Develop Reference

Accessing another activity's method

I have a medicine_activity class
package com.example.shubhmgajra.medikit;
import android.content.Intent;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
public class Medicine_Activity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG = "Medicine_Activity";
private Button btnAdd;
private ListView listMeds;
private AppDatabase db;
private ArrayAdapter<MedicineRecord> arrayAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_medicine);
btnAdd = findViewById(R.id.btnAdd);
btnAdd.setOnClickListener(this);
listMeds = findViewById(R.id.listMeds);
listMeds.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
MedicineRecord medicineRecord = db.medicineRecordDao().findMedicineById(id + 1);
Intent intent = new Intent(getApplicationContext(), MedicineInputActivity.class);
startActivity(intent);
MedicineInputActivity.getInstance().update(medicineRecord, true);
}
});
db = AppDatabase.getInstance(getApplicationContext());
FeedAdapter feedAdapter = new FeedAdapter(Medicine_Activity.this, R.layout.list_record, db.medicineRecordDao().loadAllRecords());
listMeds.setAdapter(feedAdapter);
}
#Override
protected void onResume() {
super.onResume();
}
#Override
public void onClick(View v) {
Intent intent = new Intent(this, MedicineInputActivity.class);
startActivity(intent);
}
}
In this i am trying to call update() method of another activity namely MedicineInputActivity
package com.example.shubhmgajra.medikit;
import android.content.Intent;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TimePicker;
import android.widget.Toast;
public class MedicineInputActivity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG = "MedicineInputActivity";
static EditText dosage;
static EditText medName;
static TimePicker timePicker;
static Button btnSave;
Button btnInc;
Button btnDec;
private AppDatabase db;
private static MedicineInputActivity instance;
boolean isEdit;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_medicine_input);
isEdit = false;
instance = this;
dosage = findViewById(R.id.dosage);
dosage.setShowSoftInputOnFocus(false);
dosage.setCursorVisible(false);
medName = findViewById(R.id.medName);
timePicker = findViewById(R.id.simpleTimePicker);
btnInc = findViewById(R.id.btnInc);
btnDec = findViewById(R.id.btnDec);
btnInc.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String val = dosage.getText().toString();
int tempVal = Integer.parseInt(val);
tempVal++;
dosage.setText("" + tempVal);
}
});
btnDec.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String val = dosage.getText().toString();
int tempVal = Integer.parseInt(val);
if (tempVal > 0) {
tempVal--;
}
dosage.setText("" + tempVal);
}
});
btnSave = findViewById(R.id.btnSave);
btnSave.setOnClickListener(this);
db = AppDatabase.getInstance(getApplicationContext());
}
#Override
public void onClick(View v) {
String name = medName.getText().toString();
int min = timePicker.getMinute();
int hour = timePicker.getHour();
String val = dosage.getText().toString();
int dose = Integer.parseInt(val);
MedicineRecord medicineRecord = new MedicineRecord(name, dose, min, hour);
if (validate(name)) {
if (isEdit) {
db.medicineRecordDao().updateRecord(medicineRecord);
} else {
db.medicineRecordDao().insertRecord(medicineRecord);
}
Intent intent = new Intent(this, Medicine_Activity.class);
startActivity(intent);
} else {
Toast toast = Toast.makeText(getApplicationContext(), "Medicine name cannot be empty", Toast.LENGTH_SHORT);
toast.show();
}
}
private boolean validate(String name) {
if (name.length() == 0) {
return false;
} else {
return true;
}
}
public static MedicineInputActivity getInstance() {
return instance;
}
public void update(MedicineRecord medicineRecord, boolean isEdit) {
this.isEdit = isEdit;
dosage.setText(medicineRecord.getDosage());
medName.setText(medicineRecord.getMedName());
timePicker.setHour(medicineRecord.getHour());
timePicker.setMinute(medicineRecord.getMinute());
}
}
What i am trying to achieve is when the user taps the list item, the input activity is loaded and the user can update the record. I wasnt able to find an elegant solution other than making an update method in MedicineInputActivity and then getting an instance of MedicineInputActivity in Medicine_Activity and calling update.
I am getting errors like "Attempt to invoke virtual method 'void com.example.shubhmgajra.medikit.MedicineInputActivity.update() on a null object reference".

