Move push mode to UI and add @Push annotation (#11506)

Change-Id: Idc0e5e00a8f3ddd3f56d87484089c290d52715c2

10 files changed, 239 insertions, 74 deletions

diff --git a/server/src/com/vaadin/annotations/Push.java b/server/src/com/vaadin/annotations/Push.java
new file mode 100644
index 0000000000..e97a1a34dd
--- /dev/null
+++ b/server/src/com/vaadin/annotations/Push.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2000-2013 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.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import com.vaadin.shared.communication.PushMode;
+import com.vaadin.ui.UI;
+
+/**
+ * Defines a specific {@link PushMode} for a {@link UI}.
+ * 
+ * @author Vaadin Ltd.
+ * @since 7.1
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface Push {
+    /**
+     * Returns the {@link PushMode} to use for the annotated UI.
+     * 
+     * @return the push mode to use
+     */
+    public PushMode value();
+
+}
diff --git a/server/src/com/vaadin/server/BootstrapHandler.java b/server/src/com/vaadin/server/BootstrapHandler.java
index ad491745dd..9d21e19a18 100644
--- a/server/src/com/vaadin/server/BootstrapHandler.java
+++ b/server/src/com/vaadin/server/BootstrapHandler.java
@@ -41,6 +41,7 @@ import org.jsoup.parser.Tag;
 
 import com.vaadin.shared.ApplicationConstants;
 import com.vaadin.shared.Version;
+import com.vaadin.shared.communication.PushMode;
 import com.vaadin.ui.UI;
 
 /**
@@ -68,6 +69,7 @@ public abstract class BootstrapHandler extends SynchronizedRequestHandler {
         private String widgetsetName;
         private String themeName;
         private String appId;
+        private PushMode pushMode;
 
         public BootstrapContext(VaadinResponse response,
                 BootstrapFragmentResponse bootstrapResponse) {
@@ -105,6 +107,30 @@ public abstract class BootstrapHandler extends SynchronizedRequestHandler {
             return themeName;
         }
 
+        public PushMode getPushMode() {
+            if (pushMode == null) {
+                UICreateEvent event = new UICreateEvent(getRequest(),
+                        getUIClass());
+
+                pushMode = getBootstrapResponse().getUIProvider().getPushMode(
+                        event);
+                if (pushMode == null) {
+                    pushMode = getRequest().getService()
+                            .getDeploymentConfiguration().getPushMode();
+                }
+
+                if (pushMode.isEnabled()
+                        && !getRequest().getService().ensurePushAvailable()) {
+                    /*
+                     * Fall back if not supported (ensurePushAvailable will log
+                     * information to the developer the first time this happens)
+                     */
+                    pushMode = PushMode.DISABLED;
+                }
+            }
+            return pushMode;
+        }
+
         public String getAppId() {
             if (appId == null) {
                 appId = getRequest().getService().getMainDivId(getSession(),
@@ -355,7 +381,7 @@ public abstract class BootstrapHandler extends SynchronizedRequestHandler {
                                 "position:absolute;width:0;height:0;border:0;overflow:hidden")
                         .attr("src", "javascript:false"));
 
-        if (context.getSession().getPushMode().isEnabled()) {
+        if (context.getPushMode().isEnabled()) {
             // Load client-side dependencies for push support
             fragmentNodes.add(new Element(Tag.valueOf("script"), "").attr(
                     "type", "text/javascript").attr("src",
@@ -496,7 +522,7 @@ public abstract class BootstrapHandler extends SynchronizedRequestHandler {
         appConfig.put("heartbeatInterval", vaadinService
                 .getDeploymentConfiguration().getHeartbeatInterval());
 
-        appConfig.put("pushMode", session.getPushMode().toString());
+        appConfig.put("pushMode", context.getPushMode().toString());
 
         String serviceUrl = getServiceUrl(context);
         if (serviceUrl != null) {
diff --git a/server/src/com/vaadin/server/Constants.java b/server/src/com/vaadin/server/Constants.java
index 4880bc84c0..939aba0282 100644
--- a/server/src/com/vaadin/server/Constants.java
+++ b/server/src/com/vaadin/server/Constants.java
@@ -15,6 +15,8 @@
  */
 package com.vaadin.server;
 
