create better structure inspired by ObsidianTweaks'

src/BetterFormatting.ts

@@ -0,0 +1,297 @@
+import {
+	App,
+	Editor,
+	EditorChange,
+	EditorPosition,
+	EditorRange,
+	EditorRangeOrCaret,
+	EditorSelection,
+	EditorTransaction,
+	MarkdownView,
+} from 'obsidian'
+import BindThemPlugin from './main'
+import { getMainSelection, selectionToRange } from './Utils'
+import { PRE_WIDOW_EXPAND_CHARS, POST_WIDOW_EXPAND_CHARS } from './Constants'
+
+/**
+ * BetterFormatting provides enhanced markdown formatting toggling
+ * that intelligently expands selections to word boundaries and
+ * handles widow characters.
+ */
+export class BetterFormatting {
+	public app: App
+	private plugin: BindThemPlugin
+
+	constructor(app: App, plugin: BindThemPlugin) {
+		this.app = app
+		this.plugin = plugin
+	}
+
+	/**
+	 * Expand a range by words, including intelligent handling of widow characters
+	 */
+	private expandRangeByWords(
+		editor: Editor,
+		range: EditorRange,
+		symbolStart: string,
+		symbolEnd: string
+	): EditorRange {
+		// Expand to word boundaries
+		let from = (editor.wordAt(range.from) || range).from
+		let to = (editor.wordAt(range.to) || range).to
+
+		// Include leading 'widows' (characters that should be included before the word)
+		while (true) {
+			const newFrom: EditorPosition = {
+				line: from.line,
+				ch: from.ch - 1,
+			}
+
+			const newTo: EditorPosition = {
+				line: to.line,
+				ch: to.ch + 1,
+			}
+
+			const preChar = editor.getRange(newFrom, from)
+			const postChar = editor.getRange(to, newTo)
+
+			// Don't do this if widows form a matched pair
+			if (preChar === postChar) {
+				break
+			}
+
+			if (symbolStart.endsWith(preChar)) {
+				break
+			}
+
+			if (!PRE_WIDOW_EXPAND_CHARS.includes(preChar)) {
+				break
+			}
+
+			from = newFrom
+		}
+
+		// Include trailing 'widows'
+		while (true) {
+			const newFrom: EditorPosition = {
+				line: from.line,
+				ch: from.ch - 1,
+			}
+
+			const newTo: EditorPosition = {
+				line: to.line,
+				ch: to.ch + 1,
+			}
+
+			const preChar = editor.getRange(newFrom, from)
+			const postChar = editor.getRange(to, newTo)
+
+			// Don't do this if widows form a matched pair
+			if (preChar === postChar) {
+				break
+			}
+
+			if (symbolEnd.startsWith(postChar)) {
+				break
+			}
+
+			if (!POST_WIDOW_EXPAND_CHARS.includes(postChar)) {
+				break
+			}
+
+			to = newTo
+		}
+
+		// Include leading symbolStart
+		const newFrom = { line: from.line, ch: from.ch - symbolStart.length }
+		const preString = editor.getRange(newFrom, from)
+		if (preString === symbolStart) {
+			from = newFrom
+		}
+
+		// Include following symbolEnd
+		const newTo = { line: to.line, ch: to.ch + symbolEnd.length }
+		const postString = editor.getRange(to, newTo)
+		if (postString === symbolEnd) {
+			to = newTo
+		}
+
+		return {
+			from: from,
+			to: to,
+		}
+	}
+
+	/**
+	 * Check if text in the given range is already wrapped with the specified symbols
+	 */
+	private isWrapped(
+		editor: Editor,
+		range: EditorRange,
+		symbolStart: string,
+		symbolEnd: string
+	): boolean {
+		const text = editor.getRange(range.from, range.to)
+		return text.startsWith(symbolStart) && text.endsWith(symbolEnd)
+	}
+
+	/**
+	 * Create changes to wrap text with symbols
+	 */
+	private wrap(
+		editor: Editor,
+		textRange: EditorRange,
+		selection: EditorSelection,
+		symbolStart: string,
+		symbolEnd: string
+	): [Array<EditorChange>, EditorSelection] {
+		const changes: Array<EditorChange> = [
