Make all emitters readonly

addons/xterm-addon-canvas/src/CanvasRenderer.ts

@@ -27,7 +27,7 @@ export class CanvasRenderer extends Disposable implements IRenderer {
 
   public dimensions: IRenderDimensions;
 
-  private _onRequestRedraw = new EventEmitter<IRequestRedrawEvent>();
+  private readonly _onRequestRedraw = new EventEmitter<IRequestRedrawEvent>();
   public readonly onRequestRedraw = this._onRequestRedraw.event;
 
   constructor(

addons/xterm-addon-webgl/src/WebglAddon.ts

@@ -15,9 +15,9 @@ export class WebglAddon implements ITerminalAddon {
   private _terminal?: Terminal;
   private _renderer?: WebglRenderer;
 
-  private _onChangeTextureAtlas = new EventEmitter<HTMLElement>();
+  private readonly _onChangeTextureAtlas = new EventEmitter<HTMLElement>();
   public readonly onChangeTextureAtlas = this._onChangeTextureAtlas.event;
-  private _onContextLoss = new EventEmitter<void>();
+  private readonly _onContextLoss = new EventEmitter<void>();
   public readonly onContextLoss = this._onContextLoss.event;
 
   constructor(

addons/xterm-addon-webgl/src/WebglRenderer.ts

@@ -55,11 +55,11 @@ export class WebglRenderer extends Disposable implements IRenderer {
   private _isAttached: boolean;
   private _contextRestorationTimeout: number | undefined;
 
-  private _onChangeTextureAtlas = new EventEmitter<HTMLCanvasElement>();
+  private readonly _onChangeTextureAtlas = new EventEmitter<HTMLCanvasElement>();
   public readonly onChangeTextureAtlas = this._onChangeTextureAtlas.event;
-  private _onRequestRedraw = new EventEmitter<IRequestRedrawEvent>();
+  private readonly _onRequestRedraw = new EventEmitter<IRequestRedrawEvent>();
   public readonly onRequestRedraw = this._onRequestRedraw.event;
-  private _onContextLoss = new EventEmitter<void>();
+  private readonly _onContextLoss = new EventEmitter<void>();
   public readonly onContextLoss = this._onContextLoss.event;
 
   constructor(

src/browser/Linkifier2.ts

@@ -26,9 +26,9 @@ export class Linkifier2 extends Disposable implements ILinkifier2 {
   private _activeProviderReplies: Map<Number, ILinkWithState[] | undefined> | undefined;
   private _activeLine: number = -1;
 
-  private _onShowLinkUnderline = this.register(new EventEmitter<ILinkifierEvent>());
+  private readonly _onShowLinkUnderline = this.register(new EventEmitter<ILinkifierEvent>());
   public readonly onShowLinkUnderline = this._onShowLinkUnderline.event;
-  private _onHideLinkUnderline = this.register(new EventEmitter<ILinkifierEvent>());
+  private readonly _onHideLinkUnderline = this.register(new EventEmitter<ILinkifierEvent>());
   public readonly onHideLinkUnderline = this._onHideLinkUnderline.event;
 
   constructor(

src/browser/Terminal.ts

@@ -122,26 +122,26 @@ export class Terminal extends CoreTerminal implements ITerminal {
   private _colorManager: ColorManager | undefined;
   private _theme: ITheme | undefined;
 
-  private _onCursorMove = new EventEmitter<void>();
+  private readonly _onCursorMove = new EventEmitter<void>();
   public readonly onCursorMove = this._onCursorMove.event;
-  private _onKey = new EventEmitter<{ key: string, domEvent: KeyboardEvent }>();
+  private readonly _onKey = new EventEmitter<{ key: string, domEvent: KeyboardEvent }>();
   public readonly onKey = this._onKey.event;
-  private _onRender = new EventEmitter<{ start: number, end: number }>();
+  private readonly _onRender = new EventEmitter<{ start: number, end: number }>();
   public readonly onRender = this._onRender.event;
-  private _onSelectionChange = new EventEmitter<void>();
+  private readonly _onSelectionChange = new EventEmitter<void>();
   public readonly onSelectionChange = this._onSelectionChange.event;
-  private _onTitleChange = new EventEmitter<string>();
+  private readonly _onTitleChange = new EventEmitter<string>();
   public readonly onTitleChange = this._onTitleChange.event;
-  private _onBell = new EventEmitter<void>();
+  private readonly _onBell = new EventEmitter<void>();
   public readonly onBell = this._onBell.event;
 
