Documentation editor (#9910)

#### New documentation panel:
- Shows documentation of currently-entered method.
- Open/close with Ctrl+D or the extended menu.
- Renders markdown; supports WYSIWYG editing.
- Formatting can be added by typing the same markdown special characters that will appear in the source code, e.g.:
- `# Heading`
- `## Subheading`
- `*emphasis*`
- Panel left edge can be dragged to resize similarly to visualization container.

https://github.com/enso-org/enso/assets/1047859/6feb5d23-1525-48f7-933e-c9371312decf

#### Node comments are now markdown:
![image](https://github.com/enso-org/enso/assets/1047859/c5df13fe-0290-4f1d-abb2-b2f42df274d3)

#### Top bar extended menu improvements:
- Now closes after any menu action except +/- buttons, and on defocus/Esc.
- Editor/doc-panel buttons now colored to indicate whether editor/panel is open.

https://github.com/enso-org/enso/assets/1047859/345af322-c1a8-4717-8ffc-a5c919494fed

Closes #9786.

# Important Notes
New APIs:
- `DocumentationEditor` component: Lazily-loads and instantiates the implementation component (`MilkdownEditor`).
- `AstDocumentation` component: Connects a `DocumentationEditor` to the documentation of an `Ast` node.
- `ResizeHandles` component: Supports reuse of the resize handles used by the visualization container.
- `graphStore.undoManager`: Facade for the Y.UndoManager in the project store.

app/gui2/e2e/rightDock.spec.ts

@@ -0,0 +1,19 @@
+import { expect, test } from 'playwright/test'
+import * as actions from './actions'
+import { CONTROL_KEY } from './keyboard'
+
+test('Main method documentation', async ({ page }) => {
+  await actions.goToGraph(page)
+
+  // Documentation panel hotkey opens right-dock.
+  await expect(page.getByTestId('rightDock')).not.toBeVisible()
+  await page.keyboard.press(`${CONTROL_KEY}+D`)
+  await expect(page.getByTestId('rightDock')).toBeVisible()
+
+  // Right-dock displays main method documentation.
+  await expect(page.getByTestId('rightDock')).toHaveText('The main method')
+
+  // Documentation hotkey closes right-dock.p
+  await page.keyboard.press(`${CONTROL_KEY}+D`)
+  await expect(page.getByTestId('rightDock')).not.toBeVisible()
+})

app/gui2/mock/engine.ts

@@ -45,6 +45,7 @@ export function placeholderGroups(): LibraryComponentGroup[] {
 }
 
 let mainFile = `\
+## Module documentation
 from Standard.Base import all
 
 func1 arg =
@@ -56,6 +57,7 @@ func2 a =
     r = 42 + a
     r
 
+## The main method
 main =
     five = 5
     ten = 10

app/gui2/package.json

@@ -47,6 +47,12 @@
     "@floating-ui/vue": "^1.0.6",
     "@lezer/common": "^1.1.0",
     "@lezer/highlight": "^1.1.6",
+    "@milkdown/core": "^7.3.6",
+    "@milkdown/ctx": "^7.3.6",
+    "@milkdown/preset-commonmark": "^7.3.6",
+    "@milkdown/prose": "^7.3.6",
+    "@milkdown/theme-nord": "^7.3.6",
+    "@milkdown/vue": "^7.3.6",
     "@noble/hashes": "^1.3.2",
     "@open-rpc/client-js": "^1.8.1",
     "@pinia/testing": "^0.1.3",

app/gui2/shared/ast/tree.ts

@@ -117,8 +117,24 @@ export abstract class Ast {
   }
 
   innerExpression(): Ast {
-    // TODO: Override this in `Documented`, `Annotated`, `AnnotatedBuiltin`
-    return this
+    return this.wrappedExpression()?.innerExpression() ?? this
+  }
+
+  wrappedExpression(): Ast | undefined {
+    return undefined
+  }
+
+  wrappingExpression(): Ast | undefined {
+    const parent = this.parent()
+    return parent?.wrappedExpression()?.is(this) ? parent : undefined
+  }
+
+  wrappingExpressionRoot(): Ast {
+    return this.wrappingExpression()?.wrappingExpressionRoot() ?? this
+  }
+
+  documentingAncestor(): Documented | undefined {
+    return this.wrappingExpression()?.documentingAncestor()
   }
 
   code(): string {
@@ -328,6 +344,14 @@ export abstract class MutableAst extends Ast {
     applyTextEditsToAst(this, textEdits, metadataSource ?? this.module)
   }
 