+			{
+				from: textRange.from,
+				text: symbolStart,
+			},
+			{
+				from: textRange.to,
+				text: symbolEnd,
+			},
+		]
+
+		const newSelection: EditorSelection = {
+			anchor: { ...selection.anchor },
+			head: { ...selection.head },
+		}
+		newSelection.anchor.ch += symbolStart.length
+		newSelection.head.ch += symbolEnd.length
+
+		return [changes, newSelection]
+	}
+
+	/**
+	 * Create changes to unwrap text from symbols
+	 */
+	private unwrap(
+		editor: Editor,
+		textRange: EditorRange,
+		selection: EditorSelection,
+		symbolStart: string,
+		symbolEnd: string
+	): [Array<EditorChange>, EditorSelection] {
+		const changes: Array<EditorChange> = [
+			{
+				from: textRange.from,
+				to: {
+					line: textRange.from.line,
+					ch: textRange.from.ch + symbolStart.length,
+				},
+				text: '',
+			},
+			{
+				from: {
+					line: textRange.to.line,
+					ch: textRange.to.ch - symbolEnd.length,
+				},
+				to: textRange.to,
+				text: '',
+			},
+		]
+
+		const newSelection: EditorSelection = {
+			anchor: { ...selection.anchor },
+			head: { ...selection.head },
+		}
+		newSelection.anchor.ch -= symbolStart.length
+		newSelection.head.ch -= symbolStart.length
+
+		return [changes, newSelection]
+	}
+
+	/**
+	 * Set the wrap state for a selection
+	 */
+	private setSelectionWrapState(
+		editor: Editor,
+		selection: EditorSelection,
+		wrapState: boolean,
+		symbolStart: string,
+		symbolEnd: string
+	): [Array<EditorChange>, EditorSelection] {
+		const initialRange = selectionToRange(selection)
+		const textRange: EditorRange = this.expandRangeByWords(
+			editor,
+			initialRange,
+			symbolStart,
+			symbolEnd
+		)
+
+		// Check if already wrapped
+		const alreadyWrapped = this.isWrapped(editor, textRange, symbolStart, symbolEnd)
+		if (alreadyWrapped === wrapState) {
+			return [[], selection]
+		}
+
+		// Wrap or unwrap
+		if (wrapState) {
+			return this.wrap(editor, textRange, selection, symbolStart, symbolEnd)
+		}
+
+		return this.unwrap(editor, textRange, selection, symbolStart, symbolEnd)
+	}
+
+	/**
+	 * Toggle wrapper symbols around the current selection(s)
+	 * 
+	 * Principle: Toggling twice == no-op
+	 */
+	public toggleWrapper(
+		editor: Editor,
+		view: MarkdownView,
+		symbolStart: string,
+		symbolEnd?: string
+	): void {
+		if (symbolEnd === undefined) {
+			symbolEnd = symbolStart
+		}
+
+		const selections = editor.listSelections()
+		const mainSelection = getMainSelection(editor)
+
+		// Get wrapped state of main selection
+		const mainRange: EditorRange = this.expandRangeByWords(
+			editor,
+			selectionToRange(mainSelection),
+			symbolStart,
+			symbolEnd
+		)
+
+		// Check if already wrapped
+		const isWrapped = this.isWrapped(editor, mainRange, symbolStart, symbolEnd)
+		const targetWrapState = !isWrapped
+
+		// Process all selections
+		const newChanges: Array<EditorChange> = []
+		const newSelectionRanges: Array<EditorRangeOrCaret> = []
+
+		for (const selection of selections) {
+			const [changes, newSelection] = this.setSelectionWrapState(
+				editor,
+				selection,
+				targetWrapState,
+				symbolStart,
+				symbolEnd
+			)
+
+			newChanges.push(...changes)
+			newSelectionRanges.push(selectionToRange(newSelection))
+		}
+
+		const transaction: EditorTransaction = {
+			changes: newChanges,
+			selections: newSelectionRanges,
+		}
+
+		let origin = targetWrapState ? '+' : '-'
+		origin += 'BetterFormatting_' + symbolStart + symbolEnd
+
+		editor.transaction(transaction, origin)
+	}
+}