Refactor code.

src/completion.ts

@@ -94,21 +94,17 @@ export class CompletionItemProvider implements vscode.CompletionItemProvider {
         token: vscode.CancellationToken,
         context: vscode.CompletionContext,
     ) {
+        // Triggered in the middle of a word.
         if (context.triggerKind === vscode.CompletionTriggerKind.Invoke) {
             const wordRange = document.getWordRangeAtPosition(position);
-            if (wordRange === undefined) {
+            if (wordRange === undefined) return undefined;
-                return undefined;
+            // Normalize position so that it can be treated as triggered by '@' character.
-            }
             position = wordRange.start;
-            if (document.getText(new vscode.Range(position.translate(0, -1), position)) !== '@') {
+            if (document.getText(new vscode.Range(position.translate(0, -1), position)) !== '@') return undefined;
-                return undefined;
-            }
-        }
-        if (position.character === 1) {
-            return this.completionItems;
         }
+        if (position.character === 1) return this.completionItems;
+        // Check whether the '@' character is escaped.
         if (document.getText(new vscode.Range(position.translate(0, -2), position.translate(0, -1))) === '@') {
-            // The '@' character is escaped.
             return undefined;
         } else {
             return this.completionItems;

src/document.ts

@@ -0,0 +1,64 @@
+/**
+ * document.ts
+ * 
+ * @author CismonX <admin@cismon.net>
+ * @license MIT
+ */
+
+import * as vscode from 'vscode';
+import { FoldingRangeContext } from './folding';
+import Preview from './preview';
+
+/**
+ * Manages context and events for a document.
+ */
+export default class Document {
+
+    private static readonly map = new Map<vscode.TextDocument, Document>();
+
+    static of(document: vscode.TextDocument) {
+        let documentContext = Document.map.get(document);
+        if (documentContext === undefined) {
+            Document.map.set(document, documentContext = new Document(document));
+        }
+        return documentContext;
+    }
+
+    static get(document: vscode.TextDocument) {
+        return document.languageId === 'texinfo' ? Document.of(document) : undefined;
+    }
+
+    static update(event: vscode.TextDocumentChangeEvent) {
+        const documentContext = Document.get(event.document);
+        documentContext?.foldingRange.update(event.contentChanges);
+    }
+
+    static save(document: vscode.TextDocument) {
+        const documentContext = Document.get(document);
+        documentContext?.preview?.updateWebview();
+    }
+
+    static close(document: vscode.TextDocument) {
+        Document.map.get(document)?.preview?.close();
+        Document.map.delete(document);
+    }
+
+    static clear() {
+        Document.map.forEach(document => document.preview?.close());
+        Document.map.clear();
+    }
+
+    readonly foldingRange = new FoldingRangeContext(this.document);
+
+    private preview?: Preview;
+
+    initPreview() {
+        return this.preview ??= new Preview(this);
+    }
+
+    closePreview() {
+        this.preview = undefined;
+    }
+
+    private constructor(readonly document: vscode.TextDocument) {}
+}

src/extension.ts

@@ -6,20 +6,18 @@
  */
 
 import * as vscode from 'vscode';
+import Document from './document';
 import Options from './options';
 import Preview from './preview';
 import { CompletionItemProvider } from './completion';
-import { FoldingRangeProvider, FoldingRangeContext } from './folding';
+import { FoldingRangeProvider } from './folding';
 
 export function activate(context: vscode.ExtensionContext) {
     context.subscriptions.push(
-        vscode.workspace.onDidSaveTextDocument(Preview.update),
+        vscode.workspace.onDidOpenTextDocument(Document.of),
-        vscode.workspace.onDidCloseTextDocument((document) => {
+        vscode.workspace.onDidChangeTextDocument(Document.update),
-            Preview.close(document);
+        vscode.workspace.onDidSaveTextDocument(Document.save),
-            FoldingRangeContext.close(document);
+        vscode.workspace.onDidCloseTextDocument(Document.close),
-        }),
-        vscode.workspace.onDidOpenTextDocument(FoldingRangeContext.open),
-        vscode.workspace.onDidChangeTextDocument(FoldingRangeContext.update),
         vscode.commands.registerTextEditorCommand('texinfo.showPreview', Preview.show),
         vscode.languages.registerCompletionItemProvider('texinfo', new CompletionItemProvider(), '@'),
         vscode.languages.registerFoldingRangeProvider('texinfo', new FoldingRangeProvider()),
@@ -27,7 +25,6 @@ export function activate(context: vscode.ExtensionContext) {
 }
 
 export function deactivate() {
-    Preview.clear();
+    Document.clear();
     Options.clear();
-    FoldingRangeContext.clear();
 }

src/folding.ts

@@ -6,6 +6,7 @@
  */
 
 import * as vscode from 'vscode';
+import Document from './document';
 