+import com.vaadin.shared.communication.PushMode;
+
 /**
  * TODO Document me!
  * 
@@ -63,13 +65,12 @@ public interface Constants {
             + " Widgetset version: %s\n"
             + "=================================================================";
 
-    static final String REQUIRED_ATMOSPHERE_VERSION = "1.0.12";
+    static final String REQUIRED_ATMOSPHERE_VERSION = "1.0.13";
 
     static final String INVALID_ATMOSPHERE_VERSION_WARNING = "\n"
             + "=================================================================\n"
-            + "With push enabled, Vaadin depends on Atomsphere {0} but\n"
-            + "version {1} was found. This might cause compatibility\n"
-            + "problems.\n"
+            + "Vaadin depends on Atomsphere {0} but version {1} was found.\n"
+            + "This might cause compatibility problems if push is used.\n"
             + "=================================================================";
 
     static final String ATMOSPHERE_MISSING_ERROR = "\n"
@@ -81,7 +82,21 @@ public interface Constants {
             + "If managing dependencies manually, please make sure Atmosphere\n"
             + REQUIRED_ATMOSPHERE_VERSION
             + " is included on the classpath.\n"
-            + "Push will be disabled.\n"
+            + "Will fall back to using "
+            + PushMode.class.getSimpleName()
+            + "."
+            + PushMode.DISABLED.name()
+            + ".\n"
+            + "=================================================================";
+
+    static final String PUSH_NOT_SUPPORTED_ERROR = "\n"
+            + "=================================================================\n"
+            + "Push is not supported for {0}\n"
+            + "Will fall back to using "
+            + PushMode.class.getSimpleName()
+            + "."
+            + PushMode.DISABLED.name()
+            + ".\n"
             + "=================================================================";
 
     static final String URL_PARAMETER_THEME = "theme";
diff --git a/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java b/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java
index 5cf3898c23..d11bd69997 100644
--- a/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java
+++ b/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java
@@ -17,11 +17,8 @@
 package com.vaadin.server;
 
 import java.util.Properties;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.atmosphere.util.Version;
-
 import com.vaadin.shared.communication.PushMode;
 
 /**
@@ -268,28 +265,6 @@ public class DefaultDeploymentConfiguration implements DeploymentConfiguration {
             getLogger().warning(Constants.WARNING_PUSH_MODE_NOT_RECOGNIZED);
             pushMode = PushMode.DISABLED;
         }
-
-        if (pushMode.isEnabled() && !checkAtomsphereVersion()) {
-            pushMode = PushMode.DISABLED;
-        }
-    }
-
-    private boolean checkAtomsphereVersion() {
-        try {
-            String rawVersion = Version.getRawVersion();
-            if (!Constants.REQUIRED_ATMOSPHERE_VERSION.equals(rawVersion)) {
-                getLogger().log(
-                        Level.WARNING,
-                        Constants.INVALID_ATMOSPHERE_VERSION_WARNING,
-                        new Object[] { Constants.REQUIRED_ATMOSPHERE_VERSION,
-                                rawVersion });
-            }
-            return true;
-        } catch (NoClassDefFoundError e) {
-            getLogger()
-                    .log(Level.SEVERE, Constants.ATMOSPHERE_MISSING_ERROR, e);
-            return false;
-        }
     }
 
     private Logger getLogger() {
diff --git a/server/src/com/vaadin/server/UIProvider.java b/server/src/com/vaadin/server/UIProvider.java
index a91db6b88d..0305b907e6 100644
--- a/server/src/com/vaadin/server/UIProvider.java
+++ b/server/src/com/vaadin/server/UIProvider.java
@@ -20,9 +20,11 @@ import java.io.Serializable;
 import java.lang.annotation.Annotation;
 
 import com.vaadin.annotations.PreserveOnRefresh;
+import com.vaadin.annotations.Push;
 import com.vaadin.annotations.Theme;
 import com.vaadin.annotations.Title;
 import com.vaadin.annotations.Widgetset;
+import com.vaadin.shared.communication.PushMode;
 import com.vaadin.ui.UI;
 
