PRO BIGHAIR, x, y, KEYBOARD=KEYBOARD, ACCELERATE=ACCELERATE, $
                   PERMANENT=PERMANENT, COLOR=COLOR
;
;+
; NAME:
;       BIGHAIR
;
; PURPOSE:
;
;       Gets cursor location in current window,
;       using cursor lines across the entire window.
;       /Keyboard accepts arrow keys input from keyboard, rather than mouse
;       Accelerate = number of pixels to jump in "/keyboard" mode.
;       The X and Y cursor locations (in pixels) are returned.
;       Further modification could allow Normalized or
;       Data coordinates to be returned.
;
;
;
; CATEGORY:
;       Interactive Drawing
;
;
; CALLING SEQUENCE:
;
;       IDL> BIGHAIR, x, y [,/Keyboard [,Accelerate=# pixels]]
;
; KEYWORDS:
;       KEYBOARD        Use keyboard instead of mouse
;       ACCELERATE      increase steps on usage with keyboard
;       PERMANENT       show current position permanently
;       COLOR           color to draw bighair
;
; SEE ALSO:
;
;
; MODIFICATION HISTORY:
;       Written by:      Mike Mayer, 8/29/92
;                        Jim Pendleton, Dept. Physics & Astronomy
;                        Northwestern U.
;                        Added to idlmeteo 11-june-1993 oet@sma.ch
;                        28-june-1993, oet@sma.ch, inserted short
;                        wait (0.2) after first plot, to get
;                        more stability on first plot.
;                        9-Aug-1993, oet@sma.ch, added keywords
;                        PERMANENT and COLOR
;-

if keyword_set(COLOR) then col=color else col=!d.n_colors-1

DEVICE, Get_Graphics = oldmode
DEVICE, Set_Graphics = 6 ; XOR write mode.
xmax = !D.X_Vsize
ymax = !D.Y_Vsize
!Err = 0 ; Reset.
oldx = 0
oldy = 0
If (not Keyword_Set(Accelerate)) then Begin
        Accelerate = 1.
EndIf
If (not Keyword_Set(KeyBoard)) then Begin
        PRINT, 'Press left mouse button to quit...'
        CURSOR, oldx, oldy, /Device, /Change
EndIf Else Begin
        PRINT, 'Press space bar to quit...'
        oldx = xmax/2
        oldy = ymax/2
        x = oldx
        y = oldy
EndElse
PLOTS, [oldx, oldx], [0, ymax], /Device, COLOR=col  ; Draw first crosshairs.
PLOTS, [0, xmax], [oldy, oldy], /Device, COLOR=col  ; Draw first crosshairs.
wait, 0.3
EMPTY
Up = String(27B) + '[A'
Down = String(27B) + '[B'
Right = String(27B) + '[C'
Left = String(27B) + '[D'
Clear = Get_Kbrd(0)
Null = ''
WHILE !Err NE 1 DO BEGIN
   If (Keyword_Set(Keyboard)) then Begin
           A = String(Byte(Get_Kbrd(0)))
           While ((A ne String(27B)) and (StrUpCase(A) ne ' ')) Do Begin
                   A = String(Byte(Get_Kbrd(0)))
           EndWhile
           B = String(Byte(Get_Kbrd(0)))
           C = String(Byte(Get_Kbrd(0)))
           Key = A + B + C
   EndIf Else Begin
           CURSOR, x, y, /Device, /Change
   EndElse
   PLOTS, [oldx, oldx], [0, ymax], /Device, COLOR=col ; Erase last crosshairs.
   PLOTS, [0, xmax], [oldy, oldy], /Device, COLOR=col ; Erase last crosshairs.
   If (Keyword_Set(Keyboard)) then Begin
           !Err = 0
           Case Key Of
                Up : y = oldy + Accelerate
                Down : y = oldy - Accelerate
                Left : x = oldx - Accelerate
                Right : x = oldx + Accelerate
                Null : x = x
                Else : !Err = 1
           EndCase
   EndIf
   If ((x ne oldx) or (y ne oldy)) then Begin
     if keyword_set(PERMANENT) then begin
        coords=convert_coord(x,y,/DEVICE, /TO_DATA)
        tmp_string= 'x: '+strtrim(coords(0),2) +  $
                   ' y: ' + strtrim(coords(1),2)
        print, tmp_string
     endif


           PLOTS, [x, x], [0, ymax], /Device, COLOR=col ; Draw new crosshairs.
           PLOTS, [0, xmax], [y, y], /Device, COLOR=col ; Draw new crosshairs.
           oldx = x
           oldy = y
           EMPTY
   EndIf
ENDWHILE
If (not Keyword_Set(Keyboard)) then Begin
;
; Already erased in Keyboard mode.
;
        PLOTS, [oldx, oldx], [0, ymax], /Device, COLOR=col  ; Erase last crosshairs.
        PLOTS, [0, xmax], [oldy, oldy], /Device, COLOR=col ; Erase last crosshairs.
EndIf
Empty
DEVICE, Set_Graphics = oldmode
PRINT, 'X = ' + STRTRIM(x, 2), '   Y = ' + STRTRIM(y, 2)
END