I want to implement the ...
#Override
public void onBackPressed() {
}
However, I get an error message saying, "Annotations are not allowed here". I need this method to be implemented here. Is there an alternative?
public class supbreh extends Appbreh
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_intent_breh);
if (myBundle != null) {
String name = myBundle.getString("workout");
ShowDetails(name);
}
}
private void ShowAbDetails(String mName) {
if(mName.equals("abs1")){
#Override
public void onBackPressed() { //"Not Allowed here"
}
}
void onBackPressed ()
Called when the activity has detected the user's press of the back
key. The default implementation simply finishes the current activity,
but you can override this to do whatever you want.
In here you can't declare this method inside another method .
Only override it in that one Activity
#Override
public void onBackPressed()
{
super.onBackPressed();
}
FYI
#Override
public void onBackPressed() {
Intent intent = new Intent(IndividualAbsWorkout.this, IndividualAbsWorkout.class);
startActivity(intent);
}
You can override onBackPressed as normal and call the method in ShowAbDetails() method like below.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_intent_breh);
if (myBundle != null) {
String name = myBundle.getString("workout");
ShowDetails(name);
}
}
private void ShowAbDetails(String mName) {
if(mName.equals("abs1")){
onBackPressed();
}
}
#Override
public void onBackPressed() {
// your logic here
}
Related
I am trying to call a function in a OnPreferenceClickListener which is defined in a another class. Since I have not managed to initialisation an interface in OnPreferenceClickListener. I have given an example code below:
public void onCreatePreferences(Bundle bundle, String s) {
ListPreference preference = findPreference(getString(R.string.settings_ble_choose_device_key));
preference.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
#Override
public boolean onPreferenceClick(#NonNull Preference preference) {
callFunctionInMainActivity();
return false;
}
});
}
How i can call a function witch is implement in a another class?
Thank you very much
Rene
You can implement an intent for this. Where you send a broadcast from your OnPreferenceClickListener class and implement a broadcast received in the other class to listen for this intent and invoke the method that you want. Here is an example:
public void onCreatePreferences(Bundle bundle, String s) {
ListPreference preference = findPreference(getString(R.string.settings_ble_choose_device_key));
preference.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
#Override
public boolean onPreferenceClick(#NonNull Preference preference) {
sendBroadcast(new Intent(Constants.ACTION_STOP_MAIN_SERVICE));
return true;
}
});
}
In your other class:
private final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action= intent.getAction();
if(action.equalsIgnoreCase(ConstantesIdentifiant.ACTION_STOP_MAIN_SERVICE)){
finishAffinity();
}
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
registerReceiver(broadcastReceiver, new IntentFilter(ConstantesIdentifiant.ACTION_STOP_MAIN_SERVICE));
}
#Override
protected void onDestroy() {
unbindService(mConnection);
unregisterReceiver(broadcastReceiver);
super.onDestroy();
}
I want to know how to implement AdMob rewarded video ads in a list view?
I'm using the source code from here
and I want to use it in this class StickerPackDetailsActivity.java
and the layout is gonna like this
![layout][1]
I want to lock add to WhatsApp and unlock it by watching video reward.
but this stickerdetails showed from listview from
![here][2]
so, how to implement video reward ads only in 1 specified item of the listview not all of them?
public class MainActivity extends AppCompatActivity implements RewardedVideoAdListener {
private RewardedVideoAd mRewardedVideoAd;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MobileAds.initialize(this,"ca-app-pub111111111");
mRewardedVideoAd = MobileAds.getRewardedVideoAdInstance(this);
listitem.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
loadRewardedVideoAd();
}
});
}
private void loadRewardedVideoAd() {
mRewardedVideoAd.loadAd("ca-app-pub-",
new AdRequest.Builder().build());
}
#Override
public void onRewardedVideoAdLoaded() {
}
#Override
public void onRewardedVideoAdOpened() {
}
#Override
public void onRewardedVideoStarted() {
}
#Override
public void onRewardedVideoAdClosed() {
loadRewardedVideoAd();
}
#Override
public void onRewarded(RewardItem rewardItem) {
}
#Override
public void onRewardedVideoAdLeftApplication() {
}
#Override
public void onRewardedVideoAdFailedToLoad(int i) {
}
#Override
public void onRewardedVideoCompleted() {
}
#Override
protected void onPause() {
mRewardedVideoAd.pause(this);
super.onPause();
}
#Override
protected void onResume() {
mRewardedVideoAd.resume(this);
super.onResume();
}
}
I have two Classes "BaseActivity" and "ChildActivity" i.e. ChildActivity inherts BaseActivity.
