NSAlert Close Alert Programmatically when using beginSheetModalForWindow: - cocoa

Question

I'm trying to close a modal alert sheet programmatically when called like this:
[alert beginSheetModalForWindow:contacts modalDelegate:self didEndSelector:#selector(myAlertEnded:code:context:) contextInfo:NULL];

Answer 1

I had the same issue and I solved this way.
To launch the sheet:
[myAlertSheet beginSheetModalForWindow:self.view.window modalDelegate:self didEndSelector:#selector(showAlertDidEnd: returnCode: contextInfo:) contextInfo:nil];
To programmatically close the modal sheet:
[NSApp endSheet:[myAlertSheet window]];
myAlertSheet is an NSAlert instance variable to keep track of the modal sheet on-screen. The endSheet message then calls the selector:
- (void)showAlertDidEnd:(NSAlert *)alert returnCode:(int)returnCode contextInfo:(void *)contextInfo
{...}
I hope the above is useful

Answer 2

You'd have a method like this in your controller (the modalDelegate):
- (IBAction) cancelClicked: (id) sender {
// Cancel the sheet and close.
[NSApp endSheet: [self window]];
}
... which would be wired to a Cancel button in the modal sheet (or to an OK button for that matter but that would probably invoke some spin-off processing).
You also need to implement this didEndSelector to actually remove the sheet:
- (void) didEndSheet: (id) modalSheet returnCode: (NSInteger) returnCode contextInfo: (void*) contextInfo {
// Remove the sheet.
[modalSheet orderOut: nil];
}
If I remember correctly I scooped this from an example in the Apple docs.

Answer 3

In NSWindow you'll find a method called attachedSheet. It yields a reference to a sheet attached to this window, if any. The sheet itself is also simply a NSWindow. Therefore, you might want to try this:
NSWindow *window = [NSApp mainWindow];
[[window attachedSheet] close];

Answer 4

The way I found it we need to both endSheet(alert.window) and alert.window.close().
let hostWindow = contacts
// Dismiss the sheet. Yet its window will stay on screen.
// .endSheet(:) will yield NSApplication.ModalResponse.stop
hostWindow.endSheet(alert.window)
// Close the alert window.
alert.window.close()
OR
let hostWindow = contacts
alert.beginSheetModal(for: hostWindow) { response in
switch response {
case .stop: alert.window.close()
default: fatalError("TODO")
}
}
// Later... Dismiss the sheet.
// .endSheet(:) will yield NSApplication.ModalResponse.stop
hostWindow.endSheet(alert.window)
Using NSAlert.runModal() we need instead:
let response = alert.runModal()
switch response {
case .stop: break
default: fatalError("TODO")
}
// Later... Dismiss the NSApp.modalWindow
// stopModal() will yield NSApplication.ModalResponse.stop
NSApp.stopModal()