Merge branch 'master' into 3810

src/common/Color.ts

@@ -150,15 +150,42 @@ export namespace rgb {
  * Helper functions where the source type is "rgba" (number: 0xrrggbbaa).
  */
 export namespace rgba {
+  /**
+   * Given a foreground color and a background color, either increase or reduce the luminance of the
+   * foreground color until the specified contrast ratio is met. If pure white or black is hit
+   * without the contrast ratio being met, go the other direction using the background color as the
+   * foreground color and take either the first or second result depending on which has the higher
+   * contrast ratio.
+   *
+   * `undefined` will be returned if the contrast ratio is already met.
+   *
+   * @param bgRgba The background color in rgba format.
+   * @param fgRgba The foreground color in rgba format.
+   * @param ratio The contrast ratio to achieve.
+   */
   export function ensureContrastRatio(bgRgba: number, fgRgba: number, ratio: number): number | undefined {
     const bgL = rgb.relativeLuminance(bgRgba >> 8);
     const fgL = rgb.relativeLuminance(fgRgba >> 8);
     const cr = contrastRatio(bgL, fgL);
     if (cr < ratio) {
       if (fgL < bgL) {
-        return reduceLuminance(bgRgba, fgRgba, ratio);
+        const resultA = reduceLuminance(bgRgba, fgRgba, ratio);
+        const resultARatio = contrastRatio(bgL, rgb.relativeLuminance(resultA >> 8));
+        if (resultARatio < ratio) {
+          const resultB = increaseLuminance(bgRgba, bgRgba, ratio);
+          const resultBRatio = contrastRatio(bgL, rgb.relativeLuminance(resultB >> 8));
+          return resultARatio > resultBRatio ? resultA : resultB;
+        }
+        return resultA;
       }
-      return increaseLuminance(bgRgba, fgRgba, ratio);
+      const resultA = increaseLuminance(bgRgba, fgRgba, ratio);
+      const resultARatio = contrastRatio(bgL, rgb.relativeLuminance(resultA >> 8));
+      if (resultARatio < ratio) {
+        const resultB = reduceLuminance(bgRgba, bgRgba, ratio);
+        const resultBRatio = contrastRatio(bgL, rgb.relativeLuminance(resultB >> 8));
+        return resultARatio > resultBRatio ? resultA : resultB;
+      }
+      return resultA;
     }
     return undefined;
   }

src/common/CoreTerminal.ts

@@ -68,6 +68,8 @@ export abstract class CoreTerminal extends Disposable implements ICoreTerminal {
   private _onResize = new EventEmitter<{ cols: number, rows: number }>();
   public get onResize(): IEvent<{ cols: number, rows: number }> { return this._onResize.event; }
   protected _onScroll = new EventEmitter<IScrollEvent, void>();
+  public get onWriteParsed(): IEvent<void> { return this._onWriteParsed.event; }
+  protected _onWriteParsed = new EventEmitter<void>();
   /**
    * Internally we track the source of the scroll but this is meaningless outside the library so
    * it's filtered out.
@@ -138,6 +140,7 @@ export abstract class CoreTerminal extends Disposable implements ICoreTerminal {
 
     // Setup WriteBuffer
     this._writeBuffer = new WriteBuffer((data, promiseResult) => this._inputHandler.parse(data, promiseResult));
+    this.register(forwardEvent(this._writeBuffer.onWriteParsed, this._onWriteParsed));
   }
 
   public dispose(): void {

src/common/input/WriteBuffer.ts

@@ -4,6 +4,8 @@
  * @license MIT
  */
 
+import { EventEmitter, IEvent } from 'common/EventEmitter';
+
 declare const setTimeout: (handler: () => void, timeout?: number) => void;
 
 /**
@@ -44,6 +46,8 @@ export class WriteBuffer {
   private _bufferOffset = 0;
   private _isSyncWriting = false;
   private _syncCalls = 0;
+  public get onWriteParsed(): IEvent<void> { return this._onWriteParsed.event; }
+  private _onWriteParsed = new EventEmitter<void>();
 
   constructor(private _action: (data: string | Uint8Array, promiseResult?: boolean) => void | Promise<boolean>) { }
 
@@ -220,5 +224,6 @@ export class WriteBuffer {
       this._pendingData = 0;
       this._bufferOffset = 0;
     }
+    this._onWriteParsed.fire();
   }
 }