Fix modal close animation

packages/uui-modal/lib/uui-modal-container.ts

@@ -1,7 +1,7 @@
 import { LitElement, PropertyValueMap, css, html } from 'lit';
 import { property, query, state } from 'lit/decorators.js';
 import { UUIModalSidebarElement } from './uui-modal-sidebar.element';
-import { UUIModalElement } from './uui-modal.element';
+import { UUIModalCloseEvent, UUIModalElement } from './uui-modal.element';
 import { defineElement } from '@umbraco-ui/uui-base/lib/registration';
 
 @defineElement('uui-modal-container')
@@ -23,7 +23,7 @@ export class UUIModalContainerElement extends LitElement {
 
   constructor() {
     super();
-    this.addEventListener('close', this.#onClose);
+    this.addEventListener(UUIModalCloseEvent, this.#onCloseModalClose);
   }
 
   protected firstUpdated(
@@ -38,13 +38,29 @@ export class UUIModalContainerElement extends LitElement {
   }
 
   #onSlotChange = () => {
+    const existingModals = this._modals ?? [];
+
     this._modals =
       (this.modalSlot
         ?.assignedElements({ flatten: true })
         .filter(
           el => el instanceof UUIModalElement
         ) as Array<UUIModalElement>) ?? [];
 
+    const oldModals = existingModals.filter(
+      modal => this._modals!.indexOf(modal) === -1
+    );
+    oldModals.forEach(modal =>
+      modal.removeEventListener(UUIModalCloseEvent, this.#onCloseModalClose)
+    );
+
+    const newModals = this._modals.filter(
+      modal => existingModals.indexOf(modal) === -1
+    );
+    newModals.forEach(modal =>
+      modal.addEventListener(UUIModalCloseEvent, this.#onCloseModalClose)
+    );
+
     this._sidebars = this._modals.filter(
       el => el instanceof UUIModalSidebarElement
     ) as Array<UUIModalSidebarElement>;
@@ -58,7 +74,13 @@ export class UUIModalContainerElement extends LitElement {
     this.#updateSidebars();
   };
 
-  #onClose = () => {
+  #onCloseModalClose = (event: Event) => {
+    event.stopImmediatePropagation();
+
+    event.target?.removeEventListener(
+      UUIModalCloseEvent,
+      this.#onCloseModalClose
+    );
     if (!this._modals || this._modals.length <= 1) {
       this.removeAttribute('backdrop');
       return;
@@ -99,7 +121,15 @@ export class UUIModalContainerElement extends LitElement {
       for (let i = 0; i < reversed.length; i++) {
         const sidebar = reversed[i];
         const nextSidebar = reversed[i + 1];
-        sidebar.style.setProperty('--uui-modal-offset', sidebarOffset + 'px');
+        const tempSidebarOffset = sidebarOffset; // Cache to prevent it from being overwritten before the updateComplete.
+        // The sidebar checks it's own width at sets it's --uui-modal-offset to negative that width.
+        // This enables it to slide in from the right. So we need to set the new --uui-modal-offset after the updateComplete.
+        sidebar.updateComplete.then(() => {
+          sidebar.style.setProperty(
+            '--uui-modal-offset',
+            tempSidebarOffset + 'px'
+          );
+        });
 
         // Stop the calculations if the next sidebar is hidden
         if (nextSidebar?.hasAttribute('hide')) break;

packages/uui-modal/lib/uui-modal-sidebar.element.ts

@@ -1,6 +1,6 @@
 import { css, html, PropertyValueMap } from 'lit';
 import { property } from 'lit/decorators.js';
-import { UUIModalElement } from './uui-modal.element';
+import { UUIModalCloseEvent, UUIModalElement } from './uui-modal.element';
 import { defineElement } from '@umbraco-ui/uui-base/lib/registration';
 
 export type UUIModalSidebarSize = 'small' | 'medium' | 'large' | 'full';
@@ -15,7 +15,7 @@ export class UUIModalSidebarElement extends UUIModalElement {
 
   constructor() {
     super();
-    this.addEventListener('close', this.#onClose.bind(this));
+    this.addEventListener(UUIModalCloseEvent, this.#onClose.bind(this));
   }
 
   protected firstUpdated(

packages/uui-modal/lib/uui-modal.element.ts

@@ -1,5 +1,7 @@
 import { LitElement, css } from 'lit';
 import { property, query } from 'lit/decorators.js';
+
+export const UUIModalCloseEvent = 'uui:modal-close';
 export class UUIModalElement extends LitElement {
   @query('dialog')
   protected _dialogElement?: HTMLDialogElement;
@@ -58,7 +60,7 @@ export class UUIModalElement extends LitElement {
     event?.preventDefault();
     event?.stopImmediatePropagation();
 
-    const closeEvent = new CustomEvent('close', {
+    const closeEvent = new CustomEvent(UUIModalCloseEvent, {
       cancelable: true,
     });
     this.dispatchEvent(closeEvent);