Run Fragments on Older version of Android

First generate android code by the wizard for API level 11. But it uses the support library already – so shouldn’t it run on older versions as well?

The heavy lifting already has been done. The wizard created both activities as subclasses of FragmentActivity. This is a class of the support library that allows you to access an FragmentManager using getSupportFragmentManager().

Two changes are needed to make it run on older versions.

First the generated class ItemListFragment contains a layout constant that has been introduced in API level 11: simple_list_item_activated_1. This specific layout highlights activated list items. Which is useful, if you have a multi-pane layout, because it shows the user which list item is selected and displayed in the details pane.

I ignore the highlighting for now and just try to get the code to run:

int layout = android.R.layout.simple_list_item_1;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
   layout = android.R.layout.simple_list_item_activated_1;
}
setListAdapter(new ArrayAdapter<DummyContent.DummyItem>(
      getActivity(),
      layout,
      android.R.id.text1,
      DummyContent.ITEMS));

The second problem is the ActionBar, which is not available on older devices without adding an additional library. Since this is the topic of my next post, I simply ignore the ActionBar on older devices for now. Change the line with getActionBar() to this in the ItemDetailActivity:

 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
       getActionBar().setDisplayHomeAsUpEnabled(true);
    }

Now you get a Lint warning. That the call requires API level 11 but that your manifest file states API level 7 as a minimum. Add an annotation to suppress the new API warnings for the onCreate() method:

@SuppressLint("NewApi")

Now change your AndroidManifest.xml file to support API level 7:

    <uses-sdk
       android:minSdkVersion="7"
       android:targetSdkVersion="16" />

 With these changes, you can now run the project on older devices.