Use default colors only in forced-colors mode (bug 1778068)

Author: calixteman

web/app.js

@@ -516,10 +516,12 @@ const PDFViewerApplication = {
     const container = appConfig.mainContainer,
       viewer = appConfig.viewerContainer;
     const annotationEditorMode = AppOptions.get("annotationEditorMode");
-    const pageColors = {
-      background: AppOptions.get("pageColorsBackground"),
-      foreground: AppOptions.get("pageColorsForeground"),
-    };
+    const pageColors = PDFViewerApplication.useUserDefinedColors
+      ? {
+          background: AppOptions.get("pageColorsBackground"),
+          foreground: AppOptions.get("pageColorsForeground"),
+        }
+      : null;
 
     this.pdfViewer = new PDFViewer({
       container,
@@ -730,6 +732,21 @@ const PDFViewerApplication = {
     return this.externalServices.supportedMouseWheelZoomModifierKeys;
   },
 
+  get useUserDefinedColors() {
+    // 0 - Only with HCM;
+    // 1 - Never;
+    // 2 - Always.
+    const value = this.externalServices.documentColorUse;
+    switch (value) {
+      case 1:
+        return false;
+      case 2:
+        return true;
+      default:
+        return window.matchMedia("(forced-colors: active)").matches;
+    }
+  },
+
   initPassiveLoading() {
     if (
       typeof PDFJSDev === "undefined" ||

web/firefoxcom.js

@@ -429,6 +429,11 @@ class FirefoxExternalServices extends DefaultExternalServices {
     return shadow(this, "supportedMouseWheelZoomModifierKeys", support);
   }
 
+  static get documentColorUse() {
+    const support = FirefoxCom.requestSync("documentColorUse");
+    return shadow(this, "documentColorUse", support);
+  }
+
   static get isInAutomation() {
     // Returns the value of `Cu.isInAutomation`, which is only `true` when e.g.
     // various test-suites are running in mozilla-central.