Set text in TextView in in-active fragment - android

I have managed to get an actionbar with tabs, but when I click a button, a text should be set in both Fragments. If I try this it will crash the app, because only one of the Fragments is loaded. Is there a way I could set the text in both fragments?

One solution comes to my mind is that you may save the the text's value to a preference and then load the preference from second tab.something like this:
//save the value in your first fragment to the preferences
prefs = PreferenceManager
.getDefaultSharedPreferences(view.getContext());
SharedPreferences.Editor editor = prefs.edit();
editor.putString("sampletext", "Your text value");
editor.commit();
//get the value in your second fragment
prefs = PreferenceManager
.getDefaultSharedPreferences(view.getContext());
prefs.getString("sampletext");
The second and dirty but fast solution would be to define a public static variable in your first fragment and access that variable in your second fragment.This method will be applicable only if your first fragment is not destroyed when switched to second one.

If the fragment isn't loaded, then you should save off the text somewhere so that when the fragment is loaded, it can (while instantiating the text views), set the text view to the appropriate value. (eg in the fragment's onActivityCreated() call, ask for the text to use)

Related

Updating Preference UI instance from another activity?

How do i update a Prefence UI instance that i created in a Setting Activity from another activity (Main Activity)?
I tried using these lines in Main Activity to update the Preference within Settings Activity, but I get ClassCastException.
Preference IsFeature =(Preference)((PreferenceActivity)context).findPreference((getString(R.string.key_enable_feature)));
IsFeature.setEnabled(True);
Just wondering whether theres another way to do this?
Any help, feedback or answers would be great!
You can try this:
In xml of settings get the "key" attribute from element you want to change (in bottom example it's "example_switch"). Than put this code in onClick method of button or wherever else you want to. This below takes the preference of switch in general settings and sets its value to false.
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putBoolean("example_switch", false); // "example_switch" - "key" attribute of your element | false - value
editor.commit();

Android SavedPrefrerences loading?

I am trying to make an app(http://pastebin.com/uWkP6XNY) that when you press a button, creates a custom sms message. The user can go to a second activity (http://pastebin.com/MK2NPV5R) thats full of edit-texts that when saved, will bring back strings to be used to change the custom sms.
The issues I am facing is how I initalize my variables with whats in savedpreferences. I put this in my onCreate method.
smsintroduction = (sp.getString("intro", "")); //these are both strings initalized at the top
smsbody = (sp.getString("body", ""));
On start up, since it can't get "intro" from the dictionary, it goes to a null string. I want to be able to use my save() function in my second activity to save, which I Think I already do, but be able to change my two strings above.
I put the code above to set the strings in a method that completes the finalized textbody, but it keeps giving me emptystrings.
The only thing that gets created is "!", as shown in finishedtext().
It looks like in your MainActivity in onCreateOptionsMenu you are overriding the sp member previously set in onCreate with
sp = getSharedPreferences("prefs", 0);
Try removing that line or setting those shared prefs to a different instance member.

How can I setText() (TextView) when the TextView is in another layout?

My app has 2 layouts (main layout) and (preference (prefs) layout).
When the MainActivity loads, I set setContentView(R.layout.main); - main layout
I need to then set text for a TextView in the preference layout, but it never gets set.
LayoutInflater factory = getLayoutInflater();
View inflate = factory.inflate(R.layout.prefs, null);
TextView eSerial = (TextView) inflate.findViewById(R.id.editTextSerial);
mSerial = "Test";
eSerial.setText(mSerial);
The way I get to the preference page is with a menu and then the page loads up with no change to TextView
I have searched and not found an answer yet.
Please help.
Thank you.
When the menu kicks off your prefs activity, you can populate the view with the values. user1853479 points out one way of doing this, which is to add the values to an intent. Assuming you want to store these prefs for future runs, you can also set any that for that specific run and save them in your local store. Another method is to create a singleton to store your settings, load it when your app starts, modify and save as needed, and access it from any of your activities.
Short answer: You can't do this.
Long answer:
If you are launching the preference page yourself, you must be creating an Intent to do so. Call putExtra() to store your text inside that intent. In your PreferenceActivity, call getIntent().getStringExtra() to get the text, then put it in your TextView.

PreferenceFragment - Difference between getPreferenceManager() and getPreferenceScreen()?

