refactor(tabs): ion-tabbar can be used in standalone mode

core/src/components/tabbar/tabbar.scss

@@ -7,7 +7,6 @@
   );
 
   display: flex;
-  position: relative;
 
   align-items: center;
   justify-content: center;
@@ -21,6 +20,7 @@
   user-select: none;
 
   z-index: $z-index-toolbar;
+  box-sizing: content-box;
 }
 
 :host(.ion-color) {

core/src/components/tabbar/tabbar.tsx

@@ -35,10 +35,14 @@ export class Tabbar implements ComponentInterface {
    */
   @Prop() placement: TabbarPlacement = 'bottom';
 
-  /** The selected tab component */
+  /**
+   * The selected tab component
+   */
   @Prop() selectedTab?: HTMLIonTabElement;
 
-  /** The tabs to render */
+  /**
+   * The tabs to render
+   */
   @Prop() tabs: HTMLIonTabElement[] = [];
 
   /**
@@ -51,7 +55,9 @@ export class Tabbar implements ComponentInterface {
    */
   @Prop() translucent = false;
 
-  /** Emitted when the tab bar is clicked  */
+  /**
+   * Emitted when the tab bar is clicked
+   */
   @Event() ionTabbarClick!: EventEmitter<HTMLIonTabElement>;
 
   @Listen('body:keyboardWillHide')
@@ -70,10 +76,6 @@ export class Tabbar implements ComponentInterface {
     this.updateHighlight();
   }
 
-  private getSelectedButton(): HTMLElement | null {
-    return this.el.shadowRoot!.querySelector('.tab-btn-selected');
-  }
-
   @Watch('selectedTab')
   @Listen('window:resize')
   private updateHighlight() {
@@ -81,7 +83,7 @@ export class Tabbar implements ComponentInterface {
       return;
     }
     this.queue.read(() => {
-      const btn = this.getSelectedButton();
+      const btn = this.el.shadowRoot!.querySelector('.tab-btn-selected') as HTMLElement | null;
       const highlight = this.el.shadowRoot!.querySelector('.tabbar-highlight') as HTMLElement;
       if (btn && highlight) {
         highlight.style.transform = `translate3d(${btn.offsetLeft}px,0,0) scaleX(${btn.offsetWidth})`;
@@ -94,6 +96,7 @@ export class Tabbar implements ComponentInterface {
     return {
       role: 'tablist',
       'aria-hidden': keyboardVisible ? 'true' : null,
+      'slot': 'tabbar',
       class: {
         ...createColorClasses(color),
         'tabbar-translucent': translucent,

core/src/components/tabs/tabs.scss

@@ -15,21 +15,15 @@
   z-index: $z-index-page-container;
 }
 
-ion-tabbar {
-  @include position(null, 0, 0, 0);
+.tabs-inner {
+  position: relative;
 
+  flex: 1;
+
+  contain: layout size style;
+}
+
+:host(.tabbar-hidden) ion-tabbar,
+:host(.tabbar-hidden)::slotted(ion-tabbar) {
   display: none;
-  position: absolute;
-}
-
-:host(.tabbar-visible.tabs-md)::slotted(ion-tab) {
-  bottom: 56px; // tabbar height (it's fixed!)
-}
-
-:host(.tabbar-visible.tabs-ios)::slotted(ion-tab) {
-  bottom: 50px; // tabbar height (it's fixed!)
-}
-
-:host(.tabbar-visible) ion-tabbar {
-  display: flex;
 }

core/src/components/tabs/tabs.tsx

@@ -1,12 +1,11 @@
 import { Build, Component, Element, Event, EventEmitter, Listen, Method, Prop, State } from '@stencil/core';
 
-import { Color, Config, IonicConfig, Mode, NavOutlet, RouteID, RouteWrite, TabbarLayout, TabbarPlacement } from '../../interface';
-import { createThemedClasses } from '../../utils/theme';
+import { Config, NavOutlet, RouteID, RouteWrite } from '../../interface';
 
 @Component({
   tag: 'ion-tabs',
   styleUrl: 'tabs.scss',
-  scoped: true
+  shadow: true
 })
 export class Tabs implements NavOutlet {
 
@@ -14,6 +13,7 @@ export class Tabs implements NavOutlet {
   private transitioning = false;
   private tabsId = (++tabIds);
   private leavingTab?: HTMLIonTabElement;
+  private userTabbarEl?: HTMLIonTabbarElement;
 
   @Element() el!: HTMLStencilElement;
 
@@ -23,19 +23,6 @@ export class Tabs implements NavOutlet {
   @Prop({ context: 'config' }) config!: Config;
   @Prop({ context: 'document' }) doc!: Document;
 
