BufferService listen to onBufferActivate, remove tests

src/common/TestUtils.test.ts

@@ -29,6 +29,10 @@ export class MockBufferService implements IBufferService {
     optionsService: IOptionsService = new MockOptionsService()
   ) {
     this.buffers = new BufferSet(optionsService, this);
+    // Listen to buffer activation events and automatically fire scroll events
+    this.buffers.onBufferActivate(e => {
+      this._onScroll.fire(e.activeBuffer.ydisp);
+    });
   }
   public scrollPages(pageCount: number): void {
     throw new Error('Method not implemented.');
@@ -48,10 +52,6 @@ export class MockBufferService implements IBufferService {
   public scrollLines(disp: number, suppressScrollEvent?: boolean): void {
     throw new Error('Method not implemented.');
   }
-  public syncScrollPosition(): void {
-    // Fire scroll event with current buffer position
-    this._onScroll.fire(this.buffer.ydisp);
-  }
   public resize(cols: number, rows: number): void {
     this.cols = cols;
     this.rows = rows;

src/common/buffer/BufferSet.test.ts

@@ -83,68 +83,4 @@ describe('BufferSet', () => {
     });
   });
 
-  describe('scroll position synchronization', () => {
-    it('should call syncScrollPosition when switching from alt back to normal buffer', () => {
-      bufferSet.activateNormalBuffer();
-
-      const originalYDisp = 50;
-      bufferSet.normal.ydisp = originalYDisp;
-      bufferSet.normal.ybase = 100;
-      const mockBufferService = (bufferSet as any)._bufferService as MockBufferService;
-
-      let syncScrollPositionCalled = false;
-      const originalSyncScrollPosition = mockBufferService.syncScrollPosition.bind(mockBufferService);
-      mockBufferService.syncScrollPosition = () => {
-        syncScrollPositionCalled = true;
-        originalSyncScrollPosition();
-      };
-
-      bufferSet.activateAltBuffer();
-      assert.equal(bufferSet.normal.ydisp, originalYDisp, 'Normal buffer ydisp should be preserved');
-      syncScrollPositionCalled = false;
-      bufferSet.activateNormalBuffer();
-
-      assert.equal(bufferSet.normal.ydisp, originalYDisp, 'Normal buffer ydisp should be restored');
-      assert.equal(syncScrollPositionCalled, true, 'activateNormalBuffer should call syncScrollPosition');
-      assert.equal(bufferSet.active, bufferSet.normal, 'Normal buffer should be active');
-    });
-
-    it('should preserve normal buffer scroll position when switching back from alt buffer', () => {
-      bufferSet.activateNormalBuffer();
-      const normalScrollPos = 80;
-      bufferSet.normal.ydisp = normalScrollPos;
-      bufferSet.normal.ybase = 150;
-
-      bufferSet.activateAltBuffer();
-      bufferSet.alt.ydisp = 0;
-      bufferSet.alt.ybase = 0;
-      bufferSet.activateNormalBuffer();
-
-      assert.equal(bufferSet.normal.ydisp, normalScrollPos, 'Normal buffer should maintain its scroll position');
-      assert.equal(bufferSet.active, bufferSet.normal, 'Normal buffer should be active');
-      assert.notEqual(bufferSet.normal.ydisp, bufferSet.alt.ydisp, 'Normal and alt buffer should have different scroll positions');
-    });
-
-    it('should fire scroll event with correct position when syncScrollPosition is called', () => {
-      const mockBufferService = (bufferSet as any)._bufferService as MockBufferService;
-
-      bufferSet.activateNormalBuffer();
-      const testScrollPosition = 42;
-
-      mockBufferService.buffer.ydisp = testScrollPosition;
-      assert.equal(mockBufferService.buffer.ydisp, testScrollPosition, 'Active buffer ydisp should be set correctly');
-
-      let scrollEventFired = false;
-      let scrollEventPosition = -1;
-
-      mockBufferService.onScroll((position: number) => {
-        scrollEventFired = true;
-        scrollEventPosition = position;
-      });
-
-      mockBufferService.syncScrollPosition();
-      assert.equal(scrollEventFired, true, 'syncScrollPosition should fire scroll event');
-      assert.equal(scrollEventPosition, testScrollPosition, `Scroll event should contain current buffer ydisp`);
-    });
-  });
 });

src/common/buffer/BufferSet.ts

@@ -91,8 +91,6 @@ export class BufferSet extends Disposable implements IBufferSet {
       activeBuffer: this._normal,
       inactiveBuffer: this._alt
     });
-    // Prevent scrollbar "teleport" to top of the terminal, from previous alt buffer.
-    this._bufferService.syncScrollPosition();
   }
 
   /**

src/common/services/BufferService.ts

@@ -37,6 +37,9 @@ export class BufferService extends Disposable implements IBufferService {
     this.cols = Math.max(optionsService.rawOptions.cols || 0, MINIMUM_COLS);
     this.rows = Math.max(optionsService.rawOptions.rows || 0, MINIMUM_ROWS);
     this.buffers = this._register(new BufferSet(optionsService, this));
+    this._register(this.buffers.onBufferActivate(e => {
+      this._onScroll.fire(e.activeBuffer.ydisp);
+    }));
   }
 
   public resize(cols: number, rows: number): void {
@@ -149,10 +152,4 @@ export class BufferService extends Disposable implements IBufferService {
     }
   }
 
-  /**
-   * Synchronize the scroll position by firing a scroll event with the current buffer's ydisp.
-   */
-  public syncScrollPosition(): void {
-    this._onScroll.fire(this.buffer.ydisp);
-  }
 }

src/common/services/Services.ts

@@ -22,7 +22,6 @@ export interface IBufferService {
   onScroll: Event<number>;
   scroll(eraseAttr: IAttributeData, isWrapped?: boolean): void;
   scrollLines(disp: number, suppressScrollEvent?: boolean): void;
-  syncScrollPosition(): void;
   resize(cols: number, rows: number): void;
   reset(): void;
 }