Added VarROIDescriptor variable for easy ROI Descriptor selector

src/main/java/plugins/adufour/vars/lang/VarROIDescriptor.java

+package plugins.adufour.vars.lang;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import icy.roi.ROIDescriptor;
+import icy.util.StringUtil;
+import plugins.adufour.vars.gui.model.ValueSelectionModel;
+import plugins.kernel.roi.descriptor.measure.ROIInteriorDescriptor;
+
+/**
+ * EzVar representing {@link ROIDescriptor} selector
+ * 
+ * @author Stephane.D
+ */
+public class VarROIDescriptor extends VarString
+{
+    /**
+     * @param name
+     *        Variable name
+     */
+    public VarROIDescriptor(String name)
+    {
+        super(name, "");
+
+        final List<ROIDescriptor> roiDescriptors = new ArrayList<>(ROIDescriptor.getDescriptors().keySet());
+        // build list of descriptor id
+        final List<String> descriptorsId = new ArrayList<>();
+        String sizeDescriptorId = null;
+
+        for (ROIDescriptor descriptor : roiDescriptors)
+        {
+            final String id = descriptor.getId();
+
+            // keep trace of size descriptor
+            if (StringUtil.equals(ROIInteriorDescriptor.ID, id))
+                sizeDescriptorId = id;
+
+            descriptorsId.add(id);
+        }
+
+        // alpha sort
+        Collections.sort(descriptorsId);
+
+        // initialize descriptors field
+        setDefaultEditorModel(new ValueSelectionModel<>(descriptorsId.toArray(new String[descriptorsId.size()]),
+                sizeDescriptorId, false));
+    }
+
+    public VarROIDescriptor()
+    {
+        this("Descriptor");
+    }
+}