feat: add APIs to support mojave dark modes (#14755)

* feat: add APIs to support mojave dark mode

Closes #13387

* docs: fix system-prefs typo

atom/browser/api/atom_api_system_preferences.cc

@@ -77,6 +77,12 @@ void SystemPreferences::BuildPrototype(
       .SetMethod("removeUserDefault", &SystemPreferences::RemoveUserDefault)
       .SetMethod("isSwipeTrackingFromScrollEventsEnabled",
                  &SystemPreferences::IsSwipeTrackingFromScrollEventsEnabled)
+      .SetMethod("getEffectiveAppearance",
+                 &SystemPreferences::GetEffectiveAppearance)
+      .SetMethod("getAppLevelAppearance",
+                 &SystemPreferences::GetAppLevelAppearance)
+      .SetMethod("setAppLevelAppearance",
+                 &SystemPreferences::SetAppLevelAppearance)
 #endif
       .SetMethod("isInvertedColorScheme",
                  &SystemPreferences::IsInvertedColorScheme)

atom/browser/api/atom_api_system_preferences.h

@@ -89,6 +89,12 @@ class SystemPreferences : public mate::EventEmitter<SystemPreferences>
                       mate::Arguments* args);
   void RemoveUserDefault(const std::string& name);
   bool IsSwipeTrackingFromScrollEventsEnabled();
+
+  // TODO(MarshallOfSound): Write tests for these methods once we
+  // are running tests on a Mojave machine
+  v8::Local<v8::Value> GetEffectiveAppearance(v8::Isolate* isolate);
+  v8::Local<v8::Value> GetAppLevelAppearance(v8::Isolate* isolate);
+  void SetAppLevelAppearance(mate::Arguments* args);
 #endif
   bool IsDarkMode();
   bool IsInvertedColorScheme();

atom/browser/api/atom_api_system_preferences_mac.mm

@@ -8,13 +8,58 @@
 
 #import <Cocoa/Cocoa.h>
 
+#include "atom/browser/mac/atom_application.h"
 #include "atom/browser/mac/dict_util.h"
 #include "atom/common/native_mate_converters/gurl_converter.h"
 #include "atom/common/native_mate_converters/value_converter.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/values.h"
+#include "native_mate/object_template_builder.h"
 #include "net/base/mac/url_conversions.h"
 
+namespace mate {
+template <>
+struct Converter<NSAppearance*> {
+  static bool FromV8(v8::Isolate* isolate,
+                     v8::Local<v8::Value> val,
+                     NSAppearance** out) {
+    if (val->IsNull()) {
+      *out = nil;
+      return true;
+    }
+
+    std::string name;
+    if (!mate::ConvertFromV8(isolate, val, &name)) {
+      return false;
+    }
+
+    if (name == "light") {
+      *out = [NSAppearance appearanceNamed:NSAppearanceNameAqua];
+      return true;
+    } else if (name == "dark") {
+      *out = [NSAppearance appearanceNamed:NSAppearanceNameDarkAqua];
+      return true;
+    }
+
+    return false;
+  }
+
+  static v8::Local<v8::Value> ToV8(v8::Isolate* isolate, NSAppearance* val) {
+    if (val == nil) {
+      return v8::Null(isolate);
+    }
+    if (val.name == NSAppearanceNameAqua) {
+      return mate::ConvertToV8(isolate, "light");
+    }
+    if (val.name == NSAppearanceNameDarkAqua) {
+      return mate::ConvertToV8(isolate, "dark");
+    }
+
+    return mate::ConvertToV8(isolate, "unknown");
+  }
+};
+}  // namespace mate
+
 namespace atom {
 
 namespace api {
@@ -323,6 +368,35 @@ bool SystemPreferences::IsSwipeTrackingFromScrollEventsEnabled() {
   return [NSEvent isSwipeTrackingFromScrollEventsEnabled];
 }
 
+v8::Local<v8::Value> SystemPreferences::GetEffectiveAppearance(
+    v8::Isolate* isolate) {
+  if (@available(macOS 10.14, *)) {
+    return mate::ConvertToV8(
+        isolate, [NSApplication sharedApplication].effectiveAppearance);
+  }
+  return v8::Null(isolate);
+}
+
+v8::Local<v8::Value> SystemPreferences::GetAppLevelAppearance(
+    v8::Isolate* isolate) {
+  if (@available(macOS 10.14, *)) {
+    return mate::ConvertToV8(isolate,
+                             [NSApplication sharedApplication].appearance);
+  }
+  return v8::Null(isolate);
+}
+
+void SystemPreferences::SetAppLevelAppearance(mate::Arguments* args) {
+  if (@available(macOS 10.14, *)) {
+    NSAppearance* appearance;
+    if (args->GetNext(&appearance)) {
+      [[NSApplication sharedApplication] setAppearance:appearance];
+    } else {
+      args->ThrowError("Invalid app appearance provided as first argument");
+    }
+  }
+}
+
 }  // namespace api
 
 }  // namespace atom

atom/browser/mac/atom_application.h

@@ -6,6 +6,21 @@
 #include "base/mac/scoped_nsobject.h"
 #include "base/mac/scoped_sending_event.h"
 
+// Forward Declare Appareance APIs
+@interface NSApplication (HighSierraSDK)
+@property(copy, readonly)
+    NSAppearance* effectiveAppearance API_AVAILABLE(macosx(10.14));
+@property(copy, readonly) NSAppearance* appearance API_AVAILABLE(macosx(10.14));
+- (void)setAppearance:(NSAppearance*)appearance API_AVAILABLE(macosx(10.14));
+@end
+
+extern "C" {
+#if !defined(MAC_OS_X_VERSION_10_14) || \
+    MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_14
+BASE_EXPORT extern NSString* const NSAppearanceNameDarkAqua;
+#endif  // MAC_OS_X_VERSION_10_14
+}  // extern "C"
+
 @interface AtomApplication : NSApplication <CrAppProtocol,
                                             CrAppControlProtocol,
                                             NSUserActivityDelegate> {

atom/browser/mac/atom_application.mm

@@ -11,6 +11,11 @@
 #include "base/strings/sys_string_conversions.h"
 #include "content/public/browser/browser_accessibility_state.h"
 
+#if !defined(MAC_OS_X_VERSION_10_14) || \
+    MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_14
+NSString* const NSAppearanceNameDarkAqua = @"NSAppearanceNameDarkAqua";
+#endif  // MAC_OS_X_VERSION_10_14
+
 namespace {
 
 inline void dispatch_sync_main(dispatch_block_t block) {