topic Re: Boolean button that requires a double click in LabVIEW

Boolean button that requires a double click

schieb2 — Thu, 26 Jul 2012 23:11:47 GMT

Is it possible to make a boolean true/false button to require two mouse clicks to switch. We wish this feature to avoid accidentally clicking a button that opens or closes a valve?

Thank you, Bill

Re: Boolean button that requires a double click

nathand — Thu, 26 Jul 2012 23:17:05 GMT

It can be done if you capture the "mouse down?" filter event on the boolean, and track the time between two successive events. On the first one, discard the event, and store the time. On the second one, if the time is within some "double-click" time, don't discard the event, which will allow the boolean to switch.

Can I suggest as a simpler alternative that you use a pull-down (I'm thinking an enumeration or a picture ring)? That also requires more than a passing mouse click to change the value, and is both easier to code and more intuitive.

Re: Boolean button that requires a double click

hecmar.arreola — Thu, 26 Jul 2012 23:18:25 GMT

Hi Bill -

I have to program similar functionality into my apps so that when buttons are pressed they are pressed "with intent" and not accidental. Instead of a double-click, might I suggest an "unlock" key? I have my users press and hold the CTRL key if they want to click something in the interface that does something that you don't want to do accidently (like open a valve). You can use an event to detect when a key is pressed down and check to see if it is the CTRL key (or whatever key you like), and then Enable the controls. Similarly when the key comes back up the controls are disabled again.

Re: Boolean button that requires a double click

nathand — Thu, 26 Jul 2012 23:27:44 GMT

Nickerbocker - just curious, when you do this, do you visually show that the controls are enabled and disabled? Otherwise it would seem a lot easier to me to check whether any modifier keys are pressed at the time of the mouse down event (or, with a filter event, discard if the modifier key isn't pressed).

Re: Boolean button that requires a double click

apok — Thu, 26 Jul 2012 23:33:11 GMT

add a dialog to it....

Re: Boolean button that requires a double click

schieb2 — Fri, 27 Jul 2012 00:06:49 GMT

Thank you. I will give this solution a try using space bar + mouse click.

Re: Boolean button that requires a double click

ian_fung — Fri, 27 Jul 2012 02:36:04 GMT

Hi,

Attached is sort of "timed button" that was created for another member some years ago (can't remember when was it though)...

It might be just another possible solution to your problem. So, I am adding it to the list 😉

Re: Boolean button that requires a double click

Norbert_B — Fri, 27 Jul 2012 12:42:32 GMT

@Ian: While i find the general idea very interesting, i don't like that timing is encapsulated only in the subVI. While it doesn't hog the CPU (which is good), it might give wrong impressions to new developers (no obvious wait funktion in the loop).

@OP: If it was only a double click you want to check, you might do something like in the attachment.

Norbert

Re: Boolean button that requires a double click

ian_fung — Fri, 27 Jul 2012 14:21:53 GMT

Dear Norbert

Thanks for the feedback. Fyi, it wasn't my idea but it was created based on the requirement of the member who needed such function.

Re: Boolean button that requires a double click

SteveChandler — Fri, 27 Jul 2012 17:08:09 GMT

Norbert, neat trick! I had never thought of a use for a disabled control that is not also greyed out. I never tried it but I am surprised that a disabled control still generates mouse events.

Re: Boolean button that requires a double click

altenbach — Fri, 27 Jul 2012 17:23:39 GMT

@Steve Chandler wrote:

Norbert, neat trick! I had never thought of a use for a disabled control that is not also greyed out. I never tried it but I am surprised that a disabled control still generates mouse events.

Mouse down events are independent of the operation. You can easily generate such events even for indicators. Very useful! 🙂

Re: Boolean button that requires a double click

schieb2 — Fri, 27 Jul 2012 18:35:12 GMT

Norbert: Thank you for sending this VI. It is exactly what I was looking for.

Re: Boolean button that requires a double click

MoReese — Fri, 27 Jul 2012 20:40:01 GMT

@Norbert_B wrote:

@Ian: While i find the general idea very interesting, i don't like that timing is encapsulated only in the subVI. While it doesn't hog the CPU (which is good), it might give wrong impressions to new developers (no obvious wait funktion in the loop).