Question: In my following Code Snippet, whenever i press LEFT BUTTON - it logs me "I am From Child Activity". What would i need to do if i want to call SUPER CLASS functionality by default.
public class BaseActivity extends Activity implements OnClickListener {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
};
protected void configureTitleBar(String title) {
ImageButton imgLeftButton = ((ImageButton) findViewById(R.id.actionBarLeftButton));
imgLeftButton.setOnClickListener(BaseActivity.this);
}
#Override
public void onClick(View v) {
if(v.getId() == R.id.actionBarLeftButton){
printCustomLog("I am From Base");
}
}
}
Child Activity:
public class ChildActivity extends BaseActivity implements OnClickListener{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_child);
configureTitleBar("MyTitle");
}
#Override
public void onClick(View v) {
if(v.getId() == R.id.actionBarLeftButton){
printCustomLog("I am From Child Activity");
}
}
}
If you want to get super class functionality, you can
a) Not Override the onClick() method at all (but I don't think that's what you want)
b) Call super.onClick(v) from onClick() in your child class.
The code in your ChildActivity will then be.
#Override
public void onClick(View v) {
// Check some condition if you want to handle it in Child class
if(condition){
printCustomLog("I am From Child Activity");
}
// Else, as default, call Base class's onClick()
else{
super.onClick(v);
}
}
#Override
public void onClick(View v) {
if (v.getId() == R.id.actionBarLeftButton) {
// here's my work
}
super.onClick(v); // it will call Super's OnClick
}
I'm trying to build an App for Android Lollipop (5.0). There is a login fragment and when i press login button then app automatically crashes. I'm sharing my code and error message please guide me.
BaseActivity.java
public abstract class BaseActivity extends AppCompatActivity {
protected CoreApplication coreApplication;
#Override
protected void onCreate(Bundle savedState) {
super.onCreate(savedState);
coreApplication = (CoreApplication) getApplication();
}
}
BaseAuthenticatedActivity.java
public abstract class BaseAuthenticatedActivity extends BaseActivity {
#Override
protected final void onCreate(Bundle savedState) {
super.onCreate(savedState);
if (!coreApplication.getAuth().getUser().isLoggedIn()) {
startActivity(new Intent(this, LoginActivity.class));
finish();
return;
}
onCoreApplicationCreate(savedState);
}
protected abstract void onCoreApplicationCreate(Bundle savedState);
}
LoginActivity.java
public class LoginActivity extends BaseActivity implements View.OnClickListener, LoginFragment.CallBacks {
private static final int REQUEST_NARROW_LOGIN = 1;
private View loginButton;
#Override
protected void onCreate(Bundle savedState) {
super.onCreate(savedState);
setContentView(R.layout.activity_login);
loginButton = findViewById(R.id.LoginJustChat);
if (loginButton != null) {
loginButton.setOnClickListener(this);
}
}
#Override
public void onClick(View view) {
if (view == loginButton)
startActivityForResult(new Intent(this, LoginNarrowActivity.class), REQUEST_NARROW_LOGIN);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode != RESULT_OK)
return;
if (requestCode == REQUEST_NARROW_LOGIN) {
finishLogin();
}
}
private void finishLogin() {
startActivity(new Intent(this, MainActivity.class));
finish();
}
#Override
public void onLoggedIn() {
finishLogin();
}
}
LoginNarrowActivity.java
public class LoginNarrowActivity extends BaseActivity implements LoginFragment.CallBacks {
#Override
protected void onCreate(Bundle savedState){
super.onCreate(savedState);
setContentView(R.layout.activity_login_narrow);
}
#Override
public void onLoggedIn() {
setResult(RESULT_OK);
finish();
}
}
MainActivity.java
public class MainActivity extends BaseAuthenticatedActivity {
#Override
protected void onCoreApplicationCreate(Bundle savedState) {
}
}
BaseFragment.java
public abstract class BaseFragment extends Fragment {
protected CoreApplication application;
#Override
public void onCreate(Bundle savedInstance) {
super.onCreate(savedInstance);
application = (CoreApplication) getActivity().getApplication();
}
}
LoginFragment.java
public class LoginFragment extends BaseFragment implements View.OnClickListener {
private Button loginButton;
private CallBacks callBacks;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup root, Bundle savedState) {
View view = inflater.inflate(R.layout.fragment_login, root, false);
loginButton = (Button) view.findViewById(R.id.fragment_login_loginButton);
loginButton.setOnClickListener(this);
return view;
}
#Override
public void onClick(View view) {
if (view == loginButton) {
application.getAuth().getUser().setIsLoggedIn(true);
callBacks.onLoggedIn();
}
}
// because onAttach(Activity activity) is deprecated
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof CallBacks) {
callBacks = (CallBacks) context;
} else {
throw new ClassCastException(context.toString()
+ " must implement MyListFragment.OnItemSelectedListener");
}
}
#Override
public void onDetach() {
super.onDetach();
callBacks = null;
}
public interface CallBacks {
void onLoggedIn();
}
}
Error:
java.lang.NullPointerException: Attempt to invoke interface method
'void
com.example.usama.demoapp.fragments.LoginFragment$CallBacks.onLoggedIn()'
on a null object reference
Please guide me with this.
