;+
; NAME:
;   FSC_FILESELECT
;
; PURPOSE:
;
;   The purpose of this compound widget is to provide a means
;   by which the user can type or select a file name. The
;   program is written as an "object widget", meaning that
;   the guts of the program is an object of class FSC_FILESELECT.
;   This is meant to be an example of the obvious advantages of
;   writing compound widget programs as objects.
;
; AUTHOR:
;
;   FANNING SOFTWARE CONSULTING
;   David Fanning, Ph.D.
;   1645 Sheely Drive
;   Fort Collins, CO 80526 USA
;   Phone: 970-221-0438
;   E-mail: davidf@dfanning.com
;   Coyote's Guide to IDL Programming: http://www.dfanning.com/
;
; CATEGORY:
;
;   General programming.
;
; CALLING SEQUENCE:
;
;   filenameID = FSC_FileSelect(parent)
;
; INPUT PARAMETERS:
;
;   parent -- The parent widget ID of the compound widget. Required.
;
; INPUT KEYWORDS:
;
;   Event_Pro -- The event handler procedure for this compound widget.By default: "".
;   Event_Func -- The event handler function for this compound widget. By default: "".
;
;      If neither EVENT_PRO or EVENT_FUNC is defined, program events are handled internally by the compound widget.
;
;   DirectoryName -- The initial name of the directory. By defaut: current directory.
;   Filename -- The initial file name in the filename text widget.
;   Filter -- The file filter. By default: "*".
;   Frame -- Set this keyword for a frame around the compound widget.
;   LabelFont -- The font for the label widget. By default: "".
;   LabelName -- The text on the label widgt. By default: "Filename: ".
;   LabelSize -- The X screen size of the label widget. By default: 0.
;   MustExist -- A flag that indicates selected files must exist. By default: 0.
;   NoMaxSize -- A flag to prohibit automatic text widget sizing. By default: 0.
;
;     If this keyword is not set, the compound widget will automatically resize itself to
;     the largest widget in its parent base widget. It will do this by changing the size of
;     the text widgets holding the file and directory names.
;
;   Read -- Set this keyword to have file selection for reading a file. By default: 1.
;   SelectDirectory -- The default directory for file selection. In other words, this is the
;     default directory for DIALOG_PICKFILE, which is accessed via the BROWSE buttons.
;   SelectFont -- The font for the "Browse" button. By default: "".
;   SelectTitle -- The title bar text on the file selection dialog. By default: "Select a File...".
;   TextFont -- The font for the filename text widget. By default: "".
;   UValue -- User value for any purpose.
;   Write -- Set this keyword to open a file for writing. By default: 0.
;   XSize -- The X size of the text widget holding the filename. By default: StrLen(filename) * 1.5 > 40.
;
; OUTPUT KEYWORDS:
;
;   ObjectRef -- Assign this keyword to an output variable that will hold the internal object reference.
;                With the object reference you can call object methods to easily change many properties of
;                the compound widget.
;
; COMMON BLOCKS:
;
;   None.
;
; RESTRICTIONS:
;
;   Requires the folling files from the Coyote Library:
;
;      http://www.dfanning.com/programs/error_message.pro
;
; EVENT STRUCTURE:
;
;   All events are handled internally unless either the Event_Pro or Event_Func
;   keywords are used to assign an event handler to the compound widget. All events
;   generated by the text widgets are passed to the assigned event handler.
;
;   event = { CW_FILESELECT, $     ; The name of the event structure.
;             ID: 0L, $            ; The ID of the compound widget's top-level base.
;             TOP: 0L, $           ; The widget ID of the top-level base of the hierarchy.
;             HANDLER: 0L, $       ; The event handler ID. Filled out by IDL.
;             Basename: "", $      ; The base filename without directory specifiers.
;             Filename: "", $      ; The fully qualified filename.
;             Directory: "", $     ; The name of the current file directory.
;           }
;
; EXAMPLE:
;
;   An example program is provided at the end of the FSC_FILESELECT code. To run it,
;   type these commands:
;
;      IDL> .Compile fsc_fileselect
