samples/mobilewebapp/src/main/com/google/gwt/sample/mobilewebapp/client/activity/TaskListActivity.java - gwt - Git at Google

 /*
  * Copyright 2011 Google Inc.
  *
  * 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.google.gwt.sample.mobilewebapp.client.activity;

 import com.google.gwt.activity.shared.AbstractActivity;
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.shared.EventBus;
 import com.google.gwt.event.shared.EventHandler;
 import com.google.gwt.event.shared.GwtEvent;
 import com.google.gwt.storage.client.Storage;
 import com.google.gwt.user.client.Timer;
 import com.google.gwt.user.client.ui.AcceptsOneWidget;
 import com.google.gwt.sample.mobilewebapp.client.ClientFactory;
 import com.google.gwt.sample.mobilewebapp.client.place.TaskEditPlace;
 import com.google.gwt.sample.mobilewebapp.shared.TaskProxy;
 import com.google.gwt.sample.mobilewebapp.shared.TaskProxyImpl;
 import com.google.web.bindery.requestfactory.shared.Receiver;
 import com.google.web.bindery.requestfactory.shared.ServerFailure;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
 import java.util.List;

 /**
  * Activity that presents a list of tasks.
  */
 public class TaskListActivity extends AbstractActivity implements TaskListView.Presenter {

   /**
    * Event fired when the task list is updated.
    */
   public static class TaskListUpdateEvent extends GwtEvent<TaskListActivity.TaskListUpdateHandler> {

     /**
      * Handler type.
      */
     private static Type<TaskListUpdateHandler> TYPE;

     /**
      * Gets the type associated with this event.
      *
      * @return returns the handler type
      */
     public static Type<TaskListUpdateHandler> getType() {
       if (TYPE == null) {
         TYPE = new Type<TaskListUpdateHandler>();
       }
       return TYPE;
     }

     private final List<TaskProxy> tasks;

     public TaskListUpdateEvent(List<TaskProxy> tasks) {
       this.tasks = tasks;
     }

     @Override
     public Type<TaskListUpdateHandler> getAssociatedType() {
       return TYPE;
     }

     public List<TaskProxy> getTasks() {
       return tasks;
     }

     @Override
     protected void dispatch(TaskListUpdateHandler handler) {
       handler.onTaskListUpdated(this);
     }
   }

   /**
    * Handler for {@link TaskListUpdateEvent}.
    */
   public static interface TaskListUpdateHandler extends EventHandler {

     /**
      * Called when the task list is updated.
      */
     void onTaskListUpdated(TaskListUpdateEvent event);
   }

   private static final String TASKLIST_SAVE_KEY = "TASKLIST";
   private static final String TASKSEP = "&&";
   private static final String FIELDSEP = "@@";
   private static final String FIELDEMPTY = "***";

   /**
    * The delay in milliseconds between calls to refresh the task list.
    */
   private static final int REFRESH_DELAY = 5000;

   /**
    * Convert a task proxy list into a string.
    */
   private static String getStringFromTaskProxy(List<TaskProxy> list) {
     StringBuilder sb = new StringBuilder();
     for (TaskProxy proxy : list) {
       sb.append(proxy.getDueDate() != null ? proxy.getDueDate().getTime() : FIELDEMPTY);
       sb.append(FIELDSEP);
       sb.append(proxy.getId() != null ? proxy.getId() : "");
       sb.append(FIELDSEP);
       String name = proxy.getName();
       sb.append(name != null && name.length() > 0 ? proxy.getName() : FIELDEMPTY);
       sb.append(FIELDSEP);
       String notes = proxy.getNotes();
       sb.append(notes != null && notes.length() > 0 ? proxy.getNotes() : FIELDEMPTY);
       sb.append(TASKSEP);
     }
     return sb.toString();
   }

   /**
    * Parse a task proxy list from a string.
    */
   private static List<TaskProxy> getTaskProxyFromString(String taskProxyList) {
     ArrayList<TaskProxy> list = new ArrayList<TaskProxy>(0);
     if (taskProxyList == null) {
       return list;
     }
     // taskproxy1&&taskproxy2&&taskproxy3&&...
     String taskProxyStrings[] = taskProxyList.split(TASKSEP);
     for (String taskProxyString : taskProxyStrings) {
       if (taskProxyString == null) {
         continue;
       }
       // date@@id@@name@@notes
       String taskProxyStringData[] = taskProxyString.split(FIELDSEP);
       if (taskProxyStringData.length >= 4) {
         // collect the fields
         String dateString = taskProxyStringData[0];
         String idString = taskProxyStringData[1];
         String nameString = taskProxyStringData[2];
         if (FIELDEMPTY.equals(nameString)) {
           nameString = null;
         }
         String notesString = taskProxyStringData[3];
         if (FIELDEMPTY.equals(notesString)) {
           notesString = null;
         }
         // parse the numerical fields
         Date dueDate = null;
         try {
           dueDate = new Date(Long.parseLong(dateString));
         } catch (NumberFormatException nfe) {
         }
         Long idLong = 0L;
         try {
           idLong = Long.parseLong(idString);
         } catch (NumberFormatException nfe) {
         }
         // create and populate the TaskProxy
         TaskProxyImpl taskProxy = new TaskProxyImpl();
         taskProxy.setDueDate(dueDate);
         taskProxy.setId(idLong);
         taskProxy.setName(nameString);
         taskProxy.setNotes(notesString);
         list.add(taskProxy);
       }
     }
     return list;
   }