Welcome to Android !
You got a NullPointerException. It's a very common [and lovely; since it's rather easy to debug] exception in Java. Check your LoginFragment. The following method will cause this exception to raise.
#Override
public void onClick(View view) {
if (view == loginButton) {
application.getAuth().getUser().setIsLoggedIn(true);
callBacks.onLoggedIn();
}
}
A couple of notes in order to diagnose this error:
When you declare a class member with initializing it, in this casecallBacks, Java automatically initialize it to null.
Invoking any method on a null reference will result in NPE.
Okay, let's narrow down to your specific case. You declared a class member called callBacks but never initialized it, as well as, I can see no methods that assign something to it. Therefore, that class member always remains null and thereby any subsequent method invocation on it leads us to NPE.
As a solution, you should add a setter method to your LoginFragment class in which you set that callBacks. In other side supply this object where you first create an instance of this fragment.
Update #1
when i pass Activity instead of Context as parameter in onAttach method it works. but i want to know why it is causing the error?
The why is simple. Since your activity already implemented that interface, so passing it to your LoginFragment as context will result in the condition if (context instanceof CallBacks) becoming true. However, passing bare context won't result in establishment of that if statement.
can u please tell me how i can define setter?
It's pretty simple! Just as other regular method, declare a method like this:
public void setOnLoginListener(Callbacks listener){
this.callbacks = listener;
}
Update #2
where i need to define setOnLoginListener method
Inside the LoginFragment class.
and where should i call it
In your main activity where you first instantiate LoginFragment class.
with what parameters?
Your activity, which implements that Java interface.
You can avoid setting onClickListener for the button by having adding android:onClink="login" in your xml file and a function that looks like this in your java file:
public void login(View view) {
application.getAuth().getUser().setIsLoggedIn(true);
callBacks.onLoggedIn();
}
You can try writing a public setter for the callBacks object in LoginFragment and setting it from the activity instead, like this, supposing you defined your fragment in the activity's layout file:
public class LoginNarrowActivity extends BaseActivity implements LoginFragment.CallBacks {
#Override
protected void onCreate(Bundle savedState){
super.onCreate(savedState);
setContentView(R.layout.activity_login_narrow);
LoginFragment loginFragment = (LoginFragment)getSupportFragmentManager().findFragmentById(R.id.your_fragment_id);
loginFragment.setCallBacks(this);
}
Actually the error was here in onAttach(Context context) when i pass Activity like this onAttach(Activity activity) then it worked. But i want to know why it is causing the error? and onAttach(Activity activity) is deprecated in android 5.0
I need make a perfomclick() to execute the code below. There is a button called mButtonLogin, I need make perfomclick() when activity starts.
I have tried and read many Stackoverflow examples, but I can't make it work. log cat output it's a Nullpointer exception where I place the perfomclick().
Button mButtonLogin;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_story_post);
mButtonLogin = (Button)findViewById(R.id.button_login);
myclick();
}
public void loginExample()
{
// Login listener
final OnLoginListener mOnLoginListener = new OnLoginListener()
{
//stuff
};
final OnPublishListener onPublishListener = new SimpleFacebook.OnPublishListener()
{
//stuff
};
//More stuff Final too Called feed
mButtonLogin.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View view)
{
mSimpleFacebook.login(mOnLoginListener);
mSimpleFacebook.publish(feed, onPublishListener);
}
});
}
Why am I receiving a Nullpointer exception?
Try this:
//put this in the OnCreate
mButtonLogin = (Button)findViewById(R.id.button_login);
mButtonLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mSimpleFacebook.login(mOnLoginListener);
mSimpleFacebook.publish(feed, onPublishListener);
}
});
// all your stuffs
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
mButtonLogin.performClick();
}