;      IDL> Example
;
;   Or, if you want to obtain the object reference, type this:
;
;      IDL> Example, theObject
;
;   Now you can call the object's methods. For example:
;
;      IDL theObject->SetProperty, XSize=150
;
; GETTING and SETTING VALUES:
;
;   So as not to disrupt the accepted paradigm in using compound widgets, you
;   can use the return value of the FSC_FILESELECT function with WIDGET_CONTROL to
;   get and set the "value" of the widget.
;
;       Widget_Control, filenameID, Set_Value='C:\RSI\IDL52\DATA\cyclone.dat'
;
;   The program will automatically separate the file name portion of the value
;   from the directory portion and put things in the correct text widgets.
;
;   Similarly, you can get the "value" of the widget:
;
;       Widget_Control, filenameID, Get_Value=theValue
;       Print, theValue
;
;           C:\RSI\IDL52\DATA\cyclone.dat
;
;   The return value is the fully qualified file path to the file.
;
; USING OBJECT METHODS to CHANGE PROGRAM PROPERTIES:
;
;   If you obtain the object reference, you have a great deal more control
;   over the properties of the compound widget. You obtain the object reference
;   by calling the function like this:
;
;      filenameID = FSC_FILESELECT(parent, ObjectRef=theObject)
;
; OBJECT PROCEDURE METHODS:
;
;   GetProperty -- This method allows various properties of the widget to be
;       returned via output keywords. The keywords that are available are:
;
;      DirectoryName -- The current directory.
;      Event_Func -- The name of the event handler function for this compound widget.
;      Event_Pro -- The name of the event handler procedure for this compound widget.
;      Filename -- The current base filename.
;      Filter -- The current file filter.
;      LabelName -- The text on the label widget.
;      LabelSize -- The X screen size of the label widget.
;      MustExist -- A flag that indicates selected files must exist to be selected.
;      Parent -- The parent widget of the compound widget.
;      Read=read -- The file selection for reading flag.
;      SelectTitle -- The title bar text on the file selection dialog.
;      TLB -- The top-level base of the compound widget.
;      UValue -- The user value of the compound widget.
;      Write -- The file selection for writing flag.
;      XSize -- The X size of the text widget holding the filename.
;
;   LabelSize -- This method makes sure that the directory name and file name labels
;      are the same size. Normally, this procedure is called internally. No parameters.
;
;   MatchSize -- This method resizes the compound widget so that it is as long as the
;      the longest widget in the parent base widget. This is done automatically upon
;      realization unless the NOMAXSIZE keyword is set. The method aids in writing
;      resizeable widget programs.
;
;   SetProperty -- This method allows various properties of the widget to be
;       set via input keywords. The keywords that are available are:
;
;      DirectoryName -- The current directory.
;      Event_Func -- The name of the event handler function for this compound widget.
;      Event_Pro -- The name of the event handler procedure for this compound widget.
;      Filename -- The current base filename.
;      Filter -- The current file filter.
;      LabelName -- The text on the label widget.
;      LabelSize -- The X screen size of the label widget.
;      MustExist -- A flag that indicates selected files must exist to be selected.
;      Read -- The file selection for reading flag.
;      SelectTitle -- The title bar text on the file selection dialog.
;      UValue -- The user value of the compound widget.
;      Write -- The file selection for writing flag.
;      XSize -- The X size of the text widget holding the filename.
;
;   TextSelect - Allows you to create a selection in filename text widget. See the
;                documentation for the SET_TEXT_SELECT keyword to Widget_Control.
;
;      selection -- A two-element array containing the starting position and selection length.
;
; OBJECT FUNCTION METHODS:
;
;      GetFileName -- Returns the fully qualified filename. No parameters.
;
;      GetTLB -- Returns the top-level base ID of the compound widget. No Parameters.