 /**
  * Provide folding range info for Texinfo documents.
@@ -13,7 +14,7 @@ import * as vscode from 'vscode';
 export class FoldingRangeProvider implements vscode.FoldingRangeProvider {
 
     provideFoldingRanges(document: vscode.TextDocument) {
-        return FoldingRangeContext.get(document).values;
+        return Document.of(document).foldingRange.values;
     }
 }
 
@@ -22,53 +23,6 @@ export class FoldingRangeProvider implements vscode.FoldingRangeProvider {
  */
 export class FoldingRangeContext {
 
-    private static readonly map = new Map<vscode.TextDocument, FoldingRangeContext>();
-
-    /**
-     * Initialize folding range context for a document.
-     * 
-     * @param document 
-     */
-    static open(document: vscode.TextDocument) {
-        document.languageId === 'texinfo' && FoldingRangeContext.get(document);
-    }
-
-    /**
-     * Get existing folding range context of a document, or create one if not exist. 
-     * 
-     * @param document 
-     */
-    static get(document: vscode.TextDocument) {
-        return FoldingRangeContext.map.get(document) ?? new FoldingRangeContext(document);
-    }
-
-    /**
-     * Update the folding range context of a document based on its change event.
-     * 
-     * @param event Change event of a document.
-     */
-    static update(event: vscode.TextDocumentChangeEvent) {
-        if (event.document.languageId === 'texinfo') {
-            FoldingRangeContext.get(event.document).update(event.contentChanges);
-        }
-    }
-
-    /**
-     * Destroy the folding range context of a document.
-     * 
-     * @param document 
-     */
-    static close(document: vscode.TextDocument) {
-        FoldingRangeContext.map.delete(document);
-    }
-
-    /**
-     * Destroy all existing folding range contexts.
-     */
-    static clear() {
-        FoldingRangeContext.map.clear();
-    }
-
     /**
      * Get VSCode folding ranges from the context.
      */
@@ -76,14 +30,28 @@ export class FoldingRangeContext {
         return this.foldingRanges ?? (this.foldingRanges = this.calculateFoldingRanges());
     }
 
-    private foldingRanges?: vscode.FoldingRange[];
+    private foldingRanges?: FoldingRange[];
 
     private commentRange?: { start: number, end: number };
 
     private headerStart?: number;
 
-    private constructor(private readonly document: vscode.TextDocument) {
+    /**
-        FoldingRangeContext.map.set(document, this);
+     * Update folding range context based on document change event.
+     * 
+     * @param events Events describing the changes in the document.
+     */
+    update(events: readonly vscode.TextDocumentContentChangeEvent[]) {
+        if (this.foldingRanges === undefined) return false;
+        for (const event of events) {
+            const updatedLines = event.text.split(this.document.eol === vscode.EndOfLine.LF ? '\n' : '\r\n').length;
+            // Clear cached folding range when line count changes.
+            if (updatedLines !== 1 || event.range.start.line !== event.range.end.line) {
+                this.foldingRanges = undefined;
+                return true;
+            }
+        }
+        return false;
     }
 
     /**
@@ -93,41 +61,34 @@ export class FoldingRangeContext {
      * @param end Ending line number.
      */
     private calculateFoldingRanges() {
+        this.foldingRanges = [];
         this.headerStart = undefined;
         const closingBlocks = <{ name: string, line: number }[]>[];
         let verbatim = false;
         for (let idx = this.document.lineCount - 1; idx >= 0; --idx) {
             const line = this.document.lineAt(idx).text;
-            if (!line.startsWith('@')) {
+            if (!line.startsWith('@')) continue;
-                continue;
-            }
             if (!verbatim) {
                 if (line === '@bye') {
                     // Abort anything after `@bye`.
-                    this.foldingRanges = undefined;
+                    this.foldingRanges = [];
                     this.commentRange = undefined;
                     this.headerStart = undefined;
                     continue;
                 }
-                if (this.processComment(line, idx)) {
+                if (this.processComment(line, idx)) continue;
-                    continue;
-                }
             }
             // Process block.
             if (line.startsWith('@end ')) {
-                if (verbatim) {
+                if (verbatim) continue;
-                    continue;
-                }
                 const name = line.substring(5);
                 name === 'verbatim' && (verbatim = true);
                 closingBlocks.push({ name: name, line: idx });
             } else {
                 const closingBlock = closingBlocks.pop();
-                if (closingBlock === undefined) {
+                if (closingBlock === undefined) continue;
-                    continue;
-                }
                 if (line.substring(1, closingBlock.name.length + 2).trim() === closingBlock.name) {
-                    this.insertRange(idx, closingBlock.line);
+                    this.addRange(idx, closingBlock.line, { name: closingBlock.name });
                     // If `verbatim == true` goes here, this line must be the `@verbatim` line.
                     verbatim = false;
                 } else {
@@ -135,24 +96,18 @@ export class FoldingRangeContext {
                 }
             }
         }
-        if (this.commentRange !== undefined) {
-            this.insertRange(this.commentRange.start, this.commentRange.end, vscode.FoldingRangeKind.Comment);
-            this.commentRange = undefined;
-        }
         return this.foldingRanges;
     }
 
