Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.browsing.ui.model / src / org / simantics / browsing / ui / model / children / RelationChildRule.java

diff --git a/bundles/org.simantics.browsing.ui.model/src/org/simantics/browsing/ui/model/children/RelationChildRule.java b/bundles/org.simantics.browsing.ui.model/src/org/simantics/browsing/ui/model/children/RelationChildRule.java
new file mode 100644 (file)
index 0000000..0e5b21b
--- /dev/null
+++ b/bundles/org.simantics.browsing.ui.model/src/org/simantics/browsing/ui/model/children/RelationChildRule.java
@@ -0,0 +1,69 @@
+/*******************************************************************************\r
+ * Copyright (c) 2010, 2011 Association for Decentralized Information Management in\r
+ * 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.browsing.ui.model.children;\r
+\r
+import java.util.ArrayList;\r
+import java.util.Collection;\r
+import java.util.Collections;\r
+\r
+import org.simantics.browsing.ui.model.tests.Test;\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.exception.NoInverseException;\r
+\r
+/**\r
+ * A child rule that says that there is exactly one child node whose content \r
+ * is equal to the content of the parent.\r
+ * @author Hannu Niemistö\r
+ */\r
+public class RelationChildRule implements ChildRule {\r
+\r
+    Resource relation;\r
+    Test test;\r
+    \r
+    public RelationChildRule(Resource relation, Test test) {\r
+        this.relation = relation;\r
+        this.test = test;\r
+    }\r
+    \r
+    @Override\r
+    public Collection<?> getChildren(ReadGraph graph, Object parent) throws DatabaseException {\r
+        Collection<Resource> result = graph.getObjects((Resource)parent, relation);\r
+        if(test != null) {\r
+            ArrayList<Resource> filtered = new ArrayList<Resource>(result.size());\r
+            for(Resource r : result)\r
+                if(test.test(graph, r))\r
+                    filtered.add(r); \r
+            result = filtered;\r
+        }\r
+        return result;\r
+    }\r
+\r
+    @Override\r
+    public Collection<?> getParents(ReadGraph graph, Object child)\r
+            throws DatabaseException {\r
+        try {\r
+            if(child instanceof Resource) {\r
+                Resource inverse = graph.getInverse(relation);            \r
+                return graph.getObjects((Resource)child, inverse);\r
+            }\r
+        } catch(NoInverseException e) {\r
+        }   \r
+        return Collections.emptyList();\r
+    }\r
+    \r
+    @Override\r
+    public boolean isCompatible(Class<?> contentType) {\r
+        return contentType.equals(Resource.class);\r
+    }\r
+}\r