;+
; NAME:
;   xcd
;
; PURPOSE:
;   Change current directory via mouse.
;
;   Two lists are displayed side by side.  The one on the left shows
;   directories.  Click on a directory to cd there.  The list
;   on the right shows files to help you see where you are.
;   (The list on the right does not respond to mouse clicks.)
; CATEGORY:
;   Utility.
; CALLING SEQUENCE:
;   xcd
; INPUTS:
;   None.
; KEYWORD PARAMETERS:
;   None
; OUTPUTS:
;   None.
; SIDE EFFECTS:
;   Your current directory can be changed.
; RESTRICTIONS:
;   Windows & OpenVMS platforms only.  Originally written on Windows95.
;   Should work on other Windows platforms, but I (Paul) havn't tried it.
;
;   With a little effort, one probably could port Xcd to other platforms
;   (i.e. Unix or Mac).
;
;   Note that drive names (e.g. "a:", "c:", etc.) are hardcoded in
;   xcd::init.  Change that line of code to show drive letters
;   appropriate for your system.
;
; PROCEDURE:
;   Xcd creates an object that has a reference to a DirListing, and
;   widgets for displaying that DirListing.  If the user clicks on a
;   sub-directory (or "..\") in the xcd object, or droplist-selects
;   a different drive via the xcd object, the xcd object changes
;   IDL's current directory to that location, and refreshes with a
;   new current-directory DirListing.
;
; MODIFICATION HISTORY:
;   Paul C. Sorenson, July 1997. paulcs@netcom.com.
;        Written with IDL 5.0.  The object-oriented design of Xcd is
;        based in part on an example authored by Mark Rivers.
;   Jim Pendleton, July 1997. jimp@rsinc.com
;        Modified for compatability with OpenVMS as a basis for
;        platform independent code
;   Paul C. Sorenson, July 13 1997.  Changes so that DirListing class
;        methods do not return pointers to data members.  (Better
;        object-oriented design that way.)
;
;-
function dirlisting::init, location
;
;Function DirListing::INIT: construct listing of LOCATION's contents.
;INPUT:
;  LOCATION (optional): string indicating the directory we want listing
;                       of. default is current directory.
;
catch, error_stat
if error_stat ne 0 then begin
   print, !err_string
   return, 0
   end
;
;Store name of location.
;
if n_elements(location) gt 0 then $
   pushd, location
cd, current=current
case !version.os_family of
   'Windows' : begin
      self.Drive = strmid(current, 0, 2)
      self.Path = strmid(current, 2, strlen(current))
      end
   'vms' : begin
      colon = rstrpos(current, ':')
      self.Drive = strmid(current, 0, colon + 1)
      rightbracket = rstrpos(current, ']')
      self.Path = strmid(current, colon + 1, rightbracket - colon)
      end
   else :
   endcase
;
;Obtain listing of location's contents.
;
listing = Findfile()
;listing = File_Search('*')
if n_elements(location) gt 0 then $
   popd
;
;Divide into direcory-only & file-only listings.
;
flags = bytarr(n_elements(listing))
case !version.os_family of
   'Windows' : begin
      for i=0,n_elements(listing)-1 do begin
         if rstrpos(listing[i], '\') eq (strlen(listing[i]) - 1) then $
            flags[i] = 1b
         end
      end
   'vms' : begin
      for i=0,n_elements(listing)-1 do begin
         dotdir = strpos(listing[i], '.DIR;')
         if dotdir ne -1 then begin
            flags[i] = 1b
            rightbracket = rstrpos(listing[i], ']')
            listing[i] = strmid(listing[i], rightbracket + 1, $
               dotdir - rightbracket - 1)
            end
         end
      end
   else :
   endcase

dirs_indx = where(flags, dir_count)
files_indx = where(flags eq 0b, file_count)

if dir_count gt 0 then begin
   dirs = listing[dirs_indx]
   case !version.os_family of
      'Windows' : begin
         dirs = dirs[where(dirs ne '.\')]
         end
      'vms' :
      else :
      endcase
   dirs = dirs[sort(strupcase(dirs))]
   if (!version.os_family eq 'vms') then $
      dirs = ['[-]', 'sys$login', dirs]
   end $
else begin
   if (!version.os_family eq 'vms') then begin
      dirs = ['[-]', 'sys$login']
      end $
   else begin
      dirs = ''
      end
   end

