Consolidate the Dark mode low-level helpers

Author: tiennou

Classes/Controllers/ApplicationController.m

@@ -121,6 +121,7 @@ - (void)applicationDidFinishLaunching:(NSNotification*)notification
 	setenv( "SSH_ASKPASS", [[[NSBundle mainBundle] pathForResource: @"gitx_askpasswd" ofType: @""] UTF8String], 1 );
 	setenv( "DISPLAY", "localhost:0", 1 );
 
+	[NSApp registerObserverForAppearanceChanges:self];
 	[self registerServices];
 	started = YES;
 }

Classes/Controllers/PBWebController.m

@@ -47,10 +47,11 @@ - (void) awakeFromNib
 			   name:NSWindowDidEndLiveResizeNotification
 			 object:self.view.window];
 
-	if (@available(macOS 10.14, *)) {
-		[[NSApplication sharedApplication] addObserver:self forKeyPath:@"effectiveAppearance" options:(NSKeyValueObservingOptions)0 context:PBEffectiveAppearanceContext];
-	}
-	
+	[nc addObserver:self
+		   selector:@selector(effectiveAppearanceDidChange:)
+			   name:PBEffectiveAppearanceChanged
+			 object:nil];
+
 	finishedLoading = NO;
 
 	[self.view setDrawsBackground:NO];
@@ -78,21 +79,10 @@ - (WebScriptObject *) script
 	return self.view.windowScriptObject;
 }
 
-- (void) setWebAppearance:(NSAppearance *)appearance
+- (void)effectiveAppearanceDidChange:(NSNotification *)notif
 {
-	if (@available(macOS 10.14, *)) {
-		if (appearance == nil) {
-			appearance = [NSApplication sharedApplication].effectiveAppearance;
-		}
-
-		NSAppearanceName appearanceName = [appearance bestMatchFromAppearancesWithNames:@[NSAppearanceNameDarkAqua, NSAppearanceNameAqua]];
-
-		if ([appearanceName isEqualToString:NSAppearanceNameDarkAqua]) {
-			[self.script callWebScriptMethod:@"setAppearance" withArguments:@[@"DARK"]];
-		} else {
-			[self.script callWebScriptMethod:@"setAppearance" withArguments:@[@"LIGHT"]];
-		}
-	}
+	NSString *mode = [NSApp isDarkMode] ? @"DARK" : @"LIGHT";
+	[self.script callWebScriptMethod:@"setAppearance" withArguments:@[mode]];
 }
 
 - (void)closeView
@@ -124,7 +114,7 @@ - (void) webView:(id) v didFinishLoadForFrame:(id) frame
 	finishedLoading = YES;
 	if ([self respondsToSelector:@selector(didLoad)])
 		[self performSelector:@selector(didLoad)];
-	[self setWebAppearance:nil];
+	[self effectiveAppearanceDidChange:nil];
 }
 
 - (void)webView:(WebView *)webView addMessageToConsole:(NSDictionary *)dictionary

Classes/NSAppearance+PBDarkMode.h

@@ -9,12 +9,15 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+extern NSString *const PBEffectiveAppearanceChanged;
+
 @interface NSAppearance (PBDarkMode)
 - (BOOL)isDarkMode;
 @end
 
 @interface NSApplication (PBDarkMode)
 - (BOOL)isDarkMode;
+- (void)registerObserverForAppearanceChanges:(id)observer;
 @end
 
 NS_ASSUME_NONNULL_END

Classes/NSAppearance+PBDarkMode.m

@@ -7,6 +7,8 @@
 
 #import "NSAppearance+PBDarkMode.h"
 
+NSString *const PBEffectiveAppearanceChanged = @"PBEffectiveAppearanceChanged";
+
 @implementation NSAppearance (PBDarkMode)
 
 - (BOOL)isDarkMode
@@ -33,4 +35,15 @@ - (BOOL)isDarkMode
 	}
 }
 
+- (void)registerObserverForAppearanceChanges:(id)observer
+{
+	if (@available(macOS 10.14, *)) {
+		/* This leaks the observation, but since it's tied to the life of NSApp
+		 * it doesn't matter ;-) */
+		[[NSApplication sharedApplication] addObserver:observer keyPath:@"effectiveAppearance" options:0 block:^(MAKVONotification *notification) {
+			[[NSNotificationCenter defaultCenter] postNotificationName:PBEffectiveAppearanceChanged object:observer];
+		}];
+	}
+}
+
 @end