-  private _onFocus = new EventEmitter<void>();
+  private readonly _onFocus = new EventEmitter<void>();
   public readonly onFocus = this._onFocus.event;
-  private _onBlur = new EventEmitter<void>();
+  private readonly _onBlur = new EventEmitter<void>();
   public readonly onBlur = this._onBlur.event;
-  private _onA11yCharEmitter = new EventEmitter<string>();
+  private readonly _onA11yCharEmitter = new EventEmitter<string>();
   public readonly onA11yChar = this._onA11yCharEmitter.event;
-  private _onA11yTabEmitter = new EventEmitter<number>();
+  private readonly _onA11yTabEmitter = new EventEmitter<number>();
   public readonly onA11yTab = this._onA11yTabEmitter.event;
 
   /**

src/browser/services/CharSizeService.ts

@@ -16,7 +16,7 @@ export class CharSizeService implements ICharSizeService {
 
   public get hasValidSize(): boolean { return this.width > 0 && this.height > 0; }
 
-  private _onCharSizeChange = new EventEmitter<void>();
+  private readonly _onCharSizeChange = new EventEmitter<void>();
   public readonly onCharSizeChange = this._onCharSizeChange.event;
 
   constructor(

src/browser/services/RenderService.ts

@@ -39,13 +39,13 @@ export class RenderService extends Disposable implements IRenderService {
     columnSelectMode: false
   };
 
-  private _onDimensionsChange = new EventEmitter<IRenderDimensions>();
+  private readonly _onDimensionsChange = new EventEmitter<IRenderDimensions>();
   public readonly onDimensionsChange =  this._onDimensionsChange.event;
-  private _onRenderedViewportChange = new EventEmitter<{ start: number, end: number }>();
+  private readonly _onRenderedViewportChange = new EventEmitter<{ start: number, end: number }>();
   public readonly onRenderedViewportChange = this._onRenderedViewportChange.event;
-  private _onRender = new EventEmitter<{ start: number, end: number }>();
+  private readonly _onRender = new EventEmitter<{ start: number, end: number }>();
   public readonly onRender = this._onRender.event;
-  private _onRefreshRequest = new EventEmitter<{ start: number, end: number }>();
+  private readonly _onRefreshRequest = new EventEmitter<{ start: number, end: number }>();
   public readonly onRefreshRequest = this._onRefreshRequest.event;
 
   public get dimensions(): IRenderDimensions { return this._renderer.dimensions; }

src/browser/services/SelectionService.ts

@@ -111,13 +111,13 @@ export class SelectionService extends Disposable implements ISelectionService {
   private _oldSelectionStart: [number, number] | undefined = undefined;
   private _oldSelectionEnd: [number, number] | undefined = undefined;
 
-  private _onLinuxMouseSelection = this.register(new EventEmitter<string>());
+  private readonly _onLinuxMouseSelection = this.register(new EventEmitter<string>());
   public readonly onLinuxMouseSelection = this._onLinuxMouseSelection.event;
-  private _onRedrawRequest = this.register(new EventEmitter<ISelectionRedrawRequestEvent>());
+  private readonly _onRedrawRequest = this.register(new EventEmitter<ISelectionRedrawRequestEvent>());
   public readonly onRequestRedraw = this._onRedrawRequest.event;
-  private _onSelectionChange = this.register(new EventEmitter<void>());
+  private readonly _onSelectionChange = this.register(new EventEmitter<void>());
   public readonly onSelectionChange = this._onSelectionChange.event;
-  private _onRequestScrollLines = this.register(new EventEmitter<ISelectionRequestScrollLinesEvent>());
+  private readonly _onRequestScrollLines = this.register(new EventEmitter<ISelectionRequestScrollLinesEvent>());
   public readonly onRequestScrollLines = this._onRequestScrollLines.event;
 
   constructor(

src/common/CircularList.ts

@@ -25,11 +25,11 @@ export class CircularList<T> implements ICircularList<T> {
   private _startIndex: number;
   private _length: number;
 
-  public onDeleteEmitter = new EventEmitter<IDeleteEvent>();
+  public readonly onDeleteEmitter = new EventEmitter<IDeleteEvent>();
   public readonly onDelete = this.onDeleteEmitter.event;
-  public onInsertEmitter = new EventEmitter<IInsertEvent>();
+  public readonly onInsertEmitter = new EventEmitter<IInsertEvent>();
   public readonly onInsert = this.onInsertEmitter.event;
-  public onTrimEmitter = new EventEmitter<number>();
+  public readonly onTrimEmitter = new EventEmitter<number>();
   public readonly onTrim = this.onTrimEmitter.event;
 
   constructor(

src/common/CoreTerminal.ts

@@ -61,15 +61,15 @@ export abstract class CoreTerminal extends Disposable implements ICoreTerminal {
   private _writeBuffer: WriteBuffer;
   private _windowsMode: IDisposable | undefined;
 
