Moved server files to a server src folder (#9299)

1 files changed, 52 insertions, 0 deletions

diff --git a/server/src/com/vaadin/event/dd/DragSource.java b/server/src/com/vaadin/event/dd/DragSource.java
new file mode 100644
index 0000000000..4daf0dcb18
--- /dev/null
+++ b/server/src/com/vaadin/event/dd/DragSource.java
@@ -0,0 +1,52 @@
+/*
+@VaadinApache2LicenseForJavaFiles@
+ */
+package com.vaadin.event.dd;
+
+import java.util.Map;
+
+import com.vaadin.event.Transferable;
+import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
+import com.vaadin.ui.Component;
+import com.vaadin.ui.Tree;
+
+/**
+ * DragSource is a {@link Component} that builds a {@link Transferable} for a
+ * drag and drop operation.
+ * <p>
+ * In Vaadin the drag and drop operation practically starts from client side
+ * component. The client side component initially defines the data that will be
+ * present in {@link Transferable} object on server side. If the server side
+ * counterpart of the component implements this interface, terminal
+ * implementation lets it create the {@link Transferable} instance from the raw
+ * client side "seed data". This way server side implementation may translate or
+ * extend the data that will be available for {@link DropHandler}.
+ * 
+ * @since 6.3
+ * 
+ */
+public interface DragSource extends Component {
+
+    /**
+     * DragSource may convert data added by client side component to meaningful
+     * values for server side developer or add other data based on it.
+     * 
+     * <p>
+     * For example Tree converts item identifiers to generated string keys for
+     * the client side. Vaadin developer don't and can't know anything about
+     * these generated keys, only about item identifiers. When tree node is
+     * dragged client puts that key to {@link Transferable}s client side
+     * counterpart. In {@link Tree#getTransferable(Map)} the key is converted
+     * back to item identifier that the server side developer can use.
+     * <p>
+     * 
+     * @since 6.3
+     * @param rawVariables
+     *            the data that client side initially included in
+     *            {@link Transferable}s client side counterpart.
+     * @return the {@link Transferable} instance that will be passed to
+     *         {@link DropHandler} (and/or {@link AcceptCriterion})
+     */
+    public Transferable getTransferable(Map<String, Object> rawVariables);
+
+}
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