Radio buttons without using NSMatrix

Question

In the AppKit release notes for OS X 10.10, Apple wrote:

Use of NSMatrix is informally deprecated. We expect to add the formal deprecation macros in a subsequent release, but its use is discouraged in the mean time. The primary use of NSMatrix is for radio button groups, so recall that for applications linked on 10.8 or later, radio buttons that share the same parent view and action will operate as a group.

Which is all well and good, but managing a radio group is annoying when using standalone buttons.

I searched for suggestions from others on how to handle this, to avoid having to set the state for each button separately, find the selected radio, etc, but couldn't find much discussion of it. I guess most people are waiting for Apple to formally deprecate NSMatrix, and hopefully provide a better mechanism.

Answer 1

So, answering my own question, I added some methods to my DejalAppKitCategories open source project to make this easier, and thought I'd share here for anyone else who wants to avoid NSMatrix now.

Here's the header:

@interface NSButton (DejalRadios)

@property (nonatomic, setter=dejal_setRadiosEnabled:) BOOL dejal_radiosEnabled;

- (void)dejal_selectRadioWithTag:(NSInteger)tag;
- (NSInteger)dejal_selectedRadioTag;

- (NSButton *)dejal_radioPassingTest:(BOOL (^)(NSButton *radio, BOOL *stop))predicate;
- (void)dejal_enumerateRadiosUsingBlock:(void (^)(NSButton *radio, BOOL *stop))block;

@end

And the implementation:

@implementation NSButton (DejalRadios)

/**
Assuming the receiver is a radio button, finds other radio buttons in the group (i.e. in the same superview and with the same action) and selects the one with the specified tag.  Invoke this on any of the radios in the group.  A replacement for -[NSMatrix selectCellWithTag:].

@param tag The tag value to select.

@author DJS 2015-01.
*/

- (void)dejal_selectRadioWithTag:(NSInteger)tag;
{
    [self dejal_enumerateRadiosUsingBlock:^(NSButton *radio, BOOL *stop)
     {
         radio.state = radio.tag == tag;
     }];
}

/**
Assuming the receiver is a radio button, finds other radio buttons in the group (i.e. in the same superview and with the same action) and returns the tag value of the selected radio.  Invoke this on any of the radios in the group.  A replacement for -[NSMatrix selectedTag].

@returns A tag value integer.

@author DJS 2015-01.
*/

- (NSInteger)dejal_selectedRadioTag;
{
    NSButton *foundRadio = [self dejal_radioPassingTest:^BOOL(NSButton *radio, BOOL *stop)
     {
         return radio.state;
     }];

    return foundRadio.tag;
}

/**
Returns YES if the radio group is enabled, or NO if not.  Simply returns the state of the receiver; the others are assumed to be the same.  (If you want to know if they are all enabled or disabled, probably best to use -dejal_enumerateRadiosUsingBlock: to scan the group, and handle a mixed case as needed.)

@author DJS 2015-01.
*/

- (BOOL)dejal_radiosEnabled;
{
    return self.enabled;
}

/**
Sets all of the radios in the group to be enabled or disabled.  A replacement for -[NSMatrix setEnabled:].

@author DJS 2015-01.
*/

- (void)dejal_setRadiosEnabled:(BOOL)enabled;
{
    [self dejal_enumerateRadiosUsingBlock:^(NSButton *radio, BOOL *stop)
     {
         radio.enabled = enabled;
     }];
}

/**
Assuming the receiver is a radio button, finds other radio buttons in the group (i.e. in the same superview and with the same action) and performs the block for each of them, passing the radio to the block.  Returns the one that returns YES, or nil if the block requests to stop before completion, or it completes without the block returning YES.  Invoke this on any of the radios in the group.

@param block A block that takes a radio button and stop boolean reference as parameters and returns a boolean.
@returns The found radio button, or nil if none is found.

@author DJS 2015-01.
*/

- (NSButton *)dejal_radioPassingTest:(BOOL (^)(NSButton *radio, BOOL *stop))predicate;
{
    for (NSButton *radio in self.superview.subviews)
    {
        // There's no reliable way to determine if a button is actually a radio button, but it's reasonable to assume that no non-radio will have the same action (and having the same action is what makes it a member of the group):
        if ([radio isKindOfClass:[NSButton class]] && radio.action == self.action && predicate)
        {
            BOOL stop = NO;

            if (predicate(radio, &stop))
            {
                return radio;
            }

            if (stop)
            {
                return nil;
            }
        }
    }

    return nil;
}

/**
Assuming the receiver is a radio button, finds other radio buttons in the group (i.e. in the same superview and with the same action) and performs the block for each of them, passing the radio to the block.  Invoke this on any of the radios in the group.

@param block A block that takes a radio button and stop boolean reference as parameters and returns void.

@author DJS 2015-01.
*/

- (void)dejal_enumerateRadiosUsingBlock:(void (^)(NSButton *radio, BOOL *stop))block;
{
    for (NSButton *radio in self.superview.subviews)
    {
        // There's no reliable way to determine if a button is actually a radio button, but it's reasonable to assume that no non-radio will have the same action (and having the same action is what makes it a member of the group):
        if ([radio isKindOfClass:[NSButton class]] && radio.action == self.action && block)
        {
            BOOL stop = NO;

            block(radio, &stop);

            if (stop)
            {
                return;
            }
        }
    }
}

@end

To use these methods, simply invoke on any of the radios in the group, e.g.

[self.iconNoneRadio dejal_selectRadioWithTag:self.statusIconKind];
self.iconNoneRadio.dejal_radiosEnabled = use;

And:

- (IBAction)chooseIcon:(id)sender;
{
    self.statusIconKind = self.iconNoneRadio.dejal_selectedRadioTag;

    [self maintainControls];
}

I hope this helps others! And, of course, if I'm missing anything obvious, or you have any suggestions or comments, please let me know.