| Re: widget_problem [message #61586 is a reply to message #61467] |
Wed, 23 July 2008 07:42   |
Vince Hradil
Messages: 574
Registered: December 1999
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Senior Member |
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On Jul 23, 9:34 am, Paul van Delst <Paul.vanDe...@noaa.gov> wrote:
> d.po...@gmail.com wrote:
>> On Jul 22, 5:52 pm, d.po...@gmail.com wrote:
>>> On Jul 17, 8:32 pm, Paul van Delst <Paul.vanDe...@noaa.gov> wrote:
>
>>>> Justus Skorps wrote:
>>>> >> Justus
>>>> >> stil can not fix it. i have Liam E.Gumley's book but ......
>>>> >> Cheers
>>>> >> Dave
>>>> > after u load your arrays (lets call them A) store them with
>>>> > widget_control, event.top, set_uvalue=A, /nocopy
>>>> > You have to change 'event.top' that it fits your program...
>>>> > In your second button you can now load the arrays with
>>>> > widget_control, event.top, get_uvalue=A, /nocopy
>>>> but don't forget to put them back into your uvalue when you're done!
>>>> > It is useful to
>>>> > -store the data in the main widget
>>>> > -use a structure to store every data you want
>>>> I also tend to use procedures to get the Info state:
>>>> ; Routine to get the Info state
>>>> PRO GetState, ID, Info, No_Copy = No_Copy
>>>> ; -- Get pointer
>>>> WIDGET_CONTROL, ID, GET_UVALUE = InfoPtr
>>>> IF ( PTR_VALID( InfoPtr ) EQ 0 ) THEN $
>>>> MESSAGE, 'State Information pointer is invalid'
>>>> ; -- Get state information structure
>>>> IF ( N_ELEMENTS( *InfoPtr ) EQ 0 ) THEN $
>>>> MESSAGE, 'State information structure is undefined'
>>>> IF ( KEYWORD_SET( No_Copy ) ) THEN BEGIN
>>>> Info = TEMPORARY( *InfoPtr )
>>>> ENDIF ELSE BEGIN
>>>> Info = *InfoPtr
>>>> ENDELSE
>>>> IF ( Info.Debug EQ 1 ) THEN PRINT, 'GetState'
>>>> END
>>>> and to set the info state
>>>> ; Routine to set the Info state
>>>> PRO SetState, ID, Info, No_Copy = No_Copy
>>>> ; -- Get pointer
>>>> WIDGET_CONTROL, ID, GET_UVALUE = InfoPtr
>>>> IF ( PTR_VALID( InfoPtr ) EQ 0 ) THEN $
>>>> MESSAGE, 'State information pointer is invalid'
>>>> ; -- Set state information structure
>>>> IF ( N_ELEMENTS( Info ) EQ 0 ) THEN $
>>>> MESSAGE, 'State information structure is undefined'
>>>> IF ( KEYWORD_SET( No_Copy ) ) THEN BEGIN
>>>> *InfoPtr = TEMPORARY( Info )
>>>> ENDIF ELSE BEGIN
>>>> *InfoPtr = Info
>>>> ENDELSE
>>>> IF ( (*InfoPtr).Debug EQ 1 ) THEN PRINT, 'SetState'
>>>> END
>>>> My widget event handlers then do something like:
>>>> FUNCTION ComponentTest_LogLin_Event, Event
>>>> ; -- Get main info state
>>>> GetState, Event.Top, Info
>>>> ; -- Print debug statement if required
>>>> IF ( Info.Debug EQ 1 ) THEN PRINT, 'ComponentTest_LogLin_Event'
>>>> ; -- Set the selected variable number index
>>>> Info.LogLin_Index = Event.Value
>>>> ; -- Save info state
>>>> SetState, Event.Top, Info
>>>> ; -- Display the result
>>>> ComponentTest_Display, Event.Top
>>>> RETURN, 0
>>>> END
>>>> Note how I call GetState and then SetState. Because I tend not to use /no_copy, it's
>>>> really only an issue when I update a component of the info state (like in my example
>>>> above). But, if you *do* use /no_copy, then I think you have to call SetState again to
>>>> replace the info pointer.
>>>> cheers,
>>>> paulv
>>> Thanks Justus and Paulv
>>> You help me very much. And it was very useful.
>>> Cheers
>>> Dave
>
>> Hi Justus
>> I encounter a now problem:
>> Say I have set and get 2 arrays by this method:
>> widget_control, event.top, set_uvalue=A, /nocopy
>> …
>> widget_control, event.top, get_uvalue=A, /nocopy
>
>> and from another button:
>> widget_control, event.top, set_uvalue=B, /nocopy
>> …
>> widget_control, event.top, get_uvalue=B, /nocopy
>
>> Now I want to get both A&B in another button like this:
>
>> widget_control, event.top, get_uvalue=A, /nocopy
>> widget_control, event.top, get_uvalue=B, /nocopy
>
>> But widget just accepts one array. How I can take this two arrays
>> simultaneously in another button?
>
> Don't store A and B separately. Store them both. When you create the widget hierarchy, do
> something like,
>
> Info = {A:PTR_NEW(/ALLOCATE_HEAP), $
> B:PTR_NEW(/ALLOCATE_HEAP) }
> InfoPtr = PTR_NEW( Info )
> WIDGET_CONTROL, Top_Level_Base_ID, SET_UVALUE = InfoPtr
>
> This assumes you don't know the sizes of A and B ahead of time, hence the
> PTR_NEW(/ALLOCATE_HEAP). Also, if you store a structure, then you can easily add more data
> to your widget info state as your add more functionality to your GUI application, but
> without breaking existing stuff.
>
> Then when you need to store them in an event handler:
>
> GetState, Event.Top, Info
> *Info.A = array_with_Adata
> *Info.B = array_with_Bdata
> SetState, Event.Top, Info
>
> and also get them both later on:
>
> GetState, Event.Top, Info
> X = *Info.A
> Y = *Info.B
>
> This type of thing is covered frequently in both Liam's and David's books - as well as
> numerous examples on David's websites. FWIW my methodology is shamelessly nicked (with
> some minor alterations) from Liam's book section 9.5 "A GUI Application".
>
> cheers,
>
> paulv
Darn... you type faster than I...
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