+  getOrInitDocumentation(): MutableDocumented {
+    const existing = this.documentingAncestor()
+    if (existing) return this.module.getVersion(existing)
+    return this.module
+      .getVersion(this.wrappingExpressionRoot())
+      .updateValue((ast) => Documented.new('', ast))
+  }
+
   ///////////////////
 
   /** @internal */
@@ -1575,6 +1599,14 @@ export class Documented extends Ast {
     return raw.startsWith(' ') ? raw.slice(1) : raw
   }
 
+  wrappedExpression(): Ast | undefined {
+    return this.expression
+  }
+
+  documentingAncestor(): Documented | undefined {
+    return this
+  }
+
   *concreteChildren(_verbatim?: boolean): IterableIterator<RawNodeChild> {
     const { open, elements, newlines, expression } = getAll(this.fields)
     yield open

app/gui2/src/assets/base.css

@@ -10,6 +10,7 @@
   --color-text-inversed: rgb(255 255 255);
   --color-app-bg: rgb(255 255 255 / 0.8);
   --color-menu-entry-hover-bg: rgb(0 0 0 / 0.1);
+  --color-menu-entry-selected-bg: rgb(0 0 0 / 0.05);
   --color-visualization-bg: rgb(255 242 242);
   --color-dim: rgb(0 0 0 / 0.25);
   --color-frame-bg: rgb(255 255 255 / 0.3);
@@ -47,8 +48,13 @@
   --font-mono: 'DejaVu Sans Mono', /* System monspace font stack */ ui-monospace, Menlo, Monaco,
     'Cascadia Mono', 'Segoe UI Mono', 'Roboto Mono', 'Oxygen Mono', 'Ubuntu Monospace',
     'Source Code Pro', 'Fira Mono', 'Droid Sans Mono', 'Courier New', monospace;
+  /* Default resize handle widths, used for panels. */
+  --resize-handle-inside: 3px;
+  --resize-handle-outside: 3px;
+  /* Resize handle override for the visualization container. */
   --visualization-resize-handle-inside: 3px;
   --visualization-resize-handle-outside: 3px;
+  --right-dock-default-width: 40%;
 }
 
 *,

app/gui2/src/bindings.ts

@@ -1,9 +1,18 @@
 import { defineKeybinds } from '@/util/shortcuts'
 
+export const undoBindings = defineKeybinds('undo', {
+  undo: ['Mod+Z'],
+  redo: ['Mod+Y', 'Mod+Shift+Z'],
+})
+
 export const codeEditorBindings = defineKeybinds('code-editor', {
   toggle: ['Mod+`'],
 })
 
+export const documentationEditorBindings = defineKeybinds('documentation-editor', {
+  toggle: ['Mod+D'],
+})
+
 export const interactionBindings = defineKeybinds('current-interaction', {
   cancel: ['Escape'],
 })
@@ -18,8 +27,6 @@ export const componentBrowserBindings = defineKeybinds('component-browser', {
 })
 
 export const graphBindings = defineKeybinds('graph-editor', {
-  undo: ['Mod+Z'],
-  redo: ['Mod+Y', 'Mod+Shift+Z'],
   openComponentBrowser: ['Enter'],
   toggleVisualization: ['Space'],
   deleteSelected: ['OsDelete'],

