Bug 1344910, part 1 - Add a '-moz-win-accentcolor' color keyword to expose the Win10 accent color. r=jimm

MozReview-Commit-ID: DtRcuizKRH2

layout/style/nsCSSKeywordList.h

@@ -747,6 +747,7 @@ CSS_KEY(button-focus, button_focus)
 CSS_KEY(-moz-win-media-toolbox, _moz_win_media_toolbox)
 CSS_KEY(-moz-win-communications-toolbox, _moz_win_communications_toolbox)
 CSS_KEY(-moz-win-browsertabbar-toolbox, _moz_win_browsertabbar_toolbox)
+CSS_KEY(-moz-win-accentcolor, _moz_win_accentcolor)
 CSS_KEY(-moz-win-mediatext, _moz_win_mediatext)
 CSS_KEY(-moz-win-communicationstext, _moz_win_communicationstext)
 CSS_KEY(-moz-win-glass, _moz_win_glass)

layout/style/nsCSSProps.cpp

@@ -1137,6 +1137,7 @@ const KTableEntry nsCSSProps::kColorKTable[] = {
   { eCSSKeyword__moz_oddtreerow, LookAndFeel::eColorID__moz_oddtreerow },
   { eCSSKeyword__moz_visitedhyperlinktext, NS_COLOR_MOZ_VISITEDHYPERLINKTEXT },
   { eCSSKeyword_currentcolor, NS_COLOR_CURRENTCOLOR },
+  { eCSSKeyword__moz_win_accentcolor, LookAndFeel::eColorID__moz_win_accentcolor },
   { eCSSKeyword__moz_win_mediatext, LookAndFeel::eColorID__moz_win_mediatext },
   { eCSSKeyword__moz_win_communicationstext, LookAndFeel::eColorID__moz_win_communicationstext },
   { eCSSKeyword__moz_nativehyperlinktext, LookAndFeel::eColorID__moz_nativehyperlinktext },

widget/LookAndFeel.h

@@ -158,6 +158,8 @@ public:
 
     // vista rebars
 
+    // accent color for title bar
+    eColorID__moz_win_accentcolor,
     // media rebar text
     eColorID__moz_win_mediatext,
     // communications rebar text

widget/nsXPLookAndFeel.cpp

@@ -658,6 +658,9 @@ nsXPLookAndFeel::GetStandinForNativeColor(ColorID aID)
       result = NS_RGB(0x3F, 0x3F, 0x3F); break;
     case eColorID__moz_mac_secondaryhighlight:
       result = NS_RGB(0xD4, 0xD4, 0xD4); break;
+    case eColorID__moz_win_accentcolor:
+      // Seems to be the default color (hardcoded because of bug 1065998)
+      result = NS_RGB(0x9E, 0x9E, 0x9E); break;
     case eColorID__moz_win_mediatext:
       result = NS_RGB(0xFF, 0xFF, 0xFF); break;
     case eColorID__moz_win_communicationstext:

widget/windows/nsLookAndFeel.cpp

@@ -262,6 +262,16 @@ nsLookAndFeel::NativeGetColor(ColorID aID, nscolor &aColor)
     case eColorID__moz_cellhighlight:
       idx = COLOR_3DFACE;
       break;
+    case eColorID__moz_win_accentcolor:
+      res = GetAccentColor(aColor);
+      if (NS_SUCCEEDED(res)) {
+        return res;
+      }
+      NS_WARNING("Using fallback for accent color - UI code failed to use the "
+                 "-moz-windows-accent-color-applies media query properly");
+      // Seems to be the default color (hardcoded because of bug 1065998)
+      aColor = NS_RGB(158, 158, 158);
+      return NS_OK;
     case eColorID__moz_win_mediatext:
       if (IsAppThemed()) {
         res = ::GetColorFromTheme(eUXMediaToolbar,
@@ -747,3 +757,42 @@ nsLookAndFeel::SetIntCacheImpl(const nsTArray<LookAndFeelInt>& aLookAndFeelIntCa
   }
 }
 
