Develop Reference

How to access BaseActivity ToolBar in Activity in android

i want to access toolBar in MyActivity which extends BaseActivity can access Toolbar in MainActivity.
BaseActivity
public abstract class BaseActivity extends AppCompatActivity{
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_container_base);
Toolbar toolBar = (Toolbar) findViewById(R.id.tool_bar);
}
}
MyActivity
public class MyActivity extends BaseActivity {
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// here i want to access BaseActivity Toolbar
}

Set your toolbar with setSupportActionBar in your BaseActivity:
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_container_base);
Toolbar toolBar = (Toolbar) findViewById(R.id.tool_bar);
setSupportActionBar(toolbar);
}
Then get the toolbar from getSupportActionBar after super.onCreate in MainActivity:
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActionBar actionBar = getSupportActionBar();
}
You can't cast an ActionBar to Toolbar, but if you really want to access to the toolbar, then change it to an instance variable:
protected Toolbar toolbar;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_container_base);
toolBar = (Toolbar) findViewById(R.id.tool_bar);
// ...
With protected modifier you can access to toolbar in your MainActivity.

Call LoaderManager from class which is not Activity

I'm working on to get contacts from phone, for this purpose I'm using LoaderCallbacks<Cursor> I create a new class with FetchContacts name and implement loaderManager. Now I want when ever I create object of that class loaderManager automatically initialize.
FetchContacts
public class FetchContacts implements LoaderManager.LoaderCallbacks<Cursor> {
private Context context;
FetchContacts(Context ctx){
context = ctx;
getLoaderManager().initLoader(0, null, this); // Error: Undefined method
}
// Reset of code like override methods.
MainActivity
public class MainActivity extends AppCompatActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FetchContacts fetchContacts = new FetchContacts(this);
}
}
I know the reason of error because FetchContacts is not extend from Activity class. Is it necessary to extend it from Activity class or is there and other method to call it from MainActivity ?

Pass LoaderManager as an Argument as #Mike said.
FetchContacts
public class FetchContacts implements LoaderManager.LoaderCallbacks<Cursor> {
private Context context;
FetchContacts(Context ctx, LoaderManager loaderManager){
context = ctx;
loaderManager.initLoader(0, null, this);
}
// Reset of code like override methods.
MainActivity
public class MainActivity extends AppCompatActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FetchContacts fetchContacts = new FetchContacts(this, getLoaderManager());
}
}

Toolbar in BaseActivity

I have multiple activities and fragments. I would like to set toolbar in BaseActivity (so set it only once). But need an acces to the toolbar from fragment (method like - show, hide, changeTitle etc.)
Any suggestion?
I have tried solution below, but when I want to hide fragment, NPException is shown
public abstract class BaseActivity extends AppCompatActivity {
Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(getLayoutResource());
configureToolbar();
}
protected abstract int getLayoutResource();
private void configureToolbar() {
toolbar = (Toolbar) findViewById(R.id.toolbar);
if (toolbar != null) {
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
}
public void hideToolbar() {
toolbar.setVisibility(View.GONE);
}
My activity
public class MyActivity extends BaseActivity() {
}
I call hideToolbar in fragment like:
public class MyFragment extends Fragment() {
onCreate() {
((Myactivity)getActivity).hideToolbar();
}

I have include something like yours in my project. This is sample. You can take reference from it.
BaseActivity.java class:
public abstract class BaseActivity extends AppCompatActivity {
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(getLayoutResource());
}
protected abstract int getLayoutResource();
}
ToolBarActivity.java class:
public abstract class ToolbarActivity extends BaseActivity {
protected Toolbar toolbar;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View contentView = findViewById(R.id.flToolbarContentContainer);
if (contentView instanceof ViewGroup) {
((ViewGroup) contentView)
.addView(LayoutInflater.from(this)
.inflate(getToolbarLayoutResource()
, (ViewGroup) contentView, false));
}
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
}
#Override
protected int getLayoutResource() {
return R.layout.activity_toolbar;
}
protected abstract int getToolbarLayoutResource();
public void showToolbar() {
toolbar.setVisibility(View.VISIBLE);
}
public void hideToolbar() {
toolbar.setVisibility(View.GONE);
}
}
activity_toolbar.xml layout file:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/rlToolbarContainer"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_toLeftOf="#+id/pbToolbarActivity"
android:background="#color/blue_panel_day_background"
android:theme="#style/ToolbarTheme" />
<FrameLayout
android:id="#+id/flToolbarContentContainer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/toolbar" />
</RelativeLayout>
MainActivity.java class:
public class MainActivity extends ToolbarActivity {
#Override
protected int getToolbarLayoutResource() {
return R.layout.activity_main;
}
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
homeFragment = HomeFragment.newInstance();
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.llMainActivityContainer, homeFragment)
.commit();
}
}
activity_main.xml layout file:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/llMainActivityContainer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
</LinearLayout>
Now, in Fragment class, apply:
((ToolbarActivity) getActivity()).showToolbar();
((ToolbarActivity) getActivity()).hideToolbar();

From Fragment
getActivity().getSupportActionBar();

Use:
public abstract class BaseActivity extends AppCompatActivity {
private Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(getLayoutResource());
configureToolbar();
}
protected abstract int getLayoutResource();
private void configureToolbar() {
toolbar = (Toolbar) findViewById(R.id.toolbar);
// changes made here, try to find if getSupportActionBar() is null or not after setting it - setSupportActionBar
setSupportActionBar(toolbar);
if (getSupportActionBar() != null) {
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
}
// How and where you calling this method ?
public void hideToolbar() {
toolbar.setVisibility(View.GONE);
}

To access ActionBar from Fragment try the below method
ActionBar actionBar = ((AppCompatActivity) getActivity()).getSupportActionBar();
You can now access all the methods of ActionBar

How can I get the same drawerLayout on multiple types of activities without using fragments?

I want to have the same drawerlayout for multiple types of activities.
This works, but how would I be able to use this with a different type of Activity? A FragmentActivity for example.
My base activity:
public class BaseDrawerActivity extends Activity {
protected DrawerLayout _drawerLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_base);
....stuff with drawerlayout
}
}
And then I extend the class in my stat activity:
public class StartActivity extends BaseDrawerActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LayoutInflater startInflater = getLayoutInflater();
View contentView = startInflater.inflate(R.layout.activity_start, null, false);
_drawerLayout.addView(contentView);
}
}

Extending from different classes not allowed in Java. So in that case you'll need to extend it from FragmentActivity.

How to implement parent methods to activity and FragmentActivity?

I am working on an android application,
and I have number of activities that extend from a custom activity.
Now I created a new FragmentActivity and I need the same functions that I have implemented in my custom activity.
How can I do that?
Edit
This is an simple example
public class BaseActivity extends Activity
{
protected void someFunction()
{
Log.i("TEST","This is a test");
}
}
public class MainActivity extends BaseActivity
{
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
someFunction();
}
}
this is my FragmentActivity:
public class MyFragmentActivity extends FragmentActivity
{
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// here I want to use someFunction()..
}
}

In Java you can't extend more than one class.
So I guess you should extend BaseActivity from FragmentActivity instead of Activity