   private final Storage storage;

   /**
    * A boolean indicating that we should clear the task list when started.
    */
   private final boolean clearTaskList;

   private final ClientFactory clientFactory;

   /**
    * A boolean indicating whether or not this activity is still active. The user
    * might move to another activity while this one is loading, in which case we
    * do not want to do any more work.
    */
   private boolean isDead = false;

   /**
    * The refresh timer used to periodically refresh the task list.
    */
   private Timer refreshTimer;

   /**
    * Construct a new {@link TaskListActivity}.
    *
    * @param clientFactory the {@link ClientFactory} of shared resources
    * @param clearTaskList true to clear the task list, false not to
    */
   public TaskListActivity(ClientFactory clientFactory, boolean clearTaskList) {
     this.clientFactory = clientFactory;
     this.clearTaskList = clearTaskList;
     this.storage = clientFactory.getLocalStorageIfSupported();
   }

   @Override
   public void onCancel() {
     killActivity();
   }

   @Override
   public void onStop() {
     killActivity();
   }

   public void selectTask(TaskProxy selected) {
     // Go into edit mode when a task is selected.
     clientFactory.getPlaceController().goTo(TaskEditPlace.createTaskEditPlace(selected.getId()));
   }

   public void start(AcceptsOneWidget container, EventBus eventBus) {
     // Add a handler to the 'add' button in the shell.
     clientFactory.getShell().setAddButtonHandler(new ClickHandler() {
       public void onClick(ClickEvent event) {
         clientFactory.getPlaceController().goTo(TaskEditPlace.getTaskCreatePlace());
       }
     });

     // Set the presenter on the view.
     final TaskListView view = clientFactory.getTaskListView();
     view.setPresenter(this);

     // Clear the task list and display it.
     if (clearTaskList) {
       view.clearList();
     }
     container.setWidget(view);

     // Create a timer to periodically refresh the task list.
     refreshTimer = new Timer() {
       @Override
       public void run() {
         refreshTaskList();
       }
     };

     // Load the saved task list from storage
     if (storage != null) { // if storage is supported
       String taskString = storage.getItem(TASKLIST_SAVE_KEY);
       if (taskString != null) {
         List<TaskProxy> list = getTaskProxyFromString(taskString);
         setTasks(list);
       }
     }

     // Request the task list now.
     refreshTaskList();
   }

   /**
    * Kill this activity.
    */
   private void killActivity() {
     // Ignore all incoming responses to the requests from this activity.
     isDead = true;

     // Kill the refresh timer.
     if (refreshTimer != null) {
       refreshTimer.cancel();
     }
   }

   /**
    * Refresh the task list.
    */
   private void refreshTaskList() {
     clientFactory.getRequestFactory().taskRequest().findAllTasks().fire(
         new Receiver<List<TaskProxy>>() {
           @Override
           public void onFailure(ServerFailure error) {
             // ignore
           }

           @Override
           public void onSuccess(List<TaskProxy> response) {
             // Early exit if this activity has already been canceled.
             if (isDead) {
               return;
             }

             // Display the tasks in the view.
             if (response == null) {
               setTasks(Collections.<TaskProxy> emptyList());
             } else {
               setTasks(response);

               // save the response to storage
               if (storage != null) { // if storage is supported
                 String responseString = getStringFromTaskProxy(response);
                 storage.setItem(TASKLIST_SAVE_KEY, responseString);
               }
             }

             // Restart the timer.
             refreshTimer.schedule(REFRESH_DELAY);
           }
         });
   }