-  private _onBinary = new EventEmitter<string>();
+  private readonly _onBinary = new EventEmitter<string>();
   public readonly onBinary = this._onBinary.event;
-  private _onData = new EventEmitter<string>();
+  private readonly _onData = new EventEmitter<string>();
   public readonly onData = this._onData.event;
   protected _onLineFeed = new EventEmitter<void>();
   public readonly onLineFeed = this._onLineFeed.event;
-  private _onResize = new EventEmitter<{ cols: number, rows: number }>();
+  private readonly _onResize = new EventEmitter<{ cols: number, rows: number }>();
   public readonly onResize = this._onResize.event;
-  protected _onWriteParsed = new EventEmitter<void>();
+  protected readonly _onWriteParsed = new EventEmitter<void>();
   public readonly onWriteParsed = this._onWriteParsed.event;
 
   /**

src/common/InputHandler.ts

@@ -129,32 +129,32 @@ export class InputHandler extends Disposable implements IInputHandler {
 
   private _activeBuffer: IBuffer;
 
-  private _onRequestBell = new EventEmitter<void>();
+  private readonly _onRequestBell = new EventEmitter<void>();
   public readonly onRequestBell = this._onRequestBell.event;
-  private _onRequestRefreshRows = new EventEmitter<number, number>();
+  private readonly _onRequestRefreshRows = new EventEmitter<number, number>();
   public readonly onRequestRefreshRows = this._onRequestRefreshRows.event;
-  private _onRequestReset = new EventEmitter<void>();
+  private readonly _onRequestReset = new EventEmitter<void>();
   public readonly onRequestReset = this._onRequestReset.event;
-  private _onRequestSendFocus = new EventEmitter<void>();
+  private readonly _onRequestSendFocus = new EventEmitter<void>();
   public readonly onRequestSendFocus = this._onRequestSendFocus.event;
-  private _onRequestSyncScrollBar = new EventEmitter<void>();
+  private readonly _onRequestSyncScrollBar = new EventEmitter<void>();
   public readonly onRequestSyncScrollBar = this._onRequestSyncScrollBar.event;
-  private _onRequestWindowsOptionsReport = new EventEmitter<WindowsOptionsReportType>();
+  private readonly _onRequestWindowsOptionsReport = new EventEmitter<WindowsOptionsReportType>();
   public readonly onRequestWindowsOptionsReport = this._onRequestWindowsOptionsReport.event;
 
-  private _onA11yChar = new EventEmitter<string>();
+  private readonly _onA11yChar = new EventEmitter<string>();
   public readonly onA11yChar = this._onA11yChar.event;
-  private _onA11yTab = new EventEmitter<number>();
+  private readonly _onA11yTab = new EventEmitter<number>();
   public readonly onA11yTab = this._onA11yTab.event;
-  private _onCursorMove = new EventEmitter<void>();
+  private readonly _onCursorMove = new EventEmitter<void>();
   public readonly onCursorMove = this._onCursorMove.event;
-  private _onLineFeed = new EventEmitter<void>();
+  private readonly _onLineFeed = new EventEmitter<void>();
   public readonly onLineFeed = this._onLineFeed.event;
-  private _onScroll = new EventEmitter<number>();
+  private readonly _onScroll = new EventEmitter<number>();
   public readonly onScroll = this._onScroll.event;
-  private _onTitleChange = new EventEmitter<string>();
+  private readonly _onTitleChange = new EventEmitter<string>();
   public readonly onTitleChange = this._onTitleChange.event;
-  private _onColor = new EventEmitter<IColorEvent>();
+  private readonly _onColor = new EventEmitter<IColorEvent>();
   public readonly onColor = this._onColor.event;
 
   private _parseStack: IParseStack = {

src/common/buffer/BufferSet.ts

@@ -19,7 +19,7 @@ export class BufferSet extends Disposable implements IBufferSet {
   private _alt!: Buffer;
   private _activeBuffer!: Buffer;
 
-  private _onBufferActivate = this.register(new EventEmitter<{activeBuffer: IBuffer, inactiveBuffer: IBuffer}>());
+  private readonly _onBufferActivate = this.register(new EventEmitter<{activeBuffer: IBuffer, inactiveBuffer: IBuffer}>());
   public readonly onBufferActivate = this._onBufferActivate.event;
 
   /**

src/common/buffer/Marker.ts

@@ -15,7 +15,7 @@ export class Marker extends Disposable implements IMarker {
 
   public get id(): number { return this._id; }
 
-  private _onDispose = new EventEmitter<void>();
+  private readonly _onDispose = new EventEmitter<void>();
   public readonly onDispose = this._onDispose.event;
 
   constructor(

src/common/input/WriteBuffer.ts

@@ -42,7 +42,7 @@ export class WriteBuffer {
   private _syncCalls = 0;
   private _didUserInput = false;
 
