Add support for OSC 4 ; color ; color spec

src/browser/Terminal.ts

@@ -39,7 +39,7 @@ import { MouseZoneManager } from 'browser/MouseZoneManager';
 import { AccessibilityManager } from './AccessibilityManager';
 import { ITheme, IMarker, IDisposable, ISelectionPosition, ILinkProvider } from 'xterm';
 import { DomRenderer } from 'browser/renderer/dom/DomRenderer';
-import { IKeyboardEvent, KeyboardResultType, CoreMouseEventType, CoreMouseButton, CoreMouseAction, ITerminalOptions } from 'common/Types';
+import { IKeyboardEvent, KeyboardResultType, CoreMouseEventType, CoreMouseButton, CoreMouseAction, ITerminalOptions, IAnsiColorChangeEvent } from 'common/Types';
 import { evaluateKeyboardEvent } from 'common/input/Keyboard';
 import { EventEmitter, IEvent, forwardEvent } from 'common/EventEmitter';
 import { DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
@@ -53,6 +53,7 @@ import { Linkifier2 } from 'browser/Linkifier2';
 import { CoreBrowserService } from 'browser/services/CoreBrowserService';
 import { CoreTerminal } from 'common/CoreTerminal';
 import { ITerminalOptions as IInitializedTerminalOptions } from 'common/services/Services';
+import { rgba } from 'browser/Color';
 
 // Let it work inside Node.js for automated testing purposes.
 const document: Document = (typeof window !== 'undefined') ? window.document : null as any;
@@ -148,6 +149,7 @@ export class Terminal extends CoreTerminal implements ITerminal {
     this.register(this._inputHandler.onRequestReset(() => this.reset()));
     this.register(this._inputHandler.onRequestScroll((eraseAttr, isWrapped) => this.scroll(eraseAttr, isWrapped || undefined)));
     this.register(this._inputHandler.onRequestWindowsOptionsReport(type => this._reportWindowsOptions(type)));
+    this.register(this._inputHandler.onAnsiColorChange((event) => this._changeAnsiColor(event)));
     this.register(forwardEvent(this._inputHandler.onCursorMove, this._onCursorMove));
     this.register(forwardEvent(this._inputHandler.onTitleChange, this._onTitleChange));
     this.register(forwardEvent(this._inputHandler.onA11yChar, this._onA11yCharEmitter));
@@ -157,6 +159,14 @@ export class Terminal extends CoreTerminal implements ITerminal {
     this.register(this._bufferService.onResize(e => this._afterResize(e.cols, e.rows)));
   }
 
+  private _changeAnsiColor(event: IAnsiColorChangeEvent): void {
+    const color = rgba.toColor(event.red, event.green, event.blue);
+
+    this._colorManager!.colors.ansi[event.colorIndex] = color;
+    this._renderService?.setColors(this._colorManager!.colors);
+    this.viewport?.onThemeChange(this._colorManager!.colors);
+  }
+
   public dispose(): void {
     if (this._isDisposed) {
       return;

src/browser/renderer/atlas/CharAtlasUtils.ts

@@ -18,7 +18,9 @@ export function generateConfig(scaledCharWidth: number, scaledCharHeight: number
     selection: undefined,
     // For the static char atlas, we only use the first 16 colors, but we need all 256 for the
     // dynamic character atlas.
-    ansi: colors.ansi.slice(0, 16)
+    // ansi: colors.ansi.slice(0, 16)
+    // TODO: Using entire array to support OSC 4; can this break anything?
+    ansi: colors.ansi
   };
   return {
     devicePixelRatio: window.devicePixelRatio,

src/common/InputHandler.test.ts

@@ -5,7 +5,7 @@
 
 import { assert, expect } from 'chai';
 import { InputHandler } from 'common/InputHandler';
-import { IBufferLine, IAttributeData } from 'common/Types';
+import { IBufferLine, IAttributeData, IAnsiColorChangeEvent } from 'common/Types';
 import { DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
 import { CellData } from 'common/buffer/CellData';
 import { Attributes, UnderlineStyle } from 'common/buffer/Constants';
@@ -1692,4 +1692,31 @@ describe('InputHandler', () => {
       assert.equal(coreService.decPrivateModes.origin, false);
     });
   });
+  describe('OSC', () => {
+    it('should parse correct Ansi color change data', () => {
+      // this is testing a private method
+      const parseAnsiColorChange = inputHandler['_parseAnsiColorChange'];
+
+      assert.deepEqual(
+        parseAnsiColorChange('19;rgb:a1/b2/c3'),
+        { colorIndex: 19, red: 0xa1, green: 0xb2, blue: 0xc3 }
+      );
+    }),
+    it('should ignore incorrect Ansi color change data', () => {
+      // this is testing a private method
+      const parseAnsiColorChange = inputHandler['_parseAnsiColorChange'];
+
+      assert.isNull(parseAnsiColorChange('17;rgb:a/b/c'));
+      assert.isNull(parseAnsiColorChange('17;rgb:#aabbcc'));
+      assert.isNull(parseAnsiColorChange('17;rgba:aa/bb/cc'));
+      assert.isNull(parseAnsiColorChange('rgb:aa/bb/cc'));
+    });
+    it('should fire event on Ansi color change', (done) => {
+      inputHandler.onAnsiColorChange(e => {
+        assert.deepEqual(e, { colorIndex: 17, red: 0x1a, green: 0x2b, blue: 0x3c });
+        done();
+      });
+      inputHandler.parse('\x1b]4;17;rgb:1a/2b/3c\x1b\\');
+    });
+  });
 });

