[Openmcl-devel] Errors Creating NSTimer

Gary Byers gb at clozure.com
Wed Oct 24 05:20:17 UTC 2007


The first argument to any ObjC method should be the "receiver" (the
object - instance (usually) or class (sometimes) - that might implement
a method on the message.  If this were CLOS, we might call the receiver
the first and only specialized parameter.)

In the case of
#/scheduledTimerWithTimeInterval:target:selector:userInfo:repeats:,
the receiver is the class "NSTimer" (which happens to be the value
of the variable NS:NS-TIMER.)  The bridge is complaining because
the first argument in your calls below either isn't a pointer at
all or isn't a pointer to an ObjC class or instance; getting a lisp-level
error like that is probably better than trying to send a message to
0.01d0 ...


On Tue, 23 Oct 2007, Brent Fulgham wrote:

> I'm trying to get the right Cocoa bridge syntax for calling:
>
> scheduledTimerWithTimeInterval:target:selector:userInfo:repeats:
> Returns a new NSTimer object and adds it to the current NSRunLoop object in 
> the default mode.
>
> + (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)seconds 
> target:(id)target selector:(SEL)aSelectoruserInfo:(id)userInfo 
> repeats:(BOOL)repeats
>
> NSTimeInterval is just a typedef to double, so I thought that I could just 
> pass the double value to the function, since this is how many of the example 
> Objective C programs are written, but this does not work for a variety of 
> reasons:
>
> 1.  If I attempt to simply use a bare double, it's not happy:
>
>  (let* ((TimerInterval (ccl::%double-float 0.01)))
>            (Timer 
> (#/scheduledTimerWithTimeInterval:target:selector:userInfo:repeats: 
> TimeInterval (cocoa-view self) (objc:@selector #/animate) (ccl::%null-ptr) 
> #$YES)))
>
>> Error: value 0.009999999776482582D0 is not of the expected type MACPTR.
>> While executing: CCL::SEND-UNAMBIGUOUS-MESSAGE, in process listener(1).
>
> 2.  If I attempt to use an RLET to allocate the C Type, it's still not happy:
>
> (rlet ((TimeInterval :<NST>ime<I>nterval (ccl::%double-float 0.01)))
>   (let* (
>          (Timer 
> (#/scheduledTimerWithTimeInterval:target:selector:userInfo:repeats: 
> TimeInterval (cocoa-view self) (objc:@selector #/animate) (ccl::%null-ptr) 
> #$YES))))
>     ;; add myself to list
>     (pushnew Self (animated-views Self))))
>
>> Error: value #<A Foreign Pointer [stack-allocated] (:* DOUBLE-FLOAT) 
>> #xB029BE70> is not of the expected type OBJC:OBJC-OBJECT.
>> While executing: CCL::SEND-UNAMBIGUOUS-MESSAGE, in process listener(1).
>
> I vaguely remember a mechanism to convert native C types to Cocoa analogs, 
> but I cannot find documentation of this, and may be mixing Objective C up 
> with something up.
>
> What's the correct way to deal with this particular API call?
>
> Thanks,
>
> -Brent



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