;
;      Inspect_DirectoryName -- Inspects the directory name for correctness. Requires one positional parameter.
;
;        directoryName -- The name of the directory from the directory text widget.
;        textSelection -- The current text selection position.
;
;        At the moment all this does is remove any blank characters from either
;        end of the directory name and makes sure the last character of the directory
;        name does not end in a subdirectory specifier (except for VMS).
;
;     Inspect_Filename -- Inspects the file name for correctness. Requires one positional parameter.
;
;        filename -- The name of the file from the filename text widget.
;        textSelection -- The current text selection position.
;
;        At the moment all this does is remove any blank characters from either
;        end of the file name
;
; MODIFICATION HISTORY:
;
;   Written by: David W. Fanning, 21 NOV 1999.
;   Fixed bug in File Name selection button. 18 MAR 2000. DWF.
;   Fixed an error in which directory the Browse buttons should start
;       searching. 29 SEP 2000. DWF.
;   Previously returned events only for typing in text widgets. Now
;       Browse button events are also returned. 29 SEP 2000. DWF.
;   Fixed a bug in setting the file filter. 29 SEP 2000. DWF.
;   Removed the Directory Browse button 10 AUG 2002. DWF.
;   Added ERROR_MESSAGE to error handling. 10 AUG 2002. DWF.
;   Changed the ability to specify a file filter as a string array, instead
;       of just as a scalar string. This required the use of a pointer, which
;       meant that I had to remove the FILTER field from the CW_FILESELECT
;       event structure to avoid likely memory leakage. This is a dangerous
;       change because it means programs that relied on this (I expect there
;       are very, very few) will break and it goes against my philosopy of
;       keeping my programs backward compatible. Let me know if you have
;       problems. In testing, I discoved no problems in my own code. 31 OCT 2002. DWF.
;   Fixed a problem with DIALOG_PICKFILE that sometimes allowed users to change
;       directories without selecting a file. 3 Nov 2002. DWF.
;   Fixed a problem with widget resizing with the help of Bob Portman that had plagued
;       me from the beginning. Thanks, Bob! 5 August 2003. DWF
;   Added TEXTSELECT method. 5 Aug 2003. DWF.
;   Had to add FORWARD_FUNCTION statement to get error handler compiled when using
;       DIRECTORY keyword. 24 Nov 2003. DWF.
;   Fixed a problem with too many events going to an event handler specified with
;       the EVENT_PRO or EVENT_FUNC keyword from the text widget. Now only Carriage
;       Return events are passed on to the user-specified event handler. 8 July 2004. DWF.
;   Replace all "\" characters with "/" characters in directory names. 8 Januay 2006. DWF.
;-
;
;###########################################################################
;
; LICENSE
;
; This software is OSI Certified Open Source Software.
; OSI Certified is a certification mark of the Open Source Initiative.
;
; Copyright © 2000-2006 Fanning Software Consulting
;
; This software is provided "as-is", without any express or
; implied warranty. In no event will the authors be held liable
; for any damages arising from the use of this software.
;
; Permission is granted to anyone to use this software for any
; purpose, including commercial applications, and to alter it and
; redistribute it freely, subject to the following restrictions:
;
; 1. The origin of this software must not be misrepresented; you must
;    not claim you wrote the original software. If you use this software
;    in a product, an acknowledgment in the product documentation
;    would be appreciated, but is not required.
;
; 2. Altered source versions must be plainly marked as such, and must
;    not be misrepresented as being the original software.
;
; 3. This notice may not be removed or altered from any source distribution.
;
; For more information on Open Source Software, visit the Open Source
; web site: http://www.opensource.org.
;
;###########################################################################