You can return data from second activity to the first activity when user is done updating the record. You should start second activity by calling startActivityForResult() instead of startActivity() in the first activity. You should also override onActivityResult() in the first activity. You can read more here.
UPDATE:
I think you want to send selected medicine details from Medicine_Activity to MedicineInputActivity. In that case, you can send selected medicine object by binding it to the intent as follows:
public class Medicine_Activity ... {
#Override
protected void onCreate(Bundle savedInstanceState) {
...
listMeds.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
MedicineRecord medicineRecord = db.medicineRecordDao().findMedicineById(id + 1);
Intent intent = new Intent(getApplicationContext(), MedicineInputActivity.class);
intent.putExtra("selectedMedicine", medicineRecord);
startActivity(intent);
MedicineInputActivity.getInstance().update(medicineRecord, true);
}
});
...
}
}
Then on MedicineInputActivity, you should be doing this:
public class MedicineInputActivity ... {
MedicineRecord selectedMedicineRecord;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
selectedMedicineRecord = (MedicineRecord) getIntent().getParcelableExtra("selectedMedicine");
...
}
}
To be able to do this, your MedicineRecord class should implement Parcelable interface.

savedInstanceState is null when onCreateView is called in Fragment even though I overrided onSaveInstanceState

I added up button to tool bar to navigate from fragment B to fragment A.
When I click up button, I couldn't restore the member variables of A fragment
Because savedInstanceState was null even though I Overrided
onSaveInstanceState(Bundle) and put all the variables which I wanted to restore later.
I did my best to search the reason, but I couldn't find the reason and the solutoin.
There were differeces between my situation and questions(answers) of other posts.
First, my fragment is hosted dynamically, so I couldn't give an id to my fragment in XML or something.
Second, it works when I rotate my device(savedInstanceState is not null on onCreateView()). I thought both(to rotate the device and to navigate from fragment B to fragment A) is the same situation
in that the fragment A is destroyed and recreated so onSaveInstanceState method
is called first and onCreateView is called after fragment A is recreated.
I have no idea why such situation occured. Please help me. Thanks.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if(savedInstanceState != null){
mSubtitleVisible = savedInstanceState.getBoolean(SAVED_SUBTITLE_VISIBLE);
}
View view = inflater.inflate(R.layout.fragment_crime_list, container, false);
mCrimeRecyclerView = (RecyclerView) view.findViewById(R.id.crime_recycler_view);
mCrimeRecyclerView.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
updateUI();
return view;
}
...
#Override
public void onSaveInstanceState(Bundle outState){
super.onSaveInstanceState(outState);
outState.putBoolean(SAVED_SUBTITLE_VISIBLE, mSubtitleVisible);
}
the full code of Fragment B
package com.bignerdranch.android.criminalintent;
import android.app.Activity;
import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentManager;
import android.text.Editable;
import android.text.TextWatcher;
import android.text.format.DateFormat;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import java.util.Calendar;
import java.util.Date;
import java.util.UUID;
/**
* Created by sgc109 on 2017-10-05.
*/
public class CrimeFragment extends android.support.v4.app.Fragment {
private static final String ARG_CRIME_ID = "crime_id";
private static final String DIALOG_DATE = "DialogDate";
private static final String DIALOG_TIME = "DialogTime";
private static final int REQUEST_DATE = 0;
private static final int REQUEST_TIME = 1;
private Crime mCrime;
private EditText mTitleField;
private Button mDateButton;
private Button mTimeButton;
private CheckBox mSolvedCheckBox;
public static CrimeFragment newInstance(UUID crimeId){
Bundle args = new Bundle();
args.putSerializable(ARG_CRIME_ID, crimeId);
CrimeFragment fragment = new CrimeFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
UUID crimeId = (UUID)getArguments().getSerializable(ARG_CRIME_ID);
mCrime = CrimeLab.get(getActivity()).getCrime(crimeId);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View v = inflater.inflate(R.layout.fragment_crime, container, false);
mTitleField = (EditText)v.findViewById(R.id.crime_title);
mTitleField.setText(mCrime.getTitle());
mTitleField.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
mCrime.setTitle(s.toString());
}
#Override
public void afterTextChanged(Editable s) {
}
});
mDateButton = (Button)v.findViewById(R.id.crime_date);
mDateButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
FragmentManager manager = getFragmentManager();
DatePickerFragment dialog = DatePickerFragment.newInstance(mCrime.getDate());
dialog.setTargetFragment(CrimeFragment.this, REQUEST_DATE);
dialog.show(manager, DIALOG_DATE);
}
});
mTimeButton = (Button)v.findViewById(R.id.crime_time);
mTimeButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
FragmentManager manager = getFragmentManager();
TimePickerFragment dialog = TimePickerFragment.newInstance(mCrime.getDate());
dialog.setTargetFragment(CrimeFragment.this, REQUEST_TIME);
dialog.show(manager, DIALOG_TIME);
}
});
updateDateAndTimeButton();
mSolvedCheckBox = (CheckBox)v.findViewById(R.id.crime_solved);
mSolvedCheckBox.setChecked(mCrime.isSolved());
mSolvedCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
mCrime.setSolved(isChecked);
}
});
return v;
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent intent){
if(resultCode != Activity.RESULT_OK) {
return;
}
if(requestCode == REQUEST_DATE){
Date date = (Date)intent.getSerializableExtra(DatePickerFragment.EXTRA_DATE);
mCrime.setDate(updateDate(date));
updateDateAndTimeButton();
}
else if(requestCode == REQUEST_TIME){
Date date = (Date)intent.getSerializableExtra(TimePickerFragment.EXTRA_TIME);
mCrime.setDate(updateTime(date));
updateDateAndTimeButton();
}
}
private Date updateDate(Date date){
Calendar calOld = Calendar.getInstance();
calOld.setTime(mCrime.getDate());
Calendar calNew = Calendar.getInstance();
calNew.setTime(date);
calNew.set(Calendar.HOUR_OF_DAY, calOld.get(Calendar.HOUR_OF_DAY));
calNew.set(Calendar.MINUTE, calOld.get(Calendar.MINUTE));
return calNew.getTime();
}
private Date updateTime(Date date){
Calendar calOld = Calendar.getInstance();
calOld.setTime(mCrime.getDate());
Calendar calNew = Calendar.getInstance();
calNew.setTime(date);
calNew.set(Calendar.YEAR, calOld.get(Calendar.YEAR));
calNew.set(Calendar.MONTH, calOld.get(Calendar.MONTH));
calNew.set(Calendar.DAY_OF_MONTH, calOld.get(Calendar.DAY_OF_MONTH));
return calNew.getTime();
}
private void updateDateAndTimeButton() {
mDateButton.setText(mCrime.getDateString());
mTimeButton.setText(mCrime.getTimeString());
}
public void returnResult(){
getActivity().setResult(Activity.RESULT_OK, null);
}
}

