Java tutorial
/* * * * Copyright (C) 2013 Marten Gajda <marten@dmfs.org> * * 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 com.granita.tasks.homescreen; import java.util.ArrayList; import java.util.TimeZone; import java.util.concurrent.Executor; import java.util.concurrent.Executors; import com.granita.provider.tasks.TaskContract; import com.granita.provider.tasks.TaskContract.Instances; import com.granita.provider.tasks.TaskContract.Tasks; import com.granita.tasks.R; import com.granita.tasks.model.TaskFieldAdapters; import com.granita.tasks.utils.DateFormatter; import com.granita.tasks.utils.DateFormatter.DateFormatContext; import com.granita.tasks.utils.TimeChangeListener; import com.granita.tasks.utils.TimeChangeObserver; import com.granita.tasks.utils.WidgetConfigurationDatabaseHelper; import android.annotation.SuppressLint; import android.app.Application; import android.appwidget.AppWidgetManager; import android.content.ContentUris; import android.content.Context; import android.content.Intent; import android.content.res.Resources; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.net.Uri; import android.support.v4.content.CursorLoader; import android.text.format.Time; import android.util.Log; import android.widget.RemoteViews; import android.widget.RemoteViewsService; /** * A service to keep the task list widget updated. * <p> * TODO: add support for multiple widgets with different configuration * </p> * * @author Arjun Naik<arjun@arjunnaik.in> * @author Marten Gajda <marten@dmfs.org> */ @SuppressLint("NewApi") public class TaskListWidgetUpdaterService extends RemoteViewsService { private final static String TAG = "TaskListWidgetUpdaterService"; /* * Return an instance of {@link TaskListViewsFactory} * * @see android.widget.RemoteViewsService#onGetViewFactory(android.content.Intent) */ @Override public RemoteViewsFactory onGetViewFactory(Intent intent) { return new TaskListViewsFactory(this, intent); } /** * This class implements the {@link RemoteViewsFactory} interface. It provides the data for the {@link TaskListWidgetProvider}. It loads the due tasks * asynchronously using a {@link CursorLoader}. It also provides methods to the remote views to retrieve the data. */ public static class TaskListViewsFactory implements RemoteViewsService.RemoteViewsFactory, TimeChangeListener { /** The {@link TaskListWidgetItem} array which stores the tasks to be displayed. When the cursor loads it is updated. */ private TaskListWidgetItem[] mItems = null; /** The {@link Context} of the {@link Application} to which this widget belongs. */ private Context mContext; /** The app widget id. */ private int mAppWidgetId = -1; /** This variable is used to store the current time for reference. */ private Time mNow; /** The resource from the {@link Application}. */ private Resources mResources; /** The due date formatter. */ private DateFormatter mDueDateFormatter; /** * The executor to reload the tasks. */ private final Executor mExecutor = Executors.newSingleThreadExecutor(); private String mAuthority; /** A status variable that is used in onDataSetChanged to switch between updating the view and reloading the the whole dataset **/ private boolean mDoNotReload; /** * Instantiates a new task list views factory. * * @param context * the context * @param intent * the intent */ public TaskListViewsFactory(Context context, Intent intent) { mContext = context; mAppWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID); mResources = context.getResources(); mDueDateFormatter = new DateFormatter(context); new TimeChangeObserver(context, this); mAuthority = context.getString(R.string.org_dmfs_tasks_authority); } public void reload() { mItems = null; mExecutor.execute(mReloadTasks); } /** * Required for the broadcast receiver. */ public TaskListViewsFactory() { } /* * (non-Javadoc) * * @see android.widget.RemoteViewsService.RemoteViewsFactory#onCreate() */ @Override public void onCreate() { } /* * (non-Javadoc) * * @see android.widget.RemoteViewsService.RemoteViewsFactory#onDestroy() */ @Override public void onDestroy() { // no-op } /* * (non-Javadoc) * * @see android.widget.RemoteViewsService.RemoteViewsFactory#getCount() */ @Override public int getCount() { if (mItems == null) { return 0; } return (mItems.length); } /* * (non-Javadoc) * * @see android.widget.RemoteViewsService.RemoteViewsFactory#getViewAt(int) */ @Override public RemoteViews getViewAt(int position) { TaskListWidgetItem[] items = mItems; /** We use this check because there is a small gap between when the database is updated and the widget is notified */ if (items == null || position < 0 || position >= items.length) { return null; } RemoteViews row = new RemoteViews(mContext.getPackageName(), R.layout.task_list_widget_item); String taskTitle = items[position].getTaskTitle(); row.setTextViewText(android.R.id.title, taskTitle); row.setInt(R.id.task_list_color, "setBackgroundColor", items[position].getTaskColor()); Time dueDate = items[position].getDueDate(); if (dueDate != null) { if (mNow == null) { mNow = new Time(); } mNow.clear(TimeZone.getDefault().getID()); mNow.setToNow(); dueDate.normalize(true); mNow.normalize(true); row.setTextViewText(android.R.id.text1, mDueDateFormatter.format(dueDate, DateFormatContext.WIDGET_VIEW)); // highlight overdue dates & times if ((!dueDate.allDay && dueDate.before(mNow) || dueDate.allDay && (dueDate.year < mNow.year || dueDate.yearDay <= mNow.yearDay && dueDate.year == mNow.year)) && !items[position].getIsClosed()) { row.setTextColor(android.R.id.text1, mResources.getColor(R.color.holo_red_light)); } else { row.setTextColor(android.R.id.text1, mResources.getColor(R.color.lighter_gray)); } } else { row.setTextViewText(android.R.id.text1, null); } Uri taskUri = ContentUris.withAppendedId(Tasks.getContentUri(mAuthority), items[position].getTaskId()); Intent i = new Intent(); i.setData(taskUri); row.setOnClickFillInIntent(R.id.widget_list_item, i); Log.d(TAG, "new row: " + taskTitle); return (row); } /* * Don't show any loading views * * @see android.widget.RemoteViewsService.RemoteViewsFactory#getLoadingView() */ @Override public RemoteViews getLoadingView() { return null; } /* * Only single type of list item. * * @see android.widget.RemoteViewsService.RemoteViewsFactory#getViewTypeCount() */ @Override public int getViewTypeCount() { return 1; } /* * The position corresponds to the ID. * * @see android.widget.RemoteViewsService.RemoteViewsFactory#getItemId(int) */ @Override public long getItemId(int position) { return position; } /* * * * @see android.widget.RemoteViewsService.RemoteViewsFactory#hasStableIds() */ @Override public boolean hasStableIds() { return true; } /* * Nothing to do when data set is changed. * * @see android.widget.RemoteViewsService.RemoteViewsFactory#onDataSetChanged() */ @Override public void onDataSetChanged() { if (mDoNotReload) { mDoNotReload = false; } else { reload(); } } /* * @see com.granita.tasks.utils.TimeChangeListener#onTimeUpdate(com.granita.tasks.utils.TimeChangeObserver) */ @Override public void onTimeUpdate(TimeChangeObserver timeChangeObserver) { // reload the tasks reload(); } /* * This function is not used. * * @see com.granita.tasks.utils.TimeChangeListener#onAlarm(com.granita.tasks.utils.TimeChangeObserver) */ @Override public void onAlarm(TimeChangeObserver timeChangeObserver) { // Not listening for Alarms in this service. } /** * Gets the array of {@link TaskListWidgetItem}s. * * @return the widget items */ public static TaskListWidgetItem[] getWidgetItems(Cursor mTasksCursor) { if (mTasksCursor.getCount() > 0) { TaskListWidgetItem[] items = new TaskListWidgetItem[mTasksCursor.getCount()]; int itemIndex = 0; while (mTasksCursor.moveToNext()) { items[itemIndex] = new TaskListWidgetItem(TaskFieldAdapters.TASK_ID.get(mTasksCursor), TaskFieldAdapters.TITLE.get(mTasksCursor), TaskFieldAdapters.DUE.get(mTasksCursor), TaskFieldAdapters.LIST_COLOR.get(mTasksCursor), TaskFieldAdapters.IS_CLOSED.get(mTasksCursor)); itemIndex++; } return items; } return null; } /** * A {@link Runnable} that loads the tasks to show in the widget. */ private Runnable mReloadTasks = new Runnable() { @Override public void run() { // load TaskLists for this widget WidgetConfigurationDatabaseHelper configHelper = new WidgetConfigurationDatabaseHelper(mContext); SQLiteDatabase db = configHelper.getWritableDatabase(); ArrayList<Long> lists = WidgetConfigurationDatabaseHelper.loadTaskLists(db, mAppWidgetId); db.close(); // build selection string StringBuilder selection = new StringBuilder(TaskContract.Instances.VISIBLE + ">0 and " + TaskContract.Instances.IS_CLOSED + "=0 AND (" + TaskContract.Instances.INSTANCE_START + "<=" + System.currentTimeMillis() + " OR " + TaskContract.Instances.INSTANCE_START + " is null OR " + TaskContract.Instances.INSTANCE_START + " = " + TaskContract.Instances.INSTANCE_DUE + " )"); if (lists != null && lists.size() > 0) { selection.append(" AND ( "); for (int i = 0; i < lists.size(); i++) { Long listId = lists.get(i); if (i < lists.size() - 1) { selection.append(Instances.LIST_ID).append(" = ").append(listId).append(" OR "); } else { selection.append(Instances.LIST_ID).append(" = ").append(listId).append(" ) "); } } } // load all upcoming non-completed tasks Cursor c = mContext.getContentResolver().query(TaskContract.Instances.getContentUri(mAuthority), null, selection.toString(), null, TaskContract.Instances.INSTANCE_DUE + " is null, " + TaskContract.Instances.DEFAULT_SORT_ORDER + ", " + TaskContract.Instances.PRIORITY + " is null, " + TaskContract.Instances.PRIORITY + ", " + TaskContract.Instances.CREATED + " DESC"); if (c != null) { try { mItems = getWidgetItems(c); } finally { c.close(); } } else { mItems = new TaskListWidgetItem[0]; } // tell to only update the view in the next onDataSetChanged(); mDoNotReload = true; // notify the widget manager about the update AppWidgetManager widgetManager = AppWidgetManager.getInstance(mContext); if (mAppWidgetId != -1) { widgetManager.notifyAppWidgetViewDataChanged(mAppWidgetId, R.id.task_list_widget_lv); } } }; } }