if file_count gt 0 then begin
   files = listing[files_indx]
   case !version.os_family of
      'Windows' : files = files[sort(strupcase(files))]
      'vms' : begin
          for i = 0l, n_elements(files) - 1 do begin
             rightbracket = rstrpos(files[i], ']')
             files[i] = strmid(files[i], rightbracket + 1, $
               strlen(files[i]))
             end
          files = files[sort(strupcase(files))]
          end
      endcase
   end $
else begin
   files = ''
   end
;
;Store pointers to resulting string arrays.
;
self.pSubdirNames = ptr_new(dirs, /no_copy)
self.pFileNames = ptr_new(files, /no_copy)
return, 1 ; Success.
end
;----------------------------------------------------------------------
pro dirlisting::cleanup
ptr_free, self.pSubdirNames
ptr_free, self.pFileNames
end
;----------------------------------------------------------------------
pro dirlisting__define
void = {dirlisting, $
   Drive: '',               $ ; e.g. 'c:'
   Path: '',                $ ; location.  e.g. '\foo\bar'
   pSubdirNames: ptr_new(), $ ; string array of sub-directory names
   pFileNames:   ptr_new()  $ ; string array of file names
   }
end
;----------------------------------------------------------------------
function dirlisting::SubdirNames
return, *self.pSubdirNames
end
;----------------------------------------------------------------------
function dirlisting::FileNames
return, *self.pFileNames
end
;----------------------------------------------------------------------
function dirlisting::Path
return, self.Path
end
;----------------------------------------------------------------------
function dirlisting::Drive
return, self.Drive
end
;----------------------------------------------------------------------
pro xcd::handle, event
catch, error_stat
if error_stat ne 0 then begin
   catch, /cancel
   void = dialog_message(!err_string, /error)
   self->update ; Try again, this time without "cd".
   return
   end

case event.id of
   self.wDirList: begin
      path = self.rDirListing->Path()
;
;     Construct full (if possible) pathname, and cd to it.  (Using
;     a full, rather than relative, pathname here makes xcd impervious
;     to directory changes made by other IDL programs or from the
;     command line.)
;
      case !version.os_family of
         'Windows' : begin
            if rstrpos(path, '\') ne (strlen(path) - 1) then $
               path = path + '\'
            cd, self.rDirListing->Drive() $
              + path                      $
              + (self.rDirListing->SubdirNames())[event.index]
            end
         'vms' : begin
            subdir = (self.rDirListing->SubdirNames())[event.index]
            if (subdir ne '[-]' and subdir ne 'sys$login') then begin
               rightbracket = rstrpos(path, ']')
               leftbracket = strpos(path, '[')
               path = strmid(path, leftbracket + 1, rightbracket - $
                  leftbracket - 1)
               newdir = self.rDirListing->Drive() $
                  + '[' + path + '.' $
                  + subdir + ']'
               end $
            else begin
               newdir = subdir
               end
            cd, newdir
            end
         else:
         endcase
;
      self->update
      widget_control, self.tlb, /update ; workaround.  Resize base.
      end
   self.wDriveList: begin
      widget_control, /hourglass
      case !version.os_family of
         'Windows' : cd, (*self.pDriveNames)[event.index]
         'vms' : cd, (*self.pDriveNames)[event.index] + '[000000]'
         else:
         endcase
      self->update
      widget_control, self.tlb, /update ; workaround.  Resize base.
      end
   else: begin
      end
   endcase

end
;----------------------------------------------------------------------
pro xcd_cleanup, tlb
widget_control, tlb, get_uvalue=rXcd ; get a reference to Xcd.
obj_destroy, rXcd
end
;----------------------------------------------------------------------
pro xcd::cleanup
obj_destroy, self.rDirListing
ptr_free, self.pDriveNames
cd, current=current & print, current
end
;----------------------------------------------------------------------
pro xcd_event, event
widget_control, event.top, get_uvalue=rXcd
rXcd->handle, event
end
;----------------------------------------------------------------------
pro xcd::update
;
;Procedure XCD::UPDATE: set self's widgets and state values to
;  reflect the current directory.
;
widget_control, /hourglass

