Allow to add additional trap elements to the focus trap

Signed-off-by: Julius Härtl <jus@bitgrid.net>

src/components/Modal/Modal.vue

@@ -445,6 +445,14 @@ export default {
 			type: Boolean,
 			default: true,
 		},
+
+		/**
+		 * Additional elements to add to the focus trap
+		 */
+		additionalTrapElements: {
+			type: Array,
+			default: () => [],
+		},
 	},
 
 	emits: [
@@ -505,6 +513,12 @@ export default {
 				}
 			}
 		},
+		additionalTrapElements(elements) {
+			if (this.focusTrap) {
+				const contentContainer = this.$refs.mask
+				this.focusTrap.updateContainerElements([contentContainer, ...elements])
+			}
+		},
 	},
 
 	beforeMount() {