mouse moved events are not detected by NSView

Question

I am trying to make a simple application in which there is a empty red rectangle and whenever the mouse is moved over the upper half border of the rectangle the cursor will become closed hand.

I started with selecting the foundation command line project.Made a transparent NSWindow and embedded a NSView in it with the rectangle, made window to accept mouse moved events(by method: -setAcceptsMouseMovedEvents). I have overridden -canBecomeKeyWindow and -canBecomeMainWindow window to return YES. But somehow none of the -mouseMoved events are being received by NSView.

When I put the same code by making a cocoa application project and creating my window in -applicationDidFinishLaunching method , my view was able to receive -mouseMoved events.

why is it not receiving mouse moved events when I use foundation command line utility project ?

I have also observed that whenever I make a window(carbon or cocoa) through foundation cmd line utility project , the window doesn't become key even on clicking the title bar.On clicking the title bar color remains light grey instead of becoming dark grey. Why is this happening?

I have overridden -canBecomeKeyWindow and -canBecomeMainWindow of NSwindow to return YES.

Answer 1

I would agree with what Joshua has already said. Any application that is going to show a user interface, be it a faceless background process or one which shows up in the Dock, should be in the form of an application bundle, not a plain old Mach-O executable like the Foundation tool template will create.

Also, there are reasons why views do not respond to mouseMoved: events by default:

1. Mouse moved events can quickly flood the event queue
2. There is generally little reason to use mouseMoved:, as tracking areas are far more effective and efficient.

A while back, I wrote a little test app that demonstrates the differences between these 2 approaches:

Moving your mouse around the upper view for roughly 20 seconds results in 1000 events, while in the lower view, which uses tracking areas, less than 50.

Sample GitHub project: https://github.com/NSGod/MouseMoved-vs-TrackingAreas

Again, as Joshua mentioned, it would be helpful if you could describe what you're trying to accomplish. If your app needs to be a background app (LSUIElement == 1), and present an interface without appearing in the Dock, then there are ways to do that (as Josh mentioned, a command-line, non-bundled app is not the way).

Answer 2

You have no event loop to detect events and pass them to your window because your program does not start an NSApplication. See the main.m file of a typical Cocoa application.

It might be helpful to describe what you're trying to accomplish by taking this approach. My guess is you're building a daemon but want a GUI interface to manage the otherwise "headless" daemon. That or you're building a new login management system. In either case, there are specific ways to do both and this isn't it. :-)