experiment: add item base styles and visual tests (#9185)

Author: web-padawan

packages/item/package.json

@@ -21,6 +21,8 @@
   "type": "module",
   "files": [
     "src",
+    "!src/*-base-styles.d.ts",
+    "!src/*-base-styles.js",
     "theme",
     "vaadin-*.d.ts",
     "vaadin-*.js",

packages/item/src/vaadin-item-base-styles.d.ts

@@ -0,0 +1,8 @@
+/**
+ * @license
+ * Copyright (c) 2017 - 2025 Vaadin Ltd.
+ * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
+ */
+import type { CSSResult } from 'lit';
+
+export const itemStyles: CSSResult;

packages/item/src/vaadin-item-base-styles.js

@@ -0,0 +1,59 @@
+/**
+ * @license
+ * Copyright (c) 2017 - 2025 Vaadin Ltd.
+ * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
+ */
+import '@vaadin/component-base/src/style-props.js';
+import { css } from 'lit';
+
+export const itemStyles = css`
+  @layer base {
+    :host {
+      align-items: center;
+      border-radius: var(--vaadin-item-border-radius, var(--_vaadin-radius-m));
+      box-sizing: border-box;
+      cursor: pointer;
+      display: flex;
+      gap: var(--vaadin-item-gap, 0 var(--_vaadin-gap-container-inline));
+      height: var(--vaadin-item-height, auto);
+      padding: var(--vaadin-item-padding, var(--_vaadin-padding-container));
+    }
+
+    :host([focused]) {
+      outline: var(--vaadin-focus-ring-width) solid var(--vaadin-focus-ring-color);
+      outline-offset: calc(var(--vaadin-focus-ring-width) / -1);
+    }
+
+    :host([disabled]) {
+      cursor: not-allowed;
+      opacity: 0.5;
+    }
+
+    :host([hidden]) {
+      display: none !important;
+    }
+
+    [part='checkmark'] {
+      color: var(--vaadin-item-checkmark-color, inherit);
+      display: var(--vaadin-item-checkmark-display, none);
+      visibility: hidden;
+    }
+
+    [part='checkmark']::before {
+      content: '';
+      display: block;
+      background: currentColor;
+      height: var(--vaadin-icon-size, 1lh);
+      mask-image: var(--_vaadin-icon-checkmark);
+      width: var(--vaadin-icon-size, 1lh);
+    }
+
+    :host([selected]) [part='checkmark'] {
+      visibility: visible;
+    }
+
+    [part='content'] {
+      flex: 1;
+    }
+  }
+`;

packages/item/src/vaadin-item-core-styles.d.ts

@@ -0,0 +1,8 @@
+/**
+ * @license
+ * Copyright (c) 2017 - 2025 Vaadin Ltd.
+ * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
+ */
+import type { CSSResult } from 'lit';
+
+export const itemStyles: CSSResult;

packages/item/src/vaadin-item-core-styles.js

@@ -0,0 +1,16 @@
+/**
+ * @license
+ * Copyright (c) 2017 - 2025 Vaadin Ltd.
+ * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
+ */
+import { css } from 'lit';
+
+export const itemStyles = css`
+  :host {
+    display: inline-block;
+  }
+
+  :host([hidden]) {
+    display: none !important;
+  }
+`;

packages/item/src/vaadin-item.js

@@ -6,9 +6,12 @@
 import { html, PolymerElement } from '@polymer/polymer/polymer-element.js';
 import { defineCustomElement } from '@vaadin/component-base/src/define.js';
 import { DirMixin } from '@vaadin/component-base/src/dir-mixin.js';
-import { ThemableMixin } from '@vaadin/vaadin-themable-mixin/vaadin-themable-mixin.js';
+import { registerStyles, ThemableMixin } from '@vaadin/vaadin-themable-mixin/vaadin-themable-mixin.js';
+import { itemStyles } from './vaadin-item-core-styles.js';
 import { ItemMixin } from './vaadin-item-mixin.js';
 
+registerStyles('vaadin-item', itemStyles, { moduleId: 'vaadin-item-styles' });
+
 /**
  * `<vaadin-item>` is a Web Component providing layout for items in tabs and menus.
  *
@@ -56,15 +59,6 @@ import { ItemMixin } from './vaadin-item-mixin.js';
 class Item extends ItemMixin(ThemableMixin(DirMixin(PolymerElement))) {
   static get template() {
     return html`
-      <style>
-        :host {
-          display: inline-block;
-        }
-
-        :host([hidden]) {
-          display: none !important;
-        }
-      </style>
       <span part="checkmark" aria-hidden="true"></span>
       <div part="content">
         <slot></slot>

packages/item/src/vaadin-lit-item.js

@@ -3,11 +3,12 @@
  * Copyright (c) 2017 - 2025 Vaadin Ltd.
  * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
  */
-import { css, html, LitElement } from 'lit';
+import { html, LitElement } from 'lit';
 import { defineCustomElement } from '@vaadin/component-base/src/define.js';
 import { DirMixin } from '@vaadin/component-base/src/dir-mixin.js';
 import { PolylitMixin } from '@vaadin/component-base/src/polylit-mixin.js';
 import { ThemableMixin } from '@vaadin/vaadin-themable-mixin/vaadin-themable-mixin.js';
+import { itemStyles } from './vaadin-item-core-styles.js';
 import { ItemMixin } from './vaadin-item-mixin.js';
 
 /**
@@ -25,15 +26,7 @@ class Item extends ItemMixin(ThemableMixin(DirMixin(PolylitMixin(LitElement))))
   }
 
   static get styles() {
-    return css`
-      :host {
-        display: inline-block;
-      }
-
-      :host([hidden]) {
-        display: none !important;
-      }
-    `;
+    return itemStyles;
   }
 
   /** @protected */

packages/item/test/visual/base/item.test.js

@@ -0,0 +1,57 @@
+import { fixtureSync } from '@vaadin/testing-helpers/dist/fixture.js';
+import { visualDiff } from '@web/test-runner-visual-regression';
+import '../../../src/vaadin-item.js';
+
+describe('item', () => {
+  let div, element;
+
+  function setIconVisible(container) {
+    container.style.setProperty('--vaadin-item-checkmark-display', 'block');
+  }
+
+  beforeEach(() => {
+    div = document.createElement('div');
+    div.style.display = 'inline-block';
+    div.style.padding = '10px';
+    element = fixtureSync('<vaadin-item>Basic item</vaadin-item>', div);
+  });
+
+  ['ltr', 'rtl'].forEach((dir) => {
+    describe(dir, () => {
+      before(() => {
+        document.documentElement.setAttribute('dir', dir);
+      });
+
+      after(() => {
+        document.documentElement.removeAttribute('dir');
+      });
+
+      it('basic', async () => {
+        await visualDiff(div, `${dir}-basic`);
+      });
+
+      it('checkmark', async () => {
+        setIconVisible(div);
+        await visualDiff(div, `${dir}-checkmark`);
+      });
+
+      it('selected', async () => {
+        setIconVisible(div);
+        element.setAttribute('selected', '');
+        await visualDiff(div, `${dir}-selected`);
+      });
+
+      it('focused', async () => {
+        setIconVisible(div);
+        element.setAttribute('focused', '');
+        await visualDiff(div, `${dir}-focused`);
+      });
+
+      it('disabled', async () => {
+        setIconVisible(div);
+        element.setAttribute('disabled', '');
+        await visualDiff(div, `${dir}-disabled`);
+      });
+    });
+  });
+});