Add @author and @since tags to drag and drop related new files (#8693) (#8694)

* Add @author and @since tags to drag and drop related new files (#8693)

client/src/main/java/com/vaadin/client/extensions/DragSourceExtensionConnector.java

@@ -36,6 +36,9 @@ import elemental.events.EventTarget;
 /**
  * Extension to add drag source functionality to a widget for using HTML5 drag
  * and drop. Client side counterpart of {@link DragSourceExtension}.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 @Connect(DragSourceExtension.class)
 public class DragSourceExtensionConnector extends AbstractExtensionConnector {

client/src/main/java/com/vaadin/client/extensions/DropTargetExtensionConnector.java

@@ -40,6 +40,9 @@ import elemental.events.EventTarget;
 /**
  * Extension to add drop target functionality to a widget for using HTML5 drag
  * and drop. Client side counterpart of {@link DropTargetExtension}.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 @Connect(DropTargetExtension.class)
 public class DropTargetExtensionConnector extends AbstractExtensionConnector {

server/src/main/java/com/vaadin/event/dnd/DragEndEvent.java

@@ -28,7 +28,9 @@ import com.vaadin.ui.Component;
  *
  * @param <T>
  *         Type of the component that was dragged.
+ * @author Vaadin Ltd
  * @see DragSourceExtension#addDragEndListener(DragEndListener)
+ * @since 8.1
  */
 public class DragEndEvent<T extends AbstractComponent> extends Component.Event {
     private final Map<String, String> data;

server/src/main/java/com/vaadin/event/dnd/DragEndListener.java

@@ -26,7 +26,9 @@ import com.vaadin.ui.AbstractComponent;
  *
  * @param <T>
  *         Type of draggable component.
+ * @author Vaadin Ltd
  * @see DragSourceExtension#addDragEndListener(DragEndListener)
+ * @since 8.1
  */
 @FunctionalInterface
 public interface DragEndListener<T extends AbstractComponent> extends

server/src/main/java/com/vaadin/event/dnd/DragSourceExtension.java

@@ -33,6 +33,8 @@ import com.vaadin.ui.AbstractComponent;
  *
  * @param <T>
  *         Type of the component to be extended.
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public class DragSourceExtension<T extends AbstractComponent> extends
         AbstractExtension {

server/src/main/java/com/vaadin/event/dnd/DragStartEvent.java

@@ -29,9 +29,12 @@ import com.vaadin.ui.Component;
  *
  * @param <T>
  *         Type of the component that is dragged.
+ * @author Vaadin Ltd
  * @see DragSourceExtension#addDragStartListener(DragStartListener)
+ * @since 8.1
  */
-public class DragStartEvent<T extends AbstractComponent> extends Component.Event {
+public class DragStartEvent<T extends AbstractComponent> extends
+        Component.Event {
     private final Map<String, String> data;
     private final EffectAllowed effectAllowed;
 

server/src/main/java/com/vaadin/event/dnd/DragStartListener.java

@@ -26,7 +26,9 @@ import com.vaadin.ui.AbstractComponent;
  *
  * @param <T>
  *         Type of draggable component.
+ * @author Vaadin Ltd
  * @see DragSourceExtension#addDragStartListener(DragStartListener)
+ * @since 8.1
  */
 @FunctionalInterface
 public interface DragStartListener<T extends AbstractComponent> extends

server/src/main/java/com/vaadin/event/dnd/DropEvent.java

@@ -29,7 +29,9 @@ import com.vaadin.ui.Component;
  *
  * @param <T>
  *         Type of the drop target component.
+ * @author Vaadin Ltd
  * @see DropTargetExtension#addDropListener(DropListener)
+ * @since 8.1
  */
 public class DropEvent<T extends AbstractComponent> extends Component.Event {
     private final Map<String, String> data;

server/src/main/java/com/vaadin/event/dnd/DropListener.java

@@ -26,7 +26,9 @@ import com.vaadin.ui.AbstractComponent;
  *
  * @param <T>
  *         Type of the drop target component.
+ * @author Vaadin Ltd
  * @see DropTargetExtension#addDropListener(DropListener)
+ * @since 8.1
  */
 @FunctionalInterface
 public interface DropListener<T extends AbstractComponent> extends

server/src/main/java/com/vaadin/event/dnd/DropTargetExtension.java

@@ -31,6 +31,8 @@ import com.vaadin.ui.AbstractComponent;
  *
  * @param <T>
  *         Type of the component to be extended.
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public class DropTargetExtension<T extends AbstractComponent> extends
         AbstractExtension {

shared/src/main/java/com/vaadin/shared/ui/dnd/DragSourceRpc.java

@@ -20,6 +20,9 @@ import com.vaadin.shared.communication.ServerRpc;
 /**
  * RPC for firing server side event when client side dragstart event happens on
  * drag source.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public interface DragSourceRpc extends ServerRpc {
 

shared/src/main/java/com/vaadin/shared/ui/dnd/DragSourceState.java

@@ -24,6 +24,9 @@ import com.vaadin.shared.communication.SharedState;
 
 /**
  * State class containing parameters for DragSourceExtension.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public class DragSourceState extends SharedState {
 

shared/src/main/java/com/vaadin/shared/ui/dnd/DropEffect.java

@@ -17,6 +17,9 @@ package com.vaadin.shared.ui.dnd;
 
 /**
  * Used to specify the drop effect to use on dragenter or dragover events.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public enum DropEffect {
     /**

shared/src/main/java/com/vaadin/shared/ui/dnd/DropTargetRpc.java

@@ -23,6 +23,9 @@ import com.vaadin.shared.communication.ServerRpc;
 /**
  * RPC for firing server side drop event when client side drop event happens on
  * drop target.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public interface DropTargetRpc extends ServerRpc {
 

shared/src/main/java/com/vaadin/shared/ui/dnd/DropTargetState.java

@@ -19,6 +19,9 @@ import com.vaadin.shared.communication.SharedState;
 
 /**
  * State class containing parameters for DropTargetExtension.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public class DropTargetState extends SharedState {
     /**

shared/src/main/java/com/vaadin/shared/ui/dnd/EffectAllowed.java

@@ -17,6 +17,9 @@ package com.vaadin.shared.ui.dnd;
 
 /**
  * Used to specify the effect that is allowed for a drag operation.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
  */
 public enum EffectAllowed {
     /**