Action Bar switching tabs automatically:

2019-08-29 09:31发布

问题:

I am implementing an app where user can search some songs in a separate tab.The search results for a song are info like lyrics, meaning etc. From the results, user can mark certain songs as favorite which are in another tab. When I click on the favorite songs tab, it should switch to the first tab with fragment for the search results. Here are more specific details:

  • Main Activity spawns action bar which creates 2 tabs.
  • Search Tab - Separate Fragment, Results- separate fragment
  • Favorites Tab - Separate Fragment

    public class TabsListener<T extends Fragment> implements ActionBar.TabListener {
        private Fragment mFragment;
        private final Activity mActivity;
        private final String mTag;
        private final Class<T> mClass;
    
    /** Constructor used each time a new tab is created.
      * @param activity  The host Activity, used to instantiate the fragment
      * @param tag  The identifier tag for the fragment
      * @param clz  The fragment's Class, used to instantiate the fragment
      */
    public TabsListener(Activity activity, String tag, Class<T> clz) {
        mActivity = activity;
        mTag = tag;
        mClass = clz;
    }
    
    /* The following are each of the ActionBar.TabListener callbacks */
    
    @SuppressLint("NewApi")
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        // Check if the fragment is already initialized
        if (mFragment == null) {
            // If not, instantiate and add it to the activity
            mFragment = Fragment.instantiate(mActivity, mClass.getName());
            ft.add(android.R.id.content, mFragment, mTag);
        } else {
            // If it exists, simply attach it in order to show it
            ft.attach(mFragment);
        }
    }
    
    @SuppressLint("NewApi")
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        if (mFragment != null) {
            // Detach the fragment, because another one is being attached
            ft.detach(mFragment);
            //ft.remove(mFragment);
        }
    }
    
    @SuppressLint("NewApi")
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
            ft.attach(mFragment);
        // User selected the already selected tab. Usually do nothing.
    }
    

    }

How can I implement this switching from one tab to another programatically for Action Bar?