; Copyright (c) 1998-2016 A.P. Hitchcock  All rights reserved
;+
;NAME:
;	AXB_SAVE
;
;LAST CHANGED: ----------------------------------- 12Apr-16
;
;PURPOSE:
;	This function writes an AXIS format image or spectrum to the XDR
; transferrable binary format.These files can be read using AXB_LOAD.
;
;CATEGORY:
;	STAND ALONE: utility
;
;CALLING SEQUENCE:
;	Result = AXB_SAVE(tmp [, NOF=nof, file=file, noLbl = noLbl, silent=silent])
;
;CALLED FROM AXIS:
;	Read->Images->AXIS
;
;INPUTS:
;	TMP - AXIS 1d or 2d structure
;
;KEYWORDS:
;	/NOF - no filter (default filter = '*.axb')
;	NOLBL - if set, do not query for label
;	FILE - filename to read
;	SILENT  flag to control entry to axis log
;
;OUTPUTS:
;	RESULT = filename (a blank string if the user cancels)
;
;COMMON BLOCKS:
;	@AXIS_COM	standard set of common blocks
;
;PROCEDURE:
;	uses the XDR external, machine-independent binary representation.
; Please see the IDL manual (help under 'XDR') for details.
; If the filename is not supplied via the FILE keyword, the
; user is prompted for the filename using the pick file dialog.
; If the filename is supplied, a check for overwriting is made unless
; the global flag, overwrite_all is set to 1
;
;EXAMPLE:
; Create a sample nxn image, write as binary using AXB_SAVE, read using AXB_LOAD
;	n = 100 & t = findgen(n) & d = dist(n)
;	a = {t:'2d', x:t, y:t, xl:'x (um)    E = 288.601 eV     dwell =  0.20 ms', yl:'y', d: d, dl:'test'}
;	t = AXB_SAVE(a)
;	b = AXB_LOAD(file = t)
;	splot2d, b
;
;;MODIFICATION HISTORY:
; (  fall-97 aph) first made
; (14-jun-98 aph) axis_com
; (18-jan-99 aph) keyword to allow silent writes (no file dialog)
; ( 8-jul-99 aph) FREE_LUN not just close
; ( 8-sep-99 aph) update label
; (02-jan-00 aph) AXIS standard documentation
; (09-jan-00 aph) add hourglass for long writes
; (27-feb-00 aph) add groupID to get_text
; (06-may-01 aph) remove groupID call if not running axis
; (04-jun-03 aph) add keyword to force label to current value
; (15-Jan-07 aph) add keyword silent
; (29-dec-07 aph) remove path info from log
; (02-Jan-15 aph) add no_aXis keyword to suppress loading result into aXis2000 buffer
; (26-Mar-16 aph) track down problem with wrong # y values (2d images)
;    			  when data comes from Nexus(HDF)
; (12-Apr-16 aph) remove annoying 'help' on the structure
;-

function axb_save, tmp, file = file, noLbl = noLbl, NOF=nof, no_aXis=no_aXis, silent=silent
@axis_com
on_error,2

; help, tmp, /struct
axis_on = 1			; use as internal switch to define if axis is running
if keyword_set(no_aXis) then axis_on = 0

if n_tags(tmp) NE 0 THEN BEGIN      ; check that tmp is a structure
; check if requested file exists; if so launch overwrite dialog
	IF keyword_set(file) then begin
		check_flag = 1
		if widget_info(/active) EQ 1 then begin
			if overwrite_all EQ 1 then check_flag = 0
		endif
		if check_flag EQ 1 then begin
			test = findfile(file)
	  		if test(0) EQ file then begin
	  			if widget_info(/active) EQ 1 then $
			    	t = file_overwrite(group = axis_ID, val = 1) else $
			    	t = file_overwrite(val = 1)
			    if t EQ 0 then file = pickfile2(/write, fltr='*.axb', $
			                      LFILE = file, title = 'Alternate file name')
			    if t EQ 2 then overwrite_all = 1
			endif
		endif
	ENDIF ELSE BEGIN			; filename was not supplied
		fltr='*.axb'
		if keyword_set(nof) then fltr='*'
		file = pickfile2(/write, filter=fltr, /Lpath, $
		       defpath = WritePath) ;, get_path=WritePath)
		if file EQ '' then return, file
		dln = ' '
		if NOT keyword_set(noLbl) then begin
			if widget_info(/active) EQ 1 then $
			    dln = Get_Text(PROMPT = 'Label', val = tmp.dl, group = axis_ID)  $
			    else dln = Get_Text(PROMPT = 'Label', val = tmp.dl)
			tmp.dl = dln(0)
		endif
; ------- update the aXis200buffer since the label may have been changed
		if widget_info(/active) EQ 1 and axis_on EQ 1 then begin
			Label(CurBuf) = tmp.dl
			HANDLE_value, Data(CurBuf), tmp, /set
			BLbl_upd
			widget_control, /hourglass
		endif
	ENDELSE
; ----- write the structure in binary format
	openw, iunit, file, /get_lun, /XDR
	writeu, iunit, tmp.t
	writeu, iunit, tmp.dl
	writeu, iunit, tmp.xl
	t = ax_name(file) & file_short = t(1)
	CASE tmp.t OF
	  '1d' : begin
	  		writeu, iunit, n_elements(tmp.x)
	  		writeu, iunit, tmp.x
	  		writeu, iunit, tmp.d
	  		if not keyword_set(silent) then  axis_log, 'wrote axis file: ' + file_short
	  	END
	  '2d' : begin
			writeu, iunit, tmp.yl
			writeu, iunit, n_elements(tmp.x)
			writeu, iunit, tmp.x
			writeu, iunit, n_elements(tmp.y)
			writeu, iunit, tmp.y
			writeu, iunit, tmp.d
			if not keyword_set(silent) then  axis_log, 'wrote axis file: ' + file_short
		END
		else :  print, ' Error on binary file write '
	ENDCASE
	close, iunit & free_lun, iunit
	return, file
ENDIF ELSE print, 'AXB_SAVE: not a structure'
END