Java tutorial
/* * Copyright 2012 The Stanford MobiSocial Laboratory * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package mobisocial.musubi.provider; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import org.apache.commons.io.IOUtils; import mobisocial.musubi.App; import mobisocial.musubi.R; import mobisocial.musubi.model.MIdentity; import mobisocial.musubi.model.SKIdentities; import mobisocial.musubi.model.helpers.IdentitiesManager; import mobisocial.musubi.ui.util.UiUtil; import android.content.Context; import android.database.CrossProcessCursor; import android.database.Cursor; import android.database.CursorWindow; import android.database.CursorWrapper; import android.graphics.BitmapFactory; /** * Provides "safe" access to certain fields from the identities table. * identity_id must be the last column in the cursor's projection. */ public class IdentityCursorWrapper extends CursorWrapper implements CrossProcessCursor { final Context mContext; int colThumb, colHash, colName; public IdentityCursorWrapper(Context context, Cursor cursor) { super(cursor); mContext = context; colThumb = getColumnIndex(SKIdentities.COL_THUMBNAIL); colHash = getColumnIndex(SKIdentities.COL_ID_HASH); colName = getColumnIndex(SKIdentities.COL_NAME); } // TODO: avoid extra DB call @Override public byte[] getBlob(int columnIndex) { if (columnIndex != colThumb) { return super.getBlob(columnIndex); } long identityId = getLong(getColumnCount() - 1); IdentitiesManager im = new IdentitiesManager(App.getDatabaseSource(mContext)); MIdentity ident = im.getIdentityWithThumbnailsForId(identityId); if (ident == null) { return null; } byte[] thumbnail = ident.musubiThumbnail_; if (thumbnail == null) { thumbnail = ident.thumbnail_; } if (thumbnail == null) { try { InputStream is = mContext.getResources().openRawResource(R.drawable.ic_contact_picture); thumbnail = IOUtils.toByteArray(is); } catch (IOException e) { } } return thumbnail; } // TODO: avoid extra DB call @Override public String getString(int columnIndex) { if (columnIndex != colName) { return super.getString(columnIndex); } long identityId = getLong(getColumnCount() - 1); IdentitiesManager im = new IdentitiesManager(App.getDatabaseSource(mContext)); MIdentity ident = im.getIdentityForId(identityId); return UiUtil.safeNameForIdentity(ident); } @Override public CursorWindow getWindow() { return null; } @Override public void fillWindow(int position, CursorWindow window) { if (position < 0 || position > getCount()) { return; } window.acquireReference(); try { moveToPosition(position - 1); window.clear(); window.setStartPosition(position); int columnNum = getColumnCount(); window.setNumColumns(columnNum); while (moveToNext() && window.allocRow()) { for (int i = 0; i < columnNum; i++) { if (i == colThumb || i == colHash) { byte[] field = getBlob(i); if (!window.putBlob(field, getPosition(), i)) { window.freeLastRow(); break; } } else { String field = getString(i); if (field != null) { if (!window.putString(field, getPosition(), i)) { window.freeLastRow(); break; } } else { if (!window.putNull(getPosition(), i)) { window.freeLastRow(); break; } } } } } } catch (IllegalStateException e) { // simply ignore it } finally { window.releaseReference(); } } @Override public boolean onMove(int oldPosition, int newPosition) { return true; } }