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howto force evaluation after <CR> [message #10869]

Wed, 01 August 2007 21:16

ebojd
Messages: 225
Registered: January 2007
Location: USA

Experienced Member

I have come across a trivial problem while developing an interface to drive our LiDAR (think of it as a telescope with a 3000W laser pointer attached). When I tell the telescopic mount to go to a particular elevation or azimuth via an EditDoubleNotNull field, it calls the callback function for every character typed in instead after a <CR> or moving the mousse out of the focus area. What is the easiest way to force the evaluation after a <CR>?

Follows is the prototype code:

void telescope_ctl::btn_move_el_ctl()  
 {El = (double)~jog.jog_pos_el;}


telescope_ctl::telescope_ctl()
{
  ...
  jog.jog_pos_el <<= THISBACK(btn_move_el_ctl);
  ...
}

Thanks,

EBo --

[Updated on: Wed, 01 August 2007 21:18]

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Re: howto force evaluation after <CR> [message #10870 is a reply to message #10869]

Wed, 01 August 2007 22:46

mrjt
Messages: 705
Registered: March 2007
Location: London

Contributor

I have had the same problem and solved it in two different ways depending on the situation:

1) This is the way I think it was intended to be done. Because EditField doesn't actually handle K_RETURN it is passed up to the parent window's Key function, and see if that field has focus:

if (key == K_RETURN && FocusCtrl() == &jog.jog_pos_el)
    // Do whatever

2) If you really want a callback you can do:

template<class T>
struct WithReturnCallback : public T
{
    Callback WhenReturnKey;
    virtual bool Key(dword key, int count)
    {
        if (key == K_RETURN) {
            WhenReturnKey();
            return true;
        }
        return T::Key(key, count);
    }
}

And then us it as a wrapper for the editfield.

Apologies in advance for any errors in the the above, Idon't have access to a compiler this minute.

Quote:

our LiDAR (think of it as a telescope with a 3000W laser pointer attached)

Awesome!

James.

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Re: howto force evaluation after <CR> [message #10885 is a reply to message #10870]

Thu, 02 August 2007 14:25

ebojd
Messages: 225
Registered: January 2007
Location: USA

Experienced Member

James, thanks for your reply.

mrjt wrote on Wed, 01 August 2007 15:46

I have had the same problem and solved it in two different ways depending on the situation:

...

I poked at it a little and was unable to get it to compile and/or work (but I'm sure that it is simply a function of my inexperience programming U++). Anyway, I came up with a workaround by adding a "Move To" button. I'll look into this again when I get-a-round-to-it.

Quote:

our LiDAR (think of it as a telescope with a 3000W laser pointer attached)

Awesome!

I cannot wait until I get it all working together and fire the puppy up in the field.

Thanks again,

EBo --

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Re: howto force evaluation after <CR> [message #10888 is a reply to message #10870]

Thu, 02 August 2007 19:35

mirek
Messages: 13975
Registered: November 2005

Ultimate Member

mrjt wrote on Wed, 01 August 2007 16:46

if (key == K_RETURN && FocusCtrl() == &jog.jog_pos_el)
    // Do whatever

Or just jog.HasFocus();

Mirek

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Re: howto force evaluation after <CR> [message #10891 is a reply to message #10888]

Thu, 02 August 2007 22:19

ebojd
Messages: 225
Registered: January 2007
Location: USA

Experienced Member

luzr wrote on Thu, 02 August 2007 12:35

mrjt wrote on Wed, 01 August 2007 16:46

if (key == K_RETURN && FocusCtrl() == &jog.jog_pos_el)
    // Do whatever

Or just jog.HasFocus();

Thanks Mirek, but that did not work. I'll play with it more tonight.

EBo --

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Re: howto force evaluation after <CR> [message #10960 is a reply to message #10891]

Tue, 07 August 2007 19:23

mirek
Messages: 13975
Registered: November 2005

Ultimate Member

Well given the HasFocus implementation:

	bool    HasFocus() const                   { return FocusCtrl() == this; }

it is really strange that your version should work and HasFocus not Wink

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Re: howto force evaluation after <CR> [message #10963 is a reply to message #10960]

Tue, 07 August 2007 23:55

ebojd
Messages: 225
Registered: January 2007
Location: USA

Experienced Member

I'll look at this again later. I decided that typing the number in then punching the "Go" button made more intuitive sense -- also I lost one of the power supplies on my test bench and one-thing-lead-to-another and I fried the output drivers on my embedded development system, so I have had other things on my mind...

Thanks for following up on this though...

EBo --

ps: IIRC the problem was not with HasFocus but it did not behave like I wanted -- wait to return until after 1) typeda <CR>, or 2) left focus. The "Go" button makes intuitive sense without violating the law of minimal surprise...

[Updated on: Wed, 08 August 2007 00:04]

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