fix(tab-nav): fixes preselect logic in tabs with disabled attribute

packages/components/src/components/tab-header/readme.md

@@ -18,9 +18,10 @@
 
 ## Events
 
-| Event          | Description | Type               |
-| -------------- | ----------- | ------------------ |
-| `scale-select` |             | `CustomEvent<any>` |
+| Event            | Description                                      | Type               |
+| ---------------- | ------------------------------------------------ | ------------------ |
+| `scale-disabled` | Emitted when currently selected tab got disabled | `CustomEvent<any>` |
+| `scale-select`   | Emitted on header select                         | `CustomEvent<any>` |
 
 
 ----------------------------------------------

packages/components/src/components/tab-header/tab-header.tsx

@@ -47,42 +47,47 @@ export class TabHeader {
   /** (optional) size  */
   @Prop() size?: 'small' | 'large' = 'small';
   /** (optional) Whether the tab is selected */
-  @Prop() selected?: boolean;
+  @Prop({ mutable: true }) selected?: boolean;
   /** (optional) Injected CSS styles */
   @Prop() styles?: string;
 
   @State() hasFocus: boolean = false;
 
+  /** Emitted on header select */
   @Event({ eventName: 'scale-select' }) scaleSelect: EventEmitter;
+  /** Emitted when currently selected tab got disabled */
+  @Event({ eventName: 'scale-disabled' }) scaleDisabled: EventEmitter;
 
   @Listen('click')
   handleClick(event: MouseEvent) {
     event.stopPropagation();
     if (this.disabled) {
       return;
     }
+    this.selected = true;
     this.scaleSelect.emit();
   }
 
   @Watch('selected')
   selectedChanged(newValue: boolean) {
-    if (!this.hostElement.isConnected) {
+    if (!this.hostElement.isConnected || this.disabled) {
       return;
     }
-    if (!this.disabled) {
-      if (newValue === true && this.tabsHaveFocus()) {
-        // Having focus on the host element, and not on inner elements,
-        // is required because screen readers.
-        this.hostElement.focus();
-      }
-      this.updateSlottedIcon();
+    if (newValue) {
+      this.scaleSelect.emit();
+    }
+    if (newValue && this.tabsHaveFocus()) {
+      // Having focus on the host element and not on inner elements is required because of screen readers
+      this.hostElement.focus();
     }
+    this.updateSlottedIcon();
   }
 
   @Watch('disabled')
   disabledChanged() {
     if (this.disabled) {
       this.selected = false;
+      this.scaleDisabled.emit();
     }
   }
 

packages/components/src/components/tab-nav/tab-nav.tsx

@@ -42,9 +42,12 @@ export class TabNav {
   handleSelect(event) {
     const nextTab = event.target as HTMLScaleTabHeaderElement;
     // Act only if it's a direct child
-    if (this.getAllEnabledTabs().includes(nextTab) && !nextTab.disabled) {
-      this.selectTab(nextTab);
-    }
+    this.selectNextTab(nextTab);
+  }
+
+  @Listen('scale-disabled')
+  handleDisabledTabHeader() {
+    this.selectNextTab();
   }
 
   @Listen('keydown')
@@ -92,7 +95,7 @@ export class TabNav {
       customElements.whenDefined('scale-tab-header'),
       customElements.whenDefined('scale-tab-panel'),
     ]).then(() => {
-      this.linkPanels();
+      this.linkPanelsAndSelectTab();
       this.propagateSizeToTabs();
     });
 
@@ -144,24 +147,33 @@ export class TabNav {
     return tabs[tabs.length - 1];
   }
 
-  linkPanels() {
+  linkPanelsAndSelectTab() {
     const tabs = this.getAllTabs();
-    const selectedTab =
-      tabs.find((x) => x.selected) || tabs.filter((x) => !x.disabled)[0];
-
     tabs.forEach((tab) => {
       const panel = tab.nextElementSibling;
       tab.setAttribute('aria-controls', panel.id);
       panel.setAttribute('aria-labelledby', tab.id);
     });
-    this.selectTab(selectedTab);
+    this.selectNextTab();
   }
 
