From 01d7e75ba8fa1cd37abdef9b6f2467b275ba36b9 Mon Sep 17 00:00:00 2001
From: Pale Moon <git-repo@palemoon.org>
Date: Sat, 8 Jul 2017 22:37:54 +0200
Subject: [PATCH] Add a '-moz-windows-accent-color-applies' media query.

The '-moz-windows-accent-color-applies' media query matches when the Windows 10
accent color should be used as the background of the title bar.
---
 dom/base/nsGkAtomList.h             | 2 ++
 layout/style/nsCSSRuleProcessor.cpp | 5 +++++
 layout/style/nsMediaFeatures.cpp    | 7 +++++++
 widget/LookAndFeel.h                | 9 +++++++++
 widget/windows/nsLookAndFeel.cpp    | 6 ++++++
 5 files changed, 29 insertions(+)

diff --git a/dom/base/nsGkAtomList.h b/dom/base/nsGkAtomList.h
index 78a005a0e0..903343d289 100644
--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -2139,6 +2139,7 @@ GK_ATOM(scrollbar_thumb_proportional, "scrollbar-thumb-proportional")
 GK_ATOM(images_in_menus, "images-in-menus")
 GK_ATOM(images_in_buttons, "images-in-buttons")
 GK_ATOM(overlay_scrollbars, "overlay-scrollbars")
+GK_ATOM(windows_accent_color_applies, "windows-accent-color-applies")
 GK_ATOM(windows_default_theme, "windows-default-theme")
 GK_ATOM(mac_graphite_theme, "mac-graphite-theme")
 GK_ATOM(mac_lion_theme, "mac-lion-theme")
@@ -2166,6 +2167,7 @@ GK_ATOM(_moz_scrollbar_thumb_proportional, "-moz-scrollbar-thumb-proportional")
 GK_ATOM(_moz_images_in_menus, "-moz-images-in-menus")
 GK_ATOM(_moz_images_in_buttons, "-moz-images-in-buttons")
 GK_ATOM(_moz_overlay_scrollbars, "-moz-overlay-scrollbars")
+GK_ATOM(_moz_windows_accent_color_applies, "-moz-windows-accent-color-applies")
 GK_ATOM(_moz_windows_default_theme, "-moz-windows-default-theme")
 GK_ATOM(_moz_mac_graphite_theme, "-moz-mac-graphite-theme")
 GK_ATOM(_moz_mac_lion_theme, "-moz-mac-lion-theme")
diff --git a/layout/style/nsCSSRuleProcessor.cpp b/layout/style/nsCSSRuleProcessor.cpp
index a25d39d5e9..0429a9875f 100644
--- a/layout/style/nsCSSRuleProcessor.cpp
+++ b/layout/style/nsCSSRuleProcessor.cpp
@@ -1187,6 +1187,11 @@ InitSystemMetrics()
     sSystemMetrics->AppendElement(nsGkAtoms::mac_yosemite_theme);
   }
 
+  rv = LookAndFeel::GetInt(LookAndFeel::eIntID_WindowsAccentColorApplies, &metricResult);
+  if (NS_SUCCEEDED(rv) && metricResult) {
+    sSystemMetrics->AppendElement(nsGkAtoms::windows_accent_color_applies);
+  }
+
   rv = LookAndFeel::GetInt(LookAndFeel::eIntID_DWMCompositor, &metricResult);
   if (NS_SUCCEEDED(rv) && metricResult) {
     sSystemMetrics->AppendElement(nsGkAtoms::windows_compositor);
diff --git a/layout/style/nsMediaFeatures.cpp b/layout/style/nsMediaFeatures.cpp
index 1d1d9956b6..d9073e653c 100644
--- a/layout/style/nsMediaFeatures.cpp
+++ b/layout/style/nsMediaFeatures.cpp
@@ -582,6 +582,13 @@ nsMediaFeatures::features[] = {
       { &nsGkAtoms::mac_yosemite_theme },
       GetSystemMetric
     },
+    {
+      &nsGkAtoms::_moz_windows_accent_color_applies,
+      nsMediaFeature::eMinMaxNotAllowed,
+      nsMediaFeature::eBoolInteger,
+      { &nsGkAtoms::windows_accent_color_applies },
+      GetSystemMetric
+    },
     {
         &nsGkAtoms::_moz_windows_compositor,
         nsMediaFeature::eMinMaxNotAllowed,
diff --git a/widget/LookAndFeel.h b/widget/LookAndFeel.h
index 5ecb9aea8a..0ea405b6ae 100644
--- a/widget/LookAndFeel.h
+++ b/widget/LookAndFeel.h
@@ -232,6 +232,15 @@ public:
     // Should menu items blink when they're chosen?
     eIntID_ChosenMenuItemsShouldBlink,
 
+    /*
+     * A Boolean value to determine whether the Windows accent color
+     * should be applied to the title bar.
+     *
+     * The value of this metric is not used on other platforms. These platforms
+     * should return NS_ERROR_NOT_IMPLEMENTED when queried for this metric.
+     */
+    eIntID_WindowsAccentColorApplies,
+
     /*
      * A Boolean value to determine whether the Windows default theme is
      * being used.
diff --git a/widget/windows/nsLookAndFeel.cpp b/widget/windows/nsLookAndFeel.cpp
index 4534e53376..d2ab192827 100644
--- a/widget/windows/nsLookAndFeel.cpp
+++ b/widget/windows/nsLookAndFeel.cpp
@@ -438,6 +438,12 @@ nsLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
     case eIntID_DWMCompositor:
         aResult = nsUXThemeData::CheckForCompositor();
         break;
+    case eIntID_WindowsAccentColorApplies:
+        {
+          nscolor unused;
+          aResult = NS_SUCCEEDED(GetAccentColor(unused)) ? 1 : 0;
+        }
+        break;
     case eIntID_WindowsGlass:
         // Aero Glass is only available prior to Windows 8 when DWM is used.
         aResult = (nsUXThemeData::CheckForCompositor() && !IsWin8OrLater());