2011年10月6日木曜日

Android SimpleCursorTreeAdapter を使う

1段のリストを作る ListView 用の Adapter として、 Object配列やリストをひもづける SimpleAdapter や データベースを検索して得られる Cursor をひもづける SimpleCursorAdapter などがあります。

同じように、2段のリストを作る ExpandableListView 用の Adapter として、Object の配列やリストをひもづける SimpleExpandableListAdapter というのがあります。 実は、Cursor データを ExpandableListView にひもづけるための実装クラスの Adapter はありません。変わりに抽象クラスの SimpleCursorTreeAdapter というものがあります。

# SimpleExpandableListAdapter の使い方は API DemosExpandableList3.java がわかりやすいです。

このクラスを継承した実装クラスを作って利用します。

public class SimpleCursorTreeAdapterSampleActivity extends ExpandableListActivity { private static final String[] CONTACTS_PROJECTION = new String[] { Contacts._ID, Contacts.DISPLAY_NAME }; private static final int GROUP_ID_COLUMN_INDEX = 0; private static final String[] PHONE_PROJECTION = new String[] { Phone._ID, Phone.TYPE, Phone.NUMBER }; public class ExpandableListAdapter extends SimpleCursorTreeAdapter { public ExpandableListAdapter(Context context, Cursor c, int groupLayout, String[] groupFrom, int[] groupTo, int childLayout, String[] childrenFrom,int[] childrenTo) { super(context, c, groupLayout, groupFrom, groupTo, childLayout, childrenFrom, childrenTo); } @Override protected Cursor getChildrenCursor(Cursor groupCursor) { Uri.Builder builder = Contacts.CONTENT_URI.buildUpon(); ContentUris.appendId(builder, groupCursor.getLong(GROUP_ID_COLUMN_INDEX)); builder.appendEncodedPath(Contacts.Data.CONTENT_DIRECTORY); Uri phoneNumbersUri = builder.build(); Cursor c = getContentResolver().query(phoneNumbersUri, PHONE_PROJECTION, Phone.MIMETYPE + "=?", new String[] { Phone.CONTENT_ITEM_TYPE}, null); startManagingCursor(c); return c; } } private SimpleCursorTreeAdapter mAdapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Cursor c = getContentResolver().query(Contacts.CONTENT_URI, CONTACTS_PROJECTION, Contacts.HAS_PHONE_NUMBER + "=1", null, null); mAdapter = new ExpandableListAdapter( this, c, android.R.layout.simple_expandable_list_item_1, new String[] { Contacts.DISPLAY_NAME }, new int[] { android.R.id.text1 }, android.R.layout.simple_expandable_list_item_1, new String[] { Phone.NUMBER }, new int[] { android.R.id.text1 }); startManagingCursor(c); setListAdapter(mAdapter); } }


SimpleCursorTreeAdapter にも SimpleCursorAdapter 同様 ViewBinder を設定して表示方法を変更することができます。

public class SimpleCursorTreeAdapterSampleActivity extends ExpandableListActivity { private static final String[] CONTACTS_PROJECTION = new String[] { Contacts._ID, Contacts.DISPLAY_NAME }; private static final int GROUP_ID_COLUMN_INDEX = 0; private static final String[] PHONE_PROJECTION = new String[] { Phone._ID, Phone.TYPE, Phone.NUMBER }; private static final int[] COLOR_LIST = new int[] { Color.parseColor("#002A42"), Color.parseColor("#3DC3EA"), Color.parseColor("#99417B"), Color.parseColor("#F2AE30"), Color.parseColor("#F2D338"), }; public class ExpandableListAdapter extends SimpleCursorTreeAdapter { public ExpandableListAdapter(Context context, Cursor c, int groupLayout, String[] groupFrom, int[] groupTo, int childLayout, String[] childrenFrom,int[] childrenTo) { super(context, c, groupLayout, groupFrom, groupTo, childLayout, childrenFrom, childrenTo); } @Override protected Cursor getChildrenCursor(Cursor groupCursor) { Uri.Builder builder = Contacts.CONTENT_URI.buildUpon(); ContentUris.appendId(builder, groupCursor.getLong(GROUP_ID_COLUMN_INDEX)); builder.appendEncodedPath(Contacts.Data.CONTENT_DIRECTORY); Uri phoneNumbersUri = builder.build(); Cursor c = getContentResolver().query(phoneNumbersUri, PHONE_PROJECTION, Phone.MIMETYPE + "=?", new String[] { Phone.CONTENT_ITEM_TYPE}, null); startManagingCursor(c); return c; } } private SimpleCursorTreeAdapter mAdapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Cursor c = getContentResolver().query(Contacts.CONTENT_URI, CONTACTS_PROJECTION, Contacts.HAS_PHONE_NUMBER + "=1", null, null); mAdapter = new ExpandableListAdapter( this, c, android.R.layout.simple_expandable_list_item_1, new String[] { Contacts.DISPLAY_NAME }, new int[] { android.R.id.text1 }, android.R.layout.simple_expandable_list_item_2, new String[] { Phone.TYPE, Phone.NUMBER }, new int[] { android.R.id.text1, android.R.id.text2 }); mAdapter.setViewBinder(new SimpleCursorTreeAdapter.ViewBinder() { public boolean setViewValue(View view, Cursor cursor, int columnIndex) { if (cursor.getColumnName(columnIndex).equals(Phone.TYPE)) { int type = cursor.getInt(columnIndex); String text = (String) Phone.getTypeLabel(getResources(), type, null); ((TextView) view).setText(text); ((TextView) view).setTextColor(COLOR_LIST[type % 5]); return true; } return false; } }); startManagingCursor(c); setListAdapter(mAdapter); } }