PRO FSC_FileSelect::Directory_Events, event

; This method handles any typing in the directory name text widget.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message(/Traceback)
   RETURN
ENDIF

   ; Don't deal with selection events.

IF event.type EQ 3 THEN RETURN

   ; Inspect the directory name and set it.

Widget_Control, self.dirtextID, Get_Value=dirname
dirname = dirname[0]
textSelection = Widget_Info(self.dirtextID, /Text_Select)
dirname = self->Inspect_DirectoryName(dirname, textSelection[0])
dirname = StrJoin( StrSplit(dirname, '\\', /Regex, /Extract, /Preserve_Null), '/')

self.directoryname = dirname
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect::Filename_Events, event

; This method handles any typing in the file name text widget.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message(/Traceback)
   RETURN
ENDIF

   ; Don't deal with selection events.

IF event.type EQ 3 THEN RETURN

   ; Inspect the file name and set it.

Widget_Control, self.filetextID, Get_Value=filename
filename = filename[0]
textSelection = Widget_Info(self.filetextID, /Text_Select)
filename = self->Inspect_Filename(filename, textSelection[0])
filename = StrJoin( StrSplit(filename, '\\', /Regex, /Extract, /Preserve_Null), '/')
self.filename = filename
END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect::GetFilename

; This method returns the fully-qualified filename. Checks to be
; sure the last character in the directory name is not a directory
; specifier.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN, -1
ENDIF

   ; Get the correct directory separator.

CASE StrUpCase(!Version.OS_Family) OF
   'MACOS'   : sep = ':'    ; Macintoshes
   'VMS'     : sep = ']'    ; VMS machines
   ELSE      : sep = '/'    ; Unix machines
ENDCASE

IF StrUpCase(!Version.OS_Family) NE "VMS" THEN BEGIN
   length = StrLen(self.directoryName)
   WHILE StrMid(self.directoryName, length-1, 1) EQ sep DO BEGIN
      self.directoryName = StrMid(self.directoryName, 0, length-1)
      Widget_Control, self.dirTextID, Set_Value=self.directoryName
      length = StrLen(self.directoryName)
   ENDWHILE
ENDIF

filename = Filepath(Root_Dir=self.directoryName, self.filename)
filename = StrJoin( StrSplit(filename, '\\', /Regex, /Extract, /Preserve_Null), '/')
RETURN, filename
END ;-------------------------------------------------------------------------------



FUNCTION FSC_FileSelect::GetNoMaxSize
RETURN, self.nomaxsize
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect::GetProperty, $
   DirectoryName=dirname, $        ; The current directory.
   Event_Func=event_func, $        ; The name of the event handler function for this compound widget.
   Event_Pro=event_pro, $          ; The name of the event handler procedure for this compound widget.
   Filename=filename, $            ; The current filename.
   Filter=filter, $                ; The current file filter.
   LabelName=labelname, $          ; The text on the label widget.
   LabelSize=labelsize, $          ; The X screen size of the label widget.
   MustExist=mustexist, $          ; A flag that indicates selected files must exist to be selected.
   Parent=parent, $                ; The parent widget of the compound widget.
   Read=read, $                    ; The file selection for reading flag.
   SelectTitle=selecttitle, $      ; The title bar text on the file selection dialog.
   TLB=tlb, $                      ; The top-level base of the compound widget.
   UValue=uvalue, $                ; The user value of the compound widget.
   Write=write, $                  ; The file selection for writing flag.
   XSize=xsize                     ; The X size of the text widget holding the filename.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN
ENDIF

dirname = self.directoryname
event_pro = self.event_pro
event_func = self.event_func
filename = self.filename
filter = *self.filter
labelname = self.labelname
labelsize = self.labelsize
mustexist = self.mustexist
parent=self.parent
read = self.read
selecttitle = self.selecttitle
tlb = self.tlb
uvalue = *self.uvalue
wirte = self.write
xsize = self.xsize

END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect::GetTLB
RETURN, self.tlb
END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect::Inspect_DirectoryName, dirname, textSelection

; This method removes leading and trailing blank characters
; in the directory name.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN, -1
ENDIF

thisDir = StrTrim(dirname, 2)
IF StrLen(thisDir) NE StrLen(dirname) THEN $
   textSelection = textSelection-( StrLen(dirname) - StrLen(thisDir) )
Widget_Control, Set_Value=thisDir, self.dirtextID, Set_Text_Select=[textSelection, 0]
RETURN, thisDir
END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect::Inspect_Filename, filename, textSelection

; This method removes leading and trailing blank characters
; in the filename.

