--- a/gwt-client/src/main/java/org/dive4elements/river/client/shared/model/AttributedTheme.java	Thu Aug 16 16:27:53 2018 +0200
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/shared/model/AttributedTheme.java	Thu Aug 16 16:28:03 2018 +0200
@@ -18,58 +18,77 @@
  */
 public class AttributedTheme implements Theme {
 
-    protected Map<String, String> attributes;
+    private static final long serialVersionUID = 1L;
+
+    private Map<String, String> attributes;
 
     /** CollectionItem associated with this facet/themes artifact. */
-    protected CollectionItem collectionItem;
+    private CollectionItem collectionItem;
 
     public AttributedTheme() {
         this.attributes = new HashMap<String, String>();
     }
 
+    /** Remark: only here so attributes is not final and serialization is happy */
+    public void setAttributes(final Map<String, String> attributes) {
+        this.attributes = attributes;
+    }
 
     public Set<String> getKeys() {
-        return attributes.keySet();
+        return this.attributes.keySet();
     }
 
-
-    public void addAttr(String name, String value) {
+    public void addAttr(final String name, final String value) {
         if (name != null && value != null) {
-            attributes.put(name, value);
+            this.attributes.put(name, value);
         }
     }
 
-
-    public String getAttr(String name) {
-        return attributes.get(name);
+    public String getAttr(final String name) {
+        return this.attributes.get(name);
     }
 
-
-    public Integer getAttrAsInt(String name) {
-        String attr = getAttr(name);
+    public Integer getAttrAsInt(final String name) {
+        final String attr = getAttr(name);
 
         if (attr != null && attr.length() > 0) {
             try {
                 return Integer.parseInt(attr);
             }
-            catch (NumberFormatException nfe) {
+            catch (final NumberFormatException nfe) {
+                nfe.printStackTrace();
             }
         }
 
         return null;
     }
 
+    public Double getAttrAsDouble(final String name) {
 
-    public boolean getAttrAsBoolean(String name) {
-        String attr = getAttr(name);
+        final String attr = getAttr(name);
+        if (attr == null || attr.isEmpty())
+            return null;
+
+        try {
+            return Double.parseDouble(attr);
+        }
+        catch (final NumberFormatException nfe) {
+            nfe.printStackTrace();
+            return null;
+        }
+    }
+
+    public boolean getAttrAsBoolean(final String name) {
+        final String attr = getAttr(name);
 
         if (attr != null) {
             try {
-                int num = Integer.valueOf(attr);
+                final int num = Integer.valueOf(attr);
                 return num > 0;
             }
-            catch (NumberFormatException nfe) {
+            catch (final NumberFormatException nfe) {
                 // do nothing
+                nfe.printStackTrace();
             }
         }
 
@@ -79,21 +98,21 @@
 
     @Override
     public int getPosition() {
-        Integer pos = getAttrAsInt("pos");
+        final Integer pos = getAttrAsInt("pos");
 
         return pos != null ? pos.intValue() : -1;
     }
 
 
     @Override
-    public void setPosition(int pos) {
+    public void setPosition(final int pos) {
         addAttr("pos", String.valueOf(pos));
     }
 
 
     @Override
     public int getIndex() {
-        Integer idx = getAttrAsInt("index");
+        final Integer idx = getAttrAsInt("index");
 
         return idx != null ? idx.intValue() : -1;
     }
@@ -106,7 +125,7 @@
 
 
     @Override
-    public void setActive(int active) {
+    public void setActive(final int active) {
         addAttr("active", String.valueOf(active));
     }
 
@@ -130,7 +149,7 @@
 
 
     @Override
-    public void setDescription(String description) {
+    public void setDescription(final String description) {
         if (description != null && description.length() > 0) {
             addAttr("description", description);
         }
@@ -144,18 +163,18 @@
 
 
     @Override
-    public void setVisible(int visible) {
+    public void setVisible(final int visible) {
         addAttr("visible", String.valueOf(visible));
     }
 
 
     @Override
-    public boolean equals(Object o) {
+    public boolean equals(final Object o) {
         if (!(o instanceof AttributedTheme)) {
             return false;
         }
 
-        AttributedTheme other = (AttributedTheme) o;
+        final AttributedTheme other = (AttributedTheme) o;
 
         if (other.getPosition() != getPosition()) {
             return false;
@@ -188,18 +207,15 @@
         return true;
     }
 
-
     /** Get the CollectionItem representing the facets artifact. */
     @Override
     public CollectionItem getCollectionItem() {
-        return collectionItem;
+        return this.collectionItem;
     }
 
-
     /** Set the CollectionItem representing the facets artifact. */
     @Override
-    public void setCollectionItem(CollectionItem ci) {
+    public void setCollectionItem(final CollectionItem ci) {
         this.collectionItem = ci;
     }
-}
-// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
+}
\ No newline at end of file