Question

Hi i need to implement ActionBar in my application, but i haven’t understood from where to begin.

This example i wish to get

I have tested ShareLock and other stuff, but i couldn’t successfully to implement these examples, i need to get this result using Fragments and there should be 4 Tabs.

I have used android-support-v4.jar.

Here is my Fragment Utils that i use.

public class TabManager implements TabHost.OnTabChangeListener {
    private final FragmentActivity mActivity;
    private final TabHost mTabHost;
    private final int mContainerId;
    private final HashMap<String, TabInfo> mTabs = new HashMap<String, TabInfo>();
    TabInfo mLastTab;

    static final class TabInfo {
    private final String tag;
    private final Class<?> clss;
    private final Bundle args;
    private Fragment fragment;

    TabInfo(String _tag, Class<?> _class, Bundle _args) {
        tag = _tag;
        clss = _class;
        args = _args;
    }
}

static class DummyTabFactory implements TabHost.TabContentFactory {
    private final Context mContext;

    public DummyTabFactory(Context context) {
        mContext = context;
    }

    @Override
    public View createTabContent(String tag) {
        View v = new View(mContext);
        v.setMinimumWidth(0);
        v.setMinimumHeight(0);
        return v;
    }
}

public TabManager(FragmentActivity activity, TabHost tabHost, int containerId) {
    mActivity = activity;
    mTabHost = tabHost;
    mContainerId = containerId;
    mTabHost.setOnTabChangedListener(this);
}

public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) {
    tabSpec.setContent(new DummyTabFactory(mActivity));
    String tag = tabSpec.getTag();

    TabInfo info = new TabInfo(tag, clss, args);

    // Check to see if we already have a fragment for this tab, probably
    // from a previously saved state.  If so, deactivate it, because our
    // initial state is that a tab isn't shown.
    info.fragment = mActivity.getSupportFragmentManager().findFragmentByTag(tag);
    if (info.fragment != null && !info.fragment.isDetached()) {
        FragmentTransaction ft = mActivity.getSupportFragmentManager().beginTransaction();
        ft.detach(info.fragment);
        ft.commit();
    }

    mTabs.put(tag, info);
    mTabHost.addTab(tabSpec);
}

@Override
public void onTabChanged(String tabId) {

    TabInfo newTab = mTabs.get(tabId);
    FragmentManager fragmentManager = mActivity.getSupportFragmentManager();
    if (mLastTab != newTab) {
        FragmentTransaction ft = fragmentManager.beginTransaction();
        if (mLastTab != null) {
            if (mLastTab.fragment != null) {
                ft.detach(mLastTab.fragment);
            }
        }
        fragmentManager.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
        if (newTab != null) {
            if (newTab.fragment == null) {
                newTab.fragment = Fragment.instantiate(mActivity,
                        newTab.clss.getName(), newTab.args);
                ft.add(mContainerId, newTab.fragment, newTab.tag);
            } else {
                ft.attach(newTab.fragment);
            }
        }
        mLastTab = newTab;
        ft.commit();
        mActivity.getSupportFragmentManager().executePendingTransactions();
    }
}

}

and some more….

public class FragmentsUtils {
private static String DIALOG_TAG = "dialog_tag";

/*public static MyAlertDialogFragment showDialog(FragmentManager fragmentManager, int id) {
    // DialogFragment.show() will take care of adding the fragment
    // in a transaction.  We also want to remove any currently showing
    // dialog, so make our own transaction and take care of that here.
    FragmentTransaction ft = fragmentManager.beginTransaction();
    Fragment prev = fragmentManager.findFragmentByTag(DIALOG_TAG);
    if (prev != null) {
        ft.remove(prev);
    }

    //      ft.addToBackStack(null);

    // Create and show the dialog.
    MyAlertDialogFragment newFragment = MyAlertDialogFragment.newInstance(id);
    newFragment.show(ft, DIALOG_TAG);
    return newFragment;
}*/

public static void swapFragments(FragmentManager fragmentManager, int containerViewId, Fragment newFragment, String fragmentTag) {

    if (fragmentManager == null)
        return;
    View newFragmentMainView = newFragment.getView();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    //      fragmentTransaction.replace(containerViewId, fragment);

    if (fragmentTag == null || fragmentTag.length() < 1)
        fragmentTransaction.add(containerViewId, newFragment);
    else
        fragmentTransaction.add(containerViewId, newFragment, fragmentTag);

    fragmentTransaction.addToBackStack(null);
    fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
    fragmentTransaction.commit();
}

public static void swapFragments(FragmentManager fragmentManager, int containerViewId, Fragment newFragment) {
    swapFragments(fragmentManager, containerViewId, newFragment, null);
}

}

Many thanks in advance…

Answer 1

The ActionBar is only available from API 11 (3) on. If you attempt to run an application which is making use of the ActionBar on a device which is on API 10 (2.3.3 – 2.3.7) it will not be visible.

If you need an ActionBar (essentially a robust offering to Tabs) in your application and plan to target API 10 or earlier devices, you can look the android-actionbar or ActionBarSherlock.