Because the Activity created after onCreateView .
You can use onActivityCreated method to restore the fragment's state here .
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (savedInstanceState != null) {
mSubtitleVisible = savedInstanceState.getBoolean(SAVED_SUBTITLE_VISIBLE);
}
Log.e("TAG", "onActivityCreated OK");
Log.e("TAG", savedInstanceState.getBoolean(SAVED_SUBTITLE_VISIBLE) + "");
}
Edit
Change to onViewStateRestored method,and try again .
Add log in onSaveInstanceState and onViewStateRestored ,make sure all of them work .
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (savedInstanceState != null) {
mSubtitleVisible = savedInstanceState.getBoolean(SAVED_SUBTITLE_VISIBLE);
}
Log.e("TAG", "onActivityCreated OK");
Log.e("TAG", "onActivityCreated " + savedInstanceState.getBoolean(SAVED_SUBTITLE_VISIBLE));
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBoolean(SAVED_SUBTITLE_VISIBLE, mSubtitleVisible);
Log.e("TAG", "onSaveInstanceState OK");
Log.e("TAG", "onSaveInstanceState" + mSubtitleVisible);
}
Edit
You can save the status in onSaveInstanceState and onDestroyView.
Then,restore the state in onActivityCreated
You can do like this.
Bundle savedState;
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// Restore State Here
if (!restoreStateFromArguments()) {
// First Time, Initialize something here
onFirstTimeLaunched();
}
}
protected void onFirstTimeLaunched() {
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save State Here
saveStateToArguments();
}
#Override
public void onDestroyView() {
super.onDestroyView();
// Save State Here
saveStateToArguments();
}
private void saveStateToArguments() {
if (getView() != null)
savedState = saveState();
if (savedState != null) {
Bundle b = getArguments();
b.putBundle("savedState", savedState);
}
}
private boolean restoreStateFromArguments() {
Bundle b = getArguments();
savedState = b.getBundle("savedState");
if (savedState != null) {
restoreState();
return true;
}
return false;
}
// Restore Instance State Here
private void restoreState() {
if (savedState != null) {
// For Example
uSelected.setText(savedState.getString("uSelected"));
onRestoreState(savedState);
}
}
protected void onRestoreState(Bundle savedInstanceState) {
}
// Save Instance State Here
private Bundle saveState() {
Bundle state = new Bundle();
// For Example
state.putString("uSelected", uSelected.getText().toString());
onSaveState(state);
return state;
}
protected void onSaveState(Bundle outState) {
}
Fragment life cycle