   /**
    * Set the list of tasks.
    */
   private void setTasks(List<TaskProxy> tasks) {
     clientFactory.getTaskListView().setTasks(tasks);
     clientFactory.getEventBus().fireEventFromSource(new TaskListUpdateEvent(tasks), this);
   }
 }
	/*
	* Copyright 2011 Google Inc.
	*
	* 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.google.gwt.sample.mobilewebapp.client.activity;

	import com.google.gwt.activity.shared.AbstractActivity;
	import com.google.gwt.event.dom.client.ClickEvent;
	import com.google.gwt.event.dom.client.ClickHandler;
	import com.google.gwt.event.shared.EventBus;
	import com.google.gwt.event.shared.EventHandler;
	import com.google.gwt.event.shared.GwtEvent;
	import com.google.gwt.storage.client.Storage;
	import com.google.gwt.user.client.Timer;
	import com.google.gwt.user.client.ui.AcceptsOneWidget;
	import com.google.gwt.sample.mobilewebapp.client.ClientFactory;
	import com.google.gwt.sample.mobilewebapp.client.place.TaskEditPlace;
	import com.google.gwt.sample.mobilewebapp.shared.TaskProxy;
	import com.google.gwt.sample.mobilewebapp.shared.TaskProxyImpl;
	import com.google.web.bindery.requestfactory.shared.Receiver;
	import com.google.web.bindery.requestfactory.shared.ServerFailure;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Date;
	import java.util.List;

	/**
	* Activity that presents a list of tasks.
	*/
	public class TaskListActivity extends AbstractActivity implements TaskListView.Presenter {

	/**
	* Event fired when the task list is updated.
	*/
	public static class TaskListUpdateEvent extends GwtEvent<TaskListActivity.TaskListUpdateHandler> {

	/**
	* Handler type.
	*/
	private static Type<TaskListUpdateHandler> TYPE;

	/**
	* Gets the type associated with this event.
	*
	* @return returns the handler type
	*/
	public static Type<TaskListUpdateHandler> getType() {
	if (TYPE == null) {
	TYPE = new Type<TaskListUpdateHandler>();
	}
	return TYPE;
	}

	private final List<TaskProxy> tasks;

	public TaskListUpdateEvent(List<TaskProxy> tasks) {
	this.tasks = tasks;
	}

	@Override
	public Type<TaskListUpdateHandler> getAssociatedType() {
	return TYPE;
	}

	public List<TaskProxy> getTasks() {
	return tasks;
	}

	@Override
	protected void dispatch(TaskListUpdateHandler handler) {
	handler.onTaskListUpdated(this);
	}
	}

	/**
	* Handler for {@link TaskListUpdateEvent}.
	*/
	public static interface TaskListUpdateHandler extends EventHandler {

	/**
	* Called when the task list is updated.
	*/
	void onTaskListUpdated(TaskListUpdateEvent event);
	}

	private static final String TASKLIST_SAVE_KEY = "TASKLIST";
	private static final String TASKSEP = "&&";
	private static final String FIELDSEP = "@@";
	private static final String FIELDEMPTY = "***";

	/**
	* The delay in milliseconds between calls to refresh the task list.
	*/
	private static final int REFRESH_DELAY = 5000;

	/**
	* Convert a task proxy list into a string.
	*/
	private static String getStringFromTaskProxy(List<TaskProxy> list) {
	StringBuilder sb = new StringBuilder();
	for (TaskProxy proxy : list) {
	sb.append(proxy.getDueDate() != null ? proxy.getDueDate().getTime() : FIELDEMPTY);
	sb.append(FIELDSEP);
	sb.append(proxy.getId() != null ? proxy.getId() : "");
	sb.append(FIELDSEP);
	String name = proxy.getName();
	sb.append(name != null && name.length() > 0 ? proxy.getName() : FIELDEMPTY);
	sb.append(FIELDSEP);
	String notes = proxy.getNotes();
	sb.append(notes != null && notes.length() > 0 ? proxy.getNotes() : FIELDEMPTY);
	sb.append(TASKSEP);
	}
	return sb.toString();
	}

	/**
	* Parse a task proxy list from a string.
	*/
	private static List<TaskProxy> getTaskProxyFromString(String taskProxyList) {
	ArrayList<TaskProxy> list = new ArrayList<TaskProxy>(0);
	if (taskProxyList == null) {
	return list;
	}
	// taskproxy1&&taskproxy2&&taskproxy3&&...
	String taskProxyStrings[] = taskProxyList.split(TASKSEP);
	for (String taskProxyString : taskProxyStrings) {
	if (taskProxyString == null) {
	continue;
	}
	// date@@id@@name@@notes
	String taskProxyStringData[] = taskProxyString.split(FIELDSEP);
	if (taskProxyStringData.length >= 4) {
	// collect the fields
	String dateString = taskProxyStringData[0];
	String idString = taskProxyStringData[1];
	String nameString = taskProxyStringData[2];
	if (FIELDEMPTY.equals(nameString)) {
	nameString = null;
	}
	String notesString = taskProxyStringData[3];
	if (FIELDEMPTY.equals(notesString)) {
	notesString = null;
	}
	// parse the numerical fields
	Date dueDate = null;
	try {
	dueDate = new Date(Long.parseLong(dateString));
	} catch (NumberFormatException nfe) {
	}
	Long idLong = 0L;
	try {
	idLong = Long.parseLong(idString);
	} catch (NumberFormatException nfe) {
	}
	// create and populate the TaskProxy
	TaskProxyImpl taskProxy = new TaskProxyImpl();
	taskProxy.setDueDate(dueDate);
	taskProxy.setId(idLong);
	taskProxy.setName(nameString);
	taskProxy.setNotes(notesString);
	list.add(taskProxy);
	}
	}
	return list;
	}

