Drag'n'Drop related implementations including:

- dropping MetaContact-s or simple String addresses in the Call dialog would initiate an invite and hence the creation of a conference call or if such already exist just the adding of the new callee to the conference.
- added the possibility to drag the number entered in the call field on the bottom of the contact list.
- replaced previous implementation of Drag'n'Drop in the contact list with the default drag'n'drop mechanism used in java, thus allowing the dropping of contacts outside the contact list (like in an existing call, chat or simply as a string in any other desktop application)
- extended and override the default TransferHandler to provide visual representation of the dragged object (special handling of MetaContacts is provided in the ContactListCellRenderer) and add support of MetaContact flavor.

1 files changed, 233 insertions, 7 deletions

diff --git a/src/net/java/sip/communicator/impl/gui/main/contactlist/ContactListTransferHandler.java b/src/net/java/sip/communicator/impl/gui/main/contactlist/ContactListTransferHandler.java
index e5141a3..7a177c6 100644
--- a/src/net/java/sip/communicator/impl/gui/main/contactlist/ContactListTransferHandler.java
+++ b/src/net/java/sip/communicator/impl/gui/main/contactlist/ContactListTransferHandler.java
@@ -19,7 +19,7 @@ import net.java.sip.communicator.util.*;
 import net.java.sip.communicator.util.swing.*;
 
 /**
- * A TransferHandler that we use to handle DnD operations of files in our
+ * A TransferHandler that we use to handle DnD operations in our
  * <tt>ContactList</tt>.
  *
  * @author Yana Stamcheva
@@ -32,12 +32,62 @@ public class ContactListTransferHandler
 
     private final DefaultContactList contactList;
 
+    /**
+     * Creates an instance of <tt>ContactListTransferHandler</tt> passing the
+     * <tt>contactList</tt> which uses this <tt>TransferHandler</tt>.
+     * @param contactList the <tt>DefaultContactList</tt> which uses this
+     * <tt>TransferHandler</tt>
+     */
     public ContactListTransferHandler(DefaultContactList contactList)
     {
         this.contactList = contactList;
     }
 
     /**
+     * Creates a transferable for text pane components in order to enable drag
+     * and drop of text.
+     * @param component the component for which to create a
+     * <tt>Transferable</tt>
+     * @return the created <tt>Transferable</tt>
+     */
+    public Transferable createTransferable(JComponent component)
+    {
+        if (component instanceof JList)
+        {
+            JList list = (JList) component;
+            return new ContactListTransferable(
+                list.getSelectedIndex(), list.getSelectedValue());
+        }
+
+        return super.createTransferable(component);
+    }
+
+    /**
+     * Indicates whether a component will accept an import of the given
+     * set of data flavors prior to actually attempting to import it. We return
+     * <tt>true</tt> to indicate that the transfer with at least one of the
+     * given flavors would work and <tt>false</tt> to reject the transfer.
+     * <p>
+     * @param comp component
+     * @param flavor the data formats available
+     * @return  true if the data can be inserted into the component, false
+     * otherwise
+     * @throws NullPointerException if <code>support</code> is {@code null}
+     */
+    public boolean canImport(JComponent comp, DataFlavor flavor[])
+    {
+        for (int i = 0, n = flavor.length; i < n; i++)
+        {
+            if (flavor[i].equals(metaContactDataFlavor))
+            {
+                return true;
+            }
+        }
+
+        return super.canImport(comp, flavor);
+    }
+
+    /**
      * Handles transfers to the contact list from the clip board or a
      * DND drop operation. The <tt>Transferable</tt> parameter contains the
      * data that needs to be imported.
@@ -83,16 +133,114 @@ public class ContactListTransferHandler
                         GuiActivator.getUIService().getChatWindowManager()
                             .openChat(chatPanel, false);
                     }
-
-                    // Otherwise fire files dropped event.
                     return true;
                 }
             }
         }
+        else if (t.isDataFlavorSupported(metaContactDataFlavor))
+        {
+            Object o = null;
+
+            try
+            {
+                o = t.getTransferData(metaContactDataFlavor);
+            }
+            catch (UnsupportedFlavorException e)
+            {
+                if (logger.isDebugEnabled())
+                    logger.debug("Failed to drop meta contact.", e);
+            }
+            catch (IOException e)
+            {
+                if (logger.isDebugEnabled())
+                    logger.debug("Failed to drop meta contact.", e);
+            }
+
+            if (o instanceof MetaContact
+                && comp instanceof ContactList)
+            {
+                MetaContact transferredContact = (MetaContact) o;
+                ContactList list = (ContactList) comp;
+
+                Object dest = list.getSelectedValue();
+
+                if (transferredContact != null)
+                {
+                    if (dest instanceof MetaContact)
+                    {
+                        MetaContact destContact = (MetaContact) dest;
+                        if (transferredContact != destContact)
+                        {
+                            list.moveMetaContactToMetaContact(
+                                transferredContact, destContact);
+                        }
+                        return true;
+                    }
+                    else if (dest instanceof MetaContactGroup)
+                    {
+                        MetaContactGroup destGroup = (MetaContactGroup) dest;
+
+                        if (transferredContact.getParentMetaContactGroup()
+                                != destGroup)
+                        {
+                            list.moveMetaContactToGroup(
+                                transferredContact, destGroup);
+                        }
+                        return true;
+                    }
+                }
+            }
+        }
         return false;
     }
 
