Touch Screen Input Suggestions

[tst]

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@JTCLARKE wrote:

I am designing an HMI that will be run on a touch screen computer with no keyboard or mouse.  I have integrated a 3rd party add-on that can be found here:

http://sine.ni.com/nips/cds/view/p/lang/en/nid/217168

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Well, I didn't install it or look at the code, but the page for the toolkit does say "Value change property nodes are not supported. Use user events option if validation of entered data is required before the control value is used elsewhere in the program" and that there are included examples for user events, so I would suggest looking at those.

I'm not sure why they don't support user events. If they're passing the typed value into the control (tricky, because for some controls, like trees or tables or arrays or clusters, this can be more difficult), then they should be able to use the value signaling property for everything other than latched booleans, where it probably isn't relevant anyway.

If they were just sending key down messages or simulating keyboard clicks, I would have thought the event would work regardless.

That said, I haven't thought deeply about what would be needed for this to work.

[paul_cardinale]

I peeked inside.  The data from their input pads is string data.  They're using the "Value" property for numeric and string controls; but they're using the "Path Text.Text" property for path controls.  That's probably why they don't support "Value Signaling".  But there's really no reason they couldn't convert the string to a path and use "Value Signaling".

[JTCLARKE]

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@paul_cardinale wrote:

I peeked inside.  The data from their input pads is string data.  They're using the "Value" property for numeric and string controls; but they're using the "Path Text.Text" property for path controls.  That's probably why they don't support "Value Signaling".  But there's really no reason they couldn't convert the string to a path and use "Value Signaling".

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Thank you for taking a peek in there to see how they were handling things.  I think I have a work around using their "No updates (use event)" option.  I have attached my updated code.  The only problem I am having now is when I use their "user event" trigger to then trigger my own "Value Signaling" update it seems to make the keyboard stop coming up at all until I run the keyboard close command and re-initialize it completely.  Does anyone have any ideas on that one?  Am I handling things wrong in my event case?

Thanks.

-John