app/gui2/src/components/AstDocumentation.vue

@@ -0,0 +1,44 @@
+<script setup lang="ts">
+import DocumentationEditor from '@/components/DocumentationEditor.vue'
+import { useGraphStore } from '@/stores/graph'
+import { Ast } from '@/util/ast'
+import { computed } from 'vue'
+
+const editing = defineModel<boolean>('editing', { default: false })
+const props = defineProps<{
+  ast: Ast.Ast | undefined
+  /** If provided, this property will be read to obtain the current documentation text instead of finding it in the AST.
+   *   This can be used to reduce reactive dependencies. */
+  documentation?: string
+  /** If set, the Enter key will end editing instead of inserting a newline, unless the Shift key is held. */
+  preferSingleLine?: boolean | undefined
+}>()
+
+const graphStore = useGraphStore()
+const documentation = computed({
+  get: () =>
+    props?.documentation != null ?
+      props.documentation
+    : props.ast?.documentingAncestor()?.documentation() ?? '',
+  set: (value) => {
+    const ast = props.ast
+    if (!ast) return
+    if (value.trimStart() !== '') {
+      graphStore.edit((edit) =>
+        edit.getVersion(ast).getOrInitDocumentation().setDocumentationText(value),
+      )
+    } else {
+      // Remove the documentation node.
+      const documented = props.ast?.documentingAncestor()
+      if (documented && documented.expression)
+        graphStore.edit((edit) =>
+          edit.getVersion(documented).update((documented) => documented.expression!.take()),
+        )
+    }
+  },
+})
+</script>
+
+<template>
+  <DocumentationEditor v-model="documentation" v-model:editing="editing" :preferSingleLine />
+</template>

app/gui2/src/components/ColorRing/__tests__/gradient.test.ts

@@ -41,7 +41,7 @@ function angularStops(points: Iterable<GradientPoint>) {
   return stops
 }
 
-function stopSpans(stops: Iterable<AngularStop>, radius: number) {
+function stopSpans(stops: Iterable<AngularStop>) {
   const spans = new Array<{ start: number; end: number; hue: number }>()
   let prev: AngularStop | undefined = undefined
   for (const stop of stops) {
@@ -78,7 +78,7 @@ function testGradients({ hues, radius }: { hues: number[]; radius: number }) {
   const stops = angularStops(points)
   expect(stops[0]?.angle).toBe(0)
   expect(stops[stops.length - 1]?.angle).toBe(1)
-  const spans = stopSpans(stops, radius)
+  const spans = stopSpans(stops)
   for (const span of spans) {
     expect(approximateHues).toContain(approximate(span.hue))
     if (span.start < span.end) {

app/gui2/src/components/ComponentBrowser.vue

@@ -1,10 +1,10 @@
 <script setup lang="ts">
 import { componentBrowserBindings } from '@/bindings'
+import { default as DocumentationPanel } from '@/components/ComponentBrowser/DocumentationPanel.vue'
 import { makeComponentList, type Component } from '@/components/ComponentBrowser/component'
 import { Filtering } from '@/components/ComponentBrowser/filtering'
 import { useComponentBrowserInput, type Usage } from '@/components/ComponentBrowser/input'
 import { useScrolling } from '@/components/ComponentBrowser/scrolling'
-import { default as DocumentationPanel } from '@/components/DocumentationPanel.vue'
 import GraphVisualization from '@/components/GraphEditor/GraphVisualization.vue'
 import SvgIcon from '@/components/SvgIcon.vue'
 import ToggleIcon from '@/components/ToggleIcon.vue'

app/gui2/src/components/DocumentationEditor.vue

@@ -0,0 +1,26 @@
+<script setup lang="ts">
+import { MilkdownProvider } from '@milkdown/vue'
+import { defineAsyncComponent } from 'vue'
+
+const documentation = defineModel<string>({ required: true })
+const editing = defineModel<boolean>('editing', { default: false })
+const props = defineProps<{
+  preferSingleLine?: boolean | undefined
+}>()
+
+const LazyMilkdownEditor = defineAsyncComponent(
+  () => import('@/components/DocumentationEditor/MilkdownEditor.vue'),
+)
+</script>
+
+<template>
+  <Suspense>
+    <MilkdownProvider>
+      <LazyMilkdownEditor
+        v-model="documentation"
+        v-model:editing="editing"
+        :preferSingleLine="props.preferSingleLine"
+      />
+    </MilkdownProvider>
+  </Suspense>
+</template>