundle; import com.example.util.timereminder.R; import androidx.preference.EditTextPreference; import androidx.preference.ListPreference; import androidx.preference.Preference; import androidx.preference.PreferenceFragmentCompat; import androidx.preference.PreferenceGroup; /** * Displays different preferences. */ public class PrefsFragmentExample extends PreferenceFragmentCompat { @Override public void onCreatePreferences(Bundle savedInstanceState, String rootKey) { addPreferencesFromResource(R.xml.preferences); initSummary(getPreferenceScreen()); } /** * Walks through all preferences. * * @param p The starting preference to search from. */ private void initSummary(Preference p) { if (p instanceof PreferenceGroup) { PreferenceGroup pGrp = (PreferenceGroup) p; for (int i = 0; i < pGrp.getPreferenceCount(); i++) { initSummary(pGrp.getPreference(i)); } } else { setPreferenceSummary(p); } } /** * Sets up summary providers for the preferences. * * @param p The preference to set up summary provider. */ private void setPreferenceSummary(Preference p) { // No need to set up preference summaries for checkbox preferences because // they can be set up in xml using summaryOff and summary On if (p instanceof ListPreference) { p.setSummaryProvider(ListPreference.SimpleSummaryProvider.getInstance()); } else if (p instanceof EditTextPreference) { p.setSummaryProvider(EditTextPreference.SimpleSummaryProvider.getInstance()); } } } 

Comments

2

Here,all these are cut from Eclipse sample SettingsActivity. I have to copy all these too much codes to show how these android developers choose perfectly for more generalized and stable coding style.

I left the codes for adapting the PreferenceActivity to tablet and greater API.

public class SettingsActivity extends PreferenceActivity { @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); setupSummaryUpdatablePreferencesScreen(); } private void setupSummaryUpdatablePreferencesScreen() { // In the simplified UI, fragments are not used at all and we instead // use the older PreferenceActivity APIs. // Add 'general' preferences. addPreferencesFromResource(R.xml.pref_general); // Bind the summaries of EditText/List/Dialog preferences to // their values. When their values change, their summaries are updated // to reflect the new value, per the Android Design guidelines. bindPreferenceSummaryToValue(findPreference("example_text")); bindPreferenceSummaryToValue(findPreference("example_list")); } /** * A preference value change listener that updates the preference's summary * to reflect its new value. */ private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() { private String TAG = SettingsActivity.class.getSimpleName(); @Override public boolean onPreferenceChange(Preference preference, Object value) { String stringValue = value.toString(); if (preference instanceof ListPreference) { // For list preferences, look up the correct display value in // the preference's 'entries' list. ListPreference listPreference = (ListPreference) preference; int index = listPreference.findIndexOfValue(stringValue); // Set the summary to reflect the new value. preference.setSummary( index >= 0 ? listPreference.getEntries()[index] : null); } else { // For all other preferences, set the summary to the value's // simple string representation. preference.setSummary(stringValue); } Log.i(TAG, "pref changed : " + preference.getKey() + " " + value); return true; } }; /** * Binds a preference's summary to its value. More specifically, when the * preference's value is changed, its summary (line of text below the * preference title) is updated to reflect the value. The summary is also * immediately updated upon calling this method. The exact display format is * dependent on the type of preference. * * @see #sBindPreferenceSummaryToValueListener */ private static void bindPreferenceSummaryToValue(Preference preference) { // Set the listener to watch for value changes. preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener); // Trigger the listener immediately with the preference's // current value. sBindPreferenceSummaryToValueListener.onPreferenceChange(preference, PreferenceManager .getDefaultSharedPreferences(preference.getContext()) .getString(preference.getKey(), "")); } } 

xml/pref_general.xml

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" > <!-- NOTE: EditTextPreference accepts EditText attributes. --> <!-- NOTE: EditTextPreference's summary should be set to its value by the activity code. --> <EditTextPreference android:capitalize="words" android:defaultValue="@string/pref_default_display_name" android:inputType="textCapWords" android:key="example_text" android:maxLines="1" android:selectAllOnFocus="true" android:singleLine="true" android:title="@string/pref_title_display_name" /> <!-- NOTE: Hide buttons to simplify the UI. Users can touch outside the dialog todismiss it.--> <!-- NOTE: ListPreference's summary should be set to its value by the activity code. --> <ListPreference android:defaultValue="-1" android:entries="@array/pref_example_list_titles" android:entryValues="@array/pref_example_list_values" android:key="example_list" android:negativeButtonText="@null" android:positiveButtonText="@null" android:title="@string/pref_title_add_friends_to_messages" /> </PreferenceScreen> 

values/strings_activity_settings.xml

<resources> <!-- Strings related to Settings --> <!-- Example General settings --> <string name="pref_title_display_name">Display name</string> <string name="pref_default_display_name">John Smith</string> <string name="pref_title_add_friends_to_messages">Add friends to messages</string> <string-array name="pref_example_list_titles"> <item>Always</item> <item>When possible</item> <item>Never</item> </string-array> <string-array name="pref_example_list_values"> <item>1</item> <item>0</item> <item>-1</item> </string-array> </resources> 

NOTE: Actually I just want to comment like "Google's sample for PreferenceActivity is also interesting". But I haven't enough reputation points.So please don't blame me.

