clean up AppPresenter document selection and view change logic

server/zanata-war/src/main/java/org/zanata/webtrans/client/presenter/AppPresenter.java

@@ -92,7 +92,7 @@ public interface Display extends net.customware.gwt.presenter.client.widget.Widg
    private final TranslationStats selectedDocumentStats = new TranslationStats();
    private final TranslationStats projectStats = new TranslationStats();
    private TranslationStats currentDisplayStats = new TranslationStats();
-   private MainView currentView;
+   private MainView currentView = null;
 
    private static final String WORKSPACE_TITLE_QUERY_PARAMETER_KEY = "title";
 
@@ -113,6 +113,8 @@ public AppPresenter(Display display, EventBus eventBus, final TranslationPresent
    @Override
    protected void onBind()
    {
+      documentListPresenter.bind();
+      translationPresenter.bind();
 
       registerHandler(eventBus.addHandler(NotificationEvent.getType(), new NotificationEventHandler()
       {
@@ -125,10 +127,6 @@ public void onNotification(NotificationEvent event)
          }
       }));
 
-      documentListPresenter.bind();
-      translationPresenter.bind();
-
-      showView(MainView.Documents);
 
       registerHandler(eventBus.addHandler(DocumentStatsUpdatedEvent.getType(), new DocumentStatsUpdatedEventHandler()
       {
@@ -197,23 +195,22 @@ public void onClick(ClickEvent event)
          }
       }));
 
-      display.setUserLabel(identity.getPerson().getName());
-
-      String workspaceTitle = windowLocation.getParameter(WORKSPACE_TITLE_QUERY_PARAMETER_KEY);
-
-      display.setWorkspaceNameLabel(workspaceContext.getWorkspaceName(), workspaceTitle);
-
-      window.setTitle(messages.windowTitle(workspaceContext.getWorkspaceName(), workspaceContext.getLocaleName()));
-
-      history.addValueChangeHandler(new ValueChangeHandler<String>()
+      registerHandler(history.addValueChangeHandler(new ValueChangeHandler<String>()
       {
 
          @Override
          public void onValueChange(ValueChangeEvent<String> event)
          {
             processHistoryEvent(event);
          }
-      });
+      }));
+
+      display.setUserLabel(identity.getPerson().getName());
+      String workspaceTitle = windowLocation.getParameter(WORKSPACE_TITLE_QUERY_PARAMETER_KEY);
+      display.setWorkspaceNameLabel(workspaceContext.getWorkspaceName(), workspaceTitle);
+      window.setTitle(messages.windowTitle(workspaceContext.getWorkspaceName(), workspaceContext.getLocaleName()));
+
+      showView(MainView.Documents);
 
       history.fireCurrentHistoryState();
    }
@@ -239,7 +236,7 @@ private void processHistoryEvent(ValueChangeEvent<String> event)
 
       if (docId != null && (selectedDocument == null || !selectedDocument.getId().equals(docId)))
       {
-         showDocumentInfo(docId);
+         selectDocument(docId);
          eventBus.fireEvent(new DocumentSelectionEvent(docId));
       }
 
@@ -249,48 +246,43 @@ private void processHistoryEvent(ValueChangeEvent<String> event)
          token.setView(MainView.Documents);
       }
 
-      if (token.getView() != currentView)
+      showView(token.getView());
+   }
+
+   private void showView(MainView viewToShow)
+   {
+      if (currentView != viewToShow)
       {
-         if (currentView.equals(MainView.Editor))
+         switch (viewToShow)
          {
-            translationPresenter.saveEditorPendingChange();
-         }
-         else
-         { // document list view
+         case Documents:
+            if (currentView == MainView.Editor)
+               translationPresenter.saveEditorPendingChange();
+            display.setDocumentLabel("", messages.noDocumentSelected());
+            currentDisplayStats = projectStats;
+            break;
+
+         case Editor:
             if (selectedDocument != null)
             {
                display.setDocumentLabel(selectedDocument.getPath(), selectedDocument.getName());
             }
+            currentDisplayStats = selectedDocumentStats;
+            break;
          }
-         showView(token.getView());
+         display.showInMainView(viewToShow);
+         currentView = viewToShow;
+         refreshStatsDisplay();
       }
    }
 
-   private void showView(MainView viewToShow)
-   {
-      currentView = viewToShow;
-      display.showInMainView(viewToShow);
-      switch (viewToShow)
-      {
-      case Documents:
-         currentDisplayStats = projectStats;
-         display.setDocumentLabel("", messages.noDocumentSelected());
-         break;
-
-      case Editor:
-         currentDisplayStats = selectedDocumentStats;
-         break;
-      }
-
-      refreshStatsDisplay();
-   }
-
    /**
-    * Show the name and stats for the given document
+    * Set selected document to the given document, update name and stats to
+    * match the newly selected document.
     * 
-    * @param event
+    * @param docId id of the document to select
     */
-   private void showDocumentInfo(DocumentId docId)
+   private void selectDocument(DocumentId docId)
    {
 
       if (selectedDocument == null || !docId.equals(selectedDocument.getId()))
@@ -299,9 +291,12 @@ private void showDocumentInfo(DocumentId docId)
          if (docInfo != null)
          {
             selectedDocument = docInfo;
-            display.setDocumentLabel(selectedDocument.getPath(), selectedDocument.getName());
             selectedDocumentStats.set(selectedDocument.getStats());
-            refreshStatsDisplay();
+            if (currentView == MainView.Editor)
+            {
+               display.setDocumentLabel(selectedDocument.getPath(), selectedDocument.getName());
+               refreshStatsDisplay();
+            }
          }
       }
    }