Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.diagram / src / org / simantics / diagram / synchronization / graph / ElementReorder.java

diff --git a/bundles/org.simantics.diagram/src/org/simantics/diagram/synchronization/graph/ElementReorder.java b/bundles/org.simantics.diagram/src/org/simantics/diagram/synchronization/graph/ElementReorder.java
new file mode 100644 (file)
index 0000000..0d78cd1
--- /dev/null
+++ b/bundles/org.simantics.diagram/src/org/simantics/diagram/synchronization/graph/ElementReorder.java
@@ -0,0 +1,106 @@
+/*******************************************************************************\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.diagram.synchronization.graph;\r
+\r
+import java.util.ArrayList;\r
+import java.util.HashMap;\r
+import java.util.HashSet;\r
+import java.util.List;\r
+import java.util.Map;\r
+import java.util.Set;\r
+\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.WriteGraph;\r
+import org.simantics.db.common.utils.OrderedSetUtils;\r
+import org.simantics.diagram.synchronization.ModificationAdapter;\r
+import org.simantics.diagram.ui.DiagramModelHints;\r
+import org.simantics.g2d.diagram.IDiagram;\r
+import org.simantics.g2d.element.ElementUtils;\r
+import org.simantics.g2d.element.IElement;\r
+\r
+/**\r
+ * This modification reorders the specified diagram in the graph backend\r
+ * according to the order of the elements specified argument element list.\r
+ * \r
+ * <p>\r
+ * The algorithm is linear with respect to the amount of elements on the\r
+ * diagram. It tries to minimize the number of ordered set operations.\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ */\r
+public class ElementReorder extends ModificationAdapter {\r
+\r
+    IDiagram diagram;\r
+    List<IElement> order;\r
+\r
+    public ElementReorder(IDiagram diagram, List<IElement> order) {\r
+        super(LOW_PRIORITY);\r
+        this.diagram = diagram;\r
+        this.order = order;\r
+    }\r
+\r
+    @Override\r
+    public void perform(WriteGraph g) throws Exception {\r
+        Resource l = diagram.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE);\r
+\r
+        List<Resource> graphOrder = OrderedSetUtils.toList(g, l);\r
+        Set<Resource> graphContents = new HashSet<Resource>(graphOrder);\r
+\r
+        List<Resource> diagramOrder = new ArrayList<Resource>(order.size());\r
+        Map<Resource, Integer> diagramOrderIndex = new HashMap<Resource, Integer>(order.size());\r
+        int i = 0;\r
+        for (IElement e : order) {\r
+            Object obj = ElementUtils.getObject(e);\r
+            if (obj instanceof Resource) {\r
+                Resource r = (Resource) obj;\r
+                // Only consider resources that still are in the diagram.\r
+                // This prevents errors in situations where #order contains\r
+                // elements that no longer exist in the diagram.\r
+                if (graphContents.contains(r)) {\r
+                    diagramOrder.add(r);\r
+                    diagramOrderIndex.put(r, Integer.valueOf(i));\r
+                    ++i;\r
+                }\r
+            }\r
+        }\r
+\r
+        // Reorder the backend list according to diagramOrder\r
+        i = 0;\r
+        for (Resource r : graphOrder) {\r
+            Integer di = diagramOrderIndex.get(r);\r
+            if (di != null) {\r
+                int targetIndex = di;\r
+                int graphIndex = i++;\r
+                if (graphIndex != targetIndex) {\r
+                    // Check if the predecessor of r is already correct.\r
+                    // If it is, we don't have to do anything for r.\r
+                    Resource graphPrev = OrderedSetUtils.prev(g, l, r);\r
+                    Resource after = null;\r
+                    if (targetIndex == 0) {\r
+                        after = l;\r
+                        if (l.equals(graphPrev))\r
+                            continue;\r
+                    } else {\r
+                        after = diagramOrder.get(targetIndex - 1);\r
+                        if (after.equals(graphPrev))\r
+                            continue;\r
+                    }\r
+\r
+                    // r needs to be repositioned.\r
+                    OrderedSetUtils.remove(g, l, r);\r
+                    OrderedSetUtils.addAfter(g, l, after, r);\r
+                }\r
+            }\r
+        }\r
+    }\r
+\r
+}\r