Remove dependency of portlets to liferay-integration bundle

A property can be used instead of the convenience annotation to mark a UI
as a Portlet UI registration that should be picked up by the liferay
integration. This removes the unnecessary dependency on the liferay-integration
bundle.

liferay-integration/src/main/java/com/vaadin/osgi/liferay/PortletProperties.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2000-2016 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.osgi.liferay;
+
+import javax.portlet.Portlet;
+
+import com.vaadin.ui.UI;
+
+/**
+ * Constants for Liferay {@link Portlet portlets}. This doesn't have to be used
+ * by the application developer.
+ * 
+ * @author Vaadin Ltd.
+ * @since 8.1
+ */
+public final class PortletProperties {
+    private PortletProperties() {
+
+    }
+
+    /**
+     * Property key for the Liferay category property. By default this is
+     * "category.vaadin"
+     */
+    public static final String DISPLAY_CATEGORY = "com.liferay.portlet.display-category";
+
+    /**
+     * Property key for the name of the {@link Portlet}. It is recommended to
+     * use something like the bundle symbolic name and a version string appended
+     * for the value of this property as this is used as a {@link Portlet} id.
+     */
+    public static final String PORTLET_NAME = "javax.portlet.name";
+
+    /**
+     * Property key for the {@link UI} visible name of the {@link Portlet}.
+     */
+    public static final String DISPLAY_NAME = "javax.portlet.display-name";
+
+    /**
+     * Property key for the security roles mapped to the {@link Portlet}.
+     */
+    public static final String PORTLET_SECURITY_ROLE = "javax.portlet.security-role-ref";
+
+    /**
+     * This property is used to mark the UI service as a {@link Portlet}
+     * {@link UI}. The value of this property must be non-null and will be
+     * ignored but must be present to use the {@link UI} as a {@link Portlet}.
+     * 
+     * <p>
+     * The alternative is to simply annotate the {@link UI} with
+     * {@link VaadinLiferayPortletConfiguration}.
+     */
+    public static final String PORTLET_UI_PROPERTY = "com.vaadin.osgi.liferay.portlet-ui";
+}

liferay-integration/src/main/java/com/vaadin/osgi/liferay/PortletUIServiceTrackerCustomizer.java

@@ -48,12 +48,12 @@ class PortletUIServiceTrackerCustomizer
         implements ServiceTrackerCustomizer<UI, ServiceObjects<UI>> {
 
     private static final String RESOURCE_PATH_PREFIX = "/o/%s";
-    private static final String DISPLAY_CATEGORY = "com.liferay.portlet.display-category";
+    private static final String DISPLAY_CATEGORY = PortletProperties.DISPLAY_CATEGORY;
     private static final String VAADIN_CATEGORY = "category.vaadin";
 
-    private static final String PORTLET_NAME = "javax.portlet.name";
-    private static final String DISPLAY_NAME = "javax.portlet.display-name";
-    private static final String PORTLET_SECURITY_ROLE = "javax.portlet.security-role-ref";
+    private static final String PORTLET_NAME = PortletProperties.PORTLET_NAME;
+    private static final String DISPLAY_NAME = PortletProperties.DISPLAY_NAME;
+    private static final String PORTLET_SECURITY_ROLE = PortletProperties.PORTLET_SECURITY_ROLE;
     private static final String VAADIN_RESOURCE_PATH = "javax.portlet.init-param.vaadin.resources.path";
 
     private Map<ServiceReference<UI>, ServiceRegistration<Portlet>> portletRegistrations = new HashMap<ServiceReference<UI>, ServiceRegistration<Portlet>>();
@@ -75,7 +75,11 @@ class PortletUIServiceTrackerCustomizer
             Class<? extends UI> uiClass = contributedUI.getClass();
             VaadinLiferayPortletConfiguration portletConfiguration = uiClass
                     .getAnnotation(VaadinLiferayPortletConfiguration.class);
-            if (portletConfiguration != null) {
+
+            boolean isPortletUi = uiServiceReference
+                    .getProperty(PortletProperties.PORTLET_UI_PROPERTY) != null
+                    || portletConfiguration != null;
+            if (isPortletUi) {
                 return registerPortlet(uiServiceReference,
                         portletConfiguration);
             } else {
@@ -98,8 +102,13 @@ class PortletUIServiceTrackerCustomizer
 
         OSGiUIProvider uiProvider = new OSGiUIProvider(serviceObjects);
 
-        Dictionary<String, Object> properties = createPortletProperties(
-                uiProvider, reference, configuration);
+        Dictionary<String, Object> properties = null;
+        if (configuration != null) {
+            properties = createPortletProperties(uiProvider, reference,
+                    configuration);
+        } else {
+            properties = createPortletProperties(reference);
+        }
 
         VaadinOSGiPortlet portlet = new VaadinOSGiPortlet(uiProvider);
 
@@ -157,6 +166,19 @@ class PortletUIServiceTrackerCustomizer
         }
     }
 
+    private Dictionary<String, Object> createPortletProperties(
+            ServiceReference<UI> reference) {
+        Hashtable<String, Object> properties = new Hashtable<>();
+        for (String key : reference.getPropertyKeys()) {
+            properties.put(key, reference.getProperty(key));
+        }
+        String resourcesPath = String.format(RESOURCE_PATH_PREFIX,
+                service.getResourcePathPrefix());
+        properties.put(VAADIN_RESOURCE_PATH, resourcesPath);
+
+        return properties;
+    }
+
     @Override
     public void modifiedService(ServiceReference<UI> serviceReference,
             ServiceObjects<UI> ui) {