Re: Interrogation of Shift-Key state

From	Joao Rodrigues <jr@none.com>
Newsgroups	comp.lang.javascript
Subject	Re: Interrogation of Shift-Key state
Date	2016-06-25 20:34 -0300
Organization	Aioe.org NNTP Server
Message-ID	<nkn4en$b97$1@gioia.aioe.org> (permalink)
References	<nklv6p$eap$1@gioia.aioe.org>

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On 06/25/2016 09:59 AM, Janis Papanagnou wrote:
> I want to interrogate the boolean state of the Shift-Key (pressed or not).
>
> I learned it is possible to define event-handlers to control keyup/keydown
> events,

Yes, it is, but the onkeyup event cannot be cancelled just in case you 
need to.

> then I could adjust some global variable that I can interrogate
> where I need that information. But that is bulky and seems unnecessary(?)
> complex.

A global variable is not a good idea. And you may capture the shift Key 
pressing whenever needed.

>
> My application context is a function that is triggered when a button is
> pressed. Is there a simple way to just interrogate the Shift-Key status
> in that function?

Just a simple example using the onkeydown event to prevent Shift key:

// HTML
<label for="txt1">TextBox1</label>
<input id="txt1" onkeydown="return getKey(event);" type="text" />

<script type="text/javascript">
function getKey(e) {
   if (!e) e = window.event;
   if (e.shiftKey) {
     alert('shiftKey is not allowed.');
     return false;
   }
   return true;
}
</script>

-- 
Joao Rodrigues

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Thread

Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-25 14:59 +0200
  Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-06-25 17:18 +0200
    Re: Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-25 19:47 +0200
      Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-06-25 20:07 +0200
  Re: Interrogation of Shift-Key state "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-06-25 08:51 -0700
    Re: Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-25 19:47 +0200
      Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-06-25 20:17 +0200
        Re: Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-25 21:16 +0200
          Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-06-25 22:33 +0200
            Re: Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-26 00:49 +0200
              Re: Interrogation of Shift-Key state Tim Streater <timstreater@greenbee.net> - 2016-06-26 00:06 +0100
              Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-06-26 11:05 +0200
      Re: Interrogation of Shift-Key state "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-06-25 12:17 -0700
        Re: Interrogation of Shift-Key state "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-06-25 12:23 -0700
        Re: Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-26 00:34 +0200
        Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-18 20:29 +0200
          Re: Interrogation of Shift-Key state "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-08-18 15:17 -0700
            Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-20 07:23 +0200
              Re: Interrogation of Shift-Key state "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-08-20 00:03 -0700
                Re: Interrogation of Shift-Key state Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-20 11:48 +0200
                Re: Interrogation of Shift-Key state "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-08-25 13:39 -0700
      Re: Interrogation of Shift-Key state "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-06-25 12:20 -0700
      Re: Interrogation of Shift-Key state Tim Streater <timstreater@greenbee.net> - 2016-06-25 22:33 +0100
        Re: Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-26 01:18 +0200
          Re: Interrogation of Shift-Key state Tim Streater <timstreater@greenbee.net> - 2016-06-26 00:23 +0100
            Re: Interrogation of Shift-Key state Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-26 01:37 +0200
              Re: Interrogation of Shift-Key state Tim Streater <timstreater@greenbee.net> - 2016-06-26 09:41 +0100
  Re: Interrogation of Shift-Key state - workaround Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-26 00:33 +0200
    Re: Interrogation of Shift-Key state - workaround "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-06-26 00:53 +0200
      Re: Interrogation of Shift-Key state - workaround Janis Papanagnou <janis_papanagnou@hotmail.com> - 2016-06-26 01:31 +0200
        Re: Interrogation of Shift-Key state - workaround "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-06-25 16:52 -0700
        Re: Interrogation of Shift-Key state - workaround "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-06-26 01:56 +0200
    Re: Interrogation of Shift-Key state - workaround "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-06-25 16:50 -0700
  Re: Interrogation of Shift-Key state Joao Rodrigues <jr@none.com> - 2016-06-25 20:34 -0300

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