-  reset() {
+  selectNextTab(nextTab?: HTMLScaleTabHeaderElement): void {
+    const tabs = this.getAllTabs();
+    const tabToSelect =
+      (!nextTab?.disabled && nextTab) ||
+      tabs.find((tab) => tab.selected) ||
+      tabs.filter((tab) => !tab.disabled)[0];
+    this.selectTab(tabToSelect);
+  }
+
+  reset(nextTab?: HTMLScaleTabHeaderElement) {
     const tabs = this.getAllEnabledTabs();
+    tabs.forEach((tab) => {
+      if (tab !== nextTab) {
+        tab.selected = false;
+      }
+    });
     const panels = this.getAllPanels();
-
-    tabs.forEach((tab) => (tab.selected = false));
     panels.forEach((panel) => (panel.hidden = true));
   }
 
@@ -171,10 +183,12 @@ export class TabNav {
   }
 
   selectTab(nextTab: HTMLScaleTabHeaderElement) {
+    this.reset(nextTab);
+    if (!nextTab.selected) {
+      nextTab.selected = true;
+    }
     const nextPanel = this.findPanelForTab(nextTab);
-    this.reset();
     nextPanel.hidden = false;
-    nextTab.selected = true;
   }
 
   /**

packages/components/src/html/tab-nav.html

@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<html dir="ltr" lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta
+      name="viewport"
+      content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=5.0"
+    />
+    <title>Stencil Component Starter</title>
+
+    <script type="module" src="/build/scale-components.esm.js"></script>
+    <link rel="stylesheet" href="/build/scale-components.css" />
+    <style type="text/css" media="screen, print">
+      html {
+        margin: 0;
+        padding: 0;
+      }
+
+      body {
+        margin: 0;
+        padding: 4rem;
+      }
+    </style>
+  </head>
+
+  <body>
+    <p>
+      <scale-tab-nav>
+        <scale-tab-header slot="tab">General</scale-tab-header>
+        <scale-tab-panel slot="panel">
+          1 Freegan kinfolk farm-to-table humblebrag cred…
+        </scale-tab-panel>
+        <scale-tab-header slot="tab">Usage</scale-tab-header>
+        <scale-tab-panel slot="panel">
+          2 Bespoke austin pork belly yuccie pop-up. Before they sold out…
+        </scale-tab-panel>
+        <scale-tab-header slot="tab">Style</scale-tab-header>
+        <scale-tab-panel slot="panel">
+          3 Biodiesel chia af hoodie tumeric bespoke letterpress…
+        </scale-tab-panel>
+        <scale-tab-header slot="tab">Code</scale-tab-header>
+        <scale-tab-panel slot="panel">
+          4 Asymmetrical tattooed chia, banh mi blog microdosing…
+        </scale-tab-panel>
+      </scale-tab-nav>
+    </p>
+  </body>
+  <script>
+    setTimeout(() => {
+      let tabs = document.querySelectorAll('scale-tab-header');
+      tabs[0].disabled = true;
+    }, 2000);
+    setTimeout(() => {
+      let tabs = document.querySelectorAll('scale-tab-header');
+      tabs[3].selected = true;
+    }, 4000);
+  </script>
+</html>

packages/storybook-vue/stories/components/tab-navigation/ScaleTabNav.vue

@@ -24,7 +24,7 @@
         bitters.
       </p>
     </scale-tab-panel>
-    <scale-tab-header slot="tab">
+    <scale-tab-header :selected="preselected ? true : false" slot="tab">
       <scale-icon-content-heart v-if="withIcon" /> Style
     </scale-tab-header>
     <scale-tab-panel slot="panel">
@@ -55,8 +55,10 @@ export default {
   props: {
     styles: { type: String },
     disabled: { type: Boolean, default: false },
+    preselected: { type: Boolean, default: false },
     withIcon: { type: Boolean, default: true },
     size: { type: String, default: 'small' },
+    small: { type: Boolean, default: false },
   },
 };
 </script>

