From 543b3d6c9f45b2b2b5141e02c20cca0b76a1cfc8 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Wed, 4 Dec 2019 10:54:17 -0800
Subject: [PATCH] Fix minimumContrastRatio on dom/truecolor

Fixes #2593
---
 src/browser/Color.ts                          |  2 +-
 .../renderer/dom/DomRendererRowFactory.ts     | 19 +++++++++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/browser/Color.ts b/src/browser/Color.ts
index e20f62e6e2..e40ff9e1a8 100644
--- a/src/browser/Color.ts
+++ b/src/browser/Color.ts
@@ -108,7 +108,7 @@ export function contrastRatio(l1: number, l2: number): number {
   return (l1 + 0.05) / (l2 + 0.05);
 }
 
-function rgbaToColor(r: number, g: number, b: number): IColor {
+export function rgbaToColor(r: number, g: number, b: number): IColor {
   return {
     css: toCss(r, g, b),
     rgba: toRgba(r, g, b)
diff --git a/src/browser/renderer/dom/DomRendererRowFactory.ts b/src/browser/renderer/dom/DomRendererRowFactory.ts
index cffc562423..bd922f5781 100644
--- a/src/browser/renderer/dom/DomRendererRowFactory.ts
+++ b/src/browser/renderer/dom/DomRendererRowFactory.ts
@@ -8,7 +8,7 @@ import { INVERTED_DEFAULT_COLOR } from 'browser/renderer/atlas/Constants';
 import { NULL_CELL_CODE, WHITESPACE_CELL_CHAR, Attributes } from 'common/buffer/Constants';
 import { CellData } from 'common/buffer/CellData';
 import { IOptionsService } from 'common/services/Services';
-import { ensureContrastRatio } from 'browser/Color';
+import { ensureContrastRatio, rgbaToColor } from 'browser/Color';
 import { IColorSet, IColor } from 'browser/Types';
 
 export const BOLD_CLASS = 'xterm-bold';
@@ -129,7 +129,14 @@ export class DomRendererRowFactory {
           }
           break;
         case Attributes.CM_RGB:
-          charElement.setAttribute('style', `${charElement.getAttribute('style') || ''}color:#${padStart(fg.toString(16), '0', 6)};`);
+          const color = rgbaToColor(
+            (fg >> 16) & 0xFF,
+            (fg >>  8) & 0xFF,
+            (fg      ) & 0xFF
+          );
+          if (!this._applyMinimumContrast(charElement, this._colors.background, color)) {
+            this._addStyle(charElement, `color:#${padStart(fg.toString(16), '0', 6)}`);
+          }
           break;
         case Attributes.CM_DEFAULT:
         default:
@@ -147,7 +154,7 @@ export class DomRendererRowFactory {
           charElement.classList.add(`xterm-bg-${bg}`);
           break;
         case Attributes.CM_RGB:
-          charElement.setAttribute('style', `${charElement.getAttribute('style') || ''}background-color:#${padStart(bg.toString(16), '0', 6)};`);
+          this._addStyle(charElement, `background-color:#${padStart(bg.toString(16), '0', 6)}`);
           break;
         case Attributes.CM_DEFAULT:
         default:
@@ -176,12 +183,16 @@ export class DomRendererRowFactory {
     }
 
     if (adjustedColor) {
-      element.setAttribute('style', `${element.getAttribute('style') || ''}color:${adjustedColor.css}`);
+      this._addStyle(element, `color:${adjustedColor.css}`);
       return true;
     }
 
     return false;
   }
+
+  private _addStyle(element: HTMLElement, style: string): void {
+    element.setAttribute('style', `${element.getAttribute('style') || ''}${style};`);
+  }
 }
 
 function padStart(text: string, padChar: string, length: number): string {