 public abstract class UIProvider implements Serializable {
@@ -149,4 +151,27 @@ public abstract class UIProvider implements Serializable {
             return titleAnnotation.value();
         }
     }
+
+    /**
+     * Finds the {@link PushMode} to use for a specific UI. If no specific push
+     * mode is required, <code>null</code> is returned.
+     * <p>
+     * The default implementation uses the @{@link Push} annotation if it's
+     * defined for the UI class.
+     * 
+     * @param event
+     *            the UI create event with information about the UI and the
+     *            current request.
+     * @return the push mode to use, or <code>null</code> if the default push
+     *         mode should be used
+     * 
+     */
+    public PushMode getPushMode(UICreateEvent event) {
+        Push push = getAnnotationFor(event.getUIClass(), Push.class);
+        if (push == null) {
+            return null;
+        } else {
+            return push.value();
+        }
+    }
 }
diff --git a/server/src/com/vaadin/server/VaadinService.java b/server/src/com/vaadin/server/VaadinService.java
index 43d37a72b3..6088fa55ca 100644
--- a/server/src/com/vaadin/server/VaadinService.java
+++ b/server/src/com/vaadin/server/VaadinService.java
@@ -103,6 +103,13 @@ public abstract class VaadinService implements Serializable {
     private final Iterable<RequestHandler> requestHandlers;
 
     /**
+     * Keeps track of whether a warning about missing push support has already
+     * been logged. This is used to avoid spamming the log with the same message
+     * every time a new UI is bootstrapped.
+     */
+    private boolean pushWarningEmitted = false;
+
+    /**
      * Creates a new vaadin service based on a deployment configuration
      * 
      * @param deploymentConfiguration
@@ -664,7 +671,6 @@ public abstract class VaadinService implements Serializable {
         session.setLocale(locale);
         session.setConfiguration(getDeploymentConfiguration());
         session.setCommunicationManager(new LegacyCommunicationManager(session));
-        session.setPushMode(getDeploymentConfiguration().getPushMode());
 
         ServletPortletHelper.initDefaultUIProvider(session, this);
         onVaadinSessionStarted(request, session);
@@ -1455,4 +1461,24 @@ public abstract class VaadinService implements Serializable {
                 createCriticalNotificationJSON(caption, message, details, url));
     }
 
+    /**
+     * Enables push if push support is available and push has not yet been
+     * enabled.
+     * 
+     * If push support is not available, a warning explaining the situation will
+     * be logged at least the first time this method is invoked.
+     * 
+     * @return <code>true</code> if push can be used; <code>false</code> if push
+     *         is not available.
+     */
+    public boolean ensurePushAvailable() {
+        if (!pushWarningEmitted) {
+            pushWarningEmitted = true;
+            getLogger().log(Level.WARNING, Constants.PUSH_NOT_SUPPORTED_ERROR,
+                    getClass().getSimpleName());
+        }
+        // Not supported by default for now, sublcasses may override
+        return false;
+    }
+
 }
diff --git a/server/src/com/vaadin/server/VaadinServletService.java b/server/src/com/vaadin/server/VaadinServletService.java
index f513ef1b15..088bb6d640 100644
--- a/server/src/com/vaadin/server/VaadinServletService.java
+++ b/server/src/com/vaadin/server/VaadinServletService.java
@@ -22,12 +22,15 @@ import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.List;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.atmosphere.util.Version;
+
 import com.vaadin.server.communication.PushRequestHandler;
 import com.vaadin.server.communication.ServletBootstrapHandler;
 import com.vaadin.server.communication.ServletUIInitHandler;
@@ -37,6 +40,15 @@ import com.vaadin.ui.UI;
 public class VaadinServletService extends VaadinService {
     private final VaadinServlet servlet;
 
+    private final static boolean atmosphereAvailable = checkAtmosphereSupport();
+
+    /**
+     * Keeps track of whether a warning about missing push support has already
+     * been logged. This is used to avoid spamming the log with the same message
+     * every time a new UI is bootstrapped.
+     */
+    private boolean pushWarningLogged = false;
+
     public VaadinServletService(VaadinServlet servlet,
             DeploymentConfiguration deploymentConfiguration) {
         super(deploymentConfiguration);
@@ -53,12 +65,28 @@ public class VaadinServletService extends VaadinService {
         }
     }
 
