1. Eu2.1: get_key(): how know when RELEASED
Anyone know how I can tell when a key is RELEASED? As far as I can tell,
get_key returns a bunch of -1's even when a key IS pressed, and tosses in
the actual key pressed every once and a while; it does that fast enough &
often enough to allow "if get_key() != -1" to pick up the sporadic instance
of not -1 when it occurs, but makes an "else =-1" not able to signify no
key pressed, because of all the -1's spit out along even when an actual key
is pressed.
Am I misunderstanding something here?
Dan
2. Re: Eu2.1: get_key(): how know when RELEASED
On Sat, 26 Aug 2000, Dan wrote:
> Anyone know how I can tell when a key is RELEASED? As far as I can tell,
> get_key returns a bunch of -1's even when a key IS pressed, and tosses in
> the actual key pressed every once and a while; it does that fast enough &
> often enough to allow "if get_key() != -1" to pick up the sporadic instance
> of not -1 when it occurs, but makes an "else =-1" not able to signify no
> key pressed, because of all the -1's spit out along even when an actual key
> is pressed.
>
> Am I misunderstanding something here?
Only in that the key _isn't_ pressed, even if you're sitting on it, if you have
keyboard repeat turned on. The repeat function "releases" and "presses" the key
a few times a second as long as you hold the key down.
That's why you get the key val, followed by -1's, then the key, etc.
I think (someone will correct me if I'm wrong) you'll have to go to a lower
level (dos interrupts) to get a key-release code. Will that work without
turning off the auto-repeat ?
Irv
3. Re: Eu2.1: get_key(): how know when RELEASED
from keyread.e in the archive:
-- Here's an extremely useful library routine for reading the keyboard.
-- It is used just like get_key(), except that it's called get_keys(),
-- it returns a sequence instead of an atom, and the values returned are
-- scan codes, instead of ASCII codes.
-- The advantage is that the routine will recognize multiple keypresses
-- at the same time, and return them in one sequence.
-- Also, there is no repeat delay, instead the code is returned constantly
-- until the key is released.
-- Finally, the routine is also some 10-20 times faster than get_key()
-- Regards,
-- Michael Bolin
-- June 1997
hope this helps, Hawke'
----- Original Message -----
From: irv <irv at ELLIJAY.COM>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Saturday, August 26, 2000 2:26 PM
Subject: Re: Eu2.1: get_key(): how know when RELEASED
> On Sat, 26 Aug 2000, Dan wrote:
> > Anyone know how I can tell when a key is RELEASED? As far as I can
tell,
> > get_key returns a bunch of -1's even when a key IS pressed, and tosses
in
> > the actual key pressed every once and a while; it does that fast enough
&
> > often enough to allow "if get_key() != -1" to pick up the sporadic
instance
> > of not -1 when it occurs, but makes an "else =-1" not able to signify
no
> > key pressed, because of all the -1's spit out along even when an actual
key
> > is pressed.
> >
> > Am I misunderstanding something here?
>
> Only in that the key _isn't_ pressed, even if you're sitting on it, if you
have
> keyboard repeat turned on. The repeat function "releases" and "presses"
the key
> a few times a second as long as you hold the key down.
>
> That's why you get the key val, followed by -1's, then the key, etc.
>
> I think (someone will correct me if I'm wrong) you'll have to go to a
lower
> level (dos interrupts) to get a key-release code. Will that work without
> turning off the auto-repeat ?
>
> Irv
>
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4. Re: Eu2.1: get_key(): how know when RELEASED
Irv, Hawke,
Thanks, but although I haven't yet tried it, I think I found a solution to
my problem, & it's real simple if it works: since my intention was to have
get_key() set a variable one way or another depending on whether a
particular key was pressed or not (including "not pressed" because it had
been *released*), (and I didn't really *ask* my question in that form, like
I should have!), it would seem that all I have to do is use the simple idea
of...INITIAL CONDITION to set my responding variable to what I want it to be
*if the key ISN'T pressed*, and then let it get changed by get_key if it IS
pressed. That should do it just fine. Sigh.
Dan
--------------------------------------------------------------------
On Sat, 26 Aug 2000, Dan wrote:
> Anyone know how I can tell when a key is RELEASED? As far as I can tell,
> get_key returns a bunch of -1's even when a key IS pressed, and tosses in
> the actual key pressed every once and a while; it does that fast enough &
> often enough to allow "if get_key() != -1" to pick up the sporadic
instance
> of not -1 when it occurs, but makes an "else =-1" not able to signify no
> key pressed, because of all the -1's spit out along even when an actual
key
> is pressed.
>
> Am I misunderstanding something here?
----------------------------------------------------------------------------
<and Irv wrote:>
>>Only in that the key _isn't_ pressed, even if you're sitting on it, if you
have keyboard >>repeat turned on. The repeat function "releases" and
"presses" the key
>>a few times a second as long as you hold the key down.
>>That's why you get the key val, followed by -1's, then the key, etc.
Yes, that did *finally* dawn on me after I saw how similar the quantity of
returned -1's were when key was held down!
>>I think (someone will correct me if I'm wrong) you'll have to go to a
lower
>>level (dos interrupts) to get a key-release code. Will that work without
>>turning off the auto-repeat ?
I considered that, with horror, but hopefully the "set initial condition"
solution will suffice; thanks!
>>Irv
----------------------------------------------------------------------------
---
<and Hawke wrote:>
>> from keyread.e in the archive:
>> -- Here's an extremely useful library routine for reading the keyboard.
>> -- It is used just like get_key(), except that it's called get_keys(),
>> -- it returns a sequence instead of an atom, and the values returned are
> >-- scan codes, instead of ASCII codes.
>> -- The advantage is that the routine will recognize multiple keypresses
> >-- at the same time, and return them in one sequence.
> >-- Also, there is no repeat delay, instead the code is returned
constantly
> >-- until the key is released.
> >-- Finally, the routine is also some 10-20 times faster than get_key()
> >-- Regards,
> >-- Michael Bolin
> >-- June 1997
> >hope this helps, Hawke'
Hawke, I'm going to remember this, 'cause it might come in handy another
time! Thanks.
Dan
5. Re: Eu2.1: get_key(): how know when RELEASED
- Posted by Kat <gertie at PELL.NET>
Aug 26, 2000
-
Last edited Aug 27, 2000
On 26 Aug 2000, at 16:17, Hawke' wrote:
> from keyread.e in the archive:
No match found. Try again
For those who couldn't find it, search for "keyread" without the ".e", or goto:
http://members.aol.com/jcmiura/eu/keyread.zip
Kat
6. Re: Eu2.1: get_key(): how know when RELEASED
Thanks Kat, and Hawke,
I may have to use this, as my simplistic approach worked, but not entirely
satisfactorily.
Now: does anyone have a short example of it's use handy?
Dan
(who loves examples)
----- Original Message -----
From: "Kat" <gertie at PELL.NET>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Saturday, August 26, 2000 8:05 PM
Subject: Re: Eu2.1: get_key(): how know when RELEASED
> On 26 Aug 2000, at 16:17, Hawke' wrote:
>
> > from keyread.e in the archive:
>
> No match found. Try again
> For those who couldn't find it, search for "keyread" without the ".e", or
goto:
>
> http://members.aol.com/jcmiura/eu/keyread.zip
>
> Kat
