macOS Making a window fade in and out?

[Blakeasd]

I am following a book and it gives me this code:

-(IBAction)displayOrCloseWindow:(id)sender {
	//Fades in & out nicely
	if(isOpen) {
		[[self animator] setAlphaValue:0.0];
		isOpen = NO;
	}
	else {
		[[NSApplication sharedApplication] activateIgnoringOtherApps:YES];
		[self makeKeyAndOrderFront:self];
		[[self animator] setAlphaValue:1.0];
		isOpen = YES;
	}
}

It gives me an error when compiling it? Can anyone help?

 

[chown33]

Post the exact error message text.

 

[gnasher729]

I am following a book and it gives me this code:

It gives me an error when compiling it? Can anyone help?

Yes, the compiler. Read the error message. What does it say?

 

[Blakeasd]

The error is: 'isOpen' undeclared (first use in this function)

 

[chown33]

What is the book? Be specific.


Post the code that defines the @interface for the class containing displayOrCloseWindow:.

If there isn't an isOpen instance variable, and there isn't one in a superclass, then you have the reason for the error: there is no variable named isOpen.

If the @interface does define an isOpen instance variable, make sure it's spelled exactly the same, including case.

 

[gnasher729]

The error is: 'isOpen' undeclared (first use in this function)

That explains it. The compiler tells you exactly what is wrong: You haven't declared "isOpen". Where did you think you declared it? Did you spell it wrong?

 

[Blakeasd]

The interface didn't declare anything. Does anyone know how to make a window fade in and out with out this book? Thanks

 

[GorillaPaws]

I think this article is a good place to start.

 

[gnasher729]

The interface didn't declare anything. Does anyone know how to make a window fade in and out with out this book? Thanks

Well, you know how to fix it then. The sample code gives you the essential steps (most importantly use [self animator]), and you are supposed to fill out the rest. Could it be that your question is not really how to make a window fade in and out, but how to write a Cocoa application?

 

[chown33]

The interface didn't declare anything. Does anyone know how to make a window fade in and out with out this book? Thanks

Which book? You haven't told us a title or author yet.


When I google the code snippet, I only find this:
http://dbachrach.com/blog/2008/01/cocoa-code-snippet-simple-window-fade-inout/

That's not a book, as far as I can tell. The article even says you have to define an isOpen instance variable.

 

[Blakeasd]

Whoops

Sorry about that I didn't see the part at the bottom telling my to add an instance variable. Sometimes I get so excited when I see the code I forget to read on It works now, thanks!

 

[chown33]

I'm glad it works, but I'm still puzzled why you said the code was from "following a book".

What book?