     private processComment(lineText: string, lineNum: number) {
         if (lineText.startsWith('@c')) {
-            if (!lineText.startsWith(' ', 2) && !lineText.startsWith('omment ', 2)) {
+            if (!lineText.startsWith(' ', 2) && !lineText.startsWith('omment ', 2)) return false;
-                return false;
-            }
             // Check for opening/closing header.
             if (lineText.startsWith('%**', lineText[2] === ' ' ? 3 : 9)) {
                 if (this.headerStart === undefined) {
                     this.headerStart = lineNum;
                 } else {
-                    this.insertRange(lineNum, this.headerStart);
+                    this.addRange(lineNum, this.headerStart, { kind: vscode.FoldingRangeKind.Region });
                     this.headerStart = undefined;
                 }
                 return true;
@@ -161,34 +116,28 @@ export class FoldingRangeContext {
                 this.commentRange = { start: lineNum, end: lineNum };
             } else if (this.commentRange.start - 1 === lineNum) {
                 this.commentRange.start = lineNum;
-            } else {
-                this.insertRange(this.commentRange.start, this.commentRange.end, vscode.FoldingRangeKind.Comment);
-                this.commentRange = { start: lineNum, end: lineNum };
             }
             return true;
+        } else if (this.commentRange !== undefined) {
+            this.addRange(this.commentRange.start, this.commentRange.end, { kind: vscode.FoldingRangeKind.Comment });
+            this.commentRange = undefined;
         }
         return false;
     }
 
-    private insertRange(start: number, end: number, kind?: vscode.FoldingRangeKind) {
+    private addRange(start: number, end: number, extraArgs: { name?: string, kind?: vscode.FoldingRangeKind }) {
-        (this.foldingRanges ?? (this.foldingRanges = [])).push(new vscode.FoldingRange(start, end, kind));
+        (this.foldingRanges ??= []).push(new FoldingRange(extraArgs.name ?? '', start, end, extraArgs.kind));
     }
 
-    /**
+    constructor(private readonly document: vscode.TextDocument) {}
-     * Update folding range context based on document change event.
+}
-     * 
+
-     * @param events Events describing the changes in the document.
+/**
-     */
+ * VSCode folding range with name.
-    private update(events: readonly vscode.TextDocumentContentChangeEvent[]) {
+ */
-        if (this.foldingRanges === undefined) {
+export class FoldingRange extends vscode.FoldingRange {
-            return;
+
-        }
+    constructor(readonly name: string, start: number, end: number, kind?: vscode.FoldingRangeKind) {
-        for (const event of events) {
+        super(start, end, kind);
-            const updatedLines = event.text.split(this.document.eol === vscode.EndOfLine.LF ? '\n' : '\r\n').length;
-            // Clear folding range buffer when line count changes.
-            if (updatedLines !== 1 || event.range.start.line !== event.range.end.line) {
-                this.foldingRanges = undefined;
-            }
-        }
     }
 }

src/options.ts

@@ -17,7 +17,7 @@ export default class Options {
     private static singleton?: Options;
 
     private static get instance() {
-        return Options.singleton ?? (Options.singleton = new Options('texinfo'));
+        return Options.singleton ??= new Options('texinfo');
     }
 
     static clear() {

src/preview.ts

@@ -8,6 +8,7 @@
 import * as path from 'path';
 import * as vscode from 'vscode';
 import Converter from './converter';
+import Document from './document';
 import Options from './options';
 import * as utils from './utils';
 
@@ -16,8 +17,6 @@ import * as utils from './utils';
  */
 export default class Preview {
 