	private final Storage storage;

	/**
	* A boolean indicating that we should clear the task list when started.
	*/
	private final boolean clearTaskList;

	private final ClientFactory clientFactory;

	/**
	* A boolean indicating whether or not this activity is still active. The user
	* might move to another activity while this one is loading, in which case we
	* do not want to do any more work.
	*/
	private boolean isDead = false;

	/**
	* The refresh timer used to periodically refresh the task list.
	*/
	private Timer refreshTimer;

	/**
	* Construct a new {@link TaskListActivity}.
	*
	* @param clientFactory the {@link ClientFactory} of shared resources
	* @param clearTaskList true to clear the task list, false not to
	*/
	public TaskListActivity(ClientFactory clientFactory, boolean clearTaskList) {
	this.clientFactory = clientFactory;
	this.clearTaskList = clearTaskList;
	this.storage = clientFactory.getLocalStorageIfSupported();
	}

	@Override
	public void onCancel() {
	killActivity();
	}

	@Override
	public void onStop() {
	killActivity();
	}

	public void selectTask(TaskProxy selected) {
	// Go into edit mode when a task is selected.
	clientFactory.getPlaceController().goTo(TaskEditPlace.createTaskEditPlace(selected.getId()));
	}

	public void start(AcceptsOneWidget container, EventBus eventBus) {
	// Add a handler to the 'add' button in the shell.
	clientFactory.getShell().setAddButtonHandler(new ClickHandler() {
	public void onClick(ClickEvent event) {
	clientFactory.getPlaceController().goTo(TaskEditPlace.getTaskCreatePlace());
	}
	});

	// Set the presenter on the view.
	final TaskListView view = clientFactory.getTaskListView();
	view.setPresenter(this);

	// Clear the task list and display it.
	if (clearTaskList) {
	view.clearList();
	}
	container.setWidget(view);

	// Create a timer to periodically refresh the task list.
	refreshTimer = new Timer() {
	@Override
	public void run() {
	refreshTaskList();
	}
	};

	// Load the saved task list from storage
	if (storage != null) { // if storage is supported
	String taskString = storage.getItem(TASKLIST_SAVE_KEY);
	if (taskString != null) {
	List<TaskProxy> list = getTaskProxyFromString(taskString);
	setTasks(list);
	}
	}

	// Request the task list now.
	refreshTaskList();
	}

	/**
	* Kill this activity.
	*/
	private void killActivity() {
	// Ignore all incoming responses to the requests from this activity.
	isDead = true;

	// Kill the refresh timer.
	if (refreshTimer != null) {
	refreshTimer.cancel();
	}
	}

	/**
	* Refresh the task list.
	*/
	private void refreshTaskList() {
	clientFactory.getRequestFactory().taskRequest().findAllTasks().fire(
	new Receiver<List<TaskProxy>>() {
	@Override
	public void onFailure(ServerFailure error) {
	// ignore
	}

	@Override
	public void onSuccess(List<TaskProxy> response) {
	// Early exit if this activity has already been canceled.
	if (isDead) {
	return;
	}

	// Display the tasks in the view.
	if (response == null) {
	setTasks(Collections.<TaskProxy> emptyList());
	} else {
	setTasks(response);

	// save the response to storage
	if (storage != null) { // if storage is supported
	String responseString = getStringFromTaskProxy(response);
	storage.setItem(TASKLIST_SAVE_KEY, responseString);
	}
	}

	// Restart the timer.
	refreshTimer.schedule(REFRESH_DELAY);
	}
	});
	}

	/**
	* Set the list of tasks.
	*/
	private void setTasks(List<TaskProxy> tasks) {
	clientFactory.getTaskListView().setTasks(tasks);
	clientFactory.getEventBus().fireEventFromSource(new TaskListUpdateEvent(tasks), this);
	}
	}