@Op: If it was only a double click you want to check, you might do something like in the attachment.

Norbert

I to am interested in your solution. Can you downconvert to LV10 for me? Thanks.

Re: Boolean button that requires a double click

schieb2 — Fri, 27 Jul 2012 21:00:21 GMT

Reese, Here it is in LV2010.

Re: Boolean button that requires a double click

altenbach — Fri, 27 Jul 2012 22:19:35 GMT

Norbert_B wrote:
@OP: If it was only a double click you want to check, you might do something like in the attachment.

I am still trying to wrap my head around the diffence between a "mouse down ...double-click" and a "mouse up...double-click" event. 😄

Re: Boolean button that requires a double click

odessy27 — Sat, 28 Jul 2012 16:27:14 GMT

@altenbach wrote:

Norbert_B wrote:
@Op: If it was only a double click you want to check, you might do something like in the attachment.

I am still trying to wrap my head around the diffence between a "mouse down ...double-click" and a "mouse up...double-click" event. 😄

@Norbert_B : Very cool idea indeed.

@altenbach: I was trying to find out the same soon as I saw the code. I do not see any differece in terms of execution, is it true?

Also, I think as a general principle, everyone in the forums should post vi in older version whenever possible (of course, in some times you might loose some functionality, in which case, it should be okay to post it in same version it was created in). It willl help the majority of community members who have older version to jump in to the discussion, and get the ideas such as few posted in this thread, whithout having to go through the hassle of asking for downconversion and wait for it until someone does it for them.

-Nilesh

Re: Boolean button that requires a double click

Norbert_B — Mon, 30 Jul 2012 07:29:38 GMT

The difference between mouse down and mouse up is WHEN the event is generated. Mouse down means, the event is generated as soon as the mouse button is pressed while mouse up is generated once you release the button.

For single mouse presses, it is suggested to use the mouse up event because you might realize: Hey, that's the wrong control i am pressing! So simply move (while keeping the mouse button pressed) the mouse point off the control and then release the button. The event for the control "mouse up" will not be generated since it never took place (mouse up was OUTSIDE the control!)

Another difference is that mouse down is also available as filter event while mouse up not....

A third difference is that mouse up is not generated if the control has a context menu and the mouse button used is the right one.

But to be honest, for a double click, it really doesn't matter much since if i double click as user, i click quite fast (maybe as fast as i can) so i will not rethink during the double click if the control was the correct one.... 😉

hope this helps,

Norbert

Re: Boolean button that requires a double click

MoReese — Mon, 30 Jul 2012 12:34:26 GMT

@odessy27 wrote:

Also, I think as a general principle, everyone in the forums should post vi in older version whenever possible (of course, in some times you might loose some functionality, in which case, it should be okay to post it in same version it was created in). It willl help the majority of community members who have older version to jump in to the discussion, and get the ideas such as few posted in this thread, whithout having to go through the hassle of asking for downconversion and wait for it until someone does it for them.

-Nilesh

I second this notion. I've had to ask for older versions all the time. Unfortunately, some of us are stuck with the versions we purchased until we can convince the powers-that-be of the need to upgrade.

Re: Boolean button that requires a double click

SteveChandler — Mon, 30 Jul 2012 14:17:42 GMT

@MoReese wrote:

I second this notion. I've had to ask for older versions all the time. Unfortunately, some of us are stuck with the versions we purchased until we can convince the powers-that-be of the need to upgrade.

I just posted an idea to the idea exchange that might be able to address this issue.

Re: Boolean button that requires a double click

P@Anand — Wed, 15 Aug 2012 20:55:48 GMT

@Steve Chandler wrote:

@MoReese wrote:

I second this notion. I've had to ask for older versions all the time. Unfortunately, some of us are stuck with the versions we purchased until we can convince the powers-that-be of the need to upgrade.

I just posted an idea to the idea exchange that might be able to address this issue.

I already posted here long back when I was starting with the forum (You know one thing I got my first kudo there ) but not much appreciation 😞