diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/IDetailItemModificator.java b/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/IDetailItemModificator.java
new file mode 100644
index 000000000..a3d96cd5a
--- /dev/null
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/IDetailItemModificator.java
@@ -0,0 +1,30 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.zkoss.ganttz.timetracker.zoom;
+
+/**
+ * @author Óscar González Fernández <ogonzalez@igalia.com>
+ *
+ */
+public interface IDetailItemModificator {
+
+    public DetailItem applyModificationsTo(DetailItem item);
+
+}
diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/SeveralModificators.java b/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/SeveralModificators.java
new file mode 100644
index 000000000..ebcbb1887
--- /dev/null
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/SeveralModificators.java
@@ -0,0 +1,68 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.zkoss.ganttz.timetracker.zoom;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import org.apache.commons.lang.Validate;
+
+/**
+ * @author Óscar González Fernández <ogonzalez@igalia.com>
+ *
+ */
+public class SeveralModificators implements IDetailItemModificator {
+
+    public static IDetailItemModificator empty() {
+        return new SeveralModificators(Collections
+                .<IDetailItemModificator> emptyList());
+    }
+
+    public static IDetailItemModificator create(
+            IDetailItemModificator... modificators) {
+        return new SeveralModificators(Arrays.asList(modificators));
+    }
+
+    public static IDetailItemModificator create(
+            Collection<? extends IDetailItemModificator> modificators) {
+        return new SeveralModificators(modificators);
+    }
+
+    private final List<IDetailItemModificator> modificators;
+
+    private SeveralModificators(
+            Collection<? extends IDetailItemModificator> modificators) {
+        Validate.noNullElements(modificators);
+        this.modificators = new ArrayList<IDetailItemModificator>(modificators);
+    }
+
+    @Override
+    public DetailItem applyModificationsTo(DetailItem item) {
+        DetailItem result = item;
+        for (IDetailItemModificator each : modificators) {
+            result = each.applyModificationsTo(result);
+        }
+        return result;
+    }
+
+}