Added a SearchNoResultEvent on MaterialSearch component.

Author: kevzlou7979

gwt-material/src/main/java/gwt/material/design/client/events/SearchNoResultEvent.java

@@ -0,0 +1,50 @@
+package gwt.material.design.client.events;
+
+/*
+ * #%L
+ * GwtMaterial
+ * %%
+ * Copyright (C) 2015 GwtMaterialDesign
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+
+import com.google.gwt.event.shared.EventHandler;
+import com.google.gwt.event.shared.GwtEvent;
+import com.google.gwt.event.shared.HasHandlers;
+import gwt.material.design.client.events.SearchNoResultEvent.SearchNoResultHandler;
+
+public class SearchNoResultEvent extends GwtEvent<SearchNoResultHandler> {
+
+    public interface SearchNoResultHandler extends EventHandler {
+        void onSearchNoResult(SearchNoResultEvent event);
+    }
+
+    public static final Type<SearchNoResultHandler> TYPE = new Type<>();
+
+    public static void fire(HasHandlers source) {
+        source.fireEvent(new SearchNoResultEvent());
+    }
+
+    @Override
+    public Type<SearchNoResultHandler> getAssociatedType() {
+        return TYPE;
+    }
+
+    @Override
+    protected void dispatch(SearchNoResultHandler handler) {
+        handler.onSearchNoResult(this);
+    }
+}

gwt-material/src/main/java/gwt/material/design/client/ui/MaterialSearch.java

@@ -31,6 +31,7 @@
 import gwt.material.design.client.constants.IconType;
 import gwt.material.design.client.constants.InputType;
 import gwt.material.design.client.events.SearchFinishEvent;
+import gwt.material.design.client.events.SearchNoResultEvent;
 import gwt.material.design.client.ui.html.Label;
 
 import java.util.ArrayList;
@@ -169,6 +170,11 @@ public void onClick(ClickEvent event) {
                     reset(selLink.getText());
                 }
 
+                // Fire an event if theres no search result
+                if(searchResult.getWidgetCount() == 0){
+                    SearchNoResultEvent.fire(MaterialSearch.this);
+                }
+
                 // Selection logic using key down event to navigate the search results
                 int totalItems = searchResult.getWidgetCount();
                 if(event.getNativeEvent().getKeyCode() == KeyCodes.KEY_DOWN){
@@ -195,7 +201,7 @@ public void onClick(ClickEvent event) {
 
             // Resets the search result panel
             private void reset(String keyword){
-                SearchFinishEvent.fire(MaterialSearch.this);
+                SearchNoResultEvent.fire(MaterialSearch.this);
                 curSel = -1;
                 setText(keyword);
                 searchResult.clear();
@@ -280,6 +286,13 @@ public List<SearchObject> getTempSearches() {
     public HandlerRegistration addSearchFinishHandler(SearchFinishEvent.SearchFinishHandler handler) {
         return addHandler(handler, SearchFinishEvent.TYPE);
     }
+
+    /**
+     * This handler will be triggered when there's no search result
+     */
+    public HandlerRegistration addSearchNoResultHandler(SearchNoResultEvent.SearchNoResultHandler handler) {
+        return addHandler(handler, SearchNoResultEvent.TYPE);
+    }
 }