+    private static boolean checkAtmosphereSupport() {
+        try {
+            String rawVersion = Version.getRawVersion();
+            if (!Constants.REQUIRED_ATMOSPHERE_VERSION.equals(rawVersion)) {
+                getLogger().log(
+                        Level.WARNING,
+                        Constants.INVALID_ATMOSPHERE_VERSION_WARNING,
+                        new Object[] { Constants.REQUIRED_ATMOSPHERE_VERSION,
+                                rawVersion });
+            }
+            return true;
+        } catch (NoClassDefFoundError e) {
+            return false;
+        }
+    }
+
     @Override
     protected List<RequestHandler> createRequestHandlers() {
         List<RequestHandler> handlers = super.createRequestHandlers();
         handlers.add(0, new ServletBootstrapHandler());
         handlers.add(new ServletUIInitHandler());
-        if (getDeploymentConfiguration().getPushMode().isEnabled()) {
+        if (atmosphereAvailable) {
             handlers.add(new PushRequestHandler(this));
         }
         return handlers;
@@ -312,4 +340,17 @@ public class VaadinServletService extends VaadinService {
         return Logger.getLogger(VaadinServletService.class.getName());
     }
 
+    @Override
+    public boolean ensurePushAvailable() {
+        if (atmosphereAvailable) {
+            return true;
+        } else {
+            if (!pushWarningLogged) {
+                pushWarningLogged = true;
+                getLogger().log(Level.WARNING,
+                        Constants.ATMOSPHERE_MISSING_ERROR);
+            }
+            return false;
+        }
+    }
 }
diff --git a/server/src/com/vaadin/server/VaadinSession.java b/server/src/com/vaadin/server/VaadinSession.java
index 029a384e70..e9b3eb6ada 100644
--- a/server/src/com/vaadin/server/VaadinSession.java
+++ b/server/src/com/vaadin/server/VaadinSession.java
@@ -129,8 +129,6 @@ public class VaadinSession implements HttpSessionBindingListener, Serializable {
 
     private transient Lock lock;
 
-    private PushMode pushMode;
-
     /**
      * Create a new service session tied to a Vaadin service
      * 
@@ -820,12 +818,13 @@ public class VaadinSession implements HttpSessionBindingListener, Serializable {
     public void unlock() {
         assert hasLock();
         try {
-            if (getPushMode() == PushMode.AUTOMATIC
-                    && ((ReentrantLock) getLockInstance()).getHoldCount() == 1) {
+            if (((ReentrantLock) getLockInstance()).getHoldCount() == 1) {
                 // Only push if the reentrant lock will actually be released by
                 // this unlock() invocation.
                 for (UI ui : getUIs()) {
-                    ui.push();
+                    if (ui.getPushMode() == PushMode.AUTOMATIC) {
+                        ui.push();
+                    }
                 }
             }
         } finally {
@@ -1025,39 +1024,6 @@ public class VaadinSession implements HttpSessionBindingListener, Serializable {
     }
 
     /**
-     * Returns the mode of bidirectional ("push") communication that is used in
-     * this session.
-     * 
-     * @return The push mode.
-     */
-    public PushMode getPushMode() {
-        return pushMode;
-    }
-
-    /**
-     * Sets the mode of bidirectional ("push") communication that should be used
-     * in this session. Set once on session creation and cannot be changed
-     * afterwards.
-     * 
-     * @param pushMode
-     *            The push mode to use.
-     * 
-     * @throws IllegalArgumentException
-     *             if the argument is null.
-     * @throws IllegalStateException
-     *             if the mode is already set.
-     */
-    public void setPushMode(PushMode pushMode) {
-        if (pushMode == null) {
-            throw new IllegalArgumentException("Push mode cannot be null");
-        }
-        if (this.pushMode != null) {
-            throw new IllegalStateException("Push mode already set");
-        }
-        this.pushMode = pushMode;
-    }
-
-    /**
      * Sets this session to be closed and all UI state to be discarded at the
      * end of the current request, or at the end of the next request if there is
      * no ongoing one.
diff --git a/server/src/com/vaadin/server/communication/PushHandler.java b/server/src/com/vaadin/server/communication/PushHandler.java
index f65a0cba10..bfa1067aa8 100644
--- a/server/src/com/vaadin/server/communication/PushHandler.java
+++ b/server/src/com/vaadin/server/communication/PushHandler.java
@@ -89,7 +89,7 @@ public class PushHandler implements AtmosphereHandler {
                         "Could not find the requested UI in session");
                 return;
             }
-            assert session.getPushMode().isEnabled();
+            assert ui.getPushMode().isEnabled();
 
