git decorations

extension.js

@@ -1,7 +1,8 @@
 let assert = require("node:assert");
 let path = require("node:path");
 let { homedir } = require("node:os");
-let { window, workspace, commands, Uri, EventEmitter, FileType, Selection, languages, Range, Diagnostic, DiagnosticRelatedInformation, Location } = require("vscode");
+let { window, workspace, commands, Uri, EventEmitter, FileType, Selection, languages, Range, Diagnostic, DiagnosticRelatedInformation, Location, extensions, ThemeColor } = require("vscode");
+let gitDecorations = require("./git-decorations");
 
 /**
  * The scheme is used to associate vsnetrw documents with the text content provider
@@ -120,6 +121,7 @@ async function openExplorer(dirName) {
   await languages.setTextDocumentLanguage(doc, languageId);
   moveCursorToPreviousFile();
   refreshDiagnostics();
+  gitDecorations.updateDecorations();
   refresh();
 }
 
@@ -414,14 +416,6 @@ async function provideTextDocumentContent(documentUri) {
   return listings.join("\n");
 }
 
-/**
- * @type {import("vscode").TextDocumentContentProvider}
- */
-let contentProvider = {
-  onDidChange: uriChangeEmitter.event,
-  provideTextDocumentContent,
-};
-
 let diagnostics = languages.createDiagnosticCollection("vsnetrw");
 
 /**
@@ -445,10 +439,10 @@ function refreshDiagnostics() {
     let severities = childDiagnostics.map(diagnostic => diagnostic.severity);
     let severity = Math.min(...severities);
     let name = path.basename(uri.fsPath);
-    let range = new Range(line, 0, line, name.length);
 
     let diagnostic = new Diagnostic(
-      range, `${childDiagnostics.length} problems in this file`,
+      new Range(line, 0, line, name.length),
+      `${childDiagnostics.length} problems in this file`,
       severity
     );
 
@@ -465,6 +459,14 @@ function refreshDiagnostics() {
   diagnostics.set(document.uri, ownDiagnostics);
 }
 
+/**
+ * @type {import("vscode").TextDocumentContentProvider}
+ */
+let contentProvider = {
+  onDidChange: uriChangeEmitter.event,
+  provideTextDocumentContent,
+};
+
 /**
  * @param {import("vscode").ExtensionContext} context
  */

git-decorations.js

@@ -0,0 +1,92 @@
+let assert = require("assert");
+let path = require("path");
+let { window, Uri, Range, extensions, ThemeColor } = require("vscode");
+
+let gitExt = extensions.getExtension("vscode.git")?.exports;
+
+/**
+ * @type {import("./git").API}
+ */
+let git = gitExt.getAPI(1);
+
+/**
+ * @param {string} label
+ * @param {string} [themeColorId]
+ */
+function createDecorationType(label, themeColorId) {
+  return window.createTextEditorDecorationType({
+    before: {
+      contentText: `${label} `,
+      color: themeColorId ? new ThemeColor(themeColorId) : undefined,
+    },
+  });
+}
+
+let modifiedDecorationType = createDecorationType("M", "gitDecoration.modifiedResourceForeground");
+let addedDecorationType = createDecorationType("A", "gitDecoration.addedResourceForeground");
+let deletedDecorationType = createDecorationType("D", "gitDecoration.deletedResourceForeground");
+let untrackedDecorationType = createDecorationType("U", "gitDecoration.untrackedResourceForeground");
+let ignoredDecorationType = createDecorationType("I", "gitDecoration.ignoredResourceForeground");
+let noStatusDecorationType = createDecorationType(" ");
+
+// Corresponds to `Status` enum in ./git.d.ts
+let decorationTypesByStatus = [
+  modifiedDecorationType,  // 0 INDEX_MODIFIED
+  addedDecorationType,     // 1 INDEX_ADDED
+  deletedDecorationType,   // 2 INDEX_DELETED
+  null,                    // 3 INDEX_RENAMED
+  null,                    // 4 INDEX_COPIED
+
+  modifiedDecorationType,  // 5 MODIFIED
+  deletedDecorationType,   // 6 DELETED
+  untrackedDecorationType, // 7 UNTRACKED
+  ignoredDecorationType,   // 8 IGNORED
+  addedDecorationType,     // INTENT_TO_ADD
+];
+
+function updateDecorations() {
+  if (!git) return;
+  assert(window.activeTextEditor);
+
+  let repo = git.repositories[0];
+  let changes = repo ? [
+    ...repo.state.indexChanges,
+    ...repo.state.workingTreeChanges,
+  ] : [];
+
+  let document = window.activeTextEditor.document;
+  let base = document.uri.path;
+  let lines = document.getText().split("\n");
+
+  /**
+   * @type {Record<number, number[]>}
+   */
+  let linesByStatus = {};
+
+  for (let line = 0; line < lines.length; line++) {
+    let pathToFile = path.join(base, lines[line]);
+    let uri = Uri.file(pathToFile);
+    let change = changes.find(change => change.uri.toString() === uri.toString());
+    let status = change ? change.status : -1;
+    linesByStatus[status] = linesByStatus[status] || [];
+    linesByStatus[status].push(line);
+  }
+
+  for (let key of Object.keys(linesByStatus)) {
+    let status = parseInt(key);
+
+    let decorationType = status > 0
+      ? decorationTypesByStatus[status]
+      : noStatusDecorationType;
+
+    let ranges = linesByStatus[status].map(line => {
+      return new Range(line, 0, line, lines[line].length);
+    });
+
+    if (decorationType) {
+      window.activeTextEditor.setDecorations(decorationType, ranges);
+    }
+  }
+}
+
+module.exports = { updateDecorations };