I have a tab activty in my application,
here is some simplified code:
@SuppressLint("NewApi")
public class Rhino68PanelActivity extends FragmentActivity implements ActionBar.TabListener {
static String TAG = "Rhino68PanelActivty";
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_rhino68_panel);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab().setText(mSectionsPagerAdapter.getPageTitle(i)).setTabListener(this));
}
}
@Override
protected void onDestroy() {
super.onDestroy();
Network.cancelRequests(Rhino68PanelActivity.this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.rhino68_panel, menu);
return true;
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
Fragment fragment = null;
switch (position) {
case 0: {
fragment = new OneSectionFragment();
}
break;
case 1: {
fragment = new TwoSectionFragment();
}
break;
case 2: {
fragment = new ThreeSectionFragment();
}
break;
default: {
fragment = new OneSectionFragment();
}
}
return fragment;
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return "1";
case 1:
"2";
case 2:
"3";
}
return null;
}
}
public static class oneSectionFragment extends Fragment {
private static Context mContext;
public StatusSectionFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false);
mContext = getActivity();
// update view
....
return rootView;
}
//fucntions and methods
}
public static class twoSectionFragment extends Fragment {
private static Context mContext;
public StatusSectionFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false);
mContext = getActivity();
// update view
....
return rootView;
}
//fucntions and methods
}
Now I have noticed something odd, which im not sure if it is just how it works or if i am doing something wrong.
I set a break point in each of my sectionfragments onCreateView() and now depending on how I navigate between the tabs the break points are hit or not.
case 1: If I start on tab 1, then navigate to tab 2 - no break points are hit if I then go back to tab 1 - again no break points are hit
case 2: If I start on tab 1, then navigate to tab 2 - no break points are hit if I then go to tab 3 - breakpoint in tab 3 is hit, if I then go back to 2 - no break point if I then go to 1 - tab 1 break point is hit
it seems as though it loads tab number 3 when you click on tab number 2. Now is this a property of the tab manager? or does my tab manager only think that there are 2 tabs?
Where am I meant to run code that must get update when the tab actually comes into view?