Catch, theError
IF theError NE 0 THEN BEGIN
   Catch, /Cancel
   ok = Error_Message()
   RETURN, -1
ENDIF

thisFile = StrTrim(filename, 2)
IF StrLen(thisFile) NE StrLen(filename) THEN $
   textSelection = textSelection-( StrLen(filename) - StrLen(thisFile) )
Widget_Control, Set_Value=thisFile, self.filetextID, Set_Text_Select=[textSelection, 0]
RETURN, thisFile
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect::LabelSize

; This method ensures the directory and filename labels are the same size.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN
ENDIF

fgeo = Widget_Info(self.filelabelID, /Geometry)
dgeo = Widget_Info(self.dirlabelID, /Geometry)
bestSize = fgeo.scr_xsize > dgeo.scr_xsize
Widget_Control, self.fileLabelID, Scr_XSize=bestSize
Widget_Control, self.dirLabelID, Scr_XSize=bestSize
END ;-------------------------------------------------------------------------------



PRO FSC_FileSelect::MatchSize

; This method makes the compound widget the same size as the largest
; widget in the parent base widget. It does this by adjusting
; the text widget sizes.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN
ENDIF

   ; Get the geometries of the filename widgets.

tgeo = Widget_Info(self.tlb, /Geometry)
fgeo = Widget_Info(self.filetextID, /Geometry)
bbgeo = Widget_Info(self.filebaseID, /Geometry)
lbgeo = Widget_Info(Widget_Info(self.dirbaseID, /Parent), /Geometry)
rbgeo = Widget_Info(Widget_Info(self.filebrowseID, /Parent), /Geometry)

   ; Add the bits and bobs together.

fspacing = tgeo.space
fpadding = 2*tgeo.xpad + 2*lbgeo.xpad
ffixedsize = ( bbgeo.scr_xsize - 2*bbgeo.margin - (fgeo.scr_xsize) + $
               rbgeo.scr_xsize - 2*rbgeo.margin )

   ; Get the geometries of the directory name widgets.

fgeo = Widget_Info(self.dirtextID, /Geometry)
bbgeo = Widget_Info(self.dirbaseID, /Geometry)

   ; Add the bits and bobs together.

dspacing = tgeo.space
dpadding = 2*tgeo.xpad + 2*lbgeo.xpad
dfixedsize = ( bbgeo.scr_xsize - 2*bbgeo.margin - (fgeo.scr_xsize) + $
               rbgeo.scr_xsize - 2*rbgeo.margin )

   ; Go find all the children and find the biggest one of them.

thisSize = 0
childID = Widget_Info(self.parent, /Child)
geom = Widget_Info(childID, /Geometry)
testSize = geom.scr_xsize - 2*geom.margin
thisSize = thisSize > testSize
WHILE childID NE 0 DO BEGIN
   childID = Widget_Info(childID, /Sibling)
   IF childID GT 0 THEN BEGIN
      geom = Widget_Info(childID, /Geometry)
      testSize = geom.scr_xsize - 2*geom.margin
      thisSize = thisSize > testSize
   ENDIF
ENDWHILE

   ; Resize the widgets

ftextsize = thisSize - (fspacing + fpadding + ffixedsize)
Widget_Control, self.filetextID, Scr_XSize=ftextsize

dtextsize = thisSize - (dspacing + dpadding + dfixedsize)
Widget_Control, self.dirtextID, Scr_XSize=dtextsize

END ;-------------------------------------------------------------------------------



FUNCTION FSC_FileSelect_RStrPos, Expr, SubStr, Pos

  ON_ERROR, 2
  N = N_PARAMS()
  if (n lt 2) then message, 'Incorrect number of arguments.'