Passing Boolean value from fragments to activity

I am new to android development and I am trying to pass a Boolean value from dialog fragment to the activity.
the boolean value is supposed to be decided by the user(depends on which button user clicked). However, the boolean immediately turned to false without clicking any button.
I have tried various method recommended I found on internet but none of them works for me(I guess I have some part screwed up...), these method include:
-broadcasting
-implementing interface
-intent.putExtra
and below is the code that I have came up with, could anyone help me take a look? Any help is appreciated.
Stage:
package com.example.fuj.valorsafeworldbytrade;
import android.support.v4.app.FragmentManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import static com.example.fuj.valorsafeworldbytrade.LosingDialogFragment.LOSING_FRAGMENT;
public class Stage extends AppCompatActivity {
String stage;
FragmentManager fragmentManager = getSupportFragmentManager();
LosingDialogFragment losingDialogFragment = new LosingDialogFragment();
BasicInfo basicInfo = new BasicInfo();
public void setText(){
TextView cpuReputation = (TextView) findViewById(R.id.cpu_reputation);
TextView cpuGold = (TextView) findViewById(R.id.cpu_gold);
TextView pGoldText = (TextView) findViewById(R.id.player_gold);
TextView pRepText = (TextView) findViewById(R.id.player_reputation);
cpuReputation.setText(String.valueOf(basicInfo.cRep));
cpuGold.setText(String.valueOf(basicInfo.cGold));
pGoldText.setText(String.valueOf(basicInfo.pGold));
pRepText.setText(String.valueOf(basicInfo.pRep));
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_stage);
setText();
}
protected void onStart() {
super.onStart();
stage = getIntent().getStringExtra(StageChoosingMenu.STAGE);
}
public void playerChoice(View view) {
boolean deceiveEnabled;
switch (view.getId()) {
case R.id.cooperate_button:
deceiveEnabled = false;
break;
case R.id.deceive_button:
deceiveEnabled = true;
break;
default:
throw new RuntimeException("Unknown Button ID");
}
switch (stage){
case "xumo":
xuMo(deceiveEnabled);
break;
}
}
public void xuMo(boolean playerDeceiveEnabled){
boolean cpuDeceiveEnabled;
cpuDeceiveEnabled = (Math.random() - basicInfo.faith > 0);
if (cpuDeceiveEnabled){
if (playerDeceiveEnabled){
basicInfo.playerDvsCpuD();
// faith changes to be amend w/ proper value, need record on the change of status
}
if (!playerDeceiveEnabled){
basicInfo.playerCvsCpuD();
}
}
if (!cpuDeceiveEnabled){
if (playerDeceiveEnabled){
basicInfo.playerDvsCpuC();
}
if (!playerDeceiveEnabled){
basicInfo.playerCvsCpuC();
}
}
if(basicInfo.pGold <= 0 || basicInfo.cGold <= 0 || basicInfo.pRep <= 0 || basicInfo.cRep <= 0){
//to be changed
setText();
losingDialogFragment.show(fragmentManager,LOSING_FRAGMENT);
//trying to show a alert dialog fragment
Log.d("True", String.valueOf(losingDialogFragment.tryAgainEnabled));
if(losingDialogFragment.tryAgainEnabled){//tryAgainEnabled is always false
//This is the part that I wanted to retrieve data from the user(if they want to try again or not)
basicInfo.reset();
losingDialogFragment.dismiss();
}else{
losingDialogFragment.dismiss();
}
}
setText();
// to be changed
}
}
LosingDialogFragment:
package com.example.fuj.valorsafeworldbytrade;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
/**
* Created by fuj on 20/1/2017.
*/
public class LosingDialogFragment extends DialogFragment{
public static final String LOSING_FRAGMENT = "LOSING";
public boolean tryAgainEnabled;
Intent intent = new Intent();
#Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View rootView = inflater.inflate(R.layout.fragment_lose, container, false);;
//the following code is used to set the boolean value after the user click the button
final Button tryAgainButton = (Button)rootView.findViewById(R.id.try_again_button);
tryAgainButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
tryAgainEnabled = true;
}
});
Button giveUpButton =(Button)rootView.findViewById(R.id.give_up_button);
giveUpButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
tryAgainEnabled = false;
}
});
getDialog().setTitle(LOSING_FRAGMENT);
return rootView;
}
}
I am also sorry that I am not the best with English, if any things is not clear or not polite because of my poor English, please kindly let me know. I apologize in advance for any mistakes I have made.

