Re: NSButton "reveals" keyboard shortuct [SOLVED]

FROM : Pierre Bernard
DATE : Wed Apr 23 20:48:03 2008

Answering part 1 of my own question: revealing the keyboard shortcut 
once the command key is pressed. C.f. below for the code

What remains is the second part: how does NSButton implement keyboard 
shortcuts. How would I implement and additional shortcut for a button 
which already has one.

Best,
Pierre Bernard
Houdah Software s.à r.l.



extern NSUInteger carbonToCocoaModifierFlags(UInt32 
carbonModifierFlags);
extern NSString *stringForCocoaModifierFlagsAndKeyCode(NSUInteger 
flags, NSString *keyEquivalent);


@implementation HHShortcutButton

@synthesize baseTitle;

- (id)initWithCoder:(NSCoder*)coder
{
    if ((self = [super initWithCoder:coder]) != nil) {
       [self setBaseTitle:[self title]];
   }
   
    return self;
}

- (void)viewDidMoveToWindow
{
   [super viewDidMoveToWindow];
   
   NSWindow *window = [self window];
   
   if (window != nil) {
       [[NSNotificationCenter defaultCenter] addObserver:self 
selector:@selector(windowDidUpdate:) 
name:NSWindowDidUpdateNotification object:window];
   }
}

- (void)setTitle:(NSString*)aTitle
{
   [super setTitle:aTitle];
   
   [self setBaseTitle:[self title]];
}

- (void)windowDidUpdate:(NSNotification*)notification
{
   if (GetCurrentEventKeyModifiers() & cmdKey) {
       NSString *keyEquivalent = [self keyEquivalent];
       NSUInteger keyEquivalentModifierMask = [self 
keyEquivalentModifierMask];
       
       [super 
setTitle:stringForCocoaModifierFlagsAndKeyCode
(keyEquivalentModifierMask, keyEquivalent)];
   }
   else {
       [super setTitle:[self baseTitle]];
   }
}

@end

extern NSUInteger carbonToCocoaModifierFlags(UInt32 carbonModifierFlags)
{
   NSUInteger cocoaModifierFlags = 0;
   
   if (carbonModifierFlags & shiftKey) {
       cocoaModifierFlags |= NSShiftKeyMask;
   }
   
   if (carbonModifierFlags & cmdKey) {
       cocoaModifierFlags |= NSCommandKeyMask;
   }
   
   if (carbonModifierFlags & optionKey) {
       cocoaModifierFlags |= NSAlternateKeyMask;
   }
   
   if (carbonModifierFlags & controlKey) {
       cocoaModifierFlags |= NSControlKeyMask;
   }
   
   return cocoaModifierFlags;
}

extern NSString *stringForCocoaModifierFlagsAndKeyCode(NSUInteger 
flags, NSString *keyEquivalent)
{
    return [NSString stringWithFormat:@"%@%@%@%@%@",
           (flags & NSCommandKeyMask ? [NSString stringWithFormat:@"%C + ", 
kCommandUnicode] : @""),
           (flags & NSAlternateKeyMask ? [NSString stringWithFormat:@"%C + ", 
kOptionUnicode] : @""),
           (flags & NSControlKeyMask ? [NSString stringWithFormat:@"%C + ", 
kControlUnicode] : @""),
           (flags & NSShiftKeyMask ? [NSString stringWithFormat:@"%C + ", 
kShiftUnicode] : @""),
           [keyEquivalent uppercaseString]];
}



On 22 Apr 2008, at 17:48, Pierre Bernard wrote:

> Hi!
>
> I love how the buttons in some "save before closing" sheets reveal 
> themselves by being added to the button name when the command key is 
> held for a while.
> The one example I can think of is AppleWorks 6. Wish all apps / 
> buttons had that.
>
> Is this a Carbon thing?
>
> How would I go about to implement this?
> Seeing that the button in question is not in the responder chain, I 
> guess the implementation ought to be moved to the window or window 
> controller. This doesn't strike me as the best place. I'd rather 
> have a reusable NSButton subclass.
>
> Such buttons also may have multiple shortcuts. E.g. the default save 
> button is triggered by both Enter and cmd-S. This does not seem to 
> be possible with NSButton. Again I wonder if I should override 
> keyDown: in my window controller.
>
> BTW, how are keyboard shortcuts on NSButtons implemented? Do they 
> somehow register with the window for events or does the window walk 
> the subcomponents to find one which may respond?
>
> Best,
> Pierre
>
> ---
> Pierre Bernard
> http://www.bernard-web.com/pierre
> http://www.houdah.com
>
>
>
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---
Pierre Bernard
http://www.bernard-web.com/pierre
http://www.houdah.com