Is there Any way to imitate Lion's Launchpad? - objective-c

Question

I have been struggling to imitate Launchpad.
At the beginning I thought about making NSWindow bgcolor transparent:
//make NSWindow's bgcolor transparent
[window setOpaque:NO];
[window setBackgroundColor:[NSColor clearColor]];
But now I realized it's way more ideal to
capture wallpaper
blur it and make it bg-image for NSWindow or a view
Rather than hiding all the opened windows and menubar, which was the first idea I had have come with (Still not sure with better, if you had any better idea...).
Capture & blur wallpaper used by a user
Make it background image for nswindow or a view
Fade-in to fullscreen view
Click somewhere blank or press ESC to fade-out
Are those possible to achieve without using private APIs?
Sorry if it's not clear my poor English.
Simply I'm trying to imitate Launchpad-styled full screen.
Thanks for any advice.

Answer 1

To get an image of the desktop background, use:
NSURL *imageURL = [[NSWorkspace sharedWorkspace] desktopImageuRLForScreen:[NSScreen mainScreen]
NSImage *theDekstopImage = [[NSImage alloc] initWithContentsOfURL:imageURL];
You can blur the image using CIFilter. Here's a Apple doc describing how to apply filters.
And then you can load that image into a color and set that as the background color for the window. Additionally, set the window to have no style mask (no close buttons, title frame, etc.), cover the screen, and be in front of everything except the dock:
[yourWindow setBackgroundColor:[NSColor colorWithPatternImage:theDesktopImage]];
[yourWindow setStyleMask:NSBorderlessWindowMask];
[yourWindow setLevel:kCGDockWindowLevel - 1];
[yourWindow setFrame:[[NSScreen mainScreen] frame] display:YES];
To have the window fade in, you can use NSWindow's animator proxy. (Replace 1.0 with 0.0 to make it fade out.)
[[yourWindow animator] setAlphaValue:1.0];
Of course you could customize that a bit more with things like CoreAnimation, but this should work just fine.
To handle background clicking, I suggest making a subclass of NSView where you -orderOut: your window on -mouseDown:. Then put an instance of that subclass that spans the entire frame of your window.
Also, NSViews sometimes don't respond to key events, so you can add an event listener to detect any time the escape key is pressed while your app is active:
[NSEvent addLocalMonitorForEventsMatchingMask:NSKeyDownMask handler:(NSEvent *ev)^ {
if([ev keyCode] == 0x53) {
[yourWindow orderOut:self];
}
return ev;
}