src/common/InputHandler.ts

@@ -4,7 +4,7 @@
  * @license MIT
  */
 
-import { IInputHandler, IAttributeData, IDisposable, IWindowOptions } from 'common/Types';
+import { IInputHandler, IAttributeData, IDisposable, IWindowOptions, IAnsiColorChangeEvent } from 'common/Types';
 import { C0, C1 } from 'common/data/EscapeSequences';
 import { CHARSETS, DEFAULT_CHARSET } from 'common/data/Charsets';
 import { EscapeSequenceParser } from 'common/parser/EscapeSequenceParser';
@@ -250,6 +250,8 @@ export class InputHandler extends Disposable implements IInputHandler {
   public get onScroll(): IEvent<number> { return this._onScroll.event; }
   private _onTitleChange = new EventEmitter<string>();
   public get onTitleChange(): IEvent<string> { return this._onTitleChange.event; }
+  private _onAnsiColorChange = new EventEmitter<IAnsiColorChangeEvent>();
+  public get onAnsiColorChange(): IEvent<IAnsiColorChangeEvent> { return this._onAnsiColorChange.event; }
 
   constructor(
     private readonly _bufferService: IBufferService,
@@ -372,6 +374,7 @@ export class InputHandler extends Disposable implements IInputHandler {
     this._parser.setOscHandler(2, new OscHandler((data: string) => this.setTitle(data)));
     //   3 - set property X in the form "prop=value"
     //   4 - Change Color Number
+    this._parser.setOscHandler(4, new OscHandler((data: string) => this.setAnsiColor(data)));
     //   5 - Change Special Color Number
     //   6 - Enable/disable Special Color Number c
     //   7 - current directory? (not in xterm spec, see https://gitlab.com/gnachman/iterm2/issues/3939)
@@ -2711,6 +2714,38 @@ export class InputHandler extends Disposable implements IInputHandler {
     this._iconName = data;
   }
 
+  private _parseAnsiColorChange(data: string): IAnsiColorChangeEvent | null {
+    // example data: 5;rgb:aa/bb/cc
+    const regex = /(\d+);rgb:([0-9a-fA-F]{2})\/([0-9a-fA-F]{2})\/([0-9a-fA-F]{2})/;
+    const match = data.match(regex);
+
+    if (match) {
+      return {
+        colorIndex: parseInt(match[1]),
+        red: parseInt(match[2], 16),
+        green: parseInt(match[3], 16),
+        blue: parseInt(match[4], 16)
+      };
+    }
+    return null;
+  }
+
+  /**
+   * OSC 4; <num> ; <text> ST (set ANSI color <num> to <text>)
+   *
+   * @vt: #Y    OSC    4    "Set ANSI color"   "OSC 4 ; c ; spec BEL" "Change color number `c` to the color specified by `spec`."
+   * `c` is the color index between 0 and 255. `spec` color format is 'rgb:hh/hh/hh' where `h` are hexadecimal digits.
+   */
+  public setAnsiColor(data: string): void {
+    const event = this._parseAnsiColorChange(data);
+    if (event) {
+      this._onAnsiColorChange.fire(event);
+    }
+    else {
+      this._logService.warn(`Expected format <num>;rgb:<rr>/<gg>/<bb> but got data: ${data}`);
+    }
+  }
+
   /**
    * ESC E
    * C1.NEL

src/common/Types.d.ts

@@ -328,6 +328,16 @@ export interface IWindowOptions {
   setWinLines?: boolean;
 }
 
+/**
+ * Event fired for OSC 4 command - to change ANSI color based on its index.
+ */
+export interface IAnsiColorChangeEvent {
+  colorIndex: number;
+  red: number;
+  green: number;
+  blue: number;
+}
+
 /**
  * Calls the parser and handles actions generated by the parser.
  */
@@ -389,6 +399,7 @@ export interface IInputHandler {
   /** CSI ' ~ */ deleteColumns(params: IParams): void;
   /** OSC 0
       OSC 2 */ setTitle(data: string): void;
+  /** OSC 4 */ setAnsiColor(data: string): void;
   /** ESC E */ nextLine(): void;
   /** ESC = */ keypadApplicationMode(): void;
   /** ESC > */ keypadNumericMode(): void;