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Re: Passing info and destroying widgets...



Liam Gumley wrote:

> "Robert S. Mallozzi" wrote:
> > I believe you must use XMANAGER in blocking mode for
> > this technique to work.
>
> Here's an example which works in non-blocking mode:
>
> ;---cut here---
> PRO TEST_EVENT, EVENT
>
> ;- Get pointer from top level base, then the info structure
>
> widget_control, event.top, get_uvalue=ptr
> info = *ptr
>
> ;- Handle the widget which caused this event
>
> widget_control, event.id, get_uvalue=name
> case 1 of
>   name eq 'Button 1' or name eq 'Button 2' : info.name = name
>   else : widget_control, event.top, /destroy
> endcase
>
> ;- Update the info structure
>
> *ptr = info
>
> END
>
>

I aggree to this method because sometimes I have to handle a lot of MBytes
of data.
But in difference to your solution I am using a string in the tagname to
identify pointers. This gives me the possibility
to destroy the pointers before I destroy the widget.
I have posted the routine get_tagname as attachement.


   free_ptr=get_tagname(map,'PTR*')
   FOR i=0,N_TAGS(free_ptr)-1 DO PTR_FREE,free_ptr.(i)

   WIDGET_CONTROL,map.base_0,/destroy


The  number of pointers are not unlimeted, so they should carefully be
destroyed after usage. If you don't free pointers you are caught  sometimes
later not knowing which to destroy.

Another important difference is that I don't copy the pointer into a normal
variable. All changes are done directly on the pointer.
e.g.:

 (*map.ptr_drawids)[i]=drawid



R.Bauer








;
; Copyright (c) 1998, Forschungszentrum Juelich GmbH ICG-1
; All rights reserved.
; Unauthorized reproduction prohibited.
; This software may be used, copied, or redistributed as long as it is not
; sold and this copyright notice is reproduced on each copy made.  This
; routine is provided as is without any express or implied warranties
; whatsoever.
;
;+
; NAME:
;	get_tagname
;
; PURPOSE:
;   This function generates a new structure from a given structure by a search string
;
;
; CATEGORY:
;   PROG_TOOLS/STRUCTURES
;
; CALLING SEQUENCE:
;   Result=get_tagname(structure,search_string,[without=without])
;
;  INPUTS:
;   structure:   The structure which should be scaned
;   search_string:      The string which should be used for searching in the structure
;
;  OPTIONAL INPUTS:
;   without:     A string which should not included in the result
;
; OUTPUTS:
;   The return value is a structure
;   defined by the search parameter
;
; EXAMPLE:
;   Result=get_tagname(inhalt,'pi*')
;   gives back all tags starting with pi
;
;   ** Structure <11867f8>, 1 tags, length=8, refs=1:
;      PI_NAME         STRING    'Peter Mustermann'
;
;   Result=get_tagname(inhalt,'*name')
;   gives back all tags ending with name
;
;   ** Structure <1186108>, 4 tags, length=32, refs=1:
;      PI_NAME         STRING    'Peter Mustermann'
;      NAME            STRING    'sin0'
;      PARAM_LONG_NAME STRING    'SIN(X)'
;      TIME_LONG_NAME  STRING    'time'
;
;   Result=get_tagname(inhalt,'*name*')
;   gives back all tags including name
;
;   ** Structure <1171ce8>, 5 tags, length=112, refs=1:
;      PI_NAME         STRING    'Peter Mustermann'
;      GPARAM_NAMELIST STRING    Array[10]
;      NAME            STRING    'sin0'
;      PARAM_LONG_NAME STRING    'SIN(X)'
;      TIME_LONG_NAME  STRING    'time'
;
;   Result=get_tagname(inhalt,'*name*',without='gparam_namelist')
;   gives back all tags including name without gparam_namelist
;
;   ** Structure <1180108>, 4 tags, length=32, refs=1:
;      PI_NAME         STRING    'Peter Mustermann'
;      NAME            STRING    'sin0'
;      PARAM_LONG_NAME STRING    'SIN(X)'
;      TIME_LONG_NAME  STRING    'time'
;
;   Result=get_tagname(inhalt,'name')
;   gives back the tag name named 'name'
;
;   ** Structure <118ab68>, 1 tags, length=8, refs=1:
;      NAME            STRING    'sin0'
;
;
; MODIFICATION HISTORY:
; 	Written by:	R.Bauer (ICG-1), 1998-07-30
;-



