After much success in developing an app and learning a ton about Java and Android, I'm running into a problem. I have been googling (things like toolbar, app bar, fragment, null pointer exception, actionbar, appcompatactivity, v7, v4 support libraries, theme=noactionbar etc etc.).
I also read this page.
I wouldn't have a problem if I was just using a normal Activity, but I'm getting very confused and I'm wondering if anyone can help.
Originally, I started a project with a boilerplate Navigation Drawer Activity in Android Studio 1.5.1. The app's main purpose is to display a list of people. This is done with a listFragment (because there are other things (fragments) the app does that can be selected from the navigation drawer).
My problems started when I decided to consolidate 3 very similar listfragments into one. I would do this by instead using a single listFragment and replacing the title on my Navigation Drawer's (Main) Activity's App Bar/Toolbar/Action Bar with a Spinner when this listFragment is selected from the Navigation Drawer and loaded into the main view.
The purpose of the spinner is as a way to filter the listview (listFragment) elements. The list is a list of people and the Spinner options would be something like, "Sort By:" [Recently Contacted, Favorites, Closest] (these were the initial three separate listFragments).
So... the closest thing I could find to a solution was:
How to combine Navigation Drawer and Spinner [like in Google+ App]
So I tried to adapt this solution to my problem... the only difference being that I'm using a Fragments and trying to access getActionBar() (?) from inside my Fragment.
From inside the fragment, I put:
ActionBar actionBar = getActivity()).getActionBar();
I get a warning that it may return null and it does.
I also tried:
ActionBar actionBar = getActivity()).getSupportActionBar();
with the same result.
Then I learned (and read in the main activity) that Toolbar is the new version of ActionBar... and I can see the following in the boilerplate code of my main activity:
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
So "Ahaa!!" I changed my code to:
Toolbar toolbar = getActivity()).getT.......
But there is no such getToolbar() method provided... and apparently I dont know what I'm doing.
Keep in mind:
- My Main Activity extends AppCompatActivity (I think this is required in order for Navigation Drawer to work)
- The theme of my main activity is "AppTheme.NoActionBar" (this was provided in the default code in the beginning, but makes no sense to me since there clearly is a bar at the top of the screen and it's part of the navigation drawer)
My Main Activity imports the following: import android.app.Fragment; import android.app.FragmentManager; import android.app.FragmentTransaction; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.util.Log; import android.view.View; import android.support.design.widget.NavigationView; import android.support.v4.view.GravityCompat; import android.support.v4.widget.DrawerLayout; import android.support.v7.app.ActionBarDrawerToggle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.Menu; import android.view.MenuItem; import com.android.volley.RequestQueue;
build.gradle contains: dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) testCompile 'junit:junit:4.12' compile 'com.android.support:appcompat-v7:23.1.1' compile 'com.android.support:design:23.1.1' compile 'com.android.volley:volley:1.0.0' compile 'org.immutables:gson:2.1.8' }
My basic questions are:
1) What class of object (App bar, actionbar, toolbar, ??) do I need to access from within the fragment?
2) How do I access that object from inside the fragment?
Thank you for your patience!
UPDATE:
Since posting this, I have learned that:
Toolbar and ActionBar are not the same thing. I am using a Navigation Drawer that uses "Material Design." My Main Activity extends AppCompatActivity and uses Toolbar, not ActionBar.
From my fragment, I can access the toolbar object using:
Toolbar toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
However, I can't find any tutorials that explain how to add a spinner to a TOOLBAR from a fragment. They only explain how to do it using Actionbar. (See this link I referenced earlier)
UPDATE!!!
It doesn't seem possible to create/control a spinner within a main activity toolbar from inside a fragment by accessing only the toolbar object, so Naresh and Sahil's solutions below are correct... I must use getSupportActionBar() and cast it using either (AppCompatActivity) or ([TheActualNameOfMyMainActivity]) like this:
ActionBar actionbar = ((AppCompatActivity)getActivity()).getSupportActionBar();