It's because you check the value of tryAgainEnabled exactly right after showing the Dialog. Dialog starts Asynchronously, It means that it starts in diffrent Thread and your current thread doesn't wait for dismissing Dialog, So this line of your code if(losingDialogFragment.tryAgainEnabled){ runs exactly after you show dialog, befor you set value to tryAgainEnabled. Because the default value of boolean is always false, you will get false everytime.
I suggest that use listener for this:
Dialog:
public class LosingDialogFragment extends DialogFragment {
public static final String LOSING_FRAGMENT = "LOSING";
public boolean tryAgainEnabled;
Intent intent = new Intent();
private View.OnClickListener onTryAgainButtonClickLisnter;
private View.OnClickListener onGiveUpButtonClickLisnter;
#Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View rootView = inflater.inflate(R.layout.fragment_lose, container, false);;
final Button tryAgainButton = (Button)rootView.findViewById(R.id.try_again_button);
tryAgainButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(onTryAgainButtonClickLisnter!=null)
onTryAgainButtonClickLisnter.onClick(v);
}
});
Button giveUpButton =(Button)rootView.findViewById(R.id.give_up_button);
giveUpButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(onGiveUpButtonClickLisnter!=null)
onGiveUpButtonClickLisnter.onClick(v);
}
});
getDialog().setTitle(LOSING_FRAGMENT);
return rootView;
}
public void setOnTryAgainButtonClickLisnter(View.OnClickListener onTryAgainButtonClickLisnter) {
this.onTryAgainButtonClickLisnter = onTryAgainButtonClickLisnter;
}
public void setOnGiveUpButtonClickLisnter(View.OnClickListener onGiveUpButtonClickLisnter) {
this.onGiveUpButtonClickLisnter = onGiveUpButtonClickLisnter;
}
}
In your activity call dialog like this:
LosingDialogFragment losingDialogFragment = new LosingDialogFragment();
losingDialogFragment.setOnTryAgainButtonClickLisnter(new View.OnClickListener() {
#Override
public void onClick(View v) {
tryAgain();
losingDialogFragment.dismiss();
}
});
losingDialogFragment.setOnGiveUpButtonClickLisnter(new View.OnClickListener() {
#Override
public void onClick(View v) {
giveUp();
losingDialogFragment.dismiss();
}
});
losingDialogFragment.show(fragmentManager, "");

