Add/remove extension dom elements correctly when text field attached/…

…detached (#14)

pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.vaadin.addons</groupId>
     <artifactId>autocomplete</artifactId>
-    <version>0.2.0-SNAPSHOT</version>
+    <version>0.2.1-SNAPSHOT</version>
     <packaging>bundle</packaging>
     <name>Autocomplete Extension</name>
     <organization>

src/main/java/org/vaadin/addons/autocomplete/client/AutocompleteExtensionConnector.java

@@ -102,15 +102,15 @@ protected void extend(ServerConnector serverConnector) {
 
         suggestionList.setMaxSize(getState().suggestionListSize);
 
+        if (textField.isAttached()) {
+            addExtensionElements();
+        }
+
         attachHandler = textField.addAttachHandler(event -> {
-            Element textElement = textField.getElement();
             if (event.isAttached()) {
-                textElement.getParentElement()
-                        .insertBefore(wrapper, textElement);
-                wrapper.appendChild(textElement);
-                wrapper.appendChild(suggestionList.getElement());
+                addExtensionElements();
             } else {
-                wrapper.removeFromParent();
+                removeExtensionElements();
             }
         });
 
@@ -157,10 +157,10 @@ protected void extend(ServerConnector serverConnector) {
     public void onUnregister() {
         super.onUnregister();
 
-        // Remove autocomplete wrapper
-        wrapper.getParentElement()
-                .insertBefore(textField.getElement(), wrapper);
-        wrapper.removeFromParent();
+        // Remove autocomplete elements
+        if (textField.isAttached()) {
+            removeExtensionElements();
+        }
 
         // Remove input event listener
         Optional.ofNullable(inputHandler)
@@ -171,6 +171,19 @@ public void onUnregister() {
                 .ifPresent(HandlerRegistration::removeHandler);
     }
 
+    private void addExtensionElements() {
+        Element textElement = textField.getElement();
+        textElement.getParentElement().insertBefore(wrapper, textElement);
+        wrapper.appendChild(textElement);
+        wrapper.appendChild(suggestionList.getElement());
+    }
+
+    private void removeExtensionElements() {
+        Element textElement = textField.getElement();
+        wrapper.getParentElement().insertBefore(textElement, wrapper);
+        wrapper.removeFromParent();
+    }
+
     private void onSuggestionSelected() {
         final SuggestionList.SuggestionItem selectedItem = suggestionList
                 .getSelectedItem();

src/test/java/org/vaadin/addons/autocomplete/AddRemoveUsageUI.java

@@ -0,0 +1,66 @@
+package org.vaadin.addons.autocomplete;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.vaadin.addonhelpers.AbstractTest;
+
+import com.vaadin.ui.Button;
+import com.vaadin.ui.Component;
+import com.vaadin.ui.HorizontalLayout;
+import com.vaadin.ui.Notification;
+import com.vaadin.ui.TextField;
+import com.vaadin.ui.VerticalLayout;
+
+public class AddRemoveUsageUI extends AbstractTest {
+
+    private TextField textField;
+    private AutocompleteExtension<String> extension;
+
+    @Override
+    public Component getTestComponent() {
+
+        VerticalLayout layout = new VerticalLayout();
+
+        textField = createField();
+        extension = createExtension(textField);
+
+        Button removeExtension = new Button("Remove extension",
+                e -> extension.remove());
+
+        Button addExtension = new Button("Add extension",
+                e -> extension = createExtension(textField));
+
+        Button removeField = new Button("Remove field",
+                e -> layout.removeComponent(textField));
+
+        Button addField = new Button("Add field",
+                e -> layout.addComponentAsFirst(textField));
+
+        layout.addComponents(textField,
+                new HorizontalLayout(removeExtension, addExtension),
+                new HorizontalLayout(removeField, addField));
+
+        return layout;
+    }
+
+    private TextField createField() {
+        return new TextField();
+    }
+
+    private AutocompleteExtension<String> createExtension(TextField field) {
+        AutocompleteExtension<String> extension = new AutocompleteExtension<>(
+                field);
+        extension.setSuggestionGenerator(this::suggestPlanet);
+        extension.addSuggestionSelectListener(event -> {
+            event.getSelectedItem().ifPresent(Notification::show);
+        });
+        return extension;
+    }
+
+    private List<String> suggestPlanet(String query, int cap) {
+        return DataSource.getPlanets().stream()
+                .filter(p -> p.toLowerCase().contains(query.toLowerCase()))
+                .limit(cap).collect(Collectors.toList());
+    }
+}