Rationalises protocol for application-level event theft.

OSBindings/Mac/Clock Signal/CSApplication.h

@@ -11,20 +11,22 @@
 
 #import <Cocoa/Cocoa.h>
 
-@protocol CSApplicationKeyboardEventDelegate
+@class CSApplication;
-- (void)sendEvent:(nonnull NSEvent *)event;
+
+@protocol CSApplicationEventDelegate
+- (BOOL)application:(nonnull CSApplication *)application shouldSendEvent:(nonnull NSEvent *)event;
 @end
 
 /*!
-	CSApplication differs from NSApplication in only one regard: it supports a keyboardEventDelegate.
+	CSApplication differs from NSApplication in only one regard: it supports an eventDelegate.
 
-	If a keyboardEventDelegate is installed, all keyboard events — @c NSEventTypeKeyUp,
+	If conected, an eventDelegate will be offered all application events prior to their propagation
-	@c NSEventTypeKeyDown and @c NSEventTypeFlagsChanged — will be diverted to it
+	into the application proper. It may opt to remove those events from the queue. This primarily
-	rather than passed through the usual processing. As a result keyboard shortcuts and assistive
+	provides a way to divert things like the command key that will otherwise trigger menu
-	dialogue navigations won't work.
+	shortcuts, for periods when it is appropriate to do so.
 */
 @interface CSApplication: NSApplication
-@property(nonatomic, weak, nullable) id<CSApplicationKeyboardEventDelegate> keyboardEventDelegate;
+@property(nonatomic, weak, nullable) id<CSApplicationEventDelegate> eventDelegate;
 @end
 
 

OSBindings/Mac/Clock Signal/CSApplication.m

@@ -11,27 +11,10 @@
 @implementation CSApplication
 
 - (void)sendEvent:(NSEvent *)event {
-	// The only reason to capture events here rather than at the window or view
+	// Send the event unless an event delegate says otherwise.
-	// is to divert key combinations such as command+w or command+q in the few
+	if(!self.eventDelegate || [self.eventDelegate application:self shouldSendEvent:event]) {
-	// occasions when the user would expect those to affect a running machine
-	// rather than to affect application state.
-	//
-	// Most obviously: when emulating a Macintosh, you'd expect command+q to
-	// quit the application inside the Macintosh, not to quit the emulator.
-
-	switch(event.type) {
-		case NSEventTypeKeyUp:
-		case NSEventTypeKeyDown:
-		case NSEventTypeFlagsChanged:
-			if(self.keyboardEventDelegate) {
-				[self.keyboardEventDelegate sendEvent:event];
-				return;
-			}
-
-		default:
 		[super sendEvent:event];
 	}
-
 }
 
 @end

OSBindings/Mac/Clock Signal/Views/CSOpenGLView.m

@@ -11,7 +11,7 @@
 @import CoreVideo;
 @import GLKit;
 
-@interface CSOpenGLView () <NSDraggingDestination, CSApplicationKeyboardEventDelegate>
+@interface CSOpenGLView () <NSDraggingDestination, CSApplicationEventDelegate>
 @end
 
 @implementation CSOpenGLView {
@@ -140,17 +140,15 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 	return YES;
 }
 
-- (void)propagateKeyboardEvent:(NSEvent *)event {
+- (void)keyDown:(NSEvent *)event {
-	switch(event.type) {
-		default: break;
-
-		case kCGEventKeyDown:
 	[self.responderDelegate keyDown:event];
-		break;
+}
-		case kCGEventKeyUp:
+
+- (void)keyUp:(NSEvent *)event {
 	[self.responderDelegate keyUp:event];
-		break;
+}
-		case kCGEventFlagsChanged:
+
+- (void)flagsChanged:(NSEvent *)event {
 	// Release the mouse upon a control + command.
 	if(_mouseIsCaptured &&
 		event.modifierFlags & NSEventModifierFlagControl &&
@@ -159,24 +157,15 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 	}
 
 	[self.responderDelegate flagsChanged:event];
-		break;
-	}
 }
 
-- (void)keyDown:(NSEvent *)theEvent {
+- (BOOL)application:(nonnull CSApplication *)application shouldSendEvent:(nonnull NSEvent *)event {
-	[self propagateKeyboardEvent:theEvent];
+	switch(event.type) {
+		default: return YES;
+		case NSEventTypeKeyUp:			[self keyUp:event];		return NO;
+		case NSEventTypeKeyDown:		[self keyDown:event];	return NO;
+		case NSEventTypeFlagsChanged:	[self flagsChanged:event];	return NO;
 	}
-
-- (void)keyUp:(NSEvent *)theEvent {
-	[self propagateKeyboardEvent:theEvent];
-}
-
-- (void)flagsChanged:(NSEvent *)theEvent {
-	[self propagateKeyboardEvent:theEvent];
-}
-
-- (void)sendEvent:(NSEvent *)event {
-	[self propagateKeyboardEvent:event];
 }
 
 - (void)paste:(id)sender {
@@ -245,7 +234,7 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 		CGAssociateMouseAndMouseCursorPosition(true);
 		[NSCursor unhide];
 		[self.delegate openGLViewDidReleaseMouse:self];
-		((CSApplication *)[NSApplication sharedApplication]).keyboardEventDelegate = nil;
+		((CSApplication *)[NSApplication sharedApplication]).eventDelegate = nil;
 	}
 }
 
@@ -306,7 +295,7 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 			CGAssociateMouseAndMouseCursorPosition(false);
 			[self.delegate openGLViewDidCaptureMouse:self];
 			if(self.shouldUsurpCommand) {
-				((CSApplication *)[NSApplication sharedApplication]).keyboardEventDelegate = self;
+				((CSApplication *)[NSApplication sharedApplication]).eventDelegate = self;
 			}
 
 			// Don't report the first click to the delegate; treat that as merely