Move custom mouse event handler into MouseStateService

Don't need to keep it in CoreBrowserTerminal

src/browser/CoreBrowserTerminal.ts

@@ -78,7 +78,6 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
   public browser: IBrowser = Browser as any;
 
   private _customKeyEventHandler: CustomKeyEventHandler | undefined;
-  private _customWheelEventHandler: CustomWheelEventHandler | undefined;
 
   // Browser services
   private readonly _decorationService: DecorationService;
@@ -582,7 +581,6 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
     ));
     this._instantiationService.setService(ISelectionService, this._selectionService);
     this._mouseService = this._instantiationService.createInstance(MouseService);
-    this._mouseService.setCustomWheelEventHandler(this._customWheelEventHandler);
     this._instantiationService.setService(IMouseService, this._mouseService);
     this._register(this._selectionService.onRequestScrollLines(e => this.scrollLines(e.amount, e.suppressScrollEvent)));
     this._register(this._selectionService.onSelectionChange(() => this._onSelectionChange.fire()));
@@ -727,8 +725,7 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
   }
 
   public attachCustomWheelEventHandler(customWheelEventHandler: CustomWheelEventHandler): void {
-    this._customWheelEventHandler = customWheelEventHandler;
-    this._mouseService?.setCustomWheelEventHandler(customWheelEventHandler);
+    this.mouseStateService.setCustomWheelEventHandler(customWheelEventHandler);
   }
 
   public registerLinkProvider(linkProvider: ILinkProvider): IDisposable {

src/browser/TestUtils.test.ts

@@ -393,10 +393,6 @@ export class MockMouseService implements IMouseService {
     throw new Error('Not implemented');
   }
 
-  public setCustomWheelEventHandler(): void {
-    throw new Error('Not implemented');
-  }
-
   public bindMouse(): void {
     throw new Error('Not implemented');
   }

src/browser/services/MouseService.ts

@@ -8,7 +8,6 @@ import { IBufferService, IMouseStateService, ICoreService, ILogService, IOptions
 import { CoreMouseAction, CoreMouseButton, CoreMouseEventType, IDisposable } from 'common/Types';
 import { C0 } from 'common/data/EscapeSequences';
 import { toDisposable } from 'common/Lifecycle';
-import { CustomWheelEventHandler } from 'browser/Types';
 import { ICoreBrowserService, IMouseCoordsService, IMouseService, IMouseServiceTarget, IRenderService, ISelectionService } from './Services';
 
 type RequestedMouseEvents = Record<'mouseup' | 'wheel' | 'mousedrag' | 'mousemove', EventListener | null>;
@@ -22,8 +21,6 @@ interface IMouseBindContext {
 export class MouseService implements IMouseService {
   public serviceBrand: undefined;
 
-  private _customWheelEventHandler: CustomWheelEventHandler | undefined;
-
   constructor(
     @IRenderService private readonly _renderService: IRenderService,
     @IMouseCoordsService private readonly _mouseCoordsService: IMouseCoordsService,
@@ -119,7 +116,7 @@ export class MouseService implements IMouseService {
         but = ev.button < 3 ? ev.button : CoreMouseButton.NONE;
         break;
       case 'wheel':
-        if (this._customWheelEventHandler && this._customWheelEventHandler(ev as WheelEvent) === false) {
+        if (!this._mouseStateService.allowCustomWheelEvent(ev as WheelEvent)) {
           return false;
         }
         const deltaY = (ev as WheelEvent).deltaY;
@@ -226,7 +223,7 @@ export class MouseService implements IMouseService {
       return;
     }
 
-    if (this._customWheelEventHandler && this._customWheelEventHandler(ev) === false) {
+    if (!this._mouseStateService.allowCustomWheelEvent(ev)) {
       return false;
     }
 
@@ -320,7 +317,4 @@ export class MouseService implements IMouseService {
     }
   }
 
-  public setCustomWheelEventHandler(customWheelEventHandler: CustomWheelEventHandler | undefined): void {
-    this._customWheelEventHandler = customWheelEventHandler;
-  }
 }

src/browser/services/Services.ts

@@ -4,7 +4,7 @@
  */
 
 import { IRenderDimensions, IRenderer } from 'browser/renderer/shared/Types';
-import { CustomWheelEventHandler, IColorSet, ILink, ReadonlyColorSet } from 'browser/Types';
+import { IColorSet, ILink, ReadonlyColorSet } from 'browser/Types';
 import { ISelectionRedrawRequestEvent as ISelectionRequestRedrawEvent, ISelectionRequestScrollLinesEvent } from 'browser/selection/Types';
 import { createDecorator } from 'common/services/ServiceRegistry';
 import { AllColorIndex, IDisposable, IKeyboardResult } from 'common/Types';
@@ -61,7 +61,6 @@ export const IMouseService = createDecorator<IMouseService>('MouseService');
 export interface IMouseService {
   serviceBrand: undefined;
 
-  setCustomWheelEventHandler(customWheelEventHandler: CustomWheelEventHandler | undefined): void;
   bindMouse(target: IMouseServiceTarget, register: (disposable: IDisposable) => void, focus: () => void): void;
 }
 export interface IMouseServiceTarget {

src/common/TestUtils.test.ts

@@ -82,6 +82,8 @@ export class MockMouseStateService implements IMouseStateService {
   public consumeWheelEvent(ev: WheelEvent, cellHeight: number, dpr: number): number {
     return 1;
   }
+  public setCustomWheelEventHandler(customWheelEventHandler: ((event: WheelEvent) => boolean) | undefined): void { }
+  public allowCustomWheelEvent(ev: WheelEvent): boolean { return true; }
 }
 
 export class MockCharsetService implements ICharsetService {

src/common/services/MouseStateService.ts

@@ -175,6 +175,7 @@ export class MouseStateService extends Disposable implements IMouseStateService
   private _activeEncoding: string = '';
   private _lastEvent: ICoreMouseEvent | null = null;
   private _wheelPartialScroll: number = 0;
+  private _customWheelEventHandler: ((event: WheelEvent) => boolean) | undefined;
 
   private readonly _onProtocolChange = this._register(new Emitter<CoreMouseEventType>());
   public readonly onProtocolChange = this._onProtocolChange.event;
@@ -268,6 +269,14 @@ export class MouseStateService extends Disposable implements IMouseStateService
     return amount;
   }
 
+  public setCustomWheelEventHandler(customWheelEventHandler: ((event: WheelEvent) => boolean) | undefined): void {
+    this._customWheelEventHandler = customWheelEventHandler;
+  }
+
+  public allowCustomWheelEvent(ev: WheelEvent): boolean {
+    return this._customWheelEventHandler ? this._customWheelEventHandler(ev) !== false : true;
+  }
+
   private _applyScrollModifier(amount: number, ev: WheelEvent): number {
     // Multiply the scroll speed when the modifier key is pressed
     if (ev.altKey || ev.ctrlKey || ev.shiftKey) {

src/common/services/Services.ts

@@ -70,6 +70,16 @@ export interface IMouseStateService {
    * Process wheel event taking partial scroll into account.
    */
   consumeWheelEvent(ev: WheelEvent, cellHeight?: number, dpr?: number): number;
+
+  /**
+   * Sets a custom wheel event handler that can veto wheel processing.
+   */
+  setCustomWheelEventHandler(customWheelEventHandler: ((event: WheelEvent) => boolean) | undefined): void;
+
+  /**
+   * Checks whether a wheel event should be processed.
+   */
+  allowCustomWheelEvent(ev: WheelEvent): boolean;
 }
 
 export const ICoreService = createDecorator<ICoreService>('CoreService');