Custom Objects and Android Spinners

Sat, 29 Oct 2011 01:47:00 GMT

Recently, I ran into an issue with SermonTrackr for Android that took me more than a few minutes to figure out. My task was to set the selection of the Spinner control to the ServiceType specified on the Service. I have a Spinner control that contains a list of ServiceType entities (inheriting BaseEntity). The signature of the BaseEntity and ServiceType are below:

          1: @SuppressWarnings("serial")

         2: public abstract class BaseEntity implements Serializable {

         3:     public int id;

         4: }

         5:  

         6: public class ServiceType extends BaseEntity {

         7:     public String serviceTypeName;

         8: }

When the ServiceActivity loads, I needed to set the selected ServiceType on the Spinner. I had the id of the ServiceType, but that does not necessarily match the index of the items as they appear on the Spinner. In order to get the position of the selected item in the Spinner, I iterated through the items in the ServiceTypeListAdapter, and checked the id until I found a match of the serviceTypeId. Because the Spinner is bound to the adapter, the index is easily determined. It just took me a while to figure that out. The full method that I use is shown below.

         1: private int getServiceTypeSpinnerPosition(int serviceTypeId) {

         2:         int position = -1;

         3:         int serviceTypesCount = serviceTypesAdapter.getCount();

         4:         

         5:         for (int i=0; i

         6:             int curServiceTypeId = serviceTypesAdapter.getItem(i).id;

         7:             if (serviceTypeId == curServiceTypeId) {

         8:                 position = serviceTypesAdapter.getPosition(serviceTypesAdapter.getItem(i));

         9:                 break;

        10:             }

        11:         }

        12:         

        13:         return position;

        14:     }

Until next time, keep thinking outside the box.

More ...

Thinking Outside the Box

Custom Objects and Android Spinners