Change LegacyApplication to be a UIProvider (#9402)

8 files changed, 342 insertions, 145 deletions

diff --git a/server/src/com/vaadin/Application.java b/server/src/com/vaadin/Application.java
index 745d0ad784..634f96bfe1 100644
--- a/server/src/com/vaadin/Application.java
+++ b/server/src/com/vaadin/Application.java
@@ -58,6 +58,8 @@ import com.vaadin.server.GlobalResourceHandler;
 import com.vaadin.server.RequestHandler;
 import com.vaadin.server.ServletApplicationContext;
 import com.vaadin.server.Terminal;
+import com.vaadin.server.Terminal.ErrorEvent;
+import com.vaadin.server.Terminal.ErrorListener;
 import com.vaadin.server.UIProvider;
 import com.vaadin.server.VaadinServlet;
 import com.vaadin.server.VariableOwner;
@@ -152,7 +154,8 @@ public class Application implements Terminal.ErrorListener, Serializable {
      * @since 7.0
      */
     @Deprecated
-    public static class LegacyApplication extends Application {
+    public static abstract class LegacyApplication extends AbstractUIProvider
+            implements ErrorListener {
         /**
          * Ignore initial / and then get everything up to the next /
          */
@@ -177,8 +180,8 @@ public class Application implements Terminal.ErrorListener, Serializable {
                         "mainWindow has already been set");
             }
             if (mainWindow.getApplication() == null) {
-                mainWindow.setApplication(this);
-            } else if (mainWindow.getApplication() != this) {
+                mainWindow.setApplication(Application.getCurrent());
+            } else if (mainWindow.getApplication() != Application.getCurrent()) {
                 throw new IllegalStateException(
                         "mainWindow is attached to another application");
             }
@@ -190,45 +193,44 @@ public class Application implements Terminal.ErrorListener, Serializable {
             this.mainWindow = mainWindow;
         }
 
+        public void doInit() {
+            Application.getCurrent().setErrorHandler(this);
+            init();
+        }
+
+        protected abstract void init();
+
         @Override
-        public void start(ApplicationStartEvent event) {
-            super.start(event);
-            addUIProvider(new AbstractUIProvider() {
-                @Override
-                public Class<? extends UI> getUIClass(Application application,
-                        WrappedRequest request) {
-                    if (application == LegacyApplication.this) {
-                        UI uiInstance = getUIInstance(request);
-                        if (uiInstance != null) {
-                            return uiInstance.getClass();
-                        }
-                    }
-                    return null;
-                }
+        public Class<? extends UI> getUIClass(Application application,
+                WrappedRequest request) {
+            UI uiInstance = getUIInstance(request);
+            if (uiInstance != null) {
+                return uiInstance.getClass();
+            }
+            return null;
+        }
 
-                @Override
-                public UI createInstance(Application application,
-                        Class<? extends UI> type, WrappedRequest request) {
-                    return getUIInstance(request);
-                }
+        @Override
+        public UI createInstance(Application application,
+                Class<? extends UI> type, WrappedRequest request) {
+            return getUIInstance(request);
+        }
 
-                @Override
-                public String getThemeForUI(WrappedRequest request,
-                        Class<? extends UI> uiClass) {
-                    return theme;
-                }
+        @Override
+        public String getThemeForUI(WrappedRequest request,
+                Class<? extends UI> uiClass) {
+            return theme;
+        }
 
-                @Override
-                public String getPageTitleForUI(WrappedRequest request,
-                        Class<? extends UI> uiClass) {
-                    UI uiInstance = getUIInstance(request);
-                    if (uiInstance != null) {
-                        return uiInstance.getCaption();
-                    } else {
-                        return super.getPageTitleForUI(request, uiClass);
-                    }
-                }
-            });
+        @Override
+        public String getPageTitleForUI(WrappedRequest request,
+                Class<? extends UI> uiClass) {
+            UI uiInstance = getUIInstance(request);
+            if (uiInstance != null) {
+                return uiInstance.getCaption();
+            } else {
+                return super.getPageTitleForUI(request, uiClass);
+            }
         }
 
