Add FxView utils

Author: pcastornii

patternfx-mvp/src/main/java/com/techsenger/patternfx/mvp/FxViewUtils.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2024-2025 Pavel Castornii.
+ *
+ * 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.
+ */
+
+package com.techsenger.patternfx.mvp;
+
+import com.techsenger.annotations.Nullable;
+import javafx.scene.Node;
+
+/**
+ *
+ * @author Pavel Castornii
+ */
+public final class FxViewUtils {
+
+    private static final Object VIEW_KEY = new Object();
+
+    /**
+     * Associates the given {@link FxView} view with the specified JavaFX {@link Node}.
+     * <p>
+     * This method stores a reference to the view in the node's property map, allowing the view to be
+     * retrieved later by traversing the JavaFX node tree. This is useful in scenarios where only a node is available
+     * (e.g., during focus traversal or event handling) and the associated view needs to be identified.
+     * <p>
+     * This method should be called during initialization.
+     *
+     * @param node the JavaFX node to associate with the component; must not be {@code null}
+     * @param view the view to associate with the node; must not be {@code null}
+     */
+    public static void setView(Node node, FxView<?> view) {
+        node.getProperties().put(VIEW_KEY, view);
+    }
+
+    /**
+     * Returns the {@link FxView} view associated with the given {@link Node}, or {@code null} if no view
+     * has been associated with it.
+     * <p>
+     * This method is intended for use when traversing the JavaFX node tree — for example, when walking up the parent
+     * chain from a focused node to find the nearest component boundary.
+     *
+     * @param node the JavaFX node to look up; must not be {@code null}
+     * @return the associated view, or {@code null} if none is associated
+     */
+    public static @Nullable FxView<?> getView(Node node) {
+        return (FxView<?>) node.getProperties().get(VIEW_KEY);
+    }
+
+    /**
+     * Traverses the JavaFX node tree upward from the given {@link Node}, searching for the nearest node that has
+     * an associated {@link ComponentFxView} component.
+     * <p>
+     * The search starts at the given node itself and walks up the parent chain until a component is found or the
+     * root is reached.
+     *
+     * @param node the JavaFX node to start the search from; must not be {@code null}
+     * @return the nearest {@link ComponentFxView} component found in the parent chain,
+     *         or {@code null} if no component is associated with any node up to the root
+     */
+    public static @Nullable ComponentFxView<?> findComponent(Node node) {
+        Node current = node;
+        while (current != null) {
+            FxView<?> view = getView(current);
+            if (view instanceof ParentFxView<?> component) {
+                return component;
+            }
+            current = current.getParent();
+        }
+        return null;
+    }
+
+    private FxViewUtils() {
+        // empty
+    }
+}