Clean up ButtonGroup and factor out extension logic

ts/components/ButtonGroup.svelte

@@ -4,148 +4,95 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 -->
 <script lang="typescript">
     import ButtonGroupItem from "./ButtonGroupItem.svelte";
-    import type { SvelteComponentTyped } from "svelte";
     import { setContext } from "svelte";
     import { writable } from "svelte/store";
     import { buttonGroupKey } from "./contextKeys";
     import type { Identifier } from "./identifier";
-    import { insert, add, find } from "./identifier";
+    import { insert, add } from "./identifier";
     import type { ButtonRegistration } from "./buttons";
     import { ButtonPosition } from "./buttons";
+    import type { SvelteComponent } from "./registration";
+    import { makeInterface } from "./registration";
 
     export let id: string | undefined = undefined;
     let className: string = "";
     export { className as class };
 
-    export let api = {};
-    let buttonGroupRef: HTMLDivElement;
-
-    let items: ButtonRegistration[] = [];
-
-    $: {
-        for (const [index, item] of items.entries()) {
-            if (items.length === 1) {
-                item.position.set(ButtonPosition.Standalone);
-            } else if (index === 0) {
-                item.position.set(ButtonPosition.Leftmost);
-            } else if (index === items.length - 1) {
-                item.position.set(ButtonPosition.Rightmost);
-            } else {
-                item.position.set(ButtonPosition.Center);
-            }
-        }
-    }
-
     function makeRegistration(): ButtonRegistration {
         const detach = writable(false);
         const position = writable(ButtonPosition.Standalone);
         return { detach, position };
     }
 
-    function registerButton(
-        index = items.length,
-        registration = makeRegistration()
-    ): ButtonRegistration {
-        items.splice(index, 0, registration);
-        items = items;
-        return registration;
-    }
+    const {
+        registerComponent,
+        items,
+        dynamicItems,
+        getDynamicInterface,
+    } = makeInterface(makeRegistration);
 
-    interface SvelteComponent {
-        id: string | undefined;
-        component: SvelteComponentTyped;
-        props: Record<string, unknown>;
-    }
-
-    const dynamicItems: ButtonRegistration[] = [];
-    let dynamic: SvelteComponent[] = [];
-
-    function addButton(
-        button: SvelteComponent,
-        add: (added: Element, parent: Element) => number
-    ): void {
-        const registration = makeRegistration();
-
-        const callback = (
-            mutations: MutationRecord[],
-            observer: MutationObserver
-        ): void => {
-            for (const mutation of mutations) {
-                const addedNode = mutation.addedNodes[0];
-
-                if (addedNode.nodeType === Node.ELEMENT_NODE) {
-                    const index = add(addedNode as Element, buttonGroupRef);
-
-                    if (index >= 0) {
-                        registerButton(index, registration);
-                    }
-                }
-            }
-
-            observer.disconnect();
-        };
-
-        const observer = new MutationObserver(callback);
-        observer.observe(buttonGroupRef, { childList: true });
-
-        dynamicItems.push(registration);
-        dynamic = [...dynamic, button];
-    }
-
-    const insertButton = (button: SvelteComponent, position: Identifier = 0) =>
-        addButton(button, (added, parent) => insert(added, parent, position));
-    const appendButton = (button: SvelteComponent, position: Identifier = -1) =>
-        addButton(button, (added, parent) => add(added, parent, position));
-
-    function updateRegistration(
-        f: (registration: ButtonRegistration) => void,
-        id: Identifier
-    ): void {
-        const match = find(buttonGroupRef.children, id);
-
-        if (match) {
-            const [index] = match;
-            const registration = items[index];
-            f(registration);
+    $: for (const [index, item] of $items.entries()) {
+        if ($items.length === 1) {
+            item.position.set(ButtonPosition.Standalone);
+        } else if (index === 0) {
+            item.position.set(ButtonPosition.Leftmost);
+        } else if (index === $items.length - 1) {
+            item.position.set(ButtonPosition.Rightmost);
+        } else {
+            item.position.set(ButtonPosition.Center);
         }
     }
 