I've implemented my own PreferenceFragment subclass (detailed here), and want to listen for preference changes within it. PreferenceFragment provides you with two ways of doing this:
getPreferenceManager().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
and
getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
Which one should be used? What's the difference? I don't really understand the distinction made in the Android docs.
The core difference is in their names, PreferenceManger grants access to different functionalities to the developer for managing SharedPreferences, such as retrieving the map of current preference values or setting user preferences. to their default values. PreferenceScreen handles displaying a screen of user preferences, so that the user can assign values to them. Sometimes this means displaying a list item on a screen with other preferences, that opens another screen with more preferences when clicked, as is the case when PreferenceScreens are nested.
Your question implies that you think there is a difference between what PreferenceManager.getSharedPreferences() and PreferenceScreen.getSharedPreferences() does, but according to the source code, they are identical.
PreferenceScreen:
public SharedPreferences getSharedPreferences() {
if (mPreferenceManager == null) {
return null;
}
return mPreferenceManager.getSharedPreferences();
}
So the PreferenceManger and PreferenceScreen are different entities, but the SharedPreference those method return should be the same object, since PreferenceScreen calls the method from PreferenceManager. I hope that is the answer you've been seeking.
If you have a choice, go with PreferenceManager.getSharedPreferences(), it's more obvious and one fewer method call internally.
Fun fact:
PreferenceFragment:
public PreferenceManager getPreferenceManager() {
return mPreferenceManager;
}
public PreferenceScreen getPreferenceScreen() {
return mPreferenceManager.getPreferenceScreen();
}
The first one gets the shared preferences from the PreferenceManager. The second one, from the PreferenceScreen, that inherits this method from Preference class.
I think this is not a functional difference, because both return probably the same instance of the SharedPreferences objects, but I think it's clearer to use the first one (using PreferenceManager instead of PreferenceScreen).
PreferenceScreen see domentation here
PreferenceScreen class can appear in two places:
When a PreferenceActivity points to this, it is used as the root and
is not shown (only the contained preferences are shown).
When it appears inside another preference hierarchy, it is shown and
serves as the gateway to another screen of preferences (either by
showing another screen of preferences as a Dialog or via a
startActivity(android.content.Intent) from the getIntent()). The
children of this PreferenceScreen are NOT shown in the screen that
this PreferenceScreen is shown in. Instead, a separate screen will be
shown when this preference is clicked.
PreferenceManager see documentation here:
Difference :
getPreferenceManager () returns the current preference manager associated with the fragment.
getPreferenceScreen () returns the root PreferenceScreen i.e. root preference screen used in the fragment from preference xml file(preferences.xml).

get and set listPreference from another activity not working

I'm trying to get and set a listPreference value from different activities and it's not working.
When I read and write it from my main activity, it only keeps whatever I write, so I'm assuming that I'm not targeting the listPreference correctly when I'm out of the activity because it's working inside my preference activity no problem.
I've seen some references on the developer website to CharSequence with getValue and getEntryValues but I haven't had luck getting them to work correctly either.
Here is my code for clicking a button and setting the listpreference value then it launches an intent to switch activities:
Main Activity, attempting to set the value of the listpreference to the first index value;
SharedPreferences settings = getSharedPreferences("PreferenceXML",
MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString("ListPreferenceInXML", "1");
editor.commit();
String levelCheck = settings.getString("ListPreferenceInXML","1");
In my next activity I call read the value on launch to see which listPreference is active and it is always the number I write from the mains activity listed above. The problem is when I goto the actual Preference activity and it doesn't match or update when I change it on the ListPreference and launch the same activity from there (it still reads the value I set from the Main activity button)
code as follows for activity trying to read ListPreference:
SharedPreferences settings = getSharedPreferences("PreferenceXML",
MODE_PRIVATE);
Toast.makeText(this, settings.getString("ListPreferenceInXML","1"), 1000).show();
So I finally figured it out, the problem was with the way I was calling the preferences. Instead of calling the preferences like this, in both cases;
SharedPreferences settings = getSharedPreferences("PreferenceXML",
MODE_PRIVATE);
Call them like this:
SharedPreferences settings =
PreferenceManager.getDefaultSharedPreferences(getBaseContext());
I'm not sure if there is a step missing out of the first way of calling the preferences but this 2nd way worked like a champ.

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