Question

I am developing an app in Android 4. I have three tabs in my app. What my requirement is, I want to show only 1st tab in the beginning, and after clicking on some button from tab 1, I want to show 2nd Tab, after clicking on button, the 3rd tab will be visible.

As Tabs in Android 3 on-wards, does not have setVisibility method, Please tell me how to show/hide particular tab in my case.

Any help will be appreciated.

Thank you.

UPDATE: onClick of button, I have added this code:

ActionBar actionbar = getActivity().getActionBar();
                ActionBar.Tab Tab2 = actionbar.newTab().setText("XYZ");
                ActionBar.Tab Tab3 = actionbar.newTab().setText("PQR");

                Fragment Tab2Fragment = new BFragment();
                Fragment Tab3Fragment = new CFragment();

                Tab2.setTabListener(new MyTabsListener(Tab2Fragment));
                Tab3.setTabListener(new MyTabsListener(Tab3Fragment));
                actionbar.addTab(Tab2);
                actionbar.addTab(Tab3);

But still its not working..

UPDATE: Now I can see two tabs coming, but I am getting NPE:

06-08 20:57:58.101: E/AndroidRuntime(17070): java.lang.NullPointerException

06-08 20:57:58.101: E/AndroidRuntime(17070):    at de.arvidg.exampleactionbartabs.AFragment.onActivityCreated(AFragment.java:116)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:847)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1032)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.app.BackStackRecord.run(BackStackRecord.java:622)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1382)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.app.FragmentManagerImpl$1.run(FragmentManager.java:426)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.os.Handler.handleCallback(Handler.java:605)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.os.Handler.dispatchMessage(Handler.java:92)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.os.Looper.loop(Looper.java:137)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at android.app.ActivityThread.main(ActivityThread.java:4424)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at java.lang.reflect.Method.invokeNative(Native Method)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at java.lang.reflect.Method.invoke(Method.java:511)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-08 20:57:58.101: E/AndroidRuntime(17070):    at dalvik.system.NativeStart.main(Native Method)

This is my onCreateView and onActivityCreated in AFragment are:

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.afragment, container, false);
    }

/* (non-Javadoc)
     * @see android.app.Fragment#onActivityCreated(android.os.Bundle)
     */
    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        appContext = AFragment.this;
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (mBluetoothAdapter == null) {
            Toast.makeText(getActivity(), "NO Bluetooth Available", Toast.LENGTH_LONG);
            getActivity().finish();
            return;
        }
        final Button connectBtn = (Button) getActivity().findViewById(R.id.connect_btn);
        connectBtn.setClickable(true); // NPE is occurring here...
}

Answer 1

use ActionBar.addTab() to add tabs, ActionBar.removeTabAt() to remove a tab. Also, ActionBar.getTabCount() can be used to determine the current number of tabs configured.

ActionBar actionBar = this.getActionBar();
if (actionBar.getTabCount() == 1)
{
 // 2nd tab
 MyFragment fragment = new MyFragment();
 ActionBar.Tab tab2nd = actionBar.newTab();
 tab2nd.setTabListener(fragment);
 actionBar.addTab(tab2nd);
}