Develop Reference

How to extend class with two another classes?

I want to extend my class with 2 other classes Fragment and Activity.
I tried this:
public class Frist extends Fragment , Activity
{
.....
.....
}
But it's not working. How can I fix it?

You can't extend multiple classes. Why you can't extend fragment in another class?

You should use decorator or composition pattern

Java does not support multiple inheritance
Fragment and activity both are completely different thing.
If your want to make activity having fragment over it then in android studio create project with Activity with Fragment instead of with Blank activity
Then Automatically android studio will provide with some code having fragment and classes and xml for it.

Bind listeners on customized menu across activities in Android

I am new to Android development. I want every activity has a same customized popup menu on the top right. I use a LinearLayout in xxmenu.xml and include it in each activity's layout xml files. The display is OK. As the OnClickListener should be same, I don't want to implement the OnClick functions in every activity's Java file. How can I do this?
I know Android has inherent menu solution via OptionsMenu, but I don't know if it can be customized or how (e.g., I want it on topright corner, with different backgrounds, each item has an image icon followed by texts, one-side shadow, etc.)

Make an abstract BaseActivity class that implements onCreateOptionsMenu and onOptionsItemSelected for your common menu and menu items. Then make all your other activities extend from that one.

First, the solution is to define a base class (e.g., BaseActivity) to extend Activity, and the actual activities using this menu to extend BaseActivity (e.g., MainActivity extends BaseActivity).
Second, use a separate xml to define the menu layout and include it in other layouts. A simple way to bind the listeners is to use android:onClick="toggleMenu".
Third, implement public void toggleMenu(View v) in BaseActivity.
We can also call the views and do the bindings in Java code. But I met a code sequence problem that if I get the clickable view via findViewById in BaseActivity's onCreate(), it returns null, and the binding fails. So the finding of the views and following bindings should be done in the child classes (e.g., MainActivity), after calling super.onCreate().

How to share a MediaPlayer object between multiple fragments?

I have set up 1 Main Activity (that extends Activity class) and 2 Fragments (that extends the fragment class).
I've tried setting up an Interface, which is implemented by the 2 fragments. And each fragment implements the particular function from the interface like this:
public stopMusic()
{
mediaplay.release(); // here, the mediaplay object belongs to only the respective fragment
}
Now, I know doesn't work, because the MediaPlayer object is not common to both fragments, i.e it's not being shared among them.
I'm looking to release the mediaplayer object streaming a file in Fragment1.java, if I hit a button from another fragment, like Fragment2java. Likewise, to release the mediaplayer object streaming a file in Fragment2.java, if I hit a button from Fragment1.java.
How can I make this happen? An example code would really help.

Let's say fragment A is the controlling fragment and fragment B is the media player. All communication should be done via the parent Activity. So in fragment B you create 'public interface(s)' which the parent activity implements, then the parent Activity should call the method(s) in fragment B.
Also depending on what you are really doing with the media player or whatever, does that belong in the background as opposed to fragment B?
Note: fragments should be loosely coupled and never communicate from fragment to fragment, always communicate via the parent Activity.
Hope this helps.

android -what approach to be used for some java code that repeats in many activities

I have an app that has a top menu as shown in the fig below. This is almost constantly used in all activities. For layout I have defined it in a single xml file and use <include>to include it in every layout file.I want to know if there is a way in java coding to avoid declaring all the imageButtons, and then using findViewById and onclick events for them , in each activity. The top four icons will act as menu and be available in all layouts and activities

First of all, what you are trying to achieve is against the android standards and this could affect the user experience for Android users. Instead, add the menu items on the action bar.
Anyway, you can achieve what you are looking for by defining a base class (named it like ActivityBase) and do all the initializations and listeners registrations on it. Then, extend from that base class. Bear in mind that each activity will have its own instance of the views of the base class and the state will differ from activity to another.

Although you have accepted an answer I disagree that the Application class should be used to host global methods. It can be used for maintaining global state but that's a different matter.
As others have said, use inheritance by creating a base Activity class then extend that for all of your other Activities. To make things easier, however, you can define the onClick method to be used for each of your buttons in the layout file itself by using (for example)...
android:onClick="myOnClickMethod"
As long as the base Activity defines a public method called myOnClickMethod (or whatever method name you choose) with a void return and which accepts a View parameter it will work without the need to implement View.OnClickListener and without having to set the listener in Java code. Example
public class MyBaseActivity extends Activity {
public void myOnClickMethod(View v) {
// Get the resource id of v and use switch / case to perform action needed
}
}
That's all you need.

Write it only in the first activity. Extend it to the other activities instead of extending with android.app.Activity.
Eg:
public class SecondActivity extends MainActivity{
}

Put that method in MyApplication class which extends Application. So, that it can be accessible by multiple activities.

How to manage activity inheritance in Android Development

This is a relatively general question that I have regarding to Android development.
In the Android application, I am using SlidingMenu library. Imagine the activity I am trying to implement has a Navigation Drawer (from Sliding Menu Library) and action bar tabs with View Pager and contains different fragments.
In order to have the navigation drawer in the activity, I had to inherit the application from SlidingActivity like this:
public class ActivityMain extends SlidingActivity implements TabListener {
However, to make View Pager work in this activity, I will need to use Make a FragmentPagerAdapter instance, and if I want to use it, it requires the activity extend the Fragment Activity.
My Activity already extended SlidingActivity, so there is no way to extend another super class. I am not sure what will be a proper way to solve this conflict. When I was working on the Android app, I have saw some other cases that different components in one activity requires to extend from different super class. What will be the general solution to such problem?
Thank you

If you look at the package of SlidingMenu here, they have an activity called SlidingFragmentActivity. Extend this activity instead of SlidingActivity gives you everything you need.

You can wrap your Activities in a SlidingMenu by constructing it programmatically new SlidingMenu(Context context) and then calling SlidingMenu.attachToActivity(Activity activity, SlidingMenu.SLIDING_WINDOW | SlidingMenu.SLIDING_CONTENT). SLIDING_WINDOW will include the Title/ActionBar in the content section of the SlidingMenu, while SLIDING_CONTENT does not. You can check it out in the example app AttachExample Activity.
from https://github.com/jfeinstein10/SlidingMenu