From 8f88addf9ff800c8cd83d2451cd7b091b63ee493 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sun, 22 Sep 2019 13:15:35 -0400
Subject: [PATCH] Establishes an interface for requesting shortcut theft. Not
 yet implemented.

---
 .../Mac/Clock Signal/Views/CSOpenGLView.h     | 14 +++++++
 .../Mac/Clock Signal/Views/CSOpenGLView.m     | 41 ++++++++++++++-----
 2 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.h b/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.h
index 8437bb999..25920e578 100644
--- a/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.h	
+++ b/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.h	
@@ -110,8 +110,22 @@ typedef NS_ENUM(NSInteger, CSOpenGLViewRedrawEvent) {
 @property (atomic, weak, nullable) id <CSOpenGLViewDelegate> delegate;
 @property (nonatomic, weak, nullable) id <CSOpenGLViewResponderDelegate> responderDelegate;
 
+/// Determines whether the view offers mouse capturing — i.e. if the user clicks on the view then
+/// then the system cursor is disabled and the mouse events defined by CSOpenGLViewResponderDelegate
+/// are forwarded, unless and until the user releases the mouse using the control+command shortcut.
 @property (nonatomic, assign) BOOL shouldCaptureMouse;
 
+/// Determines whether the CSOpenGLViewResponderDelegate of this window expects to use the command
+/// key as though it were any other key — i.e. all command combinations should be forwarded to the delegate,
+/// not being allowed to trigger regular application shortcuts such as command+q or command+h.
+///
+/// How the view respects this will depend on other state; if this view is one that captures the mouse then it
+/// will usurp command only while the mouse is captured.
+///
+/// TODO: what's smart behaviour if this view doesn't capture the mouse? Probably
+/// force a similar capturing behaviour?
+@property (nonatomic, assign) BOOL shouldUsurpCommand;
+
 /*!
 	Ends the timer tracking time; should be called prior to giving up the last owning reference
 	to ensure that any retain cycles implied by the timer are resolved.
diff --git a/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.m b/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.m
index 697aa138c..c57c05dfb 100644
--- a/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.m	
+++ b/OSBindings/Mac/Clock Signal/Views/CSOpenGLView.m	
@@ -7,10 +7,11 @@
 //
 
 #import "CSOpenGLView.h"
+#import "CSApplication.h"
 @import CoreVideo;
 @import GLKit;
 
-@interface CSOpenGLView () <NSDraggingDestination>
+@interface CSOpenGLView () <NSDraggingDestination, CSApplicationKeyboardEventDelegate>
 @end
 
 @implementation CSOpenGLView {
@@ -139,23 +140,43 @@ static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeSt
 	return YES;
 }
 
+- (void)propagateKeyboardEvent:(NSEvent *)event {
+	switch(event.type) {
+		default: break;
+
+		case kCGEventKeyDown:
+			[self.responderDelegate keyDown:event];
+		break;
+		case kCGEventKeyUp:
+			[self.responderDelegate keyUp:event];
+		break;
+		case kCGEventFlagsChanged:
+			// Release the mouse upon a control + command.
+			if(_mouseIsCaptured &&
+				event.modifierFlags & NSEventModifierFlagControl &&
+				event.modifierFlags & NSEventModifierFlagCommand) {
+				[self releaseMouse];
+			}
+
+			[self.responderDelegate flagsChanged:event];
+		break;
+	}
+}
+
 - (void)keyDown:(NSEvent *)theEvent {
-	[self.responderDelegate keyDown:theEvent];
+	[self propagateKeyboardEvent:theEvent];
 }
 
 - (void)keyUp:(NSEvent *)theEvent {
-	[self.responderDelegate keyUp:theEvent];
+	[self propagateKeyboardEvent:theEvent];
 }
 
 - (void)flagsChanged:(NSEvent *)theEvent {
-	[self.responderDelegate flagsChanged:theEvent];
+	[self propagateKeyboardEvent:theEvent];
+}
 
-	// Release the mouse upon a control + command.
-	if(_mouseIsCaptured &&
-		theEvent.modifierFlags & NSEventModifierFlagControl &&
-		theEvent.modifierFlags & NSEventModifierFlagCommand) {
-		[self releaseMouse];
-	}
+- (void)sendEvent:(NSEvent *)event {
+	[self propagateKeyboardEvent:event];
 }
 
 - (void)paste:(id)sender {