packages/storybook-vue/stories/components/tab-navigation/TabHeader.vue

@@ -0,0 +1,11 @@
+<script>
+export default {
+  name: 'Tab Header',
+  props: {
+    styles: { type: String },
+    disabled: { type: Boolean, default: 'false' },
+    selected: { type: Boolean, default: 'false' },
+    size: { type: ['large', 'small'], default: 'small' },
+  },
+};
+</script>

packages/storybook-vue/stories/components/tab-navigation/TabNav.stories.mdx

@@ -6,12 +6,13 @@ import {
   Description,
 } from '@storybook/addon-docs';
 import ScaleTabNav from './ScaleTabNav.vue';
+import TabHeader from './TabHeader.vue';
 import TabPanel from './TabPanel.vue';
 
 <Meta
   title="Components/Tab Navigation"
   component={ScaleTabNav}
-  subcomponents={{ 'Scale Tab Panel': TabPanel }}
+  subcomponents={{ 'Scale Tab Header': TabHeader, 'Scale Tab Panel': TabPanel }}
   argTypes={{
     styles: {
       table: {
@@ -34,14 +35,21 @@ import TabPanel from './TabPanel.vue';
       description: `(optional) DEPRECATED - size should replace small`,
       control: { type: null },
     },
+    preselected: {
+      table: {
+        disable: true,
+      },
+      description: '',
+      control: { type: null },
+    },
   }}
 />
 
 export const Template = (args, { argTypes }) => ({
   components: { ScaleTabNav },
   props: ScaleTabNav.props,
   template: `
-    <scale-tab-nav :disabled="disabled ? true : false" :size="size" :with-icon="withIcon"></scale-tab-nav>
+    <scale-tab-nav :disabled="disabled ? true : false" :preselected="preselected ? true : false" :size="size" :with-icon="withIcon"></scale-tab-nav>
   `,
 });
 
@@ -123,8 +131,9 @@ export const Template = (args, { argTypes }) => ({
   --color-hover: var(--telekom-color-text-and-icon-primary-hovered);
   --color-active: var(--telekom-color-text-and-icon-primary-pressed);
   --color-selected: var(--telekom-color-text-and-icon-primary-standard);
-  --focus-outline: var(--telekom-line-weight-highlight) solid
-    var(--telekom-color-functional-focus-standard);
+  --focus-outline: var(--telekom-line-weight-highlight) solid var(
+      --telekom-color-functional-focus-standard
+    );
   --spacing-right-slotted: var(--telekom-spacing-composition-space-04);
   --color-disabled: var(--telekom-color-text-and-icon-disabled);
   --radius: var(--telekom-radius-standard);
@@ -200,6 +209,38 @@ For Shadow Parts, please inspect the element's #shadow.
 </scale-tab-nav>
 ```
 
+## Preselected Tab
+
+<Canvas withSource="none">
+  <Story
+    name="Preselected Tab"
+    args={{ preselected: true, withIcon: false, size: 'small' }}
+  >
+    {Template.bind({})}
+  </Story>
+</Canvas>
+
+```html
+<scale-tab-nav>
+  <scale-tab-header slot="tab">General</scale-tab-header>
+  <scale-tab-panel slot="panel">
+    Freegan kinfolk farm-to-table humblebrag cred…
+  </scale-tab-panel>
+  <scale-tab-header slot="tab">Usage</scale-tab-header>
+  <scale-tab-panel slot="panel">
+    Bespoke austin pork belly yuccie pop-up. Before they sold out…
+  </scale-tab-panel>
+  <scale-tab-header selected slot="tab">Style</scale-tab-header>
+  <scale-tab-panel slot="panel">
+    Biodiesel chia af hoodie tumeric bespoke letterpress…
+  </scale-tab-panel>
+  <scale-tab-header slot="tab">Code</scale-tab-header>
+  <scale-tab-panel slot="panel">
+    Asymmetrical tattooed chia, banh mi blog microdosing…
+  </scale-tab-panel>
+</scale-tab-nav>
+```
+
 ## Large, Text & Icon
 
 <Canvas withSource="none">