Adding support for user interface extensions.
Change-Id: I1e41d16efc11be31ad4c2fb0c09e86e3dfd26706
diff --git a/core/api/src/main/java/org/onosproject/ui/UiExtension.java b/core/api/src/main/java/org/onosproject/ui/UiExtension.java
new file mode 100644
index 0000000..4e2f570
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/ui/UiExtension.java
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.ui;
+
+import com.google.common.collect.ImmutableList;
+
+import java.io.InputStream;
+import java.util.List;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * User interface extension.
+ */
+public class UiExtension {
+
+ private final String prefix;
+ private final ClassLoader classLoader;
+ private final List<UiView> views;
+
+ /**
+ * Creates a user interface extension for loading CSS and JS injections
+ * from {@code css.html} and {@code js.html} resources, respectively.
+ *
+ * @param classLoader class-loader for user interface resources
+ */
+ public UiExtension(List<UiView> views, ClassLoader classLoader) {
+ this(views, null, classLoader);
+ }
+
+ /**
+ * Creates a user interface extension using custom resource prefix. It
+ * loads CSS and JS injections from {@code path/css.html} and
+ * {@code prefix/js.html} resources, respectively.
+ *
+ * @param views list of user interface views
+ * @param path resource path prefix
+ * @param classLoader class-loader for user interface resources
+ */
+ public UiExtension(List<UiView> views, String path, ClassLoader classLoader) {
+ this.views = checkNotNull(ImmutableList.copyOf(views), "Views cannot be null");
+ this.prefix = path != null ? (path + "/") : "";
+ this.classLoader = checkNotNull(classLoader, "Class loader must be specified");
+ }
+
+ /**
+ * Returns input stream containing CSS inclusion statements.
+ *
+ * @return CSS inclusion statements
+ */
+ public InputStream css() {
+ return classLoader.getResourceAsStream(prefix + "css.html");
+ }
+
+ /**
+ * Returns input stream containing JavaScript inclusion statements.
+ *
+ * @return JavaScript inclusion statements
+ */
+ public InputStream js() {
+ return classLoader.getResourceAsStream(prefix + "js.html");
+ }
+
+ /**
+ * Returns list of user interface views contributed by this extension.
+ *
+ * @return contributed view descriptors
+ */
+ public List<UiView> views() {
+ return views;
+ }
+
+ /**
+ * Returns input stream containing specified view-specific resource.
+ *
+ * @param viewId view identifier
+ * @param path resource path, relative to the view directory
+ * @return resource input stream
+ */
+ public InputStream resource(String viewId, String path) {
+ InputStream is = classLoader.getResourceAsStream(prefix + "views/" + viewId + "/" + path);
+ return is;
+ }
+
+}
diff --git a/core/api/src/main/java/org/onosproject/ui/UiExtensionService.java b/core/api/src/main/java/org/onosproject/ui/UiExtensionService.java
new file mode 100644
index 0000000..330fbb7
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/ui/UiExtensionService.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.ui;
+
+import java.util.List;
+
+/**
+ * Service for registering user interface extensions.
+ */
+public interface UiExtensionService {
+
+ /**
+ * Registers the specified user interface extension.
+ *
+ * @param extension GUI extension to register
+ */
+ void register(UiExtension extension);
+
+ /**
+ * Unregisters the specified user interface extension.
+ *
+ * @param extension GUI extension to unregister
+ */
+ void unregister(UiExtension extension);
+
+ /**
+ * Returns the list of user interface extensions.
+ *
+ * @return list of extensions
+ */
+ List<UiExtension> getExtensions();
+
+ /**
+ * Returns the user interface extension that contributed the specified view.
+ *
+ * @param viewId view identifier
+ * @return user interface extension
+ */
+ UiExtension getViewExtension(String viewId);
+}
diff --git a/core/api/src/main/java/org/onosproject/ui/UiView.java b/core/api/src/main/java/org/onosproject/ui/UiView.java
new file mode 100644
index 0000000..2f2bc0e
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/ui/UiView.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.ui;
+
+import com.google.common.base.MoreObjects;
+
+import java.util.Objects;
+
+/**
+ * Represents user interface view addition.
+ */
+public class UiView {
+
+ private final String id;
+ private final String label;
+
+ /**
+ * Creates a new user interface view descriptor.
+ *
+ * @param id view identifier
+ * @param label view label
+ */
+ public UiView(String id, String label) {
+ this.id = id;
+ this.label = label;
+ }
+
+ /**
+ * Returns the view identifier.
+ *
+ * @return view id
+ */
+ public String id() {
+ return id;
+ }
+
+ /**
+ * Returns the view label.
+ *
+ * @return view label
+ */
+ public String label() {
+ return label;
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(id);
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj) {
+ return true;
+ }
+ if (obj == null || getClass() != obj.getClass()) {
+ return false;
+ }
+ final UiView other = (UiView) obj;
+ return Objects.equals(this.id, other.id);
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(this)
+ .add("id", id)
+ .add("label", label)
+ .toString();
+ }
+}
diff --git a/core/api/src/main/java/org/onosproject/ui/package-info.java b/core/api/src/main/java/org/onosproject/ui/package-info.java
new file mode 100644
index 0000000..dd832a5
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/ui/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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.
+ */
+
+/**
+ * Mechanism for managing dynamically registered user interface extensions.
+ */
+package org.onosproject.ui;