Move range updating to DirtyRowService

src/common/services/DirtyRowService.ts

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) 2019 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { IBufferService, IDirtyRowService } from 'common/services/Services';
+
+export class DirtyRowService implements IDirtyRowService {
+  private _start!: number;
+  private _end!: number;
+
+  public get start(): number { return this._start; }
+  public get end(): number { return this._end; }
+
+  constructor(
+    private readonly _bufferService: IBufferService
+  ) {
+    this.clearRange();
+  }
+
+  public clearRange(): void {
+    this._start = this._bufferService.buffer.y;
+    this._end = this._bufferService.buffer.y;
+  }
+
+  public markDirty(y: number): void {
+    if (y < this._start) {
+      this._start = y;
+    } else if (y > this._end) {
+      this._end = y;
+    }
+  }
+
+  public markRangeDirty(y1: number, y2: number): void {
+    if (y1 > y2) {
+      const temp = y1;
+      y1 = y2;
+      y2 = temp;
+    }
+    if (y1 < this._start) {
+      this._start = y1;
+    }
+    if (y2 > this._end) {
+      this._end = y2;
+    }
+  }
+
+  public markAllDirty(): void {
+    this.markRangeDirty(0, this._bufferService.rows - 1);
+  }
+}