Add check for open project before prompting user

There is a prompt for the user to create or open a project. However,
this is based on whether currentFileEditor is set, which is a problem
is a project load is in process. This commit adds a check to
EditorManager to see if there is an editor even though
currentFileEditor is null, in which case no prompt is shown.

Change-Id: Icf044a638fef19d7fb5660a4783f852c7ccbb6cb

appinventor/appengine/src/com/google/appinventor/client/Ode.java

@@ -475,7 +475,7 @@ public class Ode implements EntryPoint {
     getTopToolbar().updateFileMenuButtons(currentView);
     if (currentFileEditor != null) {
       deckPanel.showWidget(designTabIndex);
-    } else {
+    } else if (!editorManager.hasOpenEditor()) {  // is there a project editor pending visibility?
       OdeLog.wlog("No current file editor to show in designer");
       ErrorReporter.reportInfo(MESSAGES.chooseProject());
     }
@@ -583,6 +583,13 @@ public class Ode implements EntryPoint {
               openYoungAndroidProjectInDesigner(project);
             }
           }
+          @Override
+          public void onProjectsLoaded() {
+            // we only get here iff onProjectAdded is never called with the target project id
+            projectManager.removeProjectManagerEventListener(this);
+            switchToProjectsView();  // the user will need to select a project...
+            ErrorReporter.reportInfo(MESSAGES.chooseProject());
+          }
         });
       }
     }
@@ -1488,7 +1495,7 @@ public class Ode implements EntryPoint {
    */
   private void createWelcomeDialog(boolean force) {
     if (!shouldShowWelcomeDialog() && !force) {
-      openProjectsTab();
+      maybeShowNoProjectsDialog();
       return;
     }
     // Create the UI elements of the DialogBox
@@ -1515,7 +1522,7 @@ public class Ode implements EntryPoint {
                 "" + splashConfig.version);
             userSettings.saveSettings(null);
           }
-          openProjectsTab();
+          maybeShowNoProjectsDialog();
         }
       });
     holder.add(ok);
@@ -1527,21 +1534,18 @@ public class Ode implements EntryPoint {
   }
 
   /**
-   * Load and open the projects tab.
+   * Check the number of projects for the user and show the "no projects" dialog if no projects
+   * are present.
    */
-  private void openProjectsTab() {
-    getProjectService().getProjects(new AsyncCallback<long[]>() {
+  private void maybeShowNoProjectsDialog() {
+    projectManager.addProjectManagerEventListener(new ProjectManagerEventAdapter() {
       @Override
-          public void onSuccess(long [] projectIds) {
-          if (projectIds.length == 0 && !templateLoadingFlag) {
+      public void onProjectsLoaded() {
+        if (projectManager.projectCount() == 0 && !templateLoadingFlag) {
+          ErrorReporter.hide();  // hide the "Please choose a project" message
           createNoProjectsDialog(true);
         }
       }
-
-        @Override
-          public void onFailure(Throwable projectIds) {
-          OdeLog.elog("Could not get project list");
-        }
     });
   }
 
@@ -1642,7 +1646,7 @@ public class Ode implements EntryPoint {
     if (AppInventorFeatures.showSplashScreen() && !isReadOnly) {
       createWelcomeDialog(false);
     } else {
-      openProjectsTab();
+      maybeShowNoProjectsDialog();
     }
   }
 

appinventor/appengine/src/com/google/appinventor/client/editor/EditorManager.java

@@ -197,6 +197,15 @@ public final class EditorManager {
     scheduleAutoSaveTimer();
   }
 
+  /**
+   * Check whether there is an open project editor.
+   *
+   * @return true if at least one project is open (or in the process of opening), otherwise false
+   */
+  public boolean hasOpenEditor() {
+    return openProjectEditors.size() > 0;
+  }
+
   /**
    * Schedules the auto-save timer.
    */

appinventor/appengine/src/com/google/appinventor/client/explorer/project/ProjectManager.java

@@ -29,6 +29,11 @@ public final class ProjectManager {
   // List of listeners for any project manager events.
   private final List<ProjectManagerEventListener> projectManagerEventListeners;
 
+  /**
+   * Flag indicating whether the project infos have all loaded.
+   */
+  private volatile boolean projectsLoaded = false;
+
   /**
    * Creates a new projects manager.
    */
@@ -175,6 +180,10 @@ public final class ProjectManager {
    */
   public void addProjectManagerEventListener(ProjectManagerEventListener listener) {
     projectManagerEventListeners.add(listener);
+    if (projectsLoaded) {
+      // inform the listener that projects have already been loaded
+      listener.onProjectsLoaded();
+    }
   }
 
   /**
@@ -186,6 +195,10 @@ public final class ProjectManager {
     projectManagerEventListeners.remove(listener);
   }
 
+  public int projectCount() {
+    return projectsMap.size();
+  }
+
   private List<ProjectManagerEventListener> copyProjectManagerEventListeners() {
     return new ArrayList<ProjectManagerEventListener>(projectManagerEventListeners);
   }
@@ -212,6 +225,7 @@ public final class ProjectManager {
    * Triggers a 'projects loaded' event to be sent to the listener on the listener list.
    */
   private void fireProjectsLoaded() {
+    projectsLoaded = true;
     for (ProjectManagerEventListener listener : copyProjectManagerEventListeners()) {
       listener.onProjectsLoaded();
     }

appinventor/appengine/src/com/google/appinventor/client/explorer/project/ProjectManagerEventAdapter.java

@@ -22,8 +22,8 @@ public class ProjectManagerEventAdapter implements ProjectManagerEventListener {
   }
 
   /**
-   * Invoked after all projects have been loaded by ProjectManager
-   *
+   * Invoked after all projects have been loaded by ProjectManager. If the ProjectManager has
+   * already finished loading projects, this will be called immediately upon adding the listener.
    */
   @Override
   public void onProjectsLoaded() { }