Should i inherit from another activity class? I need to use dialog fragments on PreferenceActivity so the Activity should be FragmentActivity inheritor. I can use support library but i can't understand - from one hand i should inherit from PreferenceActivity, from another - from FragmentActivity
I need to use dialog fragments on PreferenceActivity so the Activity should be FragmentActivity inheritor.
That's not possible, short of possibly cloning the entire Android 2.x implementation of PreferenceActivity into your own class that extends FragmentActivity.
Normally, dialogs associated with preferences are handled by creating custom DialogPreference classes, not via a DialogFragment.
Related
I am using the Tabbed Activity (that includes swipes and tabs) and when I was looking at the generated code, noticed that "ActionBarActivity" is deprecated. So I went online android docs and show that I should use "AppCompatActivity" insted, I changed the extending class from ActionBarActivity to AppCompatActivity and there was no problem. However, there is another deprecated interface and that is ActionBar.TabListener. What should I use instead of this interface ?
Switch to toolbar much easier to work with you can use pagerslidingtabstrip and link it with your viewpager.
Say someone wants an Activity which both has an action bar and a preference, the first idea in mind is probably
public class MyActivity extends ActionBarActivity, PreferenceActivity
But Java doesn't allow this. I know API 11+ Activities has actionbar builtin. It's just an example of wondering how to use multiple features from multiple base classes.
EDIT: Based on the feedback it seems we have to hack in this case. IMHO it could be as simple as putting all activity utilities as fields in class Activity and implement getter/setter to use those utilities. Well, in reality, it isn't.
No you cannot extend from two classes in Java. Typically in Android to add the ActionBar to the older PreferenceActivity there are a couple of hacks you can do or libraries that also do the same thing. However, recently with the new AppCompat library they introduced the Toolbar widget which can be used to add an Actionbar to your PreferenceActivity in this case. For more information, checkout this post I recently wrote on how to add a Toolbar to your legacy SettingsActivity.
simple solution:
Firstly you can't extend multiple classes..java does not support multiple inheritance see here
Secondly using action bar sherlock library here, this gives you action bar functionality without extending the actionbaractivity plus its backwards compatiable.
Or...you can implement a custom action bar go here
As mentioned in the other answers, Java doesn't allow multiple inheritance.
If you want an ActionBar as well as something such as Preference functionality, consider using a PreferenceFragment
It's not quite the same as multiple inheritance but Fragments allow adding extra functionality to Activities.
You can create a subclass of the PreferenceActivity, called AppCompatPreferenceActivity (or whatever you would like), to use an AppCompatDelegate to provide the SupportActionBar functionality. You can then subclass the new AppCompatPreferenceActivity for your MyActivity class like so:
public class MyActivity extends AppCompatPreferenceActivity
For how to do this, check out the AppCompatPreferenceActivity sample code from the Chromium project.
I want to throw a Dialog to the user of my app to confirm some action. From the developers API guides I learnt that they prefer using DialogFragments instead of dialog class.The activity which should show the dialog is a ListActivity and already has been coded.
My question is, if I need to use the DialogFragment then my activity may still extend ListActivity? Or I need to extend FragmentActivity (my app has min sdk 2.3.6) as I know android does not support multiple inheritence?
I dont want to use ListFragments
Thanks for any help.
I think you need to use the android-support-v4 library and then create a class that extends FragmentActivity but import this line android.support.v4.app.FragmentActivity; to support fragments from v2.3.6 and up. Change your ListActivity class to then extend ListFragment and invoke the class from your FragmentActivity. You can then use the DialogFragment with other fragments. This will change the whole structure of your project but it will force you to use better up to date api code.
Seeing that you don't want to use ListFragment I wouldn't go through all this trouble of converting all your classes into Fragments just to use DialogFragment you can just use normal Dialogs, they aren't a deprecated api so I wouldn't say there's anything wrong with them.
I think the reason DialogFragments are preferred is because they want you to use Fragments when developing your app, due to versatility for Tablet apps ect.
Hope this helps
I want to use Fragments in my application, but I cannot extend FragmentActivity because my application already extends an activity that is part of a library. Since this means that I cannot call getSupportFragmentManager(), I am looking for a workaround that would allow me to use Fragments without having to extend FragmentActivity. Is it possible?
Your library is going to need to extend the FragmentActivity.
I would be concerned about a library that requires you to use their base activities anyway.
As mentioned (where possible) grab the library source code and add it as a library project to eclipse and make its activities extend the FragmentActivity class.
I have created a tab fragments in android 2.2 , with a android compatibility support library , now in my application i have few activities some of them are extends Activity class and some of them extends ListActivity.
so how can i convert the existing Activity or ListActivity into Fragments so that i can take the advantage of Fragment features ?
As to create a fragment , one has to extends Fragment class but if an activity is deriving ListActivity then what to do to convert it in a fragment?
You need to review the Fragment documentation and samples on the Android Developers website. This will explain what a Fragment is able to do, and what you should be doing inside of your fragment.
In essence, its a very simple transition over to using Fragments once you have looked over the examples. You will need an Activity to contain the Fragments still.
To make this a lot simpler, I would advise you look into the ActionBarSherlock library, which will allow you to use the ActionBar and SupportLibrary back to 2.1.
To get you started, you will want to use the Fragment and ListFragment classes, which will be very similar to a standard activity, but the life cycles are a little different with a few naming changes.
You could try deriving it from ListFragment