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I'm making a GUI API (for video games, not an OS) and would like to put into action animated buttons. I'd like to be capable to create timed events, but, within the course.illustration:
Therefore in this instance, the timer would call the class example's changeColor functionality, with argument reddish, after 30 ms. Will be there a method to perform this?
Generally, a function to call a function, which could end up being a function from a instancable course, wit n arguments, after a given period of time has ended.
The precision of the timer is usually not a large offer for me.
Thanks
jmasterx
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2 Answers
I think you could make this work portably making use of Boost.Asio - this is definitely primarily developed for async I/U but I notice no cause why the timer program code cannot become used in various other contexts. See this instance for how to give up off a timer which calls back again your program code after expiration.
The only proviso I observed is usually that you have got to call
ioservice::run
in some line with the ioservice instance you used here, or the callbacks will not really happen.There is certainly furthermore a dialogue of this quite topic on MSDN sites here by the writer of the library.
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I'd welcome anybody showing usually, but simply because significantly as I understand, you'm require to deal with this in steps. The very first step will be to generate a sure function - i.e., get the function you state, and generate an item that, when you invoke it, in convert invokes the specified function with the given parameters. Using Boost/TR1/C0x
bind
, that much would look something like this:That makes
func
an object that will invokeTextBox::changeColor(crimson)
when it'beds known as. There can be one minimal problem with this though:func
is certainly an object, not actually a functionality. Syntactically, using it appears like phoning a functionality, but that's an illusion developed by the D compiler; attempting to complete that object's tackle to something that will use it as the address of a function will fail (possibly pretty spectacularly). Sadly, at least in Windows, there's no way to specify an arbitrary parameter that will end up being exceeded to a timer callback function (though you couldpossiblymanage to perform it in thenIdEvent
parameter with some actually gross spreading, something like:To create this a bit cleaner, instead of sending your line the deal with to an unsigned integer, I'd think about conserving the deal with of the callback in an selection, and transferring its index in the variety rather:
That leaves theactuallynon-portable component: really getting the program to invoke that function after the right duration of time. Though most modern techniques have got one, each will be still unique. Under Home windows (for 1 example) you could perform something like this:
For such a easy concept, that's all as well unappealing and complicated an solution, but I truthfully put on't know of anything significantly less complex that'll work. If you have got almost any reasonable selection in the matter, I'd use something else. Also take note that this is usually really a stream-of-consciousness design - none of the program code has ended up compiled, much less actually tested. I can't observe a great reason the general idea shouldn't function, but it might take a fair quantity of effort to skin it out to something that really does (e.g., I've mainly neglected administration of the 'callbackfunctions' selection).
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