CocoaDev

Does anyone know the API to set the string in the “little yellow box” that pops up when the mouse is over a button? I would like to use this “little yellow box” when a row is selected in a table view. –zootbobbalu

The word you’re looking for is “ToolTip”. With that, you should be able to find lots of material.

cool thanks, –zootbobbalu

OK, there is a bunch of disscussion about ToolTips, but I tried to implement this and have not been able to set the tool tip durring a mouseDown: event. I’m going to search the Web, but if someone knows why simply setting a ToolTip string using setToolTip: doesn’t work please post here. –zootbobbalu

OK, here’s what I figured out. After putting this aside for half a day I decided to google “ToolTip NSView” and came up with this:

http://cocoa.mamasam.com/COCOADEV/2003/05/1/63277.php (NOTE: as of 6/2007 this link no longer works)

NSHelpManager *helpManager = [NSHelpManager sharedHelpManager];
NSAttributedString *help = 
    [[[NSAttributedString alloc] initWithString:@"Text For Tip"] autorelease];
[helpManager setContextHelp:help forObject:self];
[helpManager showContextHelpForObject:self locationHint:[NSEvent mouseLocation]];

You have to remove this context help after you are done with it:

NSHelpManager *helpManager = [NSHelpManager sharedHelpManager];
[helpManager removeContextHelpForObject:self];


self in this example is for an NSView subclass. --zootbobbalu

Neat! The ToolTip class I wrote (the bottom one) gives you a bit more control but if I had known about NSHelpManager I probably wouldn’t have bothered. —- The above code to remove the help window does not cause it to go away immediately - the user needs to press the mouse once to dismiss it. I wanted to be able to pop a window when the control key is pressed, and dismiss it when the key is raised. I tried a number of techniques to make the dialog go away, many of which crashed my app ([helpManager release]!).

What I finally did was post a set of (fake) mouse down/up events, and the box disappears. Not really the best solution, but it works.

NSHelpManager *helpManager = [NSHelpManager sharedHelpManager];
[helpManager removeContextHelpForObject:self];
NSEvent	*newEvent;
	
newEvent = [NSEvent mouseEventWithType:NSLeftMouseDown
    location:self window] mouseLocationOutsideOfEventStream]
    modifierFlags:0
    timestamp:0
    windowNumber:[[self window] windowNumber]
    context:[[self window] graphicsContext]
    eventNumber:0
    clickCount:1
    pressure:0
];
[[[NSApp postEvent:newEvent atStart:NO];
newEvent = [NSEvent mouseEventWithType:NSLeftMouseUp
    location:self window] mouseLocationOutsideOfEventStream]
    modifierFlags:0 
    timestamp:0
    windowNumber:[[self window] windowNumber]
    context:[[self window] graphicsContext]
    eventNumber:0
    clickCount:1
    pressure:0
];
[[[NSApp postEvent:newEvent atStart:NO];