-    private static readonly map = new Map<vscode.TextDocument, Preview>();
-
     /**
      * Create (if not yet created) and show preview for a Texinfo document.
      * 
@@ -25,47 +24,18 @@ export default class Preview {
      */
     static async show(editor: vscode.TextEditor) {
         const document = editor.document;
-        if (document.isUntitled) {
+        const documentContext = Document.get(document);
-            if (!await utils.prompt('Save this document to display preview.', 'Save')) {
+        if (documentContext === undefined) {
-                return;
+            return;
-            }
-            if (!await document.save()) {
-                return;
-            }
         }
-        (Preview.map.get(document) ?? new Preview(document)).panel.reveal();
+        if (document.isUntitled) {
+            if (!await utils.prompt('Save this document to display preview.', 'Save')) return;
+            if (!await document.save()) return;
+        }
+        documentContext.initPreview().panel.reveal();
     }
 
-    /**
+    private readonly document = this.documentContext.document;
-     * If the document has a corresponding Texinfo preview, update the preview.
-     * 
-     * @param document
-     */
-    static update(document: vscode.TextDocument) {
-        Preview.getByDocument(document)?.updateWebview();
-    }
-
-    /**
-     * If the document has a corresponding Texinfo preview, close the preview.
-     * 
-     * @param document
-     */
-    static close(document: vscode.TextDocument) {
-        Preview.getByDocument(document)?.destroy();
-    }
-
-    static clear() {
-        Preview.map.forEach((preview) => preview.destroy());
-    }
-    
-    /**
-     * Get associated preview instance of the given document.
-     * 
-     * @param document
-     */
-    private static getByDocument(document: vscode.TextDocument) {
-        return document.languageId !== 'texinfo' ? undefined : Preview.map.get(document);
-    }
 
     private readonly panel: vscode.WebviewPanel;
     
@@ -81,10 +51,9 @@ export default class Preview {
      */
     private pendingUpdate = false;
 
-    private constructor(private readonly document: vscode.TextDocument) {
+    constructor(private readonly documentContext: Document) {
         this.panel = vscode.window.createWebviewPanel('texinfo.preview', '', vscode.ViewColumn.Beside);
-        this.disposables.push(this.panel.onDidDispose(() => this.destroy()));
+        this.disposables.push(this.panel.onDidDispose(() => this.close()));
-        Preview.map.set(document, this);
         this.updateWebview();
     }
 
@@ -94,13 +63,13 @@ export default class Preview {
         this.panel.title = `${updating}Preview ${fileName}`;
     }
 
-    private destroy() {
+    close() {
-        this.disposables.forEach((event) => event.dispose());
+        this.disposables.forEach(event => event.dispose());
         this.panel.dispose();
-        Preview.map.delete(this.document);
+        this.documentContext.closePreview();
     }
 
-    private async updateWebview() {
+    async updateWebview() {
         if (this.updating) {
             this.pendingUpdate = true;
             return;
@@ -116,7 +85,7 @@ export default class Preview {
             if (Options.displayImage) {
                 const pathName = path.dirname(this.document.fileName);
                 // To display images in webviews, image URIs in HTML should be converted to VSCode-recognizable ones.
-                htmlCode = utils.transformHtmlImageUri(htmlCode, (src) => {
+                htmlCode = utils.transformHtmlImageUri(htmlCode, src => {
                     const srcUri = vscode.Uri.file(pathName + '/' + src);
                     return this.panel.webview.asWebviewUri(srcUri).toString();
                 });

src/utils.ts

@@ -29,7 +29,7 @@ export async function prompt(message: string, confirm: string) {
  * @returns The output data, or `undefined` if execution fails.
  */
 export function exec(path: string, args: string[], maxBuffer: number) {
-    return new Promise<string | undefined>((resolve) => {
+    return new Promise<string | undefined>(resolve => {
         child_process.execFile(path, args, { maxBuffer: maxBuffer }, (error, stdout, stderr) => {
             if (error) {
                 console.error(stderr ? stderr : error);
@@ -52,7 +52,7 @@ export function exec(path: string, args: string[], maxBuffer: number) {
 export function transformHtmlImageUri(htmlCode: string, transformer: (src: string) => string) {
     const dom = htmlparser.parse(htmlCode);
     const elements = dom.querySelectorAll('img');
-    elements.forEach((element) => {
+    elements.forEach(element => {
         const src = element.getAttribute('src');
         src && element.setAttribute('src', transformer(src));
     });