             if (req.getMethod().equalsIgnoreCase("GET")) {
                 /*
diff --git a/server/src/com/vaadin/ui/UI.java b/server/src/com/vaadin/ui/UI.java
index 70ecc1f1fa..4eff7645e2 100644
--- a/server/src/com/vaadin/ui/UI.java
+++ b/server/src/com/vaadin/ui/UI.java
@@ -40,6 +40,7 @@ import com.vaadin.server.VaadinSession;
 import com.vaadin.server.communication.PushConnection;
 import com.vaadin.shared.EventId;
 import com.vaadin.shared.MouseEventDetails;
+import com.vaadin.shared.communication.PushMode;
 import com.vaadin.shared.ui.ui.ScrollClientRpc;
 import com.vaadin.shared.ui.ui.UIConstants;
 import com.vaadin.shared.ui.ui.UIServerRpc;
@@ -129,6 +130,8 @@ public abstract class UI extends AbstractSingleComponentContainer implements
      */
     private int scrollLeft = 0;
 
+    private PushMode pushMode;
+
     private UIServerRpc rpc = new UIServerRpc() {
         @Override
         public void click(MouseEventDetails mouseDetails) {
@@ -540,6 +543,10 @@ public abstract class UI extends AbstractSingleComponentContainer implements
         // Actual theme - used for finding CustomLayout templates
         theme = request.getParameter("theme");
 
+        PushMode pushMode = PushMode.valueOf(request.getParameter("v-pushMode")
+                .toUpperCase());
+        setPushMode(pushMode);
+
         getPage().init(request);
 
         // Call the init overridden by the application developer
@@ -1156,7 +1163,7 @@ public abstract class UI extends AbstractSingleComponentContainer implements
                 return;
             }
 
-            if (!session.getPushMode().isEnabled()) {
+            if (!getPushMode().isEnabled()) {
                 throw new IllegalStateException("Push not enabled");
             }
 
@@ -1217,4 +1224,45 @@ public abstract class UI extends AbstractSingleComponentContainer implements
     public int getPollInterval() {
         return getState(false).pollInterval;
     }
+
+    /**
+     * Returns the mode of bidirectional ("push") communication that is used in
+     * this UI.
+     * 
+     * @return The push mode.
+     */
+    public PushMode getPushMode() {
+        return pushMode;
+    }
+
+    /**
+     * Sets the mode of bidirectional ("push") communication that should be used
+     * in this UI. Set once on UI creation and cannot be changed afterwards.
+     * 
+     * @param pushMode
+     *            The push mode to use.
+     * 
+     * @throws IllegalArgumentException
+     *             if the argument is null.
+     * @throws IllegalStateException
+     *             if the mode is already set or if push support is not
+     *             available.
+     */
+    public void setPushMode(PushMode pushMode) {
+        if (pushMode == null) {
+            throw new IllegalArgumentException("Push mode cannot be null");
+        }
+        if (this.pushMode != null) {
+            throw new IllegalStateException("Push mode already set");
+        }
+        if (pushMode.isEnabled()) {
+            VaadinSession session = getSession();
+            if (session != null && !session.getService().ensurePushAvailable()) {
+                throw new IllegalStateException(
+                        "Push is not available. See previous log messages for more information.");
+            }
+        }
+        this.pushMode = pushMode;
+    }
+
 }