Declare public boolean tryAgainEnabled; in your Stage Activity and youd can update that variable using ((Stage)context).tryAgainEnabled.
package com.example.fuj.valorsafeworldbytrade;
import android.support.v4.app.FragmentManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import static com.example.fuj.valorsafeworldbytrade.LosingDialogFragment.LOSING_FRAGMENT;
public class Stage extends AppCompatActivity {
String stage;
FragmentManager fragmentManager = getSupportFragmentManager();
LosingDialogFragment losingDialogFragment = new LosingDialogFragment();
BasicInfo basicInfo = new BasicInfo();
public boolean tryAgainEnabled;
public void setText(){
TextView cpuReputation = (TextView) findViewById(R.id.cpu_reputation);
TextView cpuGold = (TextView) findViewById(R.id.cpu_gold);
TextView pGoldText = (TextView) findViewById(R.id.player_gold);
TextView pRepText = (TextView) findViewById(R.id.player_reputation);
cpuReputation.setText(String.valueOf(basicInfo.cRep));
cpuGold.setText(String.valueOf(basicInfo.cGold));
pGoldText.setText(String.valueOf(basicInfo.pGold));
pRepText.setText(String.valueOf(basicInfo.pRep));
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_stage);
setText();
}
protected void onStart() {
super.onStart();
stage = getIntent().getStringExtra(StageChoosingMenu.STAGE);
}
public void playerChoice(View view) {
boolean deceiveEnabled;
switch (view.getId()) {
case R.id.cooperate_button:
deceiveEnabled = false;
break;
case R.id.deceive_button:
deceiveEnabled = true;
break;
default:
throw new RuntimeException("Unknown Button ID");
}
switch (stage){
case "xumo":
xuMo(deceiveEnabled);
break;
}
}
public void xuMo(boolean playerDeceiveEnabled){
boolean cpuDeceiveEnabled;
cpuDeceiveEnabled = (Math.random() - basicInfo.faith > 0);
if (cpuDeceiveEnabled){
if (playerDeceiveEnabled){
basicInfo.playerDvsCpuD();
// faith changes to be amend w/ proper value, need record on the change of status
}
if (!playerDeceiveEnabled){
basicInfo.playerCvsCpuD();
}
}
if (!cpuDeceiveEnabled){
if (playerDeceiveEnabled){
basicInfo.playerDvsCpuC();
}
if (!playerDeceiveEnabled){
basicInfo.playerCvsCpuC();
}
}
if(basicInfo.pGold <= 0 || basicInfo.cGold <= 0 || basicInfo.pRep <= 0 || basicInfo.cRep <= 0){
//to be changed
setText();
losingDialogFragment.show(fragmentManager,LOSING_FRAGMENT);
Log.d("True", String.valueOf(losingDialogFragment.tryAgainEnabled));
if(losingDialogFragment.tryAgainEnabled){//tryAgainEnabled is always false
basicInfo.reset();
losingDialogFragment.dismiss();
}else{
losingDialogFragment.dismiss();
}
}
setText();
// to be changed
}
}
And in Fragment
package com.example.fuj.valorsafeworldbytrade;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
/**
* Created by fuj on 20/1/2017.
*/
public class LosingDialogFragment extends DialogFragment{
public static final String LOSING_FRAGMENT = "LOSING";
Context context;
Intent intent = new Intent();
#Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View rootView = inflater.inflate(R.layout.fragment_lose, container, false);;
final Button tryAgainButton = (Button)rootView.findViewById(R.id.try_again_button);
tryAgainButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((Stage)context).tryAgainEnabled = true;
}
});
Button giveUpButton =(Button)rootView.findViewById(R.id.give_up_button);
giveUpButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((Stage)context).tryAgainEnabled = false;
}
});
getDialog().setTitle(LOSING_FRAGMENT);
return rootView;
}
}

Inconvertable types error when passing and using fragment context in listener class

