; Imagemap - imagemaps
;
; Purpose: creation of client-side image maps
; Category: web graphics
; Use: imagemap,filename[,outfilename]
; Inputs:
;   filename - *gif* filename to open and create the map for
;   outfilename - file to write the imagemap text to [defaults to imagemap.txt]
; Use:
;   An html client-side imagemap looks like:
;<map name=map>
; <area shape="poly" href="/public/icd/bas_publ.html" coords="9,31 28,52 5,60 6,43 8,31">
; <area shape="rect" href="#dml" coords="78,5 177,62">
; <area shape="circle" href="#pole" coords="128,110,20">
;</map>
;<img src=antshade.gif ismap usemap=#map border=0>
; This widget produces the text that goes inside the "map" element.
; It should be run (this is obvious) on the GIF that will be used as the image source
;
; Author: WMConnolley wmc@bas.ac.uk www.nbs.ac.uk/public/icd/wmc/
; Guarantee: none

; --- Event handler: does all the work ---

pro imagemap_event,event

; All needed data is stored in the top uvalue
widget_control,event.top,get_uvalue=goat
nx=goat.nx
;
; Select action based on event id
;
case event.id of
;
; writ: write out the imagemap text
;
goat.writ: begin
  widget_control,get_value=texto,goat.text
  openw,lun,goat.outfilename,/get
  printf,lun,texto
  free_lun,lun  
  end
; 
; relo: reload the image
;
goat.relo: begin
  goat.img=goat.img0
  tv,goat.img
  end
;
; stop - hmm, wonder what this does?
;
goat.stop: begin
  widget_control,/destroy,event.top
  end
;
; draw - mouse has moved in the draw window. What we do
;        depends on what shape is selected
;
goat.draw: begin
  case goat.mode of
;
; Polygon (click on points)
;
  'poly': begin
; press 1 (LH button) - add new node to polygon
    if (event.press eq 1) then begin
      goat.x(nx)=event.x & goat.y(nx)=event.y
      if (goat.nx ne 0) then plots,goat.x(nx-1:nx),goat.y(nx-1:nx),/dev
      plots,psym=3,symsize=2,[event.x],[event.y],/dev
      goat.nx=goat.nx+1
; press 4 (RH button) - end polygon; write nodes as text to the text screen
    endif else if (event.press eq 4) then begin
      widget_control,goat.url,get_value=url
      text='<area href="'+url+'" shape="poly" coords="'
; Note the coords are "upside down"
      for i=0,nx-1 do text=text+shtstr(goat.x(i))+","+shtstr(goat.ys-goat.y(i)-1)+" "
      text=text+shtstr(goat.x(0))+","+shtstr(goat.ys-goat.y(0)-1)
      text=text+'">'
      widget_control,set_value=text,goat.text,/append
      plots,goat.x([0,nx-1]),goat.y([0,nx-1]),/dev
      goat.nx=0
    endif
    end

;
; Circle (center point and then drag out)
;
  'circle': begin
; Press 1 - start new circle
    if (event.press eq 1) then begin
      plots,psym=3,symsize=2,[event.x],[event.y],/dev
      goat.x(0)=event.x & goat.y(0)=event.y
      a=tvrd() & goat.img=a
      goat.nx=1
    endif else if (event.release eq 1) then begin
; Release 1 - end circle and write text 
      goat.nx=0
      r=sqrt((goat.x(0)-event.x)^2+(goat.y(0)-event.y)^2)
      plots,goat.x(0)+sind(indgen(361))*r,goat.y(0)+cosd(indgen(361))*r,/dev
      widget_control,goat.url,get_value=url
      text='<area href="'+url+'" shape="circle" coords="' $
          +shtstr(goat.x(0))+','+shtstr(goat.ys-goat.y(0)-1)+','+shtstr(fix(r+.5))
; Note the coords are "upside down"
      text=text+'">'
      widget_control,set_value=text,goat.text,/append
    endif else if (nx gt 0 and event.type eq 2) then begin
; Otherwise, its a drag - rewrite image to remove previous drawn circle (cf rubberband)
      tv,goat.img
      r=sqrt((goat.x(0)-event.x)^2+(goat.y(0)-event.y)^2)
      plots,goat.x(0)+sind(indgen(361))*r,goat.y(0)+cosd(indgen(361))*r,/dev
    endif
    end