-    const showButton = (id: Identifier) =>
-        updateRegistration(({ detach }) => detach.set(false), id);
-    const hideButton = (id: Identifier) =>
-        updateRegistration(({ detach }) => detach.set(true), id);
-    const toggleButton = (id: Identifier) =>
-        updateRegistration(({ detach }) => detach.update((old) => !old), id);
+    setContext(buttonGroupKey, registerComponent);
+
+    export let api = {};
+    let buttonGroupRef: HTMLDivElement;
+
+    $: if (buttonGroupRef) {
+        const { addComponent, updateRegistration } = getDynamicInterface(
+            buttonGroupRef
+        );
+
+        const insertButton = (button: SvelteComponent, position: Identifier = 0) =>
+            addComponent(button, (added, parent) => insert(added, parent, position));
+        const appendButton = (button: SvelteComponent, position: Identifier = -1) =>
+            addComponent(button, (added, parent) => add(added, parent, position));
+
+        const showButton = (id: Identifier) =>
+            updateRegistration(({ detach }) => detach.set(false), id);
+        const hideButton = (id: Identifier) =>
+            updateRegistration(({ detach }) => detach.set(true), id);
+        const toggleButton = (id: Identifier) =>
+            updateRegistration(({ detach }) => detach.update((old) => !old), id);
 
-    setContext(
-        buttonGroupKey,
         Object.assign(api, {
-            registerButton,
             insertButton,
             appendButton,
             showButton,
             hideButton,
             toggleButton,
-        })
-    );
+        });
+    }
 </script>
 
 <style lang="scss">
     div {
-        display: flex;
-        justify-items: start;
         flex-wrap: var(--toolbar-wrap);
-
         padding: calc(var(--toolbar-size) / 10);
         margin: 0;
     }
 </style>
 
-<div bind:this={buttonGroupRef} {id} class={className} dir="ltr">
+<div
+    bind:this={buttonGroupRef}
+    {id}
+    class={`btn-group ${className}`}
+    dir="ltr"
+    role="group">
     <slot />
-    {#each dynamic as item, i}
-        <ButtonGroupItem id={item.id} registration={dynamicItems[i]}>
-            <svelte:component this={item.component} {...item.props} />
+    {#each $dynamicItems as item}
+        <ButtonGroupItem id={item[0].id} registration={item[1]}>
+            <svelte:component this={item[0].component} {...item[0].props} />
         </ButtonGroupItem>
     {/each}
 </div>

ts/components/ButtonGroupItem.svelte

@@ -8,6 +8,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
     import type { ButtonRegistration } from "./buttons";
     import { ButtonPosition } from "./buttons";
+    import type { Register } from "./registration";
 
     import { getContext, hasContext } from "svelte";
     import { buttonGroupKey } from "./contextKeys";
@@ -43,8 +44,10 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         detach.subscribe((value: boolean) => (detach_ = value));
         position.subscribe((value: ButtonPosition) => (position_ = value));
     } else if (hasContext(buttonGroupKey)) {
-        const { registerButton } = getContext(buttonGroupKey);
-        const { detach, position } = registerButton();
+        const registerComponent = getContext<Register<ButtonRegistration>>(
+            buttonGroupKey
+        );
+        const { detach, position } = registerComponent();
         detach.subscribe((value: boolean) => (detach_ = value));
         position.subscribe((value: ButtonPosition) => (position_ = value));
     } else {

ts/components/ButtonToolbar.svelte

@@ -0,0 +1,15 @@
+<!--
+Copyright: Ankitects Pty Ltd and contributors
+License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+-->
+<script lang="typescript">
+    export let id: string | undefined = undefined;
+    let className: string | undefined;
+    export { className as class };
+
+    export let nowrap = false;
+</script>
+
+<div {id} class={`btn-toolbar ${className}`} class:flex-nowrap={nowrap} role="toolbar">
+    <slot />
+</div>

ts/components/StickyBar.svelte

@@ -10,9 +10,6 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
 <style lang="scss">
     nav {
-        display: flex;
-        flex-wrap: wrap;
-
         position: sticky;
         top: 0;
         left: 0;
@@ -24,6 +21,6 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     }
 </style>
 
