Nullpointerexception using a fragmentary element
I have a problem with an application I am making, everything seemed to be working fine until I started getting an error, seemingly because I don’t believe I changed something from the moment it worked but every time I open an activity that gives me a NullPointerException it outputs the logarithm from it.
09-13 18:29:54.951: E/AndroidRuntime(4407): FATAL EXCEPTION: main
09-13 18:29:54.951: E/AndroidRuntime(4407): Process: renseew.knowyourtime, PID: 4407
09-13 18:29:54.951: E/AndroidRuntime(4407): java.lang.NullPointerException
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v13.app.FragmentCompatICS.setMenuVisibility(FragmentCompatICS.java:23)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v13.app.FragmentCompat$ICSFragmentCompatImpl.setMenuVisibility(FragmentCompat.java:41)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v13.app.FragmentCompat.setMenuVisibility(FragmentCompat.java:68)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v13.app.FragmentStatePagerAdapter.instantiateItem(FragmentStatePagerAdapter.java:120)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:837)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v4.view.ViewPager.populate(ViewPager.java:987)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v4.view.ViewPager.populate(ViewPager.java:919)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1441)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.View.measure(View.java:16497)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:762)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.View.measure(View.java:16497)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.View.measure(View.java:16497)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
09-13 18:29:54.951: E/AndroidRuntime(4407): at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:327)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.View.measure(View.java:16497)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
09-13 18:29:54.951: E/AndroidRuntime(4407): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2291)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.View.measure(View.java:16497)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1916)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1113)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1295)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.Choreographer.doCallbacks(Choreographer.java:574)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.Choreographer.doFrame(Choreographer.java:544)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.os.Handler.handleCallback(Handler.java:733)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.os.Handler.dispatchMessage(Handler.java:95)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.os.Looper.loop(Looper.java:136)
09-13 18:29:54.951: E/AndroidRuntime(4407): at android.app.ActivityThread.main(ActivityThread.java:5017)
09-13 18:29:54.951: E/AndroidRuntime(4407): at java.lang.reflect.Method.invokeNative(Native Method)
09-13 18:29:54.951: E/AndroidRuntime(4407): at java.lang.reflect.Method.invoke(Method.java:515)
09-13 18:29:54.951: E/AndroidRuntime(4407): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
09-13 18:29:54.951: E/AndroidRuntime(4407): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
09-13 18:29:54.951: E/AndroidRuntime(4407): at dalvik.system.NativeStart.main(Native Method)
this operation uses FragmentStatePagerAdapter to dynamically add tabs from fragment to activity, ive also tried to change if (position <company.size () -1) to if (position <company.size ()) unchanged (the first one worked before i started getting error) i.e. activity code.
public class UserDetails extends BaseActivity implements ActionBar.TabListener {
CompanyPagerAdapter companyPagerAdapter;
ViewPager viewPager;
Cursor cursor;
SettingsDBAdapter settingsDBAdapter;
String companyName;
private List<String> companies = new ArrayList<String>();