Y.A.M の 雑記帳: Android AsyncQueryHandler を使う - でも触れたように、UI スレッドで Cursor を取得するためのクエリを走らせると UI スレッドをブロックしていまいます。それを避けるために SimpleCursorTreeAdapter に対しても AsyncQueryHandler を使うようにすることができます。

public class AsyncQuerySimpleCursorTreeAdapterSampleActivity extends ExpandableListActivity { private static final String[] CONTACTS_PROJECTION = new String[] { Contacts._ID, Contacts.DISPLAY_NAME }; private static final int GROUP_ID_COLUMN_INDEX = 0; private static final String[] PHONE_PROJECTION = new String[] { Phone._ID, Phone.TYPE, Phone.NUMBER }; private static final int[] COLOR_LIST = new int[] { Color.parseColor("#002A42"), Color.parseColor("#3DC3EA"), Color.parseColor("#99417B"), Color.parseColor("#F2AE30"), Color.parseColor("#F2D338"), }; private static final int TOKEN_GROUP = 0; private static final int TOKEN_CHILD = 1; private static final class QueryHandler extends AsyncQueryHandler { private CursorTreeAdapter mAdapter; public QueryHandler(Context context, CursorTreeAdapter adapter) { super(context.getContentResolver()); this.mAdapter = adapter; } @Override protected void onQueryComplete(int token, Object cookie, Cursor cursor) { switch (token) { case TOKEN_GROUP: mAdapter.setGroupCursor(cursor); break; case TOKEN_CHILD: int groupPosition = (Integer) cookie; mAdapter.setChildrenCursor(groupPosition, cursor); break; } } } public class ExpandableListAdapter extends SimpleCursorTreeAdapter { public ExpandableListAdapter(Context context, int groupLayout, int childLayout, String[] groupFrom, int[] groupTo, String[] childrenFrom,int[] childrenTo) { super(context, null, groupLayout, groupFrom, groupTo, childLayout, childrenFrom, childrenTo); } @Override protected Cursor getChildrenCursor(Cursor groupCursor) { Uri.Builder builder = Contacts.CONTENT_URI.buildUpon(); ContentUris.appendId(builder, groupCursor.getLong(GROUP_ID_COLUMN_INDEX)); builder.appendEncodedPath(Contacts.Data.CONTENT_DIRECTORY); Uri phoneNumbersUri = builder.build(); mQueryHandler.startQuery(TOKEN_CHILD, groupCursor.getPosition(), phoneNumbersUri, PHONE_PROJECTION, Phone.MIMETYPE + "=?", new String[] { Phone.CONTENT_ITEM_TYPE }, null); return null; } } private QueryHandler mQueryHandler; private SimpleCursorTreeAdapter mAdapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mAdapter = new ExpandableListAdapter( this, android.R.layout.simple_expandable_list_item_1, android.R.layout.simple_expandable_list_item_2, new String[] { Contacts.DISPLAY_NAME }, new int[] { android.R.id.text1 }, new String[] { Phone.TYPE, Phone.NUMBER }, new int[] { android.R.id.text1, android.R.id.text2 }); mAdapter.setViewBinder(new SimpleCursorTreeAdapter.ViewBinder() { public boolean setViewValue(View view, Cursor cursor, int columnIndex) { if (cursor.getColumnName(columnIndex).equals(Phone.TYPE)) { int type = cursor.getInt(columnIndex); String text = (String) Phone.getTypeLabel(getResources(), type, null); ((TextView) view).setText(text); ((TextView) view).setTextColor(COLOR_LIST[type % 5]); return true; } return false; } }); setListAdapter(mAdapter); mQueryHandler = new QueryHandler(this, mAdapter); mQueryHandler.startQuery(TOKEN_GROUP, null, Contacts.CONTENT_URI, CONTACTS_PROJECTION, Contacts.HAS_PHONE_NUMBER + "=1", null, null); } @Override protected void onDestroy() { super.onDestroy(); mAdapter.changeCursor(null); mAdapter = null; } }



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