+/* static */ nsresult
+nsLookAndFeel::GetAccentColor(nscolor& aColor)
+{
+  nsresult rv;
+
+  if (!mDwmKey) {
+    mDwmKey = do_CreateInstance("@mozilla.org/windows-registry-key;1", &rv);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  rv = mDwmKey->Open(nsIWindowsRegKey::ROOT_KEY_CURRENT_USER,
+                     NS_LITERAL_STRING("SOFTWARE\\Microsoft\\Windows\\DWM"),
+                     nsIWindowsRegKey::ACCESS_QUERY_VALUE);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // The ColorPrevalence value is set to 1 when the "Show color on title bar"
+  // setting in the Color section of Window's Personalization settings is
+  // turned on.
+  uint32_t accentColor, colorPrevalence;
+  if (NS_SUCCEEDED(mDwmKey->ReadIntValue(NS_LITERAL_STRING("AccentColor"), &accentColor)) &&
+      NS_SUCCEEDED(mDwmKey->ReadIntValue(NS_LITERAL_STRING("ColorPrevalence"), &colorPrevalence)) &&
+      colorPrevalence == 1) {
+    // The order of the color components in the DWORD stored in the registry
+    // happens to be the same order as we store the components in nscolor
+    // so we can just assign directly here.
+    aColor = accentColor;
+    rv = NS_OK;
+  } else {
+    rv = NS_ERROR_NOT_AVAILABLE;
+  }
+
+  mDwmKey->Close();
+
+  return rv;
+}

widget/windows/nsLookAndFeel.h

@@ -9,6 +9,7 @@
 #include "nsXPLookAndFeel.h"
 #include "gfxFont.h"
 #include "mozilla/RangedArray.h"
+#include "nsIWindowsRegKey.h"
 
 /*
  * Gesture System Metrics
@@ -51,6 +52,13 @@ public:
   void SetIntCacheImpl(const nsTArray<LookAndFeelInt>& aLookAndFeelIntCache) override;
 
 private:
+  /**
+   * Fetches the Windows accent color from the Windows settings if
+   * the accent color is set to apply to the title bar, otherwise
+   * returns an error code.
+   */
+  nsresult GetAccentColor(nscolor& aColor);
+
   // Content process cached values that get shipped over from the browser
   // process.
   int32_t mUseAccessibilityTheme;
@@ -71,6 +79,8 @@ private:
   mozilla::RangedArray<CachedSystemFont,
                        FontID_MINIMUM,
                        FontID_MAXIMUM + 1 - FontID_MINIMUM> mSystemFontCache;
+
+  nsCOMPtr<nsIWindowsRegKey> mDwmKey;
 };
 
 #endif

widget/windows/nsWindow.cpp

@@ -5197,12 +5197,19 @@ nsWindow::ProcessMessage(UINT msg, WPARAM& wParam, LPARAM& lParam,
 
     case WM_SETTINGCHANGE:
     {
-      if (IsWin10OrLater() && mWindowType == eWindowType_invisible && lParam) {
+      if (lParam) {
         auto lParamString = reinterpret_cast<const wchar_t*>(lParam);
-        if (!wcscmp(lParamString, L"UserInteractionMode")) {
-          nsCOMPtr<nsIWindowsUIUtils> uiUtils(do_GetService("@mozilla.org/windows-ui-utils;1"));
-          if (uiUtils) {
-            uiUtils->UpdateTabletModeState();
+        if (!wcscmp(lParamString, L"ImmersiveColorSet")) {
+          // WM_SYSCOLORCHANGE is not dispatched for accent color changes
+          OnSysColorChanged();
+          break;
+        }
+        if (IsWin10OrLater() && mWindowType == eWindowType_invisible) {
+          if (!wcscmp(lParamString, L"UserInteractionMode")) {
+            nsCOMPtr<nsIWindowsUIUtils> uiUtils(do_GetService("@mozilla.org/windows-ui-utils;1"));
+            if (uiUtils) {
+              uiUtils->UpdateTabletModeState();
+            }
           }
         }
       }