         /**
@@ -273,7 +275,7 @@ public class Application implements Terminal.ErrorListener, Serializable {
          * {@inheritDoc}
          */
         @Override
-        public UI getUIForRequest(WrappedRequest request) {
+        public UI getExistingUI(WrappedRequest request) {
             UI uiInstance = getUIInstance(request);
             if (uiInstance.getUIId() == -1) {
                 // Not initialized -> Let go through createUIInstance to make it
@@ -352,7 +354,7 @@ public class Application implements Terminal.ErrorListener, Serializable {
             }
 
             legacyUINames.put(uI.getName(), uI);
-            uI.setApplication(this);
+            uI.setApplication(Application.getCurrent());
         }
 
         /**
@@ -389,6 +391,27 @@ public class Application implements Terminal.ErrorListener, Serializable {
         public Collection<UI.LegacyWindow> getWindows() {
             return Collections.unmodifiableCollection(legacyUINames.values());
         }
+
+        @Override
+        public void terminalError(ErrorEvent event) {
+            Application.getCurrent().terminalError(event);
+        }
+
+        public ApplicationContext getContext() {
+            return Application.getCurrent().getContext();
+        }
+
+        protected void close() {
+            Application.getCurrent().close();
+        }
+
+        public boolean isRunning() {
+            return Application.getCurrent().isRunning();
+        }
+
+        public URL getURL() {
+            return Application.getCurrent().getURL();
+        }
     }
 
     /**
@@ -1854,39 +1877,10 @@ public class Application implements Terminal.ErrorListener, Serializable {
         Integer uiId = getUIId(request);
 
         synchronized (this) {
-            BrowserDetails browserDetails = request.getBrowserDetails();
-            boolean hasBrowserDetails = browserDetails != null
-                    && browserDetails.getUriFragment() != null;
-
             uI = uIs.get(uiId);
-            Class<? extends UI> uiClass = null;
-
-            if (uI == null && hasBrowserDetails
-                    && !retainOnRefreshUIs.isEmpty()) {
-                uiClass = getUIClass(request);
-
-                // Check for a known UI
-
-                @SuppressWarnings("null")
-                String windowName = browserDetails.getWindowName();
-                Integer retainedUIId = retainOnRefreshUIs.get(windowName);
-
-                if (retainedUIId != null) {
-                    UI retainedUI = uIs.get(retainedUIId);
-                    // We've had the same UI instance in a window with this
-                    // name, but should we still use it?
-                    if (retainedUI.getClass() == uiClass) {
-                        uiId = retainedUIId;
-                        uI = retainedUI;
-                    } else {
-                        getLogger().info(
-                                "Not using retained UI in " + windowName
-                                        + " because retained UI was of type "
-                                        + retainedUIId.getClass() + " but "
-                                        + uiClass
-                                        + " is expected for the request.");
-                    }
-                }
+
+            if (uI == null) {
+                uI = findExistingUi(request);
             }
 
         } // end synchronized block
@@ -1896,6 +1890,48 @@ public class Application implements Terminal.ErrorListener, Serializable {
         return uI;
     }
 
+    private UI findExistingUi(WrappedRequest request) {
+        // Check if some UI provider has an existing UI available
+        for (int i = uiProviders.size() - 1; i >= 0; i--) {
+            UIProvider provider = uiProviders.get(i);
+            UI existingUi = provider.getExistingUI(request);
+            if (existingUi != null) {
+                return existingUi;
+            }
+        }
+
+        BrowserDetails browserDetails = request.getBrowserDetails();
+        boolean hasBrowserDetails = browserDetails != null
+                && browserDetails.getUriFragment() != null;
+
+        if (hasBrowserDetails && !retainOnRefreshUIs.isEmpty()) {
+            // Check for a known UI
+
+            @SuppressWarnings("null")
+            String windowName = browserDetails.getWindowName();
+            Integer retainedUIId = retainOnRefreshUIs.get(windowName);
+
+            if (retainedUIId != null) {
+                Class<? extends UI> expectedUIClass = getUIClass(request);
+                UI retainedUI = uIs.get(retainedUIId);
+                // We've had the same UI instance in a window with this
+                // name, but should we still use it?
+                if (retainedUI.getClass() == expectedUIClass) {
+                    return retainedUI;
+                } else {
+                    getLogger().info(
+                            "Not using retained UI in " + windowName
+                                    + " because retained UI was of type "
+                                    + retainedUIId.getClass() + " but "
+                                    + expectedUIClass
+                                    + " is expected for the request.");
+                }
+            }
+        }
+
+        return null;
+    }
+
     public UI createUI(WrappedRequest request) {
         Class<? extends UI> uiClass = getUIClass(request);
 
