Defer paused renderer resize to idle callback

addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts

@@ -16,7 +16,7 @@ import { tryDrawCustomChar } from 'browser/renderer/CustomGlyphs';
 import { excludeFromContrastRatioDemands, isPowerlineGlyph, isRestrictedPowerlineGlyph } from 'browser/renderer/RendererUtils';
 import { IUnicodeService } from 'common/services/Services';
 import { FourKeyMap } from 'common/MultiKeyMap';
-import { IdleTaskQueue } from 'common/IdleTaskQueue';
+import { IdleTaskQueue } from 'common/Idle';
 
 // For debugging purposes, it can be useful to set this to a really tiny value,
 // to verify that LRU eviction works.

src/browser/services/RenderService.ts

@@ -12,6 +12,7 @@ import { addDisposableDomListener } from 'browser/Lifecycle';
 import { IColorSet, IRenderDebouncerWithCallback } from 'browser/Types';
 import { IOptionsService, IBufferService, IDecorationService } from 'common/services/Services';
 import { ICharSizeService, ICoreBrowserService, IRenderService } from 'browser/services/Services';
+import { DebouncedIdleTask } from 'common/Idle';
 
 interface ISelectionState {
   start: [number, number] | undefined;
@@ -24,6 +25,7 @@ export class RenderService extends Disposable implements IRenderService {
 
   private _renderDebouncer: IRenderDebouncerWithCallback;
   private _screenDprMonitor: ScreenDprMonitor;
+  private _pausedResizeTask = new DebouncedIdleTask();
 
   private _isPaused: boolean = false;
   private _needsFullRefresh: boolean = false;
@@ -105,6 +107,7 @@ export class RenderService extends Disposable implements IRenderService {
     }
 
     if (!this._isPaused && this._needsFullRefresh) {
+      this._pausedResizeTask.flush();
       this.refreshRows(0, this._rowCount - 1);
       this._needsFullRefresh = false;
     }
@@ -204,7 +207,11 @@ export class RenderService extends Disposable implements IRenderService {
   }
 
   public onResize(cols: number, rows: number): void {
-    this._renderer.onResize(cols, rows);
+    if (this._isPaused) {
+      this._pausedResizeTask.set(() => this._renderer.onResize(cols, rows));
+    } else {
+      this._renderer.onResize(cols, rows);
+    }
     this._fullRefresh();
   }
 

src/common/IdleTaskQueue.ts → src/common/Idle.ts

@@ -9,7 +9,7 @@
  * and care should be taken to ensure they're non-urgent and will not introduce race conditions.
  */
 export class IdleTaskQueue {
-  private _tasks: Function[] = [];
+  private _tasks: (() => void)[] = [];
   private _idleCallback?: number;
   private _maxTaskDuration: number;
   private _i = 0;
@@ -24,11 +24,33 @@ export class IdleTaskQueue {
   /**
    * Adds a task to the queue which will run in a future idle callback.
    */
-  public enqueue(task: Function): void {
+  public enqueue(task: () => void): void {
     this._tasks.push(task);
     this._start();
   }
 
+  /**
+   * Flushes the queue, running all remaining tasks synchronously.
+   */
+  public flush(): void {
+    while (this._i < this._tasks.length) {
+      this._tasks[this._i++]();
+    }
+    this.clear();
+  }
+
+  /**
+   * Clears any remaining tasks from the queue, these will not be run.
+   */
+  public clear(): void {
+    if (this._idleCallback) {
+      cancelIdleCallback(this._idleCallback);
+      this._idleCallback = undefined;
+    }
+    this._i = 0;
+    this._tasks.length = 0;
+  }
+
   private _start(): void {
     if (!this._idleCallback) {
       this._idleCallback = requestIdleCallback(() => this._process());
@@ -45,8 +67,26 @@ export class IdleTaskQueue {
         return;
       }
     }
-    // Clear the queue
-    this._i = 0;
-    this._tasks.length = 0;
+    this.clear();
+  }
+}
+
+export class DebouncedIdleTask {
+  private _queue: IdleTaskQueue;
+
+  /**
+   * @param targetFps The target frame rate.
+   */
+  constructor(targetFps: number = 240) {
+    this._queue = new IdleTaskQueue(targetFps);
+  }
+
+  public set(task: () => void): void {
+    this._queue.clear();
+    this._queue.enqueue(task);
+  }
+
+  public flush(): void {
+    this._queue.flush();
   }
 }