Objective-c – How to change the state of the window close button in Cocoa

cocoaobjective c

In Cocoa Applications, you often see a little red dot in the window's close button when you have unsaved data; TextEdit is a good example of this. I've pored through the Cocoa documentation but I can't find a way to programmatically set this state. I'm sure there's some really easy way to do it, but obviously I'm missing something.

Best Answer

To set it programmatically, you can use the -setDocumentEdited: method of NSWindow. If you are writing a Document-based app, NSDocumentManager should automatically detect when there are unsaved changes to the NSUndoManager associated with the current NSDocument.

Related Solutions

Objective-c – How to print out a stack trace to the console/log in Cocoa

This code works on any thread:

NSLog(@"%@", NSThread.callStackSymbols);

Returns an array containing the call stack symbols. Each element is an NSString object with a value in a format determined by the backtrace_symbols() function.

Ios – Constants in Objective-C

You should create a header file like

// Constants.h
FOUNDATION_EXPORT NSString *const MyFirstConstant;
FOUNDATION_EXPORT NSString *const MySecondConstant;
//etc.

(you can use extern instead of FOUNDATION_EXPORT if your code will not be used in mixed C/C++ environments or on other platforms)

You can include this file in each file that uses the constants or in the pre-compiled header for the project.

You define these constants in a .m file like

// Constants.m
NSString *const MyFirstConstant = @"FirstConstant";
NSString *const MySecondConstant = @"SecondConstant";

Constants.m should be added to your application/framework's target so that it is linked in to the final product.

The advantage of using string constants instead of #define'd constants is that you can test for equality using pointer comparison (stringInstance == MyFirstConstant) which is much faster than string comparison ([stringInstance isEqualToString:MyFirstConstant]) (and easier to read, IMO).

Best Answer

Related Solutions

Objective-c – How to print out a stack trace to the console/log in Cocoa

Ios – Constants in Objective-C

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