ActionBar ab;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_details);
updateActionBarNavigation();
initialize();
setupTabs();
getCompanies();
getTabs();
}
private void initialize() {
if(ab != null)
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
viewPager = (ViewPager) findViewById(R.id.UDviewpager);
ContentResolver settingsContent = this.getContentResolver();
cursor = settingsContent.query(KnowYourTimeContentProvider.CONTENT_URI_SETTINGS, null, null, null, null);
settingsDBAdapter = new SettingsDBAdapter(getApplicationContext());
if (cursor.getCount() == 0) {
settingsDBAdapter.settingsDBOpen();
settingsDBAdapter.setDefaultSettings();
}
}
private void setupTabs() {
companyPagerAdapter = new CompanyPagerAdapter(getFragmentManager());
viewPager.setAdapter(companyPagerAdapter);
viewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
if (ab != null) {
ab.setSelectedNavigationItem(position);
}
}
});
}
private void getTabs() {
for (int i = 0; i < companyPagerAdapter.getCount(); i++) {
if (ab != null) {
ab.addTab(ab.newTab()
.setText(companyPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
}
private void getCompanies() {
cursor = settingsDBAdapter.getCompanies();
if (companies.size() != 0) {
for (int i = 0; i < companies.size(); i++) {
companyName = companies.get(i);
companies.add(companyName);
}
} else if (cursor.getCount() != 0) {
while (cursor.moveToNext()) {
companyName = cursor.getString(cursor.getColumnIndex("company"));
companies.add(companyName);
}
} else {
companyName = getString(R.string.company);
companies.add(companyName);
}
companyPagerAdapter.notifyDataSetChanged();
}
@Override
protected void onNavDrawerStateChanged(boolean isOpen, boolean isAnimating) {
super.onNavDrawerStateChanged(isOpen, isAnimating);
updateActionBarNavigation();
}
@Override
protected void onActionBarAutoShowOrHide(boolean shown) {
super.onActionBarAutoShowOrHide(shown);
}
private void updateActionBarNavigation() {
boolean show = !isNavDrawerOpen();
ab = getActionBar();
if (show && ab != null) {
ab.setDisplayShowCustomEnabled(true);
ab.setDisplayShowTitleEnabled(true);
ab.setDisplayUseLogoEnabled(false);
ab.setTitle(getString(R.string.title_user_details));
} else if (ab != null) {
ab.setDisplayShowCustomEnabled(false);
ab.setDisplayShowTitleEnabled(false);
ab.setDisplayUseLogoEnabled(true);
}
}
@Override
protected int getSelfNavDrawerItem() {
return NAVDRAWER_ITEM_USERDETAILS;
}
@Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
viewPager.setCurrentItem(tab.getPosition());
companies.get(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.usersettings_menu, menu);
return true;
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
menu.clear();
menu.add(Menu.NONE, R.id.addCompany, Menu.NONE, getString(R.string.add) + " " + getString(R.string.company));
menu.add(Menu.NONE, R.id.removeCompany, Menu.NONE, getString(R.string.subtract) + " " + getString(R.string.company));
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem menuItem) {
switch (menuItem.getItemId()) {
case R.id.addCompany:
companies.clear();
companyName = getString(R.string.company);
companies.add(companyName);
companyPagerAdapter.notifyDataSetChanged();
getTabs();
return true;
case R.id.removeCompany:
return true;
default:
return super.onOptionsItemSelected(menuItem);
}
}
public class CompanyPagerAdapter extends FragmentStatePagerAdapter {
public CompanyPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
while (position < companies.size() - 1) {
if (position < companies.size() - 1) {
position++;
return FragmentUserDetails.newInstance(companies.get(position));
}
}
return null;
}
@Override
public int getCount() {
return companies.size();
}
@Override
public CharSequence getPageTitle(int position) {
while (position < companies.size() - 1) {
if (position < companies.size() - 1) {
position++;
return companies.get(position);
}
}
return "";
}
}
}
and here is the code for the snippet that opens the activity.