;
; Square (oh, OK then, rectangle)
;
  'square': begin
; Press 1 - first corner
    if (event.press eq 1) then begin
      plots,psym=3,symsize=2,[event.x],[event.y],/dev
      goat.x(0)=event.x & goat.y(0)=event.y
      a=tvrd() & goat.img=a
      goat.nx=1 
    endif else if (event.release eq 1) then begin
; Release 1 - end rectangle
      goat.nx=0
      plots,([goat.x(0),event.x])([0,1,1,0,0]),([goat.y(0),event.y])([0,0,1,1,0]),/dev
      widget_control,goat.url,get_value=url
      text='<area href="'+url+'" shape="rect" coords="' $
          +shtstr(goat.x(0))+','+shtstr(goat.ys-goat.y(0)-1) $
          +' '+shtstr(event.x)+','+shtstr(goat.ys-event.y-1)
      text=text+'">'
      widget_control,set_value=text,goat.text,/append
    endif else if (nx gt 0 and event.type eq 2) then begin
; Otherwise drag, as for circle
      tv,goat.img
      plots,([goat.x(0),event.x])([0,1,1,0,0]),([goat.y(0),event.y])([0,0,1,1,0]),/dev
    endif
    end

  else: begin
    print,'Sorry: unrecognised mode: '+goat.mode
    end
  endcase
  widget_control,event.top,set_uvalue=goat
  end
;
; End of events in draw window
;
; Press on "poly" button
;
goat.poly: begin
  goat.mode='poly'
  goat.nx=0
  widget_control,event.top,set_uvalue=goat 
  end
;
; Press on "square" button
;
goat.squa: begin
  goat.mode='square'
  goat.nx=0
  widget_control,event.top,set_uvalue=goat
  end
;
; Press on "circle" button
;
goat.circ: begin
  goat.mode='circle'
  goat.nx=0
  widget_control,event.top,set_uvalue=goat
  end
else: begin
  ; print,'Sorry: unrecognised event id: ',event.id
  end
endcase

end

;
; --- Main pro: reads in image, creates widget, calls xmanager
;

pro imagemap,filename,outfilename

; Input verify
if (n_elements(outfilename) eq 0) then begin
  outfilename='imagemap.txt'
  message,'Note: no imagemap filename supplied; using default: '+outfilename,/cont
endif
if (n_elements(filename) eq 0) then message,'Please supply input GIF file'

; Read in the GIF into "a"
read_gif,filename,a,r,g,b
s=size(a)
xs=s(1)
ys=s(2)

; Make the widget
base=widget_base(/col)
; Draw widget at the top
draw=widget_draw(base,xsize=xs,ysize=ys,/button_events,/motion_events)
; Row of buttons
bbase=widget_base(base,/align_bottom,/row)
stop=widget_button(bbase,value='End')
relo=widget_button(bbase,value='Reload')
writ=widget_button(bbase,value='Write imagemap')
junk=widget_label(bbase,value='Select:')
poly=widget_button(bbase,value='Polygon')
squa=widget_button(bbase,value='Square')
circ=widget_button(bbase,value='Circle')
; Url (for the hrefs)
ubase=widget_base(base,/align_bottom,/row)
junk=widget_label(ubase,value='URL for hrefs')
url =widget_text(ubase,value='http://',xsize=40,ysize=1,/editable)
; Text that we generate
text=widget_text(base,/editable,ysize=10,/scroll)

; Realise the widget
widget_control,base,/real
xmanager,'imagemap',/no_bl,base

; Stuff everything we need to remember into the uvalue of the base
widget_control,base,set_uvalue={stop:stop,draw:draw,poly:poly,squa:squa,mode:'poly',x:fltarr(1000),y:fltarr(1000),nx:0,img:a,img0:a,relo:relo,ys:ys,text:text,writ:writ,circ:circ,url:url,outfilename:outfilename}

; Put the image into the draw widget
widget_control,draw,get_value=index
wset,index
tvlct,r,g,b
tv,a

end