feat: ViewComponent.getChild() allows retrieving a specific child that is directly cast to given type

Author: AlmasB

fxgl-entity/src/main/kotlin/com/almasb/fxgl/entity/components/ViewComponent.kt

@@ -173,6 +173,13 @@ class ViewComponent : Component() {
             updatableViews += node
     }
 
+    /**
+     * @return a child node at given [index] which is then cast into [type]
+     */
+    fun <T : Node> getChild(index: Int, type: Class<T>): T {
+        return type.cast(children[index])
+    }
+
     /**
      * Remove a child from this view.
      */

fxgl-entity/src/test/kotlin/com/almasb/fxgl/entity/components/ViewComponentTest.kt

@@ -14,6 +14,7 @@ import javafx.scene.Node
 import javafx.scene.Parent
 import javafx.scene.input.MouseButton
 import javafx.scene.input.MouseEvent
+import javafx.scene.shape.Circle
 import javafx.scene.shape.Rectangle
 import org.hamcrest.CoreMatchers.`is`
 import org.hamcrest.MatcherAssert.assertThat
@@ -68,6 +69,21 @@ class ViewComponentTest {
         assertThat(rect2.parent.transforms.size, `is`(0))
     }
 
+    @Test
+    fun `Get child with cast`() {
+        val rect = Rectangle()
+        val circle = Circle()
+
+        view.addChild(rect)
+        view.addChild(circle)
+
+        val rect2: Rectangle = view.getChild(0, Rectangle::class.java)
+        val circle2: Circle = view.getChild(1, Circle::class.java)
+
+        assertThat(rect2, `is`(rect))
+        assertThat(circle2, `is`(circle))
+    }
+
     @Test
     fun `View type children are correctly updated onUpdate and disposed on remove`() {
         val child = TestView()