ONOS-3461 Disable LinkDiscovery on specific device/port.

- Configuration moved from "apps" -> "devices", "ports"
  in network configuration tree

Change-Id: I030bab489939ce5326a6ebea14f246726ca024f0
diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/BasicFeatureConfig.java b/core/api/src/main/java/org/onosproject/net/config/basics/BasicFeatureConfig.java
new file mode 100644
index 0000000..fcf24bc
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/BasicFeatureConfig.java
@@ -0,0 +1,54 @@
+/*
+ * 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.net.config.basics;
+
+import org.onosproject.net.config.Config;
+
+/**
+ * Base abstraction for configuring feature on subject.
+ *
+ * @param <S> Subject type
+ */
+public abstract class BasicFeatureConfig<S> extends Config<S> {
+
+    private static final String ENABLED = "enabled";
+
+    private final boolean defaultValue;
+
+    protected BasicFeatureConfig(boolean defaultValue) {
+        this.defaultValue = defaultValue;
+    }
+
+    /**
+     * Indicates whether the feature for the subject is enabled.
+     *
+     * @return true if feature is enabled
+     */
+    public boolean enabled() {
+        return get(ENABLED, defaultValue);
+    }
+
+    /**
+     * Specifies whether the feature for the subject is to be enabled.
+     *
+     * @param enabled true to enable; false to disable; null to clear
+     * @return self
+     */
+    public BasicFeatureConfig<S> enabled(Boolean enabled) {
+        return (BasicFeatureConfig<S>) setOrClear(ENABLED, enabled);
+    }
+
+}