(Sorry for bad English)

Comments

2

You have to use bindPreferenceSummaryToValue function on the onCreate method.

Example:

 @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Add 'general' preferences, defined in the XML file addPreferencesFromResource(R.xml.pref_general); // For all preferences, attach an OnPreferenceChangeListener so the UI summary can be // updated when the preference changes. bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_location_key))); bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_units_key))); } 

See lesson 3 on Udacity Android Course: https://www.udacity.com/course/viewer#!/c-ud853/l-1474559101/e-1643578599/m-1643578601

Comments

2

For EditTextPreference:

I came to this solution, of course, just if you need particular edittextpreference but you could do this with every Preference:

............

private static final String KEY_EDIT_TEXT_PREFERENCE2 = "on_a1"; public static String value = ""; 

............

private void updatePreference(Preference preference, String key) { if (key.equals(KEY_EDIT_TEXT_PREFERENCE2)) { preference = findPreference(key); if (preference instanceof EditTextPreference) { editTextPreference = (EditTextPreference) preference; editTextPreference.setSummary(editTextPreference.getText()); value = editTextPreference.getText().toString(); return; } SharedPreferences sharedPrefs = getPreferenceManager().getSharedPreferences(); preference.setSummary(sharedPrefs.getString(KEY_EDIT_TEXT_PREFERENCE2, "")); } } 

Then in onResume();

@Override public void onResume() { super.onResume(); SharedPreferences etext = getPreferenceManager().getSharedPreferences(); String str = etext.getString("value", ""); editTextPreference = (EditTextPreference) findPreference(KEY_EDIT_TEXT_PREFERENCE2); editTextPreference.setText(str); editTextPreference.setSummary(editTextPreference.getText()); getPreferenceScreen().getSharedPreferences() .registerOnSharedPreferenceChangeListener(this); } 

In:

@Override public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { updatePreference(findPreference(key), key); } 

Comments

2

My solution is to create a custom EditTextPreference, used in XML like this: <com.example.EditTextPreference android:title="Example Title" />

EditTextPreference.java:-

package com.example; import android.content.Context; import android.util.AttributeSet; public class EditTextPreference extends android.preference.EditTextPreference { public EditTextPreference(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public EditTextPreference(Context context, AttributeSet attrs) { super(context, attrs); } public EditTextPreference(Context context) { super(context, null); } @Override protected void onDialogClosed(boolean positiveResult) { super.onDialogClosed(positiveResult); setSummary(getSummary()); } @Override public CharSequence getSummary() { return getText(); } } 

Comments

2

If you are using AndroidX you can use a custom SummaryProvider. This approach can be used for any Preference.

Example from documentation (Java):

EditTextPreference countingPreference = (EditTextPreference) findPreference("counting"); countingPreference.setSummaryProvider(new SummaryProvider<EditTextPreference>() { @Override public CharSequence provideSummary(EditTextPreference preference) { String text = preference.getText(); if (TextUtils.isEmpty(text)){ return "Not set"; } return "Length of saved value: " + text.length(); } }); 

Example from documentation (Kotlin):

val countingPreference = findPreference("counting") as EditTextPreference countingPreference.summaryProvider = SummaryProvider<EditTextPreference> { preference -> val text = preference.text if (TextUtils.isEmpty(text)) { "Not set" } else { "Length of saved value: " + text.length } } 

Comments

1

To set the summary of a ListPreference to the value selected in a dialog you could use this code:

package yourpackage; import android.content.Context; import android.util.AttributeSet; public class ListPreference extends android.preference.ListPreference { public ListPreference(Context context, AttributeSet attrs) { super(context, attrs); } protected void onDialogClosed(boolean positiveResult) { super.onDialogClosed(positiveResult); if (positiveResult) setSummary(getEntry()); } protected void onSetInitialValue(boolean restoreValue, Object defaultValue) { super.onSetInitialValue(restoreValue, defaultValue); setSummary(getEntry()); } } 

and reference the yourpackage.ListPreference object in your preferences.xml remembering to specify there your android:defaultValue as this triggers the call to onSetInitialValue().

If you want you can then modify the text before calling setSummary() to whatever suits your application.

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