手动使NSPanel / NSWindow退出密钥或不成为密钥

Question

I'm trying to create a virtual keyboard in Objective-C/Cocoa/OS X. The keyboard-window is a HUD-panel. How can I make that the panel doesn't become key if I click on the keyboard?

I already tried the following approach in the - (void)windowDidBecomeKey:(NSNotification *)notification -method (which get's called), but it doesn't work:

NSDisableScreenUpdates();
[_window orderOut:self];
[_window orderFront:self]; // Not asking it to be key
NSEnableScreenUpdates();

And the same with nil instead of self . Any ideas?

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Edit 1: I've tried to set the properties like this and this works but destroys the HUD-style:

[_window setStyleMask:NSHUDWindowMask | NSNonactivatingPanelMask];

If I do this the HUD-style is there again but also the window becomes key again:

[_window setStyleMask:NSHUDWindowMask | NSTitledWindowMask | NSNonactivatingPanelMask];

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Edit 2: Now I've also tried subclassing and added the following code to KeyboardPanel.m:

- (BOOL)canBecomeKeyWindow {
    return NO;
}

Now NSLog(@"Can become key window: %hhd", _window.canBecomeKeyWindow) returns 0 , but the panel becomes key nevertheless...

Answer 1

Use an NSPanel and set its becomesKeyOnlyIfNeeded property to true. You probably also want to use NSNonactivatingPanelMask in the style mask for the panel.

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Update:

Since you never want to let the panel become key, you can simply use a custom subclass which overrides -canBecomeKeyWindow to return false:

- (BOOL) canBecomeKeyWindow
{
    return NO;
}