Develop Reference

How to call a DialogFragment on Preference click event?

I am making an Alarm app on android. I am newbie in Android. I want to call the Time Picker dialog fragment when one of the Preferences is clicked. I already have created a class which creates the dialog. The code which i am using to call the dialog box is:
TimePickerFragment newFragment=new TimePickerFragment();
newFragment.show(getFragmentManager(), "dialog");`
The above code works for button click event but not for preference click.

If you have made the Preference Activity then try it once
just Override -
#Override
public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
String key = preference.getKey();
//check the key and open dialog
return super.onPreferenceTreeClick(preferenceScreen, preference);
}

PreferenceActivity listpreference value resets to default on reload

I am facing two problems in my app.
In my app i am using preferenceActivity that contains simple settings for the app (checkboxpreference and listpreference), i have three activities mainActivity,secondActivity and settingsActivity which is prefrenceActivity, in secondActivity i am showing a form that lets user choose a value from a spinner view , what i want to do is user can select a default value of that spinner from settingsActivity so user dont have to manually select the value of spinner everytime.
Now my first problem is: whenever i reopen my settingsActivity(preferenceActivity) the summery of the listPreference is resets to default it only shows selected value while settingsActivity is open, when i go back to mainActivity and i again open the settingsActivity the summery of listPreferece shows default value(if i open list of values,it shows last selected value checked).
Second problem is: Whenever i close the app and open again the preference value gets destroyed means the secondActivity dosent show user selected default value instead it shows the first value of spinner.
here is my code
settingsActivity:
public class settingsActivity extends PreferenceActivity
{
MainActivity mainActivity = new MainActivity();
ListPreference listpref;
#Override
public void onCreate(Bundle savedInstenceState)
{
super.onCreate(savedInstenceState);
addPreferencesFromResource(R.xml.settings);
getActionBar().setDisplayHomeAsUpEnabled(true);
listpref = (ListPreference)findPreference("prefDefaultCurrency");
listpref.setOnPreferenceChangeListener(new OnPreferenceChangeListener()
{
#Override
public boolean onPreferenceChange(Preference preference, Object value) {
// TODO Auto-generated method stub
listpref.setSummary(value.toString());
mainActivity.pref_default_currency_index = listpref.findIndexOfValue(value.toString());
return true;
}
});
CharSequence curenttext = listpref.getEntry();
mainActivity.pref_default_currency_index = listpref.findIndexOfValue(curenttext.toString());
}
pref_default_currency_index is a static int variable declared in mainActivity,
i retrive this variable to set the value of spinner in secondActivity, when user clicks a button to open an alertdialoug that contains spinner.
Please help me, thanks in advance.

I got the solution to both of my problems.. i was making it too difficult when it as very easy!!
My first problem was to get back the option user selected from listPreference from PreferenceActivity, i realized that preferenceActivity automatically saves information to SharedPrererences so what i have to do is just retrieve that information in onCreate() method and save it in a local variable.
SharedPreferences sharedPrefs= PreferenceManager.getDefaultSharedPreferences(this);
pref_default_currency_index = Integer.parseInt(sharedPrefs.getString("prefDefaultCurrency","0"));
Second problem was that whenever i open settings activity (preferenceActivity) the summery of listPreference was not showing last chosen value, to solve that problem i just have to set the summery of listPreference in setOnPreferenceChangeListener() method
listpref = (ListPreference)findPreference("prefDefaultCurrency");
listpref.setOnPreferenceChangeListener(new OnPreferenceChangeListener()
{
#Override
public boolean onPreferenceChange(Preference preference, Object value) {
// TODO Auto-generated method stub
listpref.setSummary(value.toString());
return true;
}
});
thats it, it was easy!

Spinner selected item show at first time run, after log out and login again it doesn't show selected item

I have a spinner dropdrown and it show the first time I run, but after I logout and login again, then my spinner doesn't show the selected item on UI. But when I click on it, it show dropdrow that has values inside. It just not showing on UI. May I know any suggestion, please?
My code is here.
public void setSubConSpinnerAdapter(ArrayList<SubContractor> subCon)
{
Log.e(TAG, "scopearr for adapter"+ subCon.toString());
SimpleAdapter simpleAdapter=new SimpleAdapter(getActivity(), subCon, android.R.layout.simple_spinner_item,new String[]{"sub_con_name"},new int[]{android.R.id.text1});
simpleAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spSubcon.setAdapter(simpleAdapter);
}
Here is the code for logout
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.logout:
SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(this).edit();
editor.clear();
editor.commit();
startActivity(new Intent(this, LoginAct.class));
this.finish();
return true;

Maintain the selected item position in the SharedPrefernces along with arraylist data
And while Relaunching the Activity set the position to the Spinner
spinner.setSelection(position);

Button listener not working in Preference fragment

I've created a subclass of PreferenceFragment that implements CompoundButton.OnCheckedChangeListener. I have one preference that contains a Switch (a subclass of CompoundButton). Here's the callback I've created for when the value of the switch changes:
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
mAppController.doSomething(isChecked);
Log.v("rose_tag", "hi");
}
I declare the preference in OnCreate as follows:
Switch mySwitch = (Switch) myView.findViewById(R.id.switch);
mySwitch.setEnabled(true);
mySwitch.setOnCheckedChangeListener(this);
The callback gets called when the view first opens (a breakpoint in the callback is hit), but no log prints, and the callback never gets called again, even when I switch the switch on and off. How can I make this callback work?
I also tried creating an inline anonymous listener. I also tried using a simple Button with an onClick listener, and that didn't work either.