I am trying to implement and autocomplete function for an edittext in a fragment but having trouble passing the context of the fragment to the listener/textwatcher. In the constructor, it accepts the context as a parameter but brings an "inconvertable types" error when trying to link the context to the fragment.
`EmpAddFragment mainActivity = ((EmpAddFragment)context);`
Below is the code for the listener and the fragment where it is called.
CustomAutoCompleteTextChangedListener.java:
import android.content.Context;
import android.support.v4.app.Fragment;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
public class CustomAutoCompleteTextChangedListener implements TextWatcher {
public static final String TAG = "CustomAutoCompleteTextChangedListener.java";
Context context;
View view;
Fragment fragment;
public CustomAutoCompleteTextChangedListener(Context context){
this.context = context;
}
#Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
#Override
public void onTextChanged(CharSequence userInput, int start, int before, int count) {
EmpAddFragment mainActivity = ((EmpAddFragment)context);
// query the database based on the user input
mainActivity.item = mainActivity.getItemsFromDb(userInput.toString());
// update the adapater
mainActivity.myAdapter.notifyDataSetChanged();
mainActivity.myAdapter = new ArrayAdapter<String>(mainActivity.getActivity(), android.R.layout.simple_dropdown_item_1line, mainActivity.item);
mainActivity.myAutoComplete.setAdapter(mainActivity.myAdapter);
}
}
EmpAddFragment:
import java.lang.ref.WeakReference;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.DatePickerDialog.OnDateSetListener;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.InputType;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.*;
public class EmpAddFragment extends Fragment implements OnClickListener {
// UI references
private EditText empNameEtxt;
private Button addButton;
private Button resetButton;
/*
* Change to type CustomAutoCompleteView instead of AutoCompleteTextView
* since we are extending to customize the view and disable filter
* The same with the XML view, type will be CustomAutoCompleteView
*/
CustomAutoCompleteView myAutoComplete;
// adapter for auto-complete
ArrayAdapter<String> myAdapter;
// for database operations
DataBaseHelper databaseH;
// just to add some initial value
String[] item = new String[] {"Please search..."};
private static final SimpleDateFormat formatter = new SimpleDateFormat(
"yyyy-MM-dd", Locale.ENGLISH);
DatePickerDialog datePickerDialog;
Calendar dateCalendar;
Employee employee = null;
private EmployeeDAO employeeDAO;
private AddEmpTask task;
public static final String ARG_ITEM_ID = "emp_add_fragment";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
employeeDAO = new EmployeeDAO(getActivity());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_add_emp, container,
false);
findViewsById(rootView);
setListeners();
try{
// instantiate database handler
databaseH = new DataBaseHelper(getActivity());
// autocompletetextview is in activity_main.xml
myAutoComplete = (CustomAutoCompleteView) rootView.findViewById(R.id.myautocomplete);
// add the listener so it will tries to suggest while the user types
myAutoComplete.addTextChangedListener(new CustomAutoCompleteTextChangedListener(this.getActivity()));
// set our adapter
myAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_dropdown_item_1line, item);
myAutoComplete.setAdapter(myAdapter);
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
//For orientation change.
if (savedInstanceState != null) {
dateCalendar = Calendar.getInstance();
if (savedInstanceState.getLong("dateCalendar") != 0)
dateCalendar.setTime(new Date(savedInstanceState
.getLong("dateCalendar")));
}
return rootView;
}
private void setListeners() {
Calendar newCalendar = Calendar.getInstance();
datePickerDialog = new DatePickerDialog(getActivity(),
new OnDateSetListener() {
public void onDateSet(DatePicker view, int year,
int monthOfYear, int dayOfMonth) {
dateCalendar = Calendar.getInstance();
dateCalendar.set(year, monthOfYear, dayOfMonth);
}
}, newCalendar.get(Calendar.YEAR),
newCalendar.get(Calendar.MONTH),
newCalendar.get(Calendar.DAY_OF_MONTH));
addButton.setOnClickListener(this);
resetButton.setOnClickListener(this);
}
protected void resetAllFields() {
empNameEtxt.setText("");
}
private void setEmployee() {
employee = new Employee();
employee.setName(empNameEtxt.getText().toString());
}
#Override
public void onResume() {
getActivity().setTitle(R.string.add_emp);
getActivity().getActionBar().setTitle(R.string.add_emp);
super.onResume();
}
#Override
public void onSaveInstanceState(Bundle outState) {
if (dateCalendar != null)
outState.putLong("dateCalendar", dateCalendar.getTime().getTime());
}
private void findViewsById(View rootView) {
empNameEtxt = (EditText) rootView.findViewById(R.id.etxt_name);
addButton = (Button) rootView.findViewById(R.id.button_add);
resetButton = (Button) rootView.findViewById(R.id.button_reset);
}
#Override
public void onClick(View view) {
if (view == null) {
} else if (view == addButton) {
setEmployee();
task = new AddEmpTask(getActivity());
task.execute((Void) null);
} else if (view == resetButton) {
resetAllFields();
}
}
public class AddEmpTask extends AsyncTask<Void, Void, Long> {
private final WeakReference<Activity> activityWeakRef;
public AddEmpTask(Activity context) {
this.activityWeakRef = new WeakReference<Activity>(context);
}
#Override
protected Long doInBackground(Void... arg0) {
long result = employeeDAO.save(employee);
return result;
}
#Override
protected void onPostExecute(Long result) {
if (activityWeakRef.get() != null
&& !activityWeakRef.get().isFinishing()) {
if (result != -1)
Toast.makeText(activityWeakRef.get(), "Employee Saved",
Toast.LENGTH_LONG).show();
}
}
}
// this function is used in CustomAutoCompleteTextChangedListener.java
public String[] getItemsFromDb(String searchTerm){
// add items on the array dynamically
List<MyObject> products = databaseH.read(searchTerm);
int rowCount = products.size();
String[] item = new String[rowCount];
int x = 0;
for (MyObject record : products) {
item[x] = record.objectName;
x++;
}
return item;
}
}
This is the logcat when i used
`EmpAddFragment mainActivity = new EmpAddFragment;
All other attempts output the inconvertable types error
LogCat:
07-23 06:49:17.828 2017-2017/com.example.autoFill E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.autoFill, PID: 2017
java.lang.NullPointerException
at com.example.autoFill.EmpAddFragment.getItemsFromDb(EmpAddFragment.java:209)
at com.example.autoFill.CustomAutoCompleteTextChangedListener.onTextChanged(CustomAutoCompleteTextChangedListener.java:42)
at android.widget.TextView.sendOnTextChanged(TextView.java:7408)
at android.widget.TextView.handleTextChanged(TextView.java:7467)
at android.widget.TextView$ChangeWatcher.onTextChanged(TextView.java:9187)
at android.text.SpannableStringBuilder.sendTextChanged(SpannableStringBuilder.java:962)
at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:496)
at android.text.SpannableStringBuilder.delete(SpannableStringBuilder.java:212)
at android.text.SpannableStringBuilder.delete(SpannableStringBuilder.java:30)
at android.view.inputmethod.BaseInputConnection.deleteSurroundingText(BaseInputConnection.java:243)
at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.java:382)
at com.android.internal.view.IInputConnectionWrapper$MyHandler.handleMessage(IInputConnectionWrapper.java:77)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
UPDATE:
Changed my listener constructor to:
public CustomAutoCompleteTextChangedListener(EmpAddFragment frag){
frag = fragment;
context = fragment.getActivity();
}
and the call to:
myAutoComplete.addTextChangedListener(new CustomAutoCompleteTextChangedListener(this));
But register a NullPointerException in the logcat pointing to:
myAutoComplete.addTextChangedListener(new CustomAutoCompleteTextChangedListener(this));
AND:
context = fragment.getActivity();