@@ -2167,4 +2203,8 @@ public class Application implements Terminal.ErrorListener, Serializable {
         return globalResourceHandler;
     }
 
+    public Collection<UIProvider> getUIProviders() {
+        return Collections.unmodifiableCollection(uiProviders);
+    }
+
 }
diff --git a/server/src/com/vaadin/server/AbstractUIProvider.java b/server/src/com/vaadin/server/AbstractUIProvider.java
index 49f8e3ec77..c7a137ebbd 100644
--- a/server/src/com/vaadin/server/AbstractUIProvider.java
+++ b/server/src/com/vaadin/server/AbstractUIProvider.java
@@ -115,4 +115,9 @@ public abstract class AbstractUIProvider implements UIProvider {
             return titleAnnotation.value();
         }
     }
+
+    @Override
+    public UI getExistingUI(WrappedRequest request) {
+        return null;
+    }
 }
diff --git a/server/src/com/vaadin/server/LegacyVaadinPortlet.java b/server/src/com/vaadin/server/LegacyVaadinPortlet.java
new file mode 100644
index 0000000000..036242a0c2
--- /dev/null
+++ b/server/src/com/vaadin/server/LegacyVaadinPortlet.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2011 Vaadin Ltd.
+ * 
+ * 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.vaadin.server;
+
+import javax.portlet.PortletException;
+import javax.portlet.PortletRequest;
+
+import com.vaadin.Application;
+import com.vaadin.Application.LegacyApplication;
+import com.vaadin.server.ServletPortletHelper.ApplicationClassException;
+
+public class LegacyVaadinPortlet extends VaadinPortlet {
+
+    protected Class<? extends LegacyApplication> getApplicationClass()
+            throws ClassNotFoundException {
+        try {
+            return ServletPortletHelper
+                    .getLegacyApplicationClass(getDeploymentConfiguration());
+        } catch (ApplicationClassException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    protected LegacyApplication getNewApplication(PortletRequest request)
+            throws PortletException {
+        try {
+            Class<? extends LegacyApplication> applicationClass = getApplicationClass();
+            return applicationClass.newInstance();
+        } catch (Exception e) {
+            throw new PortletException(e);
+        }
+    }
+
+    @Override
+    protected Application createApplication(PortletRequest request)
+            throws PortletException {
+        Application application = super.createApplication(request);
+
+        // Must set current before running init()
+        Application.setCurrent(application);
+
+        LegacyApplication legacyApplication = getNewApplication(request);
+        legacyApplication.doInit();
+        application.addUIProvider(legacyApplication);
+
+        return application;
+    }
+}
diff --git a/server/src/com/vaadin/server/LegacyVaadinServlet.java b/server/src/com/vaadin/server/LegacyVaadinServlet.java
new file mode 100644
index 0000000000..f53e9d4bf0
--- /dev/null
+++ b/server/src/com/vaadin/server/LegacyVaadinServlet.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2011 Vaadin Ltd.
+ * 
+ * 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.vaadin.server;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+
+import com.vaadin.Application;
+import com.vaadin.Application.LegacyApplication;
+import com.vaadin.server.ServletPortletHelper.ApplicationClassException;
+
+public class LegacyVaadinServlet extends VaadinServlet {
+
+    protected Class<? extends LegacyApplication> getApplicationClass()
+            throws ClassNotFoundException {
+        try {
+            return ServletPortletHelper
+                    .getLegacyApplicationClass(getDeploymentConfiguration());
+        } catch (ApplicationClassException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    protected LegacyApplication getNewApplication(HttpServletRequest request)
+            throws ServletException {
+        try {
+            Class<? extends LegacyApplication> applicationClass = getApplicationClass();
+            return applicationClass.newInstance();
+        } catch (Exception e) {
+            throw new ServletException(e);
+        }
+    }
+
+    @Override
+    protected Application createApplication(HttpServletRequest request)
+            throws ServletException {
+        Application application = super.createApplication(request);
+
+        // Must set current before running init()
+        Application.setCurrent(application);
+
+        LegacyApplication legacyApplication = getNewApplication(request);
+        legacyApplication.doInit();
+        application.addUIProvider(legacyApplication);
+
+        return application;
+    }
+
+}
diff --git a/server/src/com/vaadin/server/ServletPortletHelper.java b/server/src/com/vaadin/server/ServletPortletHelper.java
index 26913d8ba8..18fbb66114 100644
--- a/server/src/com/vaadin/server/ServletPortletHelper.java
+++ b/server/src/com/vaadin/server/ServletPortletHelper.java
@@ -4,6 +4,7 @@ import java.io.Serializable;
 import java.util.Properties;
 