obj_destroy, self.rDirListing
self.rDirListing = obj_new('dirlisting')

rDirListing = self.rDirListing
indx = where(strupcase(*self.pDriveNames) eq $
             strupcase(rDirListing->Drive()))
widget_control, self.wDriveList, set_droplist_select=indx(0)
widget_control, self.wLabel,     set_value=rDirListing->Path()
widget_control, self.wDirList,   set_value=rDirListing->SubdirNames()
widget_control, self.wFileList,  set_value=rDirListing->FileNames()
end
;----------------------------------------------------------------------
function xcd::init

catch, error_status
if error_status ne 0 then begin
   print, !err_string
   return, 0
   end

case !version.os_family of
   'Windows' : begin
      ;CHANGE THESE HARDCODED DRIVENAMES TO SUIT YOUR SYSTEM.
      self.pDriveNames = ptr_new(['a:', 'c:', 'd:', 'e', 'f', 'g:', 'h:', 'i'])
      end
   'vms' : begin
      openw, lun, 'sys$scratch:idl_xcdtmp.tmp', /get_lun
      printf, lun, '$ loop:'
      printf, lun, '$   disk = f$device("*", "DISK")'
      printf, lun, '$   if (disk .nes. "")'
      printf, lun, '$   then'
      printf, lun, '$       write sys$output disk'
      printf, lun, '$       goto loop'
      printf, lun, '$   endif'
      printf, lun, '$ delete/nolog/noconfirm sys$scratch:idl_xcdtmp.tmp;*'
      free_lun, lun
      spawn, '@sys$scratch:idl_xcdtmp.tmp', drives
      self.pDriveNames = ptr_new(drives)
      end
   else:
   endcase
;
;Create widgets.
;
tlb = widget_base(title='xcd', /column) ; top-level base

readout_base = widget_base(tlb, /row)
self.wDriveList = widget_droplist(readout_base, value=*self.pDriveNames)
self.wLabel = widget_label(readout_base, /dynamic_resize)

list_base = widget_base(tlb, /row)
ysize = 20 ; Looks good on my (Paul's) monitor.
self.wDirList = widget_list(list_base, ysize=ysize)
self.wFileList = widget_list(list_base, ysize=ysize)
;
;Set values.
;
self->update
self.tlb = tlb
widget_control, tlb, set_uvalue=self
;
;Center and realize tlb.
;
device, get_screen_size=scrsz
widget_control, tlb, map=0
widget_control, tlb, /realize
tlb_geometry = widget_info(tlb, /geometry)
widget_control, tlb, $
                tlb_set_xoffset= 0 > (scrsz(0) - tlb_geometry.scr_xsize) / 2, $
                tlb_set_yoffset= 0 > (scrsz(1) - tlb_geometry.scr_ysize) / 2
widget_control, tlb, map=1
widget_control, tlb, /update ; workaround.  Resize base.
;
xmanager, 'xcd', tlb, cleanup='xcd_cleanup', /just_reg, /no_block
return, 1 ; Success.
end
;----------------------------------------------------------------------
pro xcd__define
void = {xcd,        $
   tlb:         0L, $      ; top-level base
   wDriveList:  0L, $      ; droplist of available drives.
   wLabel:      0L, $      ; shows name of current directory
   wDirList:    0L, $      ; shows sub-directories in current directory
   wFileList:   0L, $      ; shows files in current directory
   pDriveNames: ptr_new(),$; String array.  e.g. ['c:', 'd:', etc.]
   rDirListing: obj_new() $; listing of current directory
   }
end
;----------------------------------------------------------------------
pro xcd
;
on_error, 2 ; Return to caller if error.

if obj_new('xcd') eq obj_new() then $
   message, 'failed to create xcd object.'

xmanager
end