I am working on a mac osx application using Xcode. I would like to add a transparent full-screen view/window on top of all applications. So that I could 'draw' on the transparent view, and behind it will be whatever application, safari, word...etc.
I tried like the following
NSRect rect = [[NSScreen mainScreen] frame]; //this is full screen size, but still with the status bar like time, battery, etc.
NSWindow *overlayWindow = [[NSWindow alloc]initWithContentRect:rect
styleMask:NSBorderlessWindowMask
backing:NSBackingStoreBuffered
defer:NO];
overlayWindow.backgroundColor = [NSColor redColor];
[self.window addChildWindow:overlayWindow ordered:NSWindowAbove];
It's a new full-screen child window of my mac-application. But it's not on top of all applications i am running on my mac.
So my question,
How to add the view on top of my mac screen view(not only the top view of my application).
Thanks so much!!!
See Apple's FunkyOverlayWindow sample code. In addition to setting the window's level, you will need to set its background color to clear and set it to non-opaque. If it's transparent but you still want it to receive mouse events for drawing (rather than letting them pass through to the windows behind it), you'll need to do [window setIgnoresMouseEvents:NO].
This looks like what you want.
NSWindow has - (void)setLevel:(NSInteger)windowLevel
With this useful predefined levels. Pick one you like. Add or subtract 1 if you want it just above or just below one of these levels.
#define NSNormalWindowLevel kCGNormalWindowLevel
#define NSFloatingWindowLevel kCGFloatingWindowLevel
#define NSSubmenuWindowLevel kCGTornOffMenuWindowLevel
#define NSTornOffMenuWindowLevel kCGTornOffMenuWindowLevel
#define NSMainMenuWindowLevel kCGMainMenuWindowLevel
#define NSStatusWindowLevel kCGStatusWindowLevel
#define NSModalPanelWindowLevel kCGModalPanelWindowLevel
#define NSPopUpMenuWindowLevel kCGPopUpMenuWindowLevel
#define NSScreenSaverWindowLevel kCGScreenSaverWindowLevel
#define NSDockWindowLevel kCGDockWindowLevel
My problem was just because I didn't set the self.window to the top layer. Then I add a childview(set to the top) to the self.window. It does nothing if I only set childview to top.
Ken and Steve's answers have reasons. Thanks a lot.