Change the constructor of your listener class
public class CustomAutoCompleteTextChangedListener implements TextWatcher {
public static final String TAG = "CustomAutoCompleteTextChangedListener.java";
Context context;
View view;
Fragment fragment;
public CustomAutoCompleteTextChangedListener(EmpAddFragment fragment){
this.fragment = fragment;
this.context = fragment.getActivity();
}
//.... rest of your listener class implementation
}
Use the calling method as follows where you face "inconvertible types"
EmpAddFragment mainFragment = ((EmpAddFragment)fragment);
Hope it works!

myAutoComplete.addTextChangedListener(new CustomAutoCompleteTextChangedListener(this.getActivity()));
with the line above you are not passing the fragment but the activity from where it is called so when you call:
EmpAddFragment mainActivity = ((EmpAddFragment)context);
it can't work because you are casting to EmpAddFragment an Activity instance.
so if you want to have the fragment instance change the listener constructor and pass the fragment.
if you want to have the activity then cast the context to the activity

Fragment crashes after adding new code

My Activity crashes as I click to open it. First It was working fine but later I added some new code and now it show unable to launch the application. The new code was a check box and onCheckedChange Listener and I am not able to find what went wrong.
CrimeFragment
package com.bignerdranch.android.criminalintent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.*;
import android.widget.CompoundButton.OnCheckedChangeListener;
public class CrimeFragment extends Fragment {
Crime mCrime;
EditText mTitleField;
Button b1;
CheckBox CB_solved;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mCrime = new Crime();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState)
{
View v = inflater.inflate(R.layout.fragment_crime, parent, false);
mTitleField = (EditText) v.findViewById(R.id.crime_title);
mTitleField.addTextChangedListener(new TextWatcher() {
public void onTextChanged(CharSequence c, int start, int before, int count) {
mCrime.setTitle(c.toString());
}
public void beforeTextChanged(CharSequence c, int start, int count, int after) {
// this space intentionally left blank
}
public void afterTextChanged(Editable c) {
// this one too
}
});
b1 = (Button) v.findViewById(R.id.button1);
b1.setText(mCrime.getDate().toString());
CB_solved = (CheckBox) v.findViewById(R.id.checkBox1);
CB_solved.setOnCheckedChangeListener(new OnCheckedChangeListener(){
public void onCheckedChanged(CompoundButton arg0, boolean arg1) {
// TODO Auto-generated method stub
mCrime.setCheck(arg1);
}
});
return v;
}
}
CrimeActivity
public class CrimeActivity extends FragmentActivity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_crime);
FragmentManager manager = getSupportFragmentManager();
Fragment fragment = manager.findFragmentById(R.id.fragmentContainer);
if (fragment == null) {
fragment = new CrimeFragment();
manager.beginTransaction()
.add(R.id.fragmentContainer, fragment)
.commit();
}
}
}