-  private _onWriteParsed = new EventEmitter<void>();
+  private readonly _onWriteParsed = new EventEmitter<void>();
   public readonly onWriteParsed = this._onWriteParsed.event;
 
   constructor(private _action: (data: string | Uint8Array, promiseResult?: boolean) => void | Promise<boolean>) { }

src/common/public/BufferNamespaceApi.ts

@@ -12,7 +12,7 @@ export class BufferNamespaceApi implements IBufferNamespaceApi {
   private _normal: BufferApiView;
   private _alternate: BufferApiView;
 
-  private _onBufferChange = new EventEmitter<IBufferApi>();
+  private readonly _onBufferChange = new EventEmitter<IBufferApi>();
   public readonly onBufferChange = this._onBufferChange.event;
 
   constructor(private _core: ICoreTerminal) {

src/common/services/BufferService.ts

@@ -6,7 +6,7 @@
 import { IBufferService, IOptionsService } from 'common/services/Services';
 import { BufferSet } from 'common/buffer/BufferSet';
 import { IBufferSet, IBuffer } from 'common/buffer/Types';
-import { EventEmitter, IEvent } from 'common/EventEmitter';
+import { EventEmitter, IEventEmitter, IEvent } from 'common/EventEmitter';
 import { Disposable } from 'common/Lifecycle';
 import { IAttributeData, IBufferLine, ScrollSource } from 'common/Types';
 
@@ -22,9 +22,9 @@ export class BufferService extends Disposable implements IBufferService {
   /** Whether the user is scrolling (locks the scroll position) */
   public isUserScrolling: boolean = false;
 
-  private _onResize = new EventEmitter<{ cols: number, rows: number }>();
+  private readonly _onResize = new EventEmitter<{ cols: number, rows: number }>();
   public readonly onResize = this._onResize.event;
-  private _onScroll = new EventEmitter<number>();
+  private readonly _onScroll = new EventEmitter<number>();
   public readonly onScroll = this._onScroll.event;
 
   public get buffer(): IBuffer { return this.buffers.active; }

src/common/services/CoreMouseService.ts

@@ -172,7 +172,7 @@ export class CoreMouseService implements ICoreMouseService {
   private _activeEncoding: string = '';
   private _lastEvent: ICoreMouseEvent | null = null;
 
-  private _onProtocolChange = new EventEmitter<CoreMouseEventType>();
+  private readonly _onProtocolChange = new EventEmitter<CoreMouseEventType>();
   public readonly onProtocolChange =  this._onProtocolChange.event;
 
   constructor(

src/common/services/CoreService.ts

@@ -34,11 +34,11 @@ export class CoreService extends Disposable implements ICoreService {
   // Circular dependency, this must be unset or memory will leak after Terminal.dispose
   private _scrollToBottom: (() => void) | undefined;
 
-  private _onData = this.register(new EventEmitter<string>());
+  private readonly _onData = this.register(new EventEmitter<string>());
   public readonly onData = this._onData.event;
-  private _onUserInput = this.register(new EventEmitter<void>());
+  private readonly _onUserInput = this.register(new EventEmitter<void>());
   public readonly onUserInput = this._onUserInput.event;
-  private _onBinary = this.register(new EventEmitter<string>());
+  private readonly _onBinary = this.register(new EventEmitter<string>());
   public readonly onBinary = this._onBinary.event;
 
   constructor(

src/common/services/DecorationService.ts

@@ -27,9 +27,9 @@ export class DecorationService extends Disposable implements IDecorationService
    */
   private readonly _decorations: SortedList<IInternalDecoration> = new SortedList(e => e?.marker.line);
 
-  private _onDecorationRegistered = this.register(new EventEmitter<IInternalDecoration>());
+  private readonly _onDecorationRegistered = this.register(new EventEmitter<IInternalDecoration>());
   public readonly onDecorationRegistered = this._onDecorationRegistered.event;
-  private _onDecorationRemoved = this.register(new EventEmitter<IInternalDecoration>());
+  private readonly _onDecorationRemoved = this.register(new EventEmitter<IInternalDecoration>());
   public readonly onDecorationRemoved = this._onDecorationRemoved.event;
 
   public get decorations(): IterableIterator<IInternalDecoration> { return this._decorations.values(); }

src/common/services/OptionsService.ts

@@ -57,7 +57,7 @@ export class OptionsService implements IOptionsService {
   public readonly rawOptions: Required<ITerminalOptions>;
   public options: Required<ITerminalOptions>;
 
-  private _onOptionChange = new EventEmitter<string>();
+  private readonly _onOptionChange = new EventEmitter<string>();
   public readonly onOptionChange = this._onOptionChange.event;
 
   constructor(options: Partial<ITerminalOptions>) {