  ; Is expr an array or a scalar? In either case, make a result
  ; that matches.
  if (size(expr, /n_dimensions) eq 0) then result = 0 $
  else result = make_array(dimension=size(expr,/dimensions), /INT)

  RSubStr = STRING(REVERSE(BYTE(SubStr))) ; Reverse the substring

  for i = 0, n_elements(expr) - 1 do begin
    Len = STRLEN(Expr[i])
    IF (N_ELEMENTS(Pos) EQ 0) THEN Start=0 ELSE Start = Len - Pos

    RString = STRING(REVERSE(BYTE(Expr[i]))) ; Reverse the string

    SubPos = STRPOS(RString, RSubStr, Start)
    IF SubPos NE -1 THEN SubPos = Len - SubPos - STRLEN(SubStr)
    result[i] = SubPos
  endfor

  RETURN, result
END ;-------------------------------------------------------------------------



PRO FSC_FileSelect::Select_File, event

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN
ENDIF

; Use the file selection dialog to obtain a filename.

currentFilename = self.filename
self.filename = ""
filename = Dialog_Pickfile( File=self.filename, $
                            Filter=*self.filter, $
                            Path=self.directoryname, $
                            Get_Path=thePath, $
                            Must_Exist=self.mustexist, $
                            Read=self.read, $
                            Title=self.selecttitle, $
                            Write=self.write )

IF filename EQ "" THEN BEGIN
   self.filename = currentFilename
   RETURN
ENDIF

   ; Remove the directory from the name.

index = StrLen(thePath)
theFilename = StrMid(filename, index)

   ; Strip the last directory separator.

length = StrLen(thePath)
thePath = StrMid(thePath, 0, length-1)

   ; Inspect the file name to make sure it is valid.

textSelection = Widget_Info(self.filetextID, /Text_Select)
filename = self->Inspect_Filename(filename, textSelection[0])

   ; Update the display.

self->SetProperty, Filename=theFilename, DirectoryName=thePath

END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect::SetFilename, theName

; This method separates the filename into directory and filename
; and adds them to the interface.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN
ENDIF

; Change back slashes to forward slashes.
theName = StrJoin( StrSplit(theName, '\\', /Regex, /Extract, /Preserve_Null), '/')

   ; Get the correct directory separator.

CASE StrUpCase(!Version.OS_Family) OF
   'MACOS'   : sep = ':'    ; Macintoshes
   'VMS'     : sep = ']'    ; VMS machines
   ELSE      : sep = '/'    ; Unix machines
ENDCASE

index = FSC_FileSelect_RStrPos(theName, sep)
IF index EQ -1 THEN BEGIN
   self->SetProperty, Filename=theName
   self.filename = theName
ENDIF ELSE BEGIN
   directoryName = StrMid(theName, 0, index)
   filename = StrMid(theName, index+1)
   self->SetProperty, Filename=filename, Directory=directoryName
   self.filename = filename
   self.directoryName = directoryName
ENDELSE
END ;-------------------------------------------------------------------------------



PRO FSC_FileSelect::SetProperty, $
   DirectoryName=dirname, $        ; The initial name of the directory. By defaut: current directory.
   Event_Func=event_func, $        ; The event handler function for this compound widget.
   Event_Pro=event_pro, $          ; The event handler procedure for this compound widget.
   Filename=filename, $            ; The initial file name in the filename text widget.
   Filter=filter, $                ; The file filter.
   LabelName=labelname, $          ; The text on the label widgt.
   LabelSize=labelsize, $          ; The X screen size of the label widget.
   MustExist=mustexist, $          ; A flag that indicates selected files must exist.
   Read=read, $                    ; Set this keyword to have file selection for reading a file.
   SelectTitle=selecttitle, $      ; The title bar text on the file selection dialog.
   UValue=uvalue, $                ; User value for any purpose.
   Write=write, $                  ; Set this keyword to open a file for writing.
   XSize=xsize                     ; The X size of the text widget holding the filename.