I can see you are trying to use PreferenceFragment as any other normal fragment. However, you must to take in count the correct mechanism, one example is you cannot use all the widgets for making a preferences view for the user, you must use the Preference objects (see Preference subclasses).
Another example is that you must use addPreferencesFromResource(int) to inflate preferences from an XML resource.
Check both links above and this example.
I hope It helps you.

If you use the anwser from Jorge Gil, you will not be able to easily get a reference to the view you are declaring in the PreferenceScreen.
However you can easily get one of the preference Object which in that case is a SwitchPreference. So in your res/xml/preferences.xml add your switch preference:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android"
android:key="screen">
<SwitchPreference
android:key="switch_preference"
android:title="title"
android:summary="summary" />
</PreferenceScreen>
Then in your PreferenceFragment/PreferenceActivity's onCreate function add this:
addPreferencesFromResource(R.xml.preferences);
SwitchPreference switchPref = (SwitchPreference) findPreference("switch_preference");
switchPref.setOnPreferenceChangeListener(new OnPreferenceChangeListener() {
#Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
Log.e(getClass().getSimpleName(),"onPreferenceChange:" + newValue);
return true;
}
});

PreferenceScreen android:summary update !

In my android application I have a PreferenceScreen parent that has 3 CheckBoxPreferences as children.
When I click the parent preferenceScreen, and the 3 checkboxes are displayed, I select one of them, and in the Preference.OnPreferenceChangeListener asociated with the checkboxes I set the parent's preferenceScreen summary with:
Parent.setSummary("string depending on the selection")
The thing is that when I return to the parent, it's summary is not updated, even if internally the value has correspondingly changed to the value setted.
Has anyone any idea regarding this behavior?

Use
Parent.setSummary("string depending on the selection");
((BaseAdapter)getPreferenceScreen().getRootAdapter()).notifyDataSetChanged();
works like a charm and can be used regardless the place you change the summary.

This is the correct way
Preference pref = findPreference(getString(R.string.key_of_pref));
PreferenceScreen parent = (PreferenceScreen) sf.findPreference(getString(R.string.key_of_preference_screen));
pref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
#Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
boolean newValueBool = (Boolean) newValue;
parent.setSummary(newValueBool ? "Summary is true" : "Summary is false");
((BaseAdapter) getPreferenceScreen().getRootAdapter()).notifyDataSetChanged();
// true to update the state of the Preference with the new value
// in case you want to disallow the change return false
return true;
}
});

I discovered that it seems to work by following up setSummary() with getListView().invalidate()

You can use BaseAdapter.notifyDataSetChanged() on the parent PreferenceScreen to update the UI. See here for example code: Update existing Preference-item in a PreferenceActivity upon returning from a (sub)PreferenceScreen

If you're using support preference than go for:
findPreference("your_preference").setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
public boolean onPreferenceChange(Preference preference, Object o) {
getListView().getAdapter().notifyDataSetChanged();
return true;
}
});

The new insistence on fragments instead of activities seems to make this harder. The invalidate route didn't seem to work nor approaches using the underlying View. Thanks to halxinate's answer I have now managed to work this through. For people who are as new as I am to all this here are a few more details:
When creating the settings fragment, save a reference in your main activity, e.g.:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch (item.getItemId()) {
case R.id.action_preferences:
if (getFragmentManager().getBackStackEntryCount() < 1) {
FragmentTransaction trans = getFragmentManager()
.beginTransaction();
// Save a reference to the settings fragment
settingsFrag = new SettingsFragment();
trans.replace(R.id.container, settingsFrag);
trans.addToBackStack(null);
trans.commit();
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Then when you want to update the summaries of the outer PreferenceScreen from the OnSharedPreferenceChangeListener use this sort of thing. Note that you need to have defined a key in your preference fragment xml for the outer PreferenceScreen (in this case android:key="prefs_root"):
public static void setOuterSummaries(SettingsFragment sf) {
// Set the outer preferences summaries
if (sf == null)
return;
//Code to update the summaries....
// Force the parent screen summaries to update
prefScr = (PreferenceScreen) sf.findPreference("prefs_root");
if (prefScr != null)
((BaseAdapter) prefScr.getRootAdapter()).notifyDataSetChanged();
}
OnSharedPreferenceChangeListener listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
public void onSharedPreferenceChanged(SharedPreferences prefs,
String key) {
Log.e("L", "Change");
setOuterSummaries(settingsFrag);
}
};
Note that you could save a reference to the BaseAdapter instead of to the settings fragment but this approach seems safer when you think of generalizing it to a multi-fragment situation or code which dynamically creates the fragment content.