Re: Multiple widget_draw's and bad convert_coord

[Ben Tupper <btupper(at)bigelow.org>]

> convert_coord always returns the
> coordinates from the last plot even if I'm clicking in the first plot,

Hi Todd,

Yes, in direct graphics the *LAST* coordinate conversion parameters
(scaling and offset values for the plot) are saved... earlier parameters
get bumped out and like my hero, Bill Bradely, are quickly forgotten.

I have amended your code below (I've never used common blocks before...
it worked here but you never know what my wealth of brute force and
ignorance will lead to.)

You could perform the device to data calculation directly... the online
help 'Direct Graphics 2d Coordinate Conversion' has a table with the
necessary conversions listed.  Liam Gumley (www.Gumley.com) has some
frame tools that will save the important stuff for each window setup...
then you can simply advance/retreat through your 'frames'.

Ben

;;----- Begin test code ---------
pro bad_test_event, ev, base
		;add the last 4 items to the common block
  common windowstuff, win1, win2, widget1, widget2, XS1, XS2, YS1, YS2

  if( tag_names( ev, /structure_name ) eq 'WIDGET_DRAW' ) then begin
      case ev.id of
          widget1: begin
              wset, win1
              		;RESTORE the values of !X.S and !Y.S before the conversion
              !X.S = XS1
              !Y.S = YS1
             result = convert_coord( ev.x, ev.y, /device, /to_data )
             print, result
          end
          widget2: begin
              wset, win2
              ;RESTORE the values of !X.S and !Y.S before the conversion
              !X.S = XS2
              !Y.S = YS2
             result = convert_coord( ev.x, ev.y, /device, /to_data )
             print, result
          end
      endcase
  endif
end ;; bad_test_event

pro bad_test

		;add 4 extra items to the common block
  common windowstuff, win1, win2, widget1, widget2, XS1, XS2, YS1, YS2

  base = widget_base( /column )
  widget1 = widget_draw( base, xsize=300, ysize=300, /button_events ) 
  widget2 = widget_draw( base, xsize=300, ysize=300, /button_events )

  widget_control, base, /realize

  widget_control, widget1, get_value = win1
  widget_control, widget2, get_value = win2

  wset, win1
  plot, findgen(50), findgen(50)^2
  	;SAVE the coordiante transform parameters established by a call to PLOT
  XS1 = !X.S
  YS1 = !Y.S

  wset, win2
   ;SAVE the coordiante transform parameters established by a call to PLOT
  plot, findgen(50)+50, sin(findgen(50)/49.*!pi)
  XS2 = !X.S
  YS2 = !Y.S

  wset, win1
  xmanager, 'bad_test', base

end
;; --------- End test code ---------------

-- 
Ben Tupper
Bigelow Laboratory for Ocean Sciences
180 McKown Point Rd.
W. Boothbay Harbor, ME 04575
btupper@bigelow.org