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN
ENDIF

IF N_Elements(dirname) NE 0 THEN BEGIN
   dirname = StrJoin( StrSplit(dirname, '\\', /Regex, /Extract, /Preserve_Null), '/')
   self.directoryname = dirname
   Widget_Control, self.dirtextID, Set_Value=dirname
ENDIF

IF N_Elements(event_pro) NE 0 THEN BEGIN
   self.event_pro = event_pro
   Widget_Control, self.tlb, Event_Pro=event_pro
ENDIF

IF N_Elements(event_func) NE 0 THEN BEGIN
   self.event_func = event_func
   Widget_Control, self.tlb, Event_Func=event_func
ENDIF

IF N_Elements(filename) NE 0 THEN BEGIN
   self.filename = filename
   strlength = StrLen(filename)
   Widget_Control, self.filetextID, Set_Value=filename
ENDIF

IF N_Elements(labelname) NE 0 THEN BEGIN
   self.labelname = labelname
   Widget_Control, self.filelabelID, Set_Value=labelname
ENDIF

IF N_Elements(labelsize) NE 0 THEN BEGIN
   Widget_Control, self.filelabelID, Scr_XSize=labelsize
ENDIF

IF N_Elements(filter) NE 0 THEN *self.filter = filter
IF N_Elements(mustexist) NE 0 THEN self.mustexist = mustexist
IF N_Elements(read) NE 0 THEN self.read = read
IF N_Elements(selecttitle) NE 0 THEN self.selecttitle = selecttitle
IF N_Elements(uvalue) NE 0 THEN *self.uvalue = uvalue
IF N_Elements(write) NE 0 THEN self.write = write

IF N_Elements(xsize) NE 0 THEN BEGIN
   Widget_Control, self.filetextID, XSize=xsize
   Widget_Control, self.dirtextID, XSize=xsize
ENDIF

END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect::TextSelect, selection

Catch, theError
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN
ENDIF

IF N_Elements(selection) NE 2 THEN Message, 'Text selection array is not a two-element array: [beginSelection, selectionLength]'
Widget_Control, self.fileTextID, Set_Text_Select=selection

END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect::CLEANUP
Ptr_Free, self.uvalue
Ptr_Free, self.filter
END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect::INIT, $
   parent, $                       ; The parent widget ID of the compound widget.
   DirectoryName=dirname, $        ; The initial name of the directory. By defaut: current directory.
   Event_Pro=event_pro, $          ; The event handler procedure for this compound widget.By default: "".
   Event_Func=event_func, $        ; The event handler function for this compound widget. By default: "".
   Filename=filename, $            ; The initial file name in the filename text widget.
   Filter=filter, $                ; The file filter. By default: "*".
   Frame=frame, $                  ; Set this keyword for a frame around the compound widget.
   LabelFont=labelfont, $          ; The font for the label widget. By default: "".
   LabelName=labelname, $          ; The text on the label widgt. By default: "Filename: ".
   LabelSize=labelsize, $          ; The X screen size of the label widget. By default: 0.
   MustExist=mustexist, $          ; A flag that indicates selected files must exist. By default: 0.
   NoMaxSize=nomaxsize, $          ; A flag to prohibit automatica text widget sizing. By default: 0.
   Read=read, $                    ; Set this keyword to have file selection for reading a file. By default: 1.
   Scr_XSize=scr_xsize, $          ; The X screen size of the compound widget. By default: 0
   SelectFont=selectfont, $        ; The font for the "Browse" button. By default: "".
   Selectdir=selectdir, $          ; The inital directory for file and directory selections.
   SelectTitle=selecttitle, $      ; The title bar text on the file selection dialog. By default: "Select a File...".
   TextFont=textfont, $            ; The font for the filename text widget. By default: "".
   UValue=uvalue, $                ; User value for any purpose.
   Write=write, $                  ; Set this keyword to open a file for writing. By default: 0.
   XSize=xsize                     ; The X size of the text widget holding the filename. By default: StrLen(filename) * 1.5 > 40.