FUNCTION get_tagname, struct,search_string,$
   without     = without


   IF N_PARAMS() LT 2  THEN BEGIN
      MESSAGE,'result=get_tagname(struct,search_string)',/info
      RETURN,' '
   ENDIF

   n_search_string = N_ELEMENTS(search_string)-1
   FOR o=0,n_search_string  DO BEGIN
      search = (search_string[o])(0)


      IF STRPOS(search,'*') EQ -1 THEN BEGIN
         only=1
         begining=1 ; removed ;nn
         tag_such=search
      ENDIF


      IF STRPOS(search,'*') GT 0 THEN BEGIN
         begining=1
         only=0
         tag_such=STRMID(search,0,STRPOS(search,'*'))
      ENDIF

      IF STRPOS(search,'*') EQ 0 THEN BEGIN
         begining=0
         only=0
         IF STRPOS(reverse_text(search),'*') NE 0 THEN BEGIN
            tag_such=STRMID(search,1,STRLEN(search)-1)
            ende=1
            ENDIF ELSE BEGIN
            ende=0
            tag_such=STRMID(search,1,STRLEN(search)-2)
         ENDELSE
      ENDIF
      CATCH,errvar

;if errvar ne 0 then goto , help

      tag_such=STRUPCASE(tag_such)

      tags=TAG_NAMES(struct)

      tcount=   STRPOS(tags, tag_such)
      count=WHERE(tcount NE -1,m)

      IF m EQ 0 THEN RETURN,-1

      IF KEYWORD_SET(begining) THEN BEGIN
         count =  WHERE(tcount EQ 0,m)
         IF m EQ 0 THEN RETURN,-1
      ENDIF

      IF KEYWORD_SET(only) THEN BEGIN
         a=WHERE(tags(count) NE tag_such,zaehler)
         IF zaehler GT 0 THEN BEGIN
            count(a)=-1
            mcount=WHERE(count NE -1,m)
            IF m EQ 0 THEN RETURN,-1
            count=count(mcount)
         ENDIF
      ENDIF

      IF KEYWORD_SET(ende) THEN BEGIN
         en=WHERE(STRPOS(reverse_string(tags[count]),reverse_string(tag_such)) EQ 0,count_en)
         IF count_en GT 0 THEN count=count[en] ELSE RETURN,-1

      ENDIF

      IF N_ELEMENTS(without) GT 0 THEN BEGIN
         without=STRUPCASE(without)
         a=WHERE(tags(count) EQ without,zaehler)
         IF zaehler GT 0 THEN BEGIN
            count(a)=-1
            mcount=WHERE(count NE -1,m)
            count=count(mcount)
         ENDIF
      ENDIF

      IF m GT 0 THEN BEGIN

         keyws=tags(count)

         FOR i=0 , N_ELEMENTS(count)-1 DO $
               IF N_ELEMENTS(antwort) EQ 0 THEN antwort=CREATE_STRUCT(keyws[i],struct.(count[i])) ELSE $
               antwort=CREATE_STRUCT(antwort,keyws(i),struct.(count[i]))
      ENDIF


   ENDFOR
   IF N_ELEMENTS(antwort) EQ 0 THEN BEGIN
      MESSAGE,'nothing found like '+tag_such,/cont
      RETURN,antwort
   ENDIF
   RETURN, antwort


END