-  /**
-   * The mode determines which platform styles to use.
-   * Possible values are: `"ios"` or `"md"`.
-   */
-  @Prop() mode!: Mode;
-
-  /**
-   * The color to use from your application's color palette.
-   * Default options are: `"primary"`, `"secondary"`, `"tertiary"`, `"success"`, `"warning"`, `"danger"`, `"light"`, `"medium"`, and `"dark"`.
-   * For more information on colors, see [theming](/docs/theming/basics).
-   */
-  @Prop() color?: Color;
-
   /**
    * A unique name for the tabs.
    */
@@ -46,29 +33,6 @@ export class Tabs implements NavOutlet {
    */
   @Prop() tabbarHidden = false;
 
-  /**
-   * If true, show the tab highlight bar under the selected tab.
-   */
-  @Prop({ mutable: true }) tabbarHighlight?: boolean;
-
-  /**
-   * Set the layout of the text and icon in the tabbar. Available options: `"icon-top"`, `"icon-start"`, `"icon-end"`, `"icon-bottom"`, `"icon-hide"`, `"label-hide"`.
-   */
-  @Prop({ mutable: true }) tabbarLayout?: TabbarLayout;
-
-  /**
-   * Set the position of the tabbar, relative to the content. Available options: `"top"`, `"bottom"`.
-   */
-  @Prop({ mutable: true }) tabbarPlacement?: TabbarPlacement;
-
-  /**
-   * If true, the tabs will be translucent.
-   * Note: In order to scroll content behind the tabs, the `fullscreen`
-   * attribute needs to be set on the content.
-   * Defaults to `false`.
-   */
-  @Prop() translucent = false;
-
   /**
    * If true, the tabs will use the router and `selectedTab` will not do anything.
    */
@@ -94,18 +58,16 @@ export class Tabs implements NavOutlet {
    */
   @Event() ionNavDidChange!: EventEmitter<void>;
 
-  componentWillLoad() {
+  async componentWillLoad() {
     if (!this.useRouter) {
       this.useRouter = !!this.doc.querySelector('ion-router') && !this.el.closest('[no-router]');
     }
+    this.userTabbarEl = this.el.querySelector('ion-tabbar') || undefined;
 
-    this.loadConfig('tabbarPlacement', 'bottom');
-    this.loadConfig('tabbarLayout', 'icon-top');
-    this.loadConfig('tabbarHighlight', false);
-
-    this.initTabs();
+    await this.initTabs();
 
     this.ionNavWillLoad.emit();
+    this.componentWillUpdate();
   }
 
   componentDidLoad() {
@@ -117,6 +79,14 @@ export class Tabs implements NavOutlet {
     this.selectedTab = this.leavingTab = undefined;
   }
 
+  componentWillUpdate() {
+    const tabbarEl = this.userTabbarEl;
+    if (tabbarEl) {
+      tabbarEl.tabs = this.tabs.slice();
+      tabbarEl.selectedTab = this.selectedTab;
+    }
+  }
+
   @Listen('ionTabMutated')
   protected onTabMutated() {
     this.el.forceUpdate();
@@ -202,6 +172,7 @@ export class Tabs implements NavOutlet {
       tab.btnId = 'tab-' + id;
       tab.id = 'tabpanel-' + id;
     });
+    return Promise.all(tabs.map(tab => tab.componentOnReady()));
   }
 
   private async initSelect(): Promise<void> {
@@ -236,13 +207,6 @@ export class Tabs implements NavOutlet {
     }
   }
 
-  private loadConfig(attrKey: keyof IonicConfig, fallback: any) {
-    const val = (this as any)[attrKey];
-    if (typeof val === 'undefined') {
-      (this as any)[attrKey] = this.config.get(attrKey, fallback);
-    }
-  }
-
   private setActive(selectedTab: HTMLIonTabElement): Promise<void> {
     if (this.transitioning) {
       return Promise.reject('transitioning already happening');
@@ -300,26 +264,24 @@ export class Tabs implements NavOutlet {
   hostData() {
     return {
       class: {
-        ...createThemedClasses(this.mode, 'tabs'),
-        'tabbar-visible': !this.tabbarHidden
+        'tabbar-hidden': this.tabbarHidden
       }
     };
   }
 
   render() {
-    return (
-      <ion-tabbar
-        mode={this.mode}
-        tabs={this.tabs.slice()}
-        color={this.color}
-        selectedTab={this.selectedTab}
-        highlight={this.tabbarHighlight}
-        placement={this.tabbarPlacement}
-        layout={this.tabbarLayout}
-        translucent={this.translucent}
-      >
-      </ion-tabbar>
-    );
+    return [
+      <div class="tabs-inner">
+        <slot></slot>
+      </div>,
+      <slot name="tabbar">
+        <ion-tabbar
+          tabs={this.tabs.slice()}
+          selectedTab={this.selectedTab}
+        >
+        </ion-tabbar>
+      </slot>
+    ];
   }
 }
 

core/src/components/tabs/test/basic/index.html

@@ -63,6 +63,8 @@
 
       <ion-tab disabled label="Messages" icon="chatboxes" component="page-one">
       </ion-tab>
+
+      <ion-tabbar></ion-tabbar>
     </ion-tabs>
   </ion-app>