 import com.vaadin.Application;
+import com.vaadin.Application.LegacyApplication;
 import com.vaadin.shared.ApplicationConstants;
 import com.vaadin.ui.UI;
 
@@ -41,28 +42,22 @@ class ServletPortletHelper implements Serializable {
         }
     }
 
-    static Class<? extends Application> getApplicationClass(
+    static Class<? extends LegacyApplication> getLegacyApplicationClass(
             DeploymentConfiguration deploymentConfiguration)
             throws ApplicationClassException {
         Properties initParameters = deploymentConfiguration
                 .getApplicationConfiguration().getInitParameters();
         String applicationParameter = initParameters.getProperty("application");
-        String uiParameter = initParameters
-                .getProperty(Application.UI_PARAMETER);
         ClassLoader classLoader = deploymentConfiguration.getClassLoader();
 
         if (applicationParameter == null) {
-
-            // Validate the parameter value
-            verifyUIClass(uiParameter, classLoader);
-
-            // Application can be used if a valid rootLayout is defined
-            return Application.class;
+            throw new ApplicationClassException(
+                    "No \"application\" init parameter found");
         }
 
         try {
-            return (Class<? extends Application>) classLoader
-                    .loadClass(applicationParameter);
+            return classLoader.loadClass(applicationParameter).asSubclass(
+                    LegacyApplication.class);
         } catch (final ClassNotFoundException e) {
             throw new ApplicationClassException(
                     "Failed to load application class: " + applicationParameter,
@@ -138,4 +133,25 @@ class ServletPortletHelper implements Serializable {
                 ApplicationConstants.HEARTBEAT_REQUEST_PATH);
     }
 
+    public static void initDefaultUIProvider(Application application,
+            DeploymentConfiguration deploymentConfiguration)
+            throws ApplicationClassException {
+        String uiProperty = deploymentConfiguration
+                .getApplicationConfiguration().getInitParameters()
+                .getProperty(Application.UI_PARAMETER);
+        if (uiProperty != null) {
+            verifyUIClass(uiProperty, deploymentConfiguration.getClassLoader());
+            application.addUIProvider(new DefaultUIProvider());
+        }
+    }
+
+    public static void checkUiProviders(Application newApplication)
+            throws ApplicationClassException {
+        if (newApplication.getUIProviders().isEmpty()) {
+            throw new ApplicationClassException(
+                    "No UIProvider has been added to the application and there is no \""
+                            + Application.UI_PARAMETER + "\" init parameter.");
+        }
+    }
+
 }
diff --git a/server/src/com/vaadin/server/UIProvider.java b/server/src/com/vaadin/server/UIProvider.java
index 60b79cdbb9..6a45b06c63 100644
--- a/server/src/com/vaadin/server/UIProvider.java
+++ b/server/src/com/vaadin/server/UIProvider.java
@@ -78,4 +78,23 @@ public interface UIProvider {
     public String getThemeForUI(WrappedRequest request,
             Class<? extends UI> uiClass);
 
