ONOS-7963 workflow invocation trigger on ONOS event

Change-Id: Ie9014bfa77f5514c3580042f9ff2add8e42f25f6
diff --git a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/WorkflowEventMetaData.java b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/WorkflowEventMetaData.java
new file mode 100644
index 0000000..24a485c
--- /dev/null
+++ b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/WorkflowEventMetaData.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2019-present Open Networking Foundation
+ *
+ * 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.workflow.api;
+
+
+import com.google.common.base.MoreObjects;
+
+/**
+ * A class representing meta data for workflow event.
+ */
+public class WorkflowEventMetaData {
+
+    private boolean isTriggerSet = false;
+    private ProgramCounter programCounter;
+
+    /**
+     * Constructor of workflow event meta data.
+     * @param isTriggerSet trigger event set for the the workflow
+     * @param programCounter program counter representing worklet type for registered event
+     */
+    public WorkflowEventMetaData(boolean isTriggerSet, ProgramCounter programCounter) {
+        this.isTriggerSet = isTriggerSet;
+        this.programCounter = programCounter;
+    }
+
+    /**
+     * Copy constructor of workflow event meta data.
+     * @param workflowEventMetaData object of WorkflowEventMetaData
+     */
+    public WorkflowEventMetaData(WorkflowEventMetaData workflowEventMetaData) {
+        this.isTriggerSet = workflowEventMetaData.getTriggerFlag();
+        this.programCounter = workflowEventMetaData.getProgramCounter().clone();
+    }
+
+    /**
+     * Returns program counter value related to worflow event.
+     * @return programCounter
+     */
+    public ProgramCounter getProgramCounter() {
+        return programCounter;
+    }
+
+    /**
+     * Returns trigger flag for the workflow.
+     * @return triggerFlag
+     */
+    public boolean getTriggerFlag() {
+        return isTriggerSet;
+    }
+
+
+    /**
+     * Sets true or false for triggerFlag of the workflow.
+     * @param triggerFlag flag to indicate trigger event set for the workflow
+     */
+    public void setTriggerFlag(boolean triggerFlag) {
+        this.isTriggerSet = triggerFlag;
+    }
+
+    /**
+     * Sets program counter representing worklet type for registered event of the workflow.
+     * @param programCounter program counter representing worklet type for registered event
+     */
+    public void setProgramCounterString(ProgramCounter programCounter) {
+        this.programCounter = programCounter;
+    }
+
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("trigger-flag", getTriggerFlag())
+                .add("program-counter", getProgramCounter())
+                .toString();
+    }
+
+}