     /**
+     * Overrides <tt>TransferHandler.getVisualRepresentation(Transferable t)</tt>
+     * in order to return a custom drag icon.
+     * <p>
+     * The default parent implementation of this method returns null.
+     *
+     * @param t  the data to be transferred; this value is expected to have been
+     * created by the <code>createTransferable</code> method
+     * @return the icon to show when dragging
+     */
+    public Icon getVisualRepresentation(Transferable t)
+    {
+        ContactListCellRenderer renderer = null;
+
+        if (t instanceof ContactListTransferable)
+        {
+            ContactListTransferable transferable = ((ContactListTransferable) t);
+
+            try
+            {
+                renderer = (ContactListCellRenderer)
+                    contactList.getCellRenderer()
+                        .getListCellRendererComponent(
+                        contactList,
+                        transferable.getTransferData(metaContactDataFlavor),
+                        transferable.getTransferIndex(), false, false);
+            }
+            catch (UnsupportedFlavorException e)
+            {
+                if (logger.isDebugEnabled())
+                    logger.debug(
+                        "Unsupported flavor while" +
+                        " obtaining transfer data.", e);
+            }
+            catch (IOException e)
+            {
+                if (logger.isDebugEnabled())
+                    logger.debug(
+                        "The data for the request flavor" +
+                        " is no longer available.", e);
+            }
+        }
+
+        return renderer;
+    }
+
+    /**
      * Returns the <tt>ChatPanel</tt> corresponding to the currently selected
      * contact.
      *
@@ -109,13 +257,91 @@ public class ContactListTransferHandler
             MetaContact metaContact = (MetaContact) selectedObject;
 
             // Obtain the corresponding chat panel.
-            chatPanel
-                = GuiActivator
-                    .getUIService()
-                        .getChatWindowManager()
+            chatPanel = GuiActivator.getUIService().getChatWindowManager()
                             .getContactChat(metaContact, true);
         }
 
         return chatPanel;
     }
+
+    /**
+     * Transferable for JList that enables drag and drop of contacts.
+     */
+    public class ContactListTransferable implements Transferable
+    {
+        private int transferredIndex;
+
+        private Object transferredObject;
+
+        /**
+         * Creates an instance of <tt>ContactListTransferable</tt>.
+         * @param index the index of the transferred object in the list
+         * @param o the transferred list object
+         */
+        public ContactListTransferable(int index, Object o)
+        {
+            this.transferredIndex = index;
+            this.transferredObject = o;
+        }
+
+        /**
+         * Returns supported flavors.
+         * @return an array of supported flavors
+         */
+        public DataFlavor[] getTransferDataFlavors()
+        {
+            return new DataFlavor[] {   metaContactDataFlavor,
+                                        DataFlavor.stringFlavor};
+        }
+
+        /**
+         * Returns <tt>true</tt> if the given <tt>flavor</tt> is supported,
+         * otherwise returns <tt>false</tt>.
+         * @param flavor the data flavor to verify
+         * @return <tt>true</tt> if the given <tt>flavor</tt> is supported,
+         * otherwise returns <tt>false</tt>
+         */
+        public boolean isDataFlavorSupported(DataFlavor flavor)
+        {
+            return metaContactDataFlavor.equals(flavor)
+                    || DataFlavor.stringFlavor.equals(flavor);
+        }
+
+        /**
+         * Returns the selected text.
+         * @param flavor the flavor
+         * @return the selected text
+         * @exception UnsupportedFlavorException if the requested data flavor
+         * is not supported.
+         * @exception IOException if the data is no longer available in the
+         * requested flavor.
+         */
+        public Object getTransferData(DataFlavor flavor)
+            throws  UnsupportedFlavorException,
+                    IOException
+        {
+            if (metaContactDataFlavor.equals(flavor))
+            {
+                return transferredObject;
+            }
+            else if (DataFlavor.stringFlavor.equals(flavor))
+            {
+                if (transferredObject instanceof MetaContact)
+                    return ((MetaContact) transferredObject).getDisplayName();
+            }
+            else
+                throw new UnsupportedFlavorException(flavor);
+
+            return null;
+        }
+
+        /**
+         * Returns the index of the transferred list cell.
+         * @return the index of the transferred list cell
+         */
+        public int getTransferIndex()
+        {
+            return transferredIndex;
+        }
+    }
 }