+    /**
+     * Finds an existing {@link UI} for a request.
+     * <p>
+     * Implementations should take care to not return an UI instance that might
+     * be used in some other browser as that might cause synchronization issues
+     * when changes from one browser window are not present in the other.
+     * <p>
+     * If no UI provider returns an existing UI, the framework does also check
+     * the window.name for an existing instance with
+     * {@link #isUiPreserved(WrappedRequest, Class)} before falling back to
+     * bootstrapping and creating a new UI instance.
+     * 
+     * @param request
+     *            the request for which a UI is desired
+     * @return a UI belonging to the request, or <code>null</code> if this UI
+     *         provider doesn't have an existing UI for the request.
+     */
+    public UI getExistingUI(WrappedRequest request);
+
 }
diff --git a/server/src/com/vaadin/server/VaadinPortlet.java b/server/src/com/vaadin/server/VaadinPortlet.java
index bf8fb5dc84..eae01e9369 100644
--- a/server/src/com/vaadin/server/VaadinPortlet.java
+++ b/server/src/com/vaadin/server/VaadinPortlet.java
@@ -814,7 +814,7 @@ public class VaadinPortlet extends GenericPortlet implements Constants {
 
             if (restartApplication) {
                 closeApplication(application, request.getPortletSession(false));
-                return createApplication(request);
+                return createAndRegisterApplication(request);
             } else if (closeApplication) {
                 closeApplication(application, request.getPortletSession(false));
                 return null;
@@ -826,7 +826,7 @@ public class VaadinPortlet extends GenericPortlet implements Constants {
         // No existing application was found
 
         if (requestCanCreateApplication) {
-            return createApplication(request);
+            return createAndRegisterApplication(request);
         } else {
             throw new SessionExpiredException();
         }
@@ -845,9 +845,16 @@ public class VaadinPortlet extends GenericPortlet implements Constants {
         }
     }
 
-    private Application createApplication(PortletRequest request)
+    private Application createAndRegisterApplication(PortletRequest request)
             throws PortletException {
-        Application newApplication = getNewApplication(request);
+        Application newApplication = createApplication(request);
+
+        try {
+            ServletPortletHelper.checkUiProviders(newApplication);
+        } catch (ApplicationClassException e) {
+            throw new PortletException(e);
+        }
+
         final PortletApplicationContext2 context = getApplicationContext(request
                 .getPortletSession());
         context.setApplication(newApplication, new PortletCommunicationManager(
@@ -855,6 +862,20 @@ public class VaadinPortlet extends GenericPortlet implements Constants {
         return newApplication;
     }
 
+    protected Application createApplication(PortletRequest request)
+            throws PortletException {
+        Application application = new Application();
+
+        try {
+            ServletPortletHelper.initDefaultUIProvider(application,
+                    getDeploymentConfiguration());
+        } catch (ApplicationClassException e) {
+            throw new PortletException(e);
+        }
+
+        return application;
+    }
+
     private Application getExistingApplication(PortletRequest request,
             boolean allowSessionCreation) throws MalformedURLException,
             SessionExpiredException {
@@ -880,26 +901,6 @@ public class VaadinPortlet extends GenericPortlet implements Constants {
         return null;
     }
 
