Add event handler to node, preventing duplicate handlers for NativeFi…

…leOpenPicker class

jpro-file/src/main/java/one/jpro/platform/file/picker/NativeFileOpenPicker.java

@@ -12,6 +12,7 @@
 import javafx.stage.Window;
 import one.jpro.platform.file.FileSource;
 import one.jpro.platform.file.NativeFileSource;
+import one.jpro.platform.file.util.NodeUtils;
 
 import java.io.File;
 import java.util.List;
@@ -23,6 +24,7 @@
  * the native file system.
  *
  * @author Besmir Beqiri
+ * @author Indrit Beqiri
  */
 public class NativeFileOpenPicker extends BaseFileOpenPicker {
 
@@ -50,7 +52,7 @@ public NativeFileOpenPicker(Node node) {
                 new WeakListChangeListener<>(getNativeExtensionFilterListChangeListener(fileChooser)));
 
         // Define the action that should be performed when the user clicks on the node.
-        node.addEventHandler(MouseEvent.MOUSE_CLICKED, actionEvent -> {
+        NodeUtils.addEventHandler(node, MouseEvent.MOUSE_CLICKED, actionEvent -> {
             Window window = node.getScene().getWindow();
             if (getSelectionMode() == SelectionMode.MULTIPLE) {
                 final List<File> files = fileChooser.showOpenMultipleDialog(window);

jpro-file/src/main/java/one/jpro/platform/file/util/NodeUtils.java

@@ -1,5 +1,8 @@
 package one.jpro.platform.file.util;
 
+import javafx.event.Event;
+import javafx.event.EventHandler;
+import javafx.event.EventType;
 import javafx.scene.Node;
 
 import java.util.Map;
@@ -8,10 +11,12 @@
  * Utility class for working with nodes.
  *
  * @author Besmir Beqiri
+ * @author Indrit Beqiri
  */
 public interface NodeUtils {
 
     Object MULTI_FILE_UPLOADER_KEY = new Object();
+    Object EVENT_HANDLER_KEY = new Object();
 
     /**
      * Retrieves the value of a property associated with the given key from a node.
@@ -22,19 +27,42 @@ public interface NodeUtils {
      * @param <K>          the type of the key
      * @param <V>          the type of the value
      * @return the value of the property associated with the given key,
-     * or the default value if the property does not exist
+     *         or the default value if the property does not exist
      */
     static <K, V> V getPropertyValue(Node node, K key, V defaultValue) {
-        Map<Object, Object> properties = node.getProperties();
+        final Map<Object, Object> nodeProperties = node.getProperties();
 
         // Check if property exists
-        if (properties.containsKey(key)) {
+        if (nodeProperties.containsKey(key)) {
             // Return the property value
-            return (V) properties.get(key);
+            return (V) nodeProperties.get(key);
         } else {
             // Set the default value and return it
-            properties.put(key, defaultValue);
+            nodeProperties.put(key, defaultValue);
             return defaultValue;
         }
     }
+
+    /**
+     * Adds an event handler to the specified node for the given event type.
+     * If an event handler for the event type is already added, it will not add another one.
+     *
+     * @param node         the node to which the event handler will be added
+     * @param eventType    the type of the event to handle
+     * @param eventHandler the event handler to be added
+     * @param <T>          the type of the event
+     */
+    static <T extends Event> void addEventHandler(Node node, EventType<T> eventType,
+                                                  EventHandler<? super T> eventHandler) {
+        final Map<Object, Object> nodeProperties = node.getProperties();
+
+        // Create the event handler key for the given event type
+        final String eventTypeKey = EVENT_HANDLER_KEY + "_" + eventType.getName();
+
+        // Check if the event handler is already added
+        if (!nodeProperties.containsKey(eventTypeKey)) {
+            node.addEventHandler(eventType, eventHandler);
+            nodeProperties.put(eventTypeKey, eventHandler);
+        }
+    }
 }