public class FragmentUserDetails extends Fragment implements AdapterView.OnItemClickListener, View.OnClickListener {
private BaseAdapter listAdapter;
private Cursor settingsCursor, companyCursor;
private String payrate, payperiod, weekstart, allowances, maritalstatus;
private String companyname;
private Switch cbMaritalStatus;
public EditText etCompanyName, etPayrate;
private Spinner sPayPeriod, sPeriodStart, sAllowances;
SettingsDBAdapter settingsDBAdapter;
static FragmentUserDetails newInstance(String title) {
FragmentUserDetails fragmentUserDetails = new FragmentUserDetails();
Bundle args = new Bundle();
args.putString("title", title);
fragmentUserDetails.setArguments(args);
return fragmentUserDetails;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_user_details, container, false);
initialization(view);
return view;
}
private void initialization(View view) {
etCompanyName = (EditText) view.findViewById(R.id.UDedittextCompany);
etPayrate = (EditText) view.findViewById(R.id.UDedittextPayrate);
sPayPeriod = (Spinner) view.findViewById(R.id.UDspinnerPayPeriod);
sPeriodStart = (Spinner) view.findViewById(R.id.UDspinnerPeriodStart);
sAllowances = (Spinner) view.findViewById(R.id.UDspinnerAllowances);
cbMaritalStatus = (Switch) view.findViewById(R.id.UDswitchMaritalStatus);
Button save = (Button) view.findViewById(R.id.UDbuttonSaveSettings);
save.setOnClickListener(this);
ContentResolver settingsContent = getActivity().getContentResolver();
settingsCursor = settingsContent.query(KnowYourTimeContentProvider.CONTENT_URI_SETTINGS, null, null, null, null);
settingsDBAdapter = new SettingsDBAdapter(getActivity().getApplicationContext());
companyname = getArguments().getString("title");
if (settingsCursor.getCount() != 0) {
while (settingsCursor.moveToNext()) {
companyCursor = settingsDBAdapter.fetchCompanyInfo(companyname);
}
if (companyCursor.getCount() != 0) {
while (companyCursor.moveToNext()) {
payrate = companyCursor.getString(companyCursor.getColumnIndex("payrate"));
payperiod = companyCursor.getString(companyCursor.getColumnIndex("payperiod"));
weekstart = companyCursor.getString(companyCursor.getColumnIndex("weekstart"));
allowances = companyCursor.getString(companyCursor.getColumnIndex("allowances"));
maritalstatus = companyCursor.getString(companyCursor.getColumnIndex("maritalstatus"));
}
} else {
payrate = "";
payperiod = getString(R.string.weekly);
weekstart = getString(R.string.sunday);
allowances = "0";
maritalstatus = getString(R.string.no);
}
} else {
companyname = getString(R.string.company);
}
etCompanyName.setText(companyname);
etPayrate.setText(payrate);
sPayPeriod.setSelection(getIndex(sPayPeriod, payperiod));
sPeriodStart.setSelection(getIndex(sPeriodStart, weekstart));
sAllowances.setSelection(getIndex(sAllowances, allowances));
if (maritalstatus.equals(getString(R.string.yes))) {
cbMaritalStatus.setChecked(true);
} else {
cbMaritalStatus.setChecked(false);
}
}
}
Sorry for putting up so much code that you just don't know what's causing the problem. thanks in advance for any help
Update:
so the error seems to be coming from getItem()
using the debugger. it goes through one time just fine (which makes sense because there is 1 line at the beginning), but the second time it crashes. I also changed the code inside it to
public Fragment getItem(int position) {
FragmentUserDetails fragment = null;
if (position < companies.size() - 1) {
fragment = FragmentUserDetails.newInstance(companies.get(position));
}
return fragment;
}
to make it simpler as suggested. still getting the same error. thanks again for any help
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Your implementation getItem()
looks incredibly suspicious. It may or may not be related to your current error. Analyze the current code:
public Fragment getItem(int position) {
while (position < companies.size() - 1) {
if (position < companies.size() - 1) {
position++;
return FragmentUserDetails.newInstance(companies.get(position));
}
}
return null;
}
To continue this analysis, we need to define the prerequisites:
-
companies
contains 5String
s. The exact values do not matter. -
position
is a 0-base with a value2
.
In this particular situation, the conditions while
and if
are evaluated to true
, so it position
increases and we immediately return
get the value newInstance()
.
This shows something very important: as long as the condition while
is true
, the condition is if
also true
, and we will return the value immediately. This completely eliminates the need for a loop while
.
Now that we see that this implementation is wrong, go back and check what we want to achieve. The basic idea is what we want to return Fragment
for "company" in the index position
. The simplest implementation is very simple:
public Fragment getItem(int position) {
return FragmentUserDetails.newInstance(companies.get(position));
}
In theory, position
it should never be out of range, but if you want to be safe, you can add an if statement to check for errors:
public Fragment getItem(int position) {
if (0 <= position && position < companies.size()) {
return FragmentUserDetails.newInstance(companies.get(position));
}
}
Now, if you still don't get the expected behavior, the error is somewhere else and we will need to analyze other sections of your code.
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