-    protected Class<? extends Application> getApplicationClass()
-            throws ApplicationClassException {
-        return ServletPortletHelper
-                .getApplicationClass(getDeploymentConfiguration());
-    }
-
-    protected Application getNewApplication(PortletRequest request)
-            throws PortletException {
-        try {
-            final Application application = getApplicationClass().newInstance();
-            return application;
-        } catch (final IllegalAccessException e) {
-            throw new PortletException("getNewApplication failed", e);
-        } catch (final InstantiationException e) {
-            throw new PortletException("getNewApplication failed", e);
-        } catch (final ApplicationClassException e) {
-            throw new PortletException("getNewApplication failed", e);
-        }
-    }
-
     private void handleServiceException(WrappedPortletRequest request,
             WrappedPortletResponse response, Application application,
             Throwable e) throws IOException, PortletException {
diff --git a/server/src/com/vaadin/server/VaadinServlet.java b/server/src/com/vaadin/server/VaadinServlet.java
index ba19072503..8f33382110 100644
--- a/server/src/com/vaadin/server/VaadinServlet.java
+++ b/server/src/com/vaadin/server/VaadinServlet.java
@@ -603,7 +603,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
 
             if (restartApplication) {
                 closeApplication(application, request.getSession(false));
-                return createApplication(request);
+                return createAndRegisterApplication(request);
             } else if (closeApplication) {
                 closeApplication(application, request.getSession(false));
                 return null;
@@ -619,7 +619,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
              * If the request is such that it should create a new application if
              * one as not found, we do that.
              */
-            return createApplication(request);
+            return createAndRegisterApplication(request);
         } else {
             /*
              * The application was not found and a new one should not be
@@ -630,6 +630,24 @@ public class VaadinServlet extends HttpServlet implements Constants {
 
     }
 
+    private Application createAndRegisterApplication(HttpServletRequest request)
+            throws ServletException {
+        Application newApplication = createApplication(request);
+
+        try {
+            ServletPortletHelper.checkUiProviders(newApplication);
+        } catch (ApplicationClassException e) {
+            throw new ServletException(e);
+        }
+
+        final ServletApplicationContext context = getApplicationContext(request
+                .getSession());
+        context.setApplication(newApplication,
+                createCommunicationManager(newApplication));
+
+        return newApplication;
+    }
+
     /**
      * Check if the request should create an application if an existing
      * application is not found.
@@ -699,14 +717,16 @@ public class VaadinServlet extends HttpServlet implements Constants {
      * @throws ServletException
      * @throws MalformedURLException
      */
-    private Application createApplication(HttpServletRequest request)
-            throws ServletException, MalformedURLException {
-        Application newApplication = getNewApplication(request);
+    protected Application createApplication(HttpServletRequest request)
+            throws ServletException {
+        Application newApplication = new Application();
 
-        final ServletApplicationContext context = getApplicationContext(request
-                .getSession());
-        context.setApplication(newApplication,
-                createCommunicationManager(newApplication));
+        try {
+            ServletPortletHelper.initDefaultUIProvider(newApplication,
+                    getDeploymentConfiguration());
+        } catch (ApplicationClassException e) {
+            throw new ServletException(e);
+        }
 
         return newApplication;
     }
@@ -849,35 +869,6 @@ public class VaadinServlet extends HttpServlet implements Constants {
     }
 
     /**
-     * Creates a new application for the given request.
-     * 
-     * @param request
-     *            the HTTP request.
-     * @return A new Application instance.
-     * @throws ServletException
-     */
-    protected Application getNewApplication(HttpServletRequest request)
-            throws ServletException {
-
-        // Creates a new application instance
-        try {
-            Class<? extends Application> applicationClass = ServletPortletHelper
-                    .getApplicationClass(getDeploymentConfiguration());
-
-            final Application application = applicationClass.newInstance();
-            application.addUIProvider(new DefaultUIProvider());
-
-            return application;
-        } catch (final IllegalAccessException e) {
-            throw new ServletException("getNewApplication failed", e);
-        } catch (final InstantiationException e) {
-            throw new ServletException("getNewApplication failed", e);
-        } catch (ApplicationClassException e) {
-            throw new ServletException("getNewApplication failed", e);
-        }
-    }
-
-    /**
      * Starts the application if it is not already running.
      * 
      * @param request