android.support.v4.app.Fragment#equals ( )源码实例Demo

/**
 * 用Fragment替换内容区
 *
 * @param targetFragment 用来替换的Fragment
 */
public void changeFragment(Fragment targetFragment) {
    if (targetFragment.equals(currentFragment)) {
        return;
    }
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    if (!targetFragment.isAdded()) {
        transaction.add(R.id.main_body, targetFragment, targetFragment.getClass()
                .getName());
    }
    if (targetFragment.isHidden()) {
        transaction.show(targetFragment);
    }
    if (currentFragment != null && currentFragment.isVisible()) {
        transaction.hide(currentFragment);
    }
    currentFragment = targetFragment;
    transaction.commit();
}
 

public void updateLib() {
    if (mPreventRescan){
        mPreventRescan = false;
        return;
    }
    FragmentManager fm = getSupportFragmentManager();
    Fragment current = fm.findFragmentById(R.id.fragment_placeholder);
    if (current != null && current instanceof IRefreshable)
        ((IRefreshable) current).refresh();
    else
        MediaLibrary.getInstance().scanMediaItems();
    Fragment fragment = fm.findFragmentByTag(SidebarAdapter.SidebarEntry.ID_AUDIO);
    if (fragment != null && !fragment.equals(current)) {
        ((MediaBrowserFragment)fragment).clear();
    }
    fragment = fm.findFragmentByTag(SidebarAdapter.SidebarEntry.ID_VIDEO);
    if (fragment != null && !fragment.equals(current)) {
        ((MediaBrowserFragment)fragment).clear();
    }
}
 

@SuppressLint("RestrictedApi")
private static String getIndex(Fragment fragment) {
    String index;
    if (fragment.getParentFragment() != null) {
        index = getIndex(fragment.getParentFragment()) + "-";
    } else {
        index = "";
    }

    FragmentManager fragmentManager = fragment.getFragmentManager();
    if (fragmentManager != null) {
        List<Fragment> fragments = fragmentManager.getFragments();
        if (fragments != null && !fragments.isEmpty()) {
            for (int i = 0; i < fragments.size(); i++) {
                if (fragment.equals(fragments.get(i))) {
                    index += i;
                    break;
                }
            }
        }
    }

    return index;
}
 

@Override
public int getItemPosition(Object object) {

    Fragment f = (Fragment) object;
    for ( int i = 0; i < mOrder.length; i++ ) {
        if ( f.equals(mOrder[i]) )
            return i;
    }

    return POSITION_NONE;
}