ActionBar on sub3.0 devices - implementing ActionBarSherlock with my customized system?
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28-05-2021 - |
Question
My app has progressed enough to start testing it out on a variety of devices. Now, I would like for people sub 3.0 to be able to use my app. Granted, I am using the compatibility library with the standard actionbar, which obviously crashes the app as soon as it starts when the SDK version is 10 or lower, as expected. I understand that I could use the ABS library, but my concern is my customized ViewPager and TabAdapter. Here's the code:
public class Polling extends FragmentActivity {
private ViewPager mViewPager;
private TabsAdapter mTabsAdapter;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//sharedPreferences = getPreferences(MODE_PRIVATE);
mViewPager = new ViewPager(this);
mViewPager.setId(R.id.pager);
setContentView(mViewPager);
final ActionBar bar = getActionBar();
bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
bar.setDisplayShowTitleEnabled(false);
bar.setDisplayShowHomeEnabled(false);
mTabsAdapter = new TabsAdapter(this, mViewPager);
mTabsAdapter.addTab(bar.newTab().setText(R.string.login),
LoginFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.economics),
EconFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.elections),
ElectionsFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.politics),
PoliticsFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.science),
ScienceFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.finance),
FinanceFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.religion),
ReligionFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.military),
MilitaryFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText(R.string.international),
InternationalFragment.class, null);
}
public static class TabsAdapter extends FragmentPagerAdapter
implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
private final Context mContext;
private final ActionBar mActionBar;
private final ViewPager mViewPager;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
static final class TabInfo {
private final Class<?> clss;
private final Bundle args;
TabInfo(Class<?> _class, Bundle _args) {
clss = _class;
args = _args;
}
}
public TabsAdapter(FragmentActivity activity, ViewPager pager) {
super(activity.getSupportFragmentManager());
mContext = activity;
mActionBar = activity.getActionBar();
mViewPager = pager;
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
}
public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
TabInfo info = new TabInfo(clss, args);
tab.setTag(info);
tab.setTabListener(this);
mTabs.add(info);
mActionBar.addTab(tab);
notifyDataSetChanged();
}
public int getCount() {
return mTabs.size();
}
public Fragment getItem(int position) {
TabInfo info = mTabs.get(position);
return Fragment.instantiate(mContext, info.clss.getName(), info.args);
}
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
public void onPageSelected(int position) {
mActionBar.setSelectedNavigationItem(position);
}
public void onPageScrollStateChanged(int state) {
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
mViewPager.setCurrentItem(tab.getPosition());
Log.v(TAG, "clicked");
Object tag = tab.getTag();
for (int i=0; i<mTabs.size(); i++) {
if (mTabs.get(i) == tag) {
mViewPager.setCurrentItem(i);
}
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {}
public void onTabReselected(Tab tab, FragmentTransaction ft) {}
public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) {}
@Override
public void onTabSelected(Tab tab, android.app.FragmentTransaction ft) {
Object tag = tab.getTag();
for (int i=0; i<mTabs.size(); i++) {
if (mTabs.get(i) == tag) {
mViewPager.setCurrentItem(i);
}
}
}
public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {}
}
Should I just say screw backwards compatibility? I mean, that's a lot of potential installs that I lose by saying you can't use the app if it's Gingerbread or lower.
Solution
With ActionBarSherlock you can support Android 2.1 and newer with extremely simple replacements in your code.
- Change
getActionBar
togetSupportActionBar
- Change all menu-related imports to use
com.actionbarsherlock.view.*
rather thanandroid.view.*
. - Change all fragment-related imports to use
android.support.v4.app.*
rather thanandroid.app.*
. - Extend
SherlockFragmentActivity
rather thanActivity
. - Use
Theme.Sherlock
(or another ABS theme) in your manifest.
That should be all that is necessary to get a functioning app that looks identical on all platforms!
If you need more help be sure to check out the following resources:
- Website: http://actionbarsherlock.com
- Google Group: http://abs.io/forum
- StackOverflow tag: https://stackoverflow.com/questions/tagged/actionbarsherlock
- GitHub repository: http://abs.io/github
OTHER TIPS
Since most phones use Android 2.3.x or lower, I'd say you are unnecessarily lower your potential audience by a great deal. For your custom ViewPager and TabAdapter, just extend the one provided by ABS and you should be fine.