basic indentation support in code blocks (#7494)

Signed-off-by: Victor Ilyushchenko <alt13ri@gmail.com>

plugins/text-editor-resources/src/components/extension/indent.ts

@@ -0,0 +1,152 @@
+//
+// Copyright © 2024 Hardcore Engineering Inc.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import { Extension } from '@tiptap/core'
+import { type Node } from '@tiptap/pm/model'
+import { type EditorState, TextSelection, type Transaction } from '@tiptap/pm/state'
+
+export interface IndendOptions {
+  indentUnit: string
+  allowedNodes: string[]
+}
+
+export const indentExtensionOptions: IndendOptions = {
+  indentUnit: '  ',
+  allowedNodes: ['mermaid', 'codeBlock']
+}
+
+export const IndentExtension = Extension.create<IndendOptions>({
+  name: 'huly-indent',
+  addKeyboardShortcuts () {
+    return {
+      Tab: ({ editor }) => {
+        if (!editor.isEditable) return false
+        return this.editor.commands.command(({ state, dispatch }) => {
+          return dispatch?.(adjustIndent(state, 1, this.options))
+        })
+      },
+      'Shift-Tab': ({ editor }) => {
+        if (!editor.isEditable) return false
+        return this.editor.commands.command(({ state, dispatch }) => {
+          return dispatch?.(adjustIndent(state, -1, this.options))
+        })
+      }
+    }
+  }
+})
+
+export function adjustIndent (state: EditorState, direction: -1 | 1, options: IndendOptions): Transaction | undefined {
+  const { selection } = state
+  if (selection instanceof TextSelection) {
+    return adjustSelectionIndent(state, selection, direction, options)
+  }
+}
+
+export function adjustSelectionIndent (
+  state: EditorState,
+  selection: TextSelection,
+  direction: -1 | 1,
+  options: IndendOptions
+): Transaction | undefined {
+  const ranges = getLinesInSelection(state, selection).filter((range) =>
+    options.allowedNodes.some((n) => n === range.node.type.name)
+  )
+
+  if (ranges.length === 0) return
+
+  const { indentUnit } = options
+
+  const indentLevelOffset = (pos: number, direction: -1 | 1): number => {
+    const unitSize = indentUnit.length
+    const levelAdjustment = direction === -1 && pos % unitSize !== 0 ? 0 : direction
+    const indentPos = Math.floor((pos + levelAdjustment * unitSize) / unitSize) * unitSize
+    return indentPos - pos
+  }
+
+  const tr = state.tr
+
+  if (ranges.length === 1) {
+    const range = ranges[0]
+    const withinIndent = selection.from >= range.from && selection.to <= range.from + range.indent && range.indent > 0
+    if (!withinIndent && direction > 0) {
+      const indentOffset = indentLevelOffset(selection.from - range.from, direction)
+      tr.insertText(indentUnit.slice(0, indentOffset), selection.from, selection.to)
+      return
+    }
+  }
+
+  let insertionOffset = 0
+  for (const range of ranges) {
+    if (direction > 0 ? range.text === '' : range.indent === 0) {
+      continue
+    }
+    const indentOffset = indentLevelOffset(range.indent, direction)
+    const from = range.from + insertionOffset
+    if (indentOffset > 0) {
+      tr.insertText(indentUnit.slice(0, indentOffset), from)
+    } else {
+      tr.insertText('', from, from - indentOffset)
+    }
+    insertionOffset += indentOffset
+  }
+
+  tr.setSelection(selection.map(tr.doc, tr.mapping))
+
+  return tr
+}
+
+function countLeadingSpace (str: string): number {
+  const match = str.match(/^(\s*)/)
+  return match !== null ? match[0].length : 0
+}
+
+interface LineRange {
+  node: Node
+  text: string
+  from: number
+  indent: number
+  to: number
+}
+
+function getLinesInSelection (state: EditorState, selection: TextSelection): LineRange[] {
+  const { from, to } = selection // Selection start and end positions
+  const ranges: LineRange[] = []
+
+  state.doc.nodesBetween(from, to, (node: Node, pos: number) => {
+    if (!node.isTextblock) return
+
+    let currentPos = pos + 1
+    const lines = node.textContent.split('\n')
+
+    for (const line of lines) {
+      const lineStart = currentPos
+      const lineEnd = currentPos + line.length
+
+      if (lineStart <= to && lineEnd >= from) {
+        ranges.push({
+          node,
+          from: lineStart,
+          indent: countLeadingSpace(line),
+          to: lineEnd,
+          text: line
+        })
+      }
+
+      currentPos = lineEnd + 1
+    }
+  })
+
+  return ranges
+}

plugins/text-editor-resources/src/kits/editor-kit.ts

@@ -37,6 +37,7 @@ import { Table, TableCell, TableRow } from '../components/extension/table'
 import { DefaultKit, type DefaultKitOptions } from './default-kit'
 import { MermaidExtension, type MermaidOptions, mermaidOptions } from '../components/extension/mermaid'
 import { DrawingBoardExtension, type DrawingBoardOptions } from '../components/extension/drawingBoard'
+import { type IndendOptions, IndentExtension, indentExtensionOptions } from '../components/extension/indent'
 
 export interface EditorKitOptions extends DefaultKitOptions {
   history?: false
@@ -53,6 +54,7 @@ export interface EditorKitOptions extends DefaultKitOptions {
   | false
   drawingBoard?: DrawingBoardOptions | false
   mermaid?: MermaidOptions | false
+  indent?: IndendOptions | false
   mode?: 'full' | 'compact'
   note?: NoteOptions | false
   submit?: SubmitOptions | false
@@ -260,6 +262,13 @@ async function buildEditorKit (): Promise<Extension<EditorKitOptions, any>> {
                 staticKitExtensions.push([850, MermaidExtension.configure(this.options.mermaid ?? mermaidOptions)])
               }
 
+              if (this.options.indent !== false) {
+                staticKitExtensions.push([
+                  860,
+                  IndentExtension.configure(this.options.indent ?? indentExtensionOptions)
+                ])
+              }
+
               if (this.options.toolbar !== false) {
                 staticKitExtensions.push([
                   900,