Panel Visible OK on Nib Load but cannot be made visible from toolbar click

Question

I have a MacOS Objective C project in Xcode with two Nib files. In the second Nib I have an NSPanel object. I have created an outlet for it as shown below:

@property (weak) IBOutlet NSPanel *Settings;

If I check "Visible at launch" in the Identity inspector it appears at launch. However if I uncheck this option and try and make it visible from a toolbar item click using the action from the toolbar click as follows:

- (IBAction)SettingsClick:(id)sender {
[_Settings setIsVisible:true];}

the panel does not become visible. I've also tried the code

[self.Settings makeKeyAndOrderFront: self];

in the action but this does not result in the panel becoming visible either.

If I make the panel visible at launch, closing it closes the second Nib-defined window as well.

Answer 1

If change the way the second Nib is displayed from

[[self loadWithNibNamed:@"ImageSplit" owner:self ] display];

to

[[self loadWithNibNamed:@"ImageSplit" owner:self ] setNeedsDisplay:true];

then the toolboxitem action

[self.Settings makeKeyAndOrderFront: self];

shows the Settings panel OK when the toolbox item is clicked the first time. However, if the second Nib is closed and re-opened, clicking on the toolbar item does not show the Settings panel. Also the panel does not always appear - sometimes a Clean Build folder is required, sometimes more than once so the problem is still not solved.