--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ * VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.ui.dnd;\r
+\r
+import org.eclipse.jface.viewers.ISelectionProvider;\r
+import org.eclipse.jface.viewers.IStructuredSelection;\r
+import org.eclipse.swt.dnd.DND;\r
+import org.eclipse.swt.dnd.DragSource;\r
+import org.eclipse.swt.dnd.DragSourceEvent;\r
+import org.eclipse.swt.dnd.DragSourceListener;\r
+import org.eclipse.swt.dnd.TextTransfer;\r
+import org.eclipse.swt.dnd.Transfer;\r
+import org.eclipse.swt.widgets.Control;\r
+import org.simantics.db.Session;\r
+import org.simantics.db.common.ResourceArray;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.ui.utils.ResourceAdaptionUtils;\r
+\r
+/**\r
+ * A basic combined implementation of an SWT {@link DragSource} and\r
+ * {@link DragSourceListener} that supports the following transfers:\r
+ * <ul>\r
+ * <li>{@link TextTransfer}</li>\r
+ * <li>{@link ResourceReferenceTransfer}</li>\r
+ * <li>{@link LocalObjectTransfer}</li>\r
+ * </ul>\r
+ * \r
+ * <p>\r
+ * Initialization requires the SWT {@link Control} which the drag source is\r
+ * attached, an {@link ISelectionProvider} for the control and a database\r
+ * session.\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ */\r
+public class BasicDragSource implements DragSourceListener, SessionContainer {\r
+\r
+ private Transfer[] transferAgents;\r
+\r
+ private ISelectionProvider selectionProvider;\r
+\r
+ private IStructuredSelection sel;\r
+\r
+ private ResourceArray[] resources;\r
+\r
+ private Session session;\r
+\r
+ private String purpose;\r
+\r
+ /**\r
+ * @param selectionProvider\r
+ * @param sourceControl\r
+ * @param session the database Session to be used for serialization by this\r
+ * drag source or <code>null</code> to put this drag source in\r
+ * disabled state at construction time. To later enable this drag\r
+ * source, use {@link #setSession(Session)} to set the resource\r
+ * serializer.\r
+ */\r
+ public BasicDragSource(ISelectionProvider selectionProvider, Control sourceControl, Session session) {\r
+ this(selectionProvider, sourceControl, session, null);\r
+ }\r
+\r
+ /**\r
+ * @param selectionProvider\r
+ * @param sourceControl\r
+ * @param session the database Session to be used for serialization by this\r
+ * drag source or <code>null</code> to put this drag source in\r
+ * disabled state at construction time. To later enable this drag\r
+ * source, use {@link #setSession(Session)} to set the resource\r
+ * serializer.\r
+ * @param purpose a string for defining a designation of the purpose of this\r
+ * drag source. <code>null</code> indicates no special purpose.\r
+ */\r
+ public BasicDragSource(ISelectionProvider selectionProvider, Control sourceControl, Session session, String purpose) {\r
+ this.selectionProvider = selectionProvider;\r
+ this.transferAgents = new Transfer[] { \r
+ TextTransfer.getInstance(), \r
+ ResourceReferenceTransfer.createInstance(purpose),\r
+ LocalObjectTransfer.getTransfer()\r
+ };\r
+ this.session = session;\r
+ this.purpose = purpose;\r
+ DragSource source = new DragSource(sourceControl, DND.DROP_LINK | DND.DROP_MOVE | DND.DROP_COPY | DND.DROP_DEFAULT);\r
+ source.setTransfer(transferAgents);\r
+ source.addDragListener(this);\r
+\r
+ // NOTE: This will disable SWT DND selection screenshot painting.\r
+ source.setDragSourceEffect(new NoImageDragSourceEffect(sourceControl));\r
+ }\r
+\r
+ @Override\r
+ public Session getSession() {\r
+ return session;\r
+ }\r
+\r
+ @Override\r
+ public void setSession(Session session) {\r
+ this.session = session;\r
+ }\r
+\r
+ public void dragStart(DragSourceEvent event) {\r
+ // Don't start dragging by default.\r
+ event.doit = false;\r
+\r
+ // Drag won't work without a database session.\r
+ if (session == null)\r
+ return;\r
+\r
+ // Allow drag to start only if the selection is non-empty.\r
+ sel = (IStructuredSelection) selectionProvider.getSelection();\r
+ if (sel == null || sel.isEmpty())\r
+ return;\r
+\r
+ resources = ResourceAdaptionUtils.toResourceArrays(sel);\r
+\r
+ event.doit = resources.length > 0; \r
+ }\r
+\r
+ public void dragSetData(DragSourceEvent event) {\r
+ if (ResourceReferenceTransfer.getInstance().isSupportedType(event.dataType)) {\r
+ event.data = resources; \r
+ } else if (LocalObjectTransfer.getTransfer().isSupportedType(event.dataType)) {\r
+ event.data = sel;\r
+ } else if (TextTransfer.getInstance().isSupportedType(event.dataType)) {\r
+ try {\r
+ event.data = ResourceTransferUtils.createStringTransferable(session, resources, purpose);\r
+ } catch (DatabaseException e) {\r
+ event.doit = false;\r
+ e.printStackTrace();\r
+ }\r
+ }\r
+ }\r
+\r
+ public void dragFinished(DragSourceEvent event) {\r
+ // release resources\r
+ sel = null;\r
+ resources = null;\r
+ }\r
+\r
+}\r
Code Review / simantics / platform.git / blobdiff