I have been attempting to call a method from my home activity which should fire once a button is clicked on my settings fragment. The result of this button click should call the greenTorso() and swap an image on my avatar fragment. I am currently getting a null pointer error, please see the logcat attached. I'm not even sure if this is the right way to go about this, but been stuck for a couple of days now and hoped someone could help. Thanks in advance.
My home activity:
public class Home extends AppCompatActivity implements SettingsFragment.Communicator {
private TextView name, email;
Button LogoutButton;
UserSessionManager sessionManager;
Button button;
ImageView Torso;
public void communicateWith(){
AvatarFragment avatarFragment = (AvatarFragment)getSupportFragmentManager().findFragmentById(R.id.nav_avatar);
avatarFragment.greenTorso();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
getWindow().setBackgroundDrawableResource(R.drawable.background2); // sets background to background2.png
this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN); // hides keyboard on boot
sessionManager = new UserSessionManager(getApplicationContext());
TextView lblName = (TextView) findViewById(R.id.lblName);
TextView lblEmail = (TextView) findViewById(R.id.lblEmail);
BottomNavigationView bottomNav = findViewById(R.id.bottom_nav);
bottomNav.setOnNavigationItemSelectedListener(navListener);
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
new HomeFragment()).commit();
if(sessionManager.checkLogin())
finish();
// get user data from session
HashMap<String, String> user = sessionManager.getUserDetails();
// get name
String name = user.get(UserSessionManager.KEY_NAME);
// get email
String email = user.get(UserSessionManager.KEY_EMAIL);
//lblName.setText(Html.fromHtml("Name: <b>" + name + "</b>"));
lblEmail.setText(Html.fromHtml("Welcome: <b>" + email + "</b>"));
LogoutButton=(Button)findViewById(R.id.LogoutButton);
Toast.makeText(getApplicationContext(),
"User Login Status: " + sessionManager.isUserLoggedIn(),
Toast.LENGTH_LONG).show();
LogoutButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// Clear the User session data
// and redirect user to LoginActivity
sessionManager.logoutUser();
}
});
}
private BottomNavigationView.OnNavigationItemSelectedListener navListener =
new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
Fragment selectedFragment = null;
switch (menuItem.getItemId()) {
case R.id.nav_steps:
selectedFragment = new HomeFragment();
break;
case R.id.nav_avatar:
selectedFragment = new AvatarFragment();
break;
case R.id.nav_settings:
selectedFragment = new SettingsFragment();
break;
}
getSupportFragmentManager()
.beginTransaction().replace(R.id.fragment_container,selectedFragment).commit();
return true;
}
};
}
My settings fragment:
public class SettingsFragment extends Fragment {
public Button button;
public ImageView Torso;
public ImageView ShopGreenTorso;
private Communicator interfaceImplementor;
public interface Communicator
{
public void communicateWith();
}
@Override
public void onAttach(Activity context) {
super.onAttach(context);
this.interfaceImplementor = (Communicator)context;
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_settings, container, false);
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Button button = (Button) getActivity().findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// ImageView torso = (ImageView) getActivity().findViewById(R.id.Torso);
interfaceImplementor.communicateWith();
}
});
}
}
My avatar fragment:
public class AvatarFragment extends Fragment {
public ImageView IV;
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_avatar, container, false);
return rootView;
}
public void greenTorso()
{
ImageView IV =(ImageView) getActivity().findViewById(R.id.Torso);
IV.setBackgroundResource(R.drawable.torso2green);
}
}
Avatar layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:src="http://schemas.android.com/apk/res-auto"
android:background="@android:color/holo_orange_dark"
>
<ImageView
android:layout_width="500dp"
android:layout_height="530dp"
android:layout_centerInParent="true"
android:orientation="vertical"
android:layout_marginStart="30dp"
android:layout_marginEnd="30dp"
android:id="@+id/Torso"
android:src="@drawable/torso2" >
</ImageView>
</RelativeLayout>
Settings layout:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#D3D3D3"
android:weightSum="10"
tools:context=".Home">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_marginTop="100dp"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Shop"
android:textSize="26sp"
android:textStyle="bold"
android:gravity="center"
android:layout_marginBottom="10dp"/>
<androidx.cardview.widget.CardView
android:id="@+id/cardview1"
android:layout_width="match_parent"
android:layout_height="150dp"
android:layout_below="@+id/cardview"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:layout_marginLeft="16dp"
android:layout_marginTop="10dp"
android:layout_marginRight="16dp"
app:cardBackgroundColor="@color/white"
app:cardCornerRadius="15dp"
app:cardElevation="10dp">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
</LinearLayout>
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:gravity="center_horizontal"
android:paddingLeft="10dp"
android:text="Green Torso"
android:textColor="@color/cardview_dark_background"
android:textSize="20sp"
android:textStyle="bold" />
<ImageView
android:id="@+id/ShopGreenTorso"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:background="@drawable/torso2green" />
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="30dp"
android:layout_gravity="bottom"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginBottom="10dp"
android:background="@drawable/register_button"
android:shadowColor="@color/colorPrimary"
android:text="10,000S Buy"
android:textColor="@color/white">
</Button>
</androidx.cardview.widget.CardView>
My navigation:
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@+id/nav_steps"
android:icon="@drawable/ic_directions_walk_black_24dp"
android:title="Steps" />
<item
android:id="@+id/nav_avatar"
android:icon="@drawable/ic_face_black_24dp"
android:title="Avatar" />
<item
android:id="@+id/nav_settings"
android:icon="@drawable/ic_build_black_24dp"
android:title="Settings" />
</menu>
