Develop Android Launcher

1public class MainActivity extends Activity {
2 private GridView mGrid;
3
4 @Override
5 public void onCreate(Bundle savedInstanceState) {
6 super.onCreate(savedInstanceState);
7 // set layout for the main screen
8 setContentView(R.layout.layout_main);
9 // load list application
10 mGrid = (GridView)findViewById(R.id.lvApps);
11 // create new adapter
12 AppInfoAdapter adapter = new AppInfoAdapter(this, Utilities.getInstalledApplication(this), getPackageManager());
13 // set adapter to list view
14 mGrid.setAdapter(adapter);
15 // implement event when an item on list view is selected
16 mGrid.setOnItemClickListener(new OnItemClickListener() {
17 @Override
18 public void onItemClick(AdapterView<?> parent, View view, int pos, long id) {
19 // get the list adapter
20 AppInfoAdapter appInfoAdapter = (AppInfoAdapter)parent.getAdapter();
21 // get selected item on the list
22 ApplicationInfo appInfo = (ApplicationInfo)appInfoAdapter.getItem(pos);
23 // launch the selected application
24 Utilities.launchApp(parent.getContext(), getPackageManager(), appInfo.packageName);
25 }
26 });
27 }
28}

1public class AppInfoAdapter extends BaseAdapter {
2 private Context mContext;
3 private List<ApplicationInfo> mListAppInfo;
4 private PackageManager mPackManager;
5
6 public AppInfoAdapter(Context c, List<ApplicationInfo> list, PackageManager pm) {
7 mContext = c;
8 mListAppInfo = list;
9 mPackManager = pm;
10 }
11
12 @Override
13 public int getCount() {
14 return mListAppInfo.size();
15 }
16
17 @Override
18 public Object getItem(int position) {
19 return mListAppInfo.get(position);
20 }
21
22 @Override
23 public long getItemId(int position) {
24 return position;
25 }
26
27 @Override
28 public View getView(int position, View convertView, ViewGroup parent) {
29 // get the selected entry
30 ApplicationInfo entry = mListAppInfo.get(position);
31
32 // reference to convertView
33 View v = convertView;
34
35 // inflate new layout if null
36 if(v == null) {
37 LayoutInflater inflater = LayoutInflater.from(mContext);
38 v = inflater.inflate(R.layout.layout_appinfo, null);
39 }
40
41 // load controls from layout resources
42 ImageView ivAppIcon = (ImageView)v.findViewById(R.id.ivIcon);
43 TextView tvAppName = (TextView)v.findViewById(R.id.tvName);
44 TextView tvPkgName = (TextView)v.findViewById(R.id.tvPack);
45
46 // set data to display
47 ivAppIcon.setImageDrawable(entry.loadIcon(mPackManager));
48 tvAppName.setText(entry.loadLabel(mPackManager));
49 tvPkgName.setText(entry.packageName);
50
51 // return view
52 return v;
53 }
54
55}

1public class Utilities {
2
3 /*
4 * Get all installed application on mobile and return a list
5 * @param c Context of application
6 * @return list of installed applications
7 */
8 public static List<ApplicationInfo> getInstalledApplication(Context c) {
9 return c.getPackageManager().getInstalledApplications(PackageManager.GET_META_DATA);
10 }
11
12 /*
13 * Launch an application
14 * @param c Context of application
15 * @param pm the related package manager of the context
16 * @param pkgName Name of the package to run
17 */
18 public static boolean launchApp(Context c, PackageManager pm, String pkgName) {
19 // query the intent for lauching
20 Intent intent = pm.getLaunchIntentForPackage(pkgName);
21 // if intent is available
22 if(intent != null) {
23 try {
24 // launch application
25 c.startActivity(intent);
26 // if succeed
27 return true;
28
29 // if fail
30 } catch(ActivityNotFoundException ex) {
31 // quick message notification
32 Toast toast = Toast.makeText(c, "Application Not Found", Toast.LENGTH_LONG);
33 // display message
34 toast.show();
35 }
36 }
37 // by default, fail to launch
38 return false;
39 }
40}