Add a fallback to Declarative*Generator

Change-Id: I7eca92ca6e2eb234000cb9c9533974fcd357d33f

5 files changed, 30 insertions, 9 deletions

diff --git a/server/src/main/java/com/vaadin/ui/AbstractListing.java b/server/src/main/java/com/vaadin/ui/AbstractListing.java
index 2f455fa27b..6f0463b822 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractListing.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractListing.java
@@ -324,8 +324,10 @@ public abstract class AbstractListing<T> extends AbstractComponent {
                     Boolean.class));
         }
 
-        setItemCaptionGenerator(new DeclarativeCaptionGenerator<>());
-        setItemIconGenerator(new DeclarativeIconGenerator<>());
+        setItemCaptionGenerator(
+                new DeclarativeCaptionGenerator<>(getItemCaptionGenerator()));
+        setItemIconGenerator(
+                new DeclarativeIconGenerator<>(getItemIconGenerator()));
 
         List<T> readItems = readItems(design, context);
         if (!readItems.isEmpty() && this instanceof Listing) {
diff --git a/server/src/main/java/com/vaadin/ui/ComboBox.java b/server/src/main/java/com/vaadin/ui/ComboBox.java
index f0f90eab22..2b91236843 100644
--- a/server/src/main/java/com/vaadin/ui/ComboBox.java
+++ b/server/src/main/java/com/vaadin/ui/ComboBox.java
@@ -84,11 +84,18 @@ public class ComboBox<T> extends AbstractSingleSelect<T>
      */
     protected static class DeclarativeStyleGenerator<T>
             implements StyleGenerator<T> {
+
+        private StyleGenerator<T> fallback;
         private Map<T, String> styles = new HashMap<>();
 
+        public DeclarativeStyleGenerator(StyleGenerator<T> fallback) {
+            this.fallback = fallback;
+        }
+
         @Override
         public String apply(T item) {
-            return styles.get(item);
+            return styles.containsKey(item) ? styles.get(item)
+                    : fallback.apply(item);
         }
 
         /**
@@ -581,7 +588,7 @@ public class ComboBox<T> extends AbstractSingleSelect<T>
 
     @Override
     protected List<T> readItems(Element design, DesignContext context) {
-        setStyleGenerator(new DeclarativeStyleGenerator<>());
+        setStyleGenerator(new DeclarativeStyleGenerator<>(getStyleGenerator()));
         return super.readItems(design, context);
     }
 
diff --git a/server/src/main/java/com/vaadin/ui/DeclarativeCaptionGenerator.java b/server/src/main/java/com/vaadin/ui/DeclarativeCaptionGenerator.java
index 9aa6035d9d..617315459d 100644
--- a/server/src/main/java/com/vaadin/ui/DeclarativeCaptionGenerator.java
+++ b/server/src/main/java/com/vaadin/ui/DeclarativeCaptionGenerator.java
@@ -28,16 +28,22 @@ import java.util.Map;
  */
 class DeclarativeCaptionGenerator<T> implements ItemCaptionGenerator<T> {
 
+    private ItemCaptionGenerator<T> fallback;
     private Map<T, String> captions = new HashMap<>();
 
+    public DeclarativeCaptionGenerator(ItemCaptionGenerator<T> fallback) {
+        this.fallback = fallback;
+    }
+
     @Override
     public String apply(T item) {
-        return captions.get(item);
+        return captions.containsKey(item) ? captions.get(item)
+                : fallback.apply(item);
     }
 
     /**
      * Sets a {@code caption} for the {@code item}.
-     * 
+     *
      * @param item
      *            a data item
      * @param caption
diff --git a/server/src/main/java/com/vaadin/ui/DeclarativeIconGenerator.java b/server/src/main/java/com/vaadin/ui/DeclarativeIconGenerator.java
index 984ac4cf47..926de395b3 100644
--- a/server/src/main/java/com/vaadin/ui/DeclarativeIconGenerator.java
+++ b/server/src/main/java/com/vaadin/ui/DeclarativeIconGenerator.java
@@ -30,16 +30,22 @@ import com.vaadin.server.Resource;
  */
 class DeclarativeIconGenerator<T> implements IconGenerator<T> {
 
+    private IconGenerator<T> fallback;
     private Map<T, Resource> captions = new HashMap<>();
 
+    public DeclarativeIconGenerator(IconGenerator<T> fallback) {
+        this.fallback = fallback;
+    }
+
     @Override
     public Resource apply(T item) {
-        return captions.get(item);
+        return captions.containsKey(item) ? captions.get(item)
+                : fallback.apply(item);
     }
 
     /**
      * Sets an {@code icon} for the {@code item}.
-     * 
+     *
      * @param item
      *            a data item
      * @param icon
diff --git a/server/src/main/java/com/vaadin/ui/DeclarativeItemEnabledProvider.java b/server/src/main/java/com/vaadin/ui/DeclarativeItemEnabledProvider.java
index f16e54f1b2..adb2ade00f 100644
--- a/server/src/main/java/com/vaadin/ui/DeclarativeItemEnabledProvider.java
+++ b/server/src/main/java/com/vaadin/ui/DeclarativeItemEnabledProvider.java
@@ -39,7 +39,7 @@ class DeclarativeItemEnabledProvider<T> implements SerializablePredicate<T> {
 
     /**
      * Adds the {@code item} to disabled items list.
-     * 
+     *
      * @param item
      *            a data item
      * @param caption