-<nav {id} class="pb-1 {className}">
+<nav {id} class={`pb-1 ${className}`}>
     <slot />
 </nav>

ts/components/registration.ts

@@ -0,0 +1,110 @@
+// Copyright: Ankitects Pty Ltd and contributors
+// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+import type { SvelteComponentTyped } from "svelte/internal";
+import type { Readable } from "svelte/store";
+import { writable } from "svelte/store";
+import type { Identifier } from "./identifier";
+import { find } from "./identifier";
+
+export interface SvelteComponent {
+    component: SvelteComponentTyped;
+    id: string | undefined;
+    props: Record<string, unknown> | undefined;
+}
+
+export type Register<T> = (index?: number, registration?: T) => T;
+
+export interface RegistrationAPI<T> {
+    registerComponent: Register<T>;
+    items: Readable<T[]>;
+    dynamicItems: Readable<[SvelteComponent, T][]>;
+    getDynamicInterface: (elementRef: HTMLElement) => DynamicRegistrationAPI<T>;
+}
+
+export interface DynamicRegistrationAPI<T> {
+    addComponent: (
+        component: SvelteComponent,
+        add: (added: Element, parent: Element) => number
+    ) => void;
+    updateRegistration: (
+        update: (registration: T) => void,
+        position: Identifier
+    ) => void;
+}
+
+export function makeInterface<T>(makeRegistration: () => T): RegistrationAPI<T> {
+    const registrations: T[] = [];
+    const items = writable(registrations);
+
+    function registerComponent(
+        index: number = registrations.length,
+        registration = makeRegistration()
+    ): T {
+        registrations.splice(index, 0, registration);
+        items.set(registrations);
+        return registration;
+    }
+
+    const dynamicRegistrations: [SvelteComponent, T][] = [];
+    const dynamicItems = writable(dynamicRegistrations);
+
+    function getDynamicInterface(elementRef: HTMLElement): DynamicRegistrationAPI<T> {
+        function addComponent(
+            component: SvelteComponent,
+            add: (added: Element, parent: Element) => number
+        ): void {
+            const registration = makeRegistration();
+
+            const callback = (
+                mutations: MutationRecord[],
+                observer: MutationObserver
+            ): void => {
+                for (const mutation of mutations) {
+                    const addedNode = mutation.addedNodes[0];
+
+                    if (addedNode.nodeType === Node.ELEMENT_NODE) {
+                        const index = add(addedNode as Element, elementRef);
+
+                        if (index >= 0) {
+                            registerComponent(index, registration);
+                        }
+                    }
+                }
+
+                observer.disconnect();
+            };
+
+            const observer = new MutationObserver(callback);
+            observer.observe(elementRef, { childList: true });
+
+            dynamicRegistrations.push([component, registration]);
+            dynamicItems.set(dynamicRegistrations);
+        }
+
+        function updateRegistration(
+            update: (registration: T) => void,
+            position: Identifier
+        ): void {
+            const match = find(elementRef.children, position);
+
+            if (match) {
+                const [index] = match;
+                const registration = registrations[index];
+                update(registration);
+                items.set(registrations);
+            }
+        }
+
+        return {
+            addComponent,
+            updateRegistration,
+        };
+    }
+
+    return {
+        registerComponent,
+        items,
+        dynamicItems,
+        getDynamicInterface,
+    };
+}

ts/editor/EditorToolbar.svelte

@@ -47,6 +47,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
     import WithTheming from "components/WithTheming.svelte";
     import StickyBar from "components/StickyBar.svelte";
+    import ButtonToolbar from "components/ButtonToolbar.svelte";
 
     import NoteTypeButtons from "./NoteTypeButtons.svelte";
     import FormatInlineButtons from "./FormatInlineButtons.svelte";
@@ -75,10 +76,12 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
 <WithTheming {style}>
     <StickyBar>
-        <NoteTypeButtons api={notetypeButtons} />
-        <FormatInlineButtons api={formatInlineButtons} />
-        <FormatBlockButtons api={formatBlockButtons} />
-        <ColorButtons api={colorButtons} />
-        <TemplateButtons api={templateButtons} />
+        <ButtonToolbar>
+            <NoteTypeButtons api={notetypeButtons} />
+            <FormatInlineButtons api={formatInlineButtons} />
+            <FormatBlockButtons api={formatBlockButtons} />
+            <ColorButtons api={colorButtons} />
+            <TemplateButtons api={templateButtons} />
+        </ButtonToolbar>
     </StickyBar>
 </WithTheming>

ts/editor/bootstrap.scss

@@ -5,4 +5,5 @@
 $btn-disabled-opacity: 0.4;
 
 @import "ts/sass/bootstrap/buttons";
+@import "ts/sass/bootstrap/button-group";
 @import "ts/sass/bootstrap/dropdown";