Java tutorial
/** * Copyright (C) 2010-2012 Regis Montoya (aka r3gis - www.r3gis.fr) * This file is part of CSipSimple. * * CSipSimple is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * If you own a pjsip commercial license you can also redistribute it * and/or modify it under the terms of the GNU Lesser General Public License * as an android library. * * CSipSimple is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with CSipSimple. If not, see <http://www.gnu.org/licenses/>. */ package com.csipsimple.ui.favorites; import android.content.Context; import android.database.ContentObserver; import android.database.Cursor; import android.database.MatrixCursor; import android.database.MergeCursor; import android.provider.BaseColumns; import android.support.v4.content.AsyncTaskLoader; import android.text.TextUtils; import com.csipsimple.api.SipProfile; import com.csipsimple.utils.contacts.ContactsWrapper; import java.util.ArrayList; public class FavLoader extends AsyncTaskLoader<Cursor> { private Cursor currentResult; public FavLoader(Context context) { super(context); } private ContentObserver loaderObserver = new ForceLoadContentObserver(); @Override public Cursor loadInBackground() { // First of all, get all active accounts ArrayList<SipProfile> accounts = SipProfile.getAllProfiles(getContext(), true, new String[] { SipProfile.FIELD_ID, SipProfile.FIELD_ACC_ID, SipProfile.FIELD_ACTIVE, SipProfile.FIELD_DISPLAY_NAME, SipProfile.FIELD_WIZARD, SipProfile.FIELD_PRIORITY, SipProfile.FIELD_ANDROID_GROUP, SipProfile.FIELD_PUBLISH_ENABLED, SipProfile.FIELD_REG_URI, SipProfile.FIELD_PROXY }); Cursor[] cursorsToMerge = new Cursor[2 * accounts.size()]; int i = 0; for (SipProfile acc : accounts) { cursorsToMerge[i++] = createHeaderCursorFor(acc); cursorsToMerge[i++] = createContentCursorFor(acc); } getContext().getContentResolver().registerContentObserver(SipProfile.ACCOUNT_STATUS_URI, true, loaderObserver); if (cursorsToMerge.length > 0) { MergeCursor mg = new MergeCursor(cursorsToMerge); mg.registerContentObserver(loaderObserver); return mg; } else { return null; } } /** * Called when there is new data to deliver to the client. The super class * will take care of delivering it; the implementation here just adds a * little more logic. */ @Override public void deliverResult(Cursor c) { if (isReset()) { // An async query came in while the loader is stopped. We // don't need the result. if (currentResult != null) { onReleaseResources(currentResult); } } currentResult = c; if (isStarted()) { // If the Loader is currently started, we can immediately // deliver its results. super.deliverResult(c); } } /** * Handles a request to start the Loader. */ @Override protected void onStartLoading() { if (currentResult != null && !takeContentChanged()) { // If we currently have a result available, deliver it // immediately. deliverResult(currentResult); } else { forceLoad(); } } /** * Handles a request to stop the Loader. */ @Override protected void onStopLoading() { // Attempt to cancel the current load task if possible. cancelLoad(); } /** * Handles a request to cancel a load. */ @Override public void onCanceled(Cursor c) { super.onCanceled(c); // At this point we can release the resources associated with 'apps' // if needed. onReleaseResources(c); } /** * Handles a request to completely reset the Loader. */ @Override protected void onReset() { super.onReset(); // Ensure the loader is stopped onStopLoading(); // At this point we can release the resources associated with 'apps' // if needed. if (currentResult != null) { onReleaseResources(currentResult); currentResult = null; } } /** * Helper function to take care of releasing resources associated with an * actively loaded data set. */ protected void onReleaseResources(Cursor c) { if (c != null) { c.unregisterContentObserver(loaderObserver); c.close(); } getContext().getContentResolver().unregisterContentObserver(loaderObserver); } /** * Creates a cursor that contains a single row and maps the section to the * given value. */ private Cursor createHeaderCursorFor(SipProfile account) { MatrixCursor matrixCursor = new MatrixCursor( new String[] { BaseColumns._ID, ContactsWrapper.FIELD_TYPE, SipProfile.FIELD_DISPLAY_NAME, SipProfile.FIELD_WIZARD, SipProfile.FIELD_ANDROID_GROUP, SipProfile.FIELD_PUBLISH_ENABLED, SipProfile.FIELD_REG_URI, SipProfile.FIELD_PROXY, SipProfile.FIELD_ACC_ID }); String proxies = ""; if (account.proxies != null) { proxies = TextUtils.join(SipProfile.PROXIES_SEPARATOR, account.proxies); } matrixCursor .addRow(new Object[] { account.id, ContactsWrapper.TYPE_GROUP, account.display_name, account.wizard, account.android_group, account.publish_enabled, account.reg_uri, proxies, account.acc_id }); return matrixCursor; } /** * Creates a cursor that contains contacts group corresponding to an sip * account. */ private Cursor createContentCursorFor(SipProfile account) { Cursor c = null; if (!TextUtils.isEmpty(account.android_group)) { c = ContactsWrapper.getInstance().getContactsByGroup(getContext(), account.android_group); } if (c != null) { return c; } MatrixCursor mc = new MatrixCursor(new String[] { BaseColumns._ID, ContactsWrapper.FIELD_TYPE }); mc.addRow(new Object[] { account.id, ContactsWrapper.TYPE_CONFIGURE }); return mc; } }