Catch, theError
;theError = 0
IF theError NE 0 THEN BEGIN
   Catch, /Cancel
   ok = Error_Message()
   RETURN, 0
ENDIF

   ; Populate self object.

self.parent = parent
self.directoryname = dirname
self.event_pro = event_pro
self.event_func = event_func
self.filename = filename
self.filter = Ptr_New(filter)
self.frame = frame
self.labelfont = labelfont
self.labelname = labelname
self.labelsize = labelsize
self.mustexist = mustexist
self.nomaxsize = nomaxsize
self.read = read
self.selectdir = selectdir
self.selectfont = selectfont
self.selecttitle = selecttitle
self.textfont = textfont
self.uvalue = Ptr_New(uvalue)
self.write = write
self.xsize = xsize


   ; Build widgets.

self.tlb = Widget_Base( self.parent, $
                        Event_Func = self.event_func, $
                        Event_Pro = self.event_pro, $
                        Frame = self.frame, $
                        Func_Get_Value='FSC_FileSelect_Get_Value', $
                        Pro_Set_Value='FSC_FileSelect_Set_Value', $
                        Row = 1, $
                        Base_Align_Center=1, $
                        UValue=*self.uvalue )

   ; Put the self object in the first child of the TLB.

leftbase = Widget_Base(self.tlb, Row=2, UValue=self)

self.dirbaseID = Widget_Base(leftbase, Row=1)

self.dirlabelID = Widget_Label( self.dirbaseID, $
                             Font=self.labelfont, $
                             Scr_XSize=self.labelsize, $
                             Value='Directory: ' )


self.dirtextID = Widget_Text( self.dirbaseID, $
                           All_Events=1, $
                           Editable=1, $
                           Event_Func='FSC_FileSelect_Event_Handler', $
                           Font=self.textfont, $
                           UValue={method:'Directory_Events', object:self}, $
                           Value=self.directoryname, $
                           XSize=self.xsize, $
                           YSize=1 )


self.filebaseID = Widget_Base(leftbase, Row=1)

self.filelabelID = Widget_Label( self.filebaseID, $
                             Font=self.labelfont, $
                             Kill_Notify='FSC_FileSelect_Kill_Notify', $
                             Notify_Realize='FSC_FileSelect_Notify_Realize', $
                             Scr_XSize=self.labelsize, $
                             UValue=self, $
                             Value=self.labelname )


self.filetextID = Widget_Text( self.filebaseID, $
                           All_Events=1, $
                           Editable=1, $
                           Event_Func='FSC_FileSelect_Event_Handler', $
                           Font=self.textfont, $
                           UValue={method:'Filename_Events', object:self}, $
                           Value=self.filename, $
                           XSize=self.xsize, $
                           YSize=1 )

rightbase = Widget_Base(self.tlb, Row=1, Base_Align_Center=1)
self.filebrowseID = Widget_Button( rightbase, $
                               Event_Func='FSC_FileSelect_Event_Handler', $
                               UValue={method:'Select_File', object:self}, $
                               Value='Browse')


RETURN, 1
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect__Define

   objectClass = { FSC_FileSelect, $      ; The object class FSC_FILESELECT.
                   parent: 0L, $          ; The ID of the parent widget.
                   tlb: 0L, $             ; The ID of the top-level base widget for the compound widget.
                   filebaseID: 0L, $      ; The ID of the filename base widget.
                   dirbaseID: 0L, $       ; The ID of the directory base widget.
                   filelabelID: 0L, $     ; The ID of the filename label widget.
                   dirlabelID: 0L, $      ; The ID of the directory label widget.
                   filetextID: 0L, $      ; The ID of the filename text widget.
                   dirtextID: 0L, $       ; The ID of the directory text widget.
                   filebrowseID: 0L, $    ; The ID of the file browse button widget.
                   dirbrowseID: 0L, $     ; Unused currently. Left here for compatibility reasons..
                   event_pro: "", $       ; The user-defined name of the event procedure for the widget.
                   event_func: "", $      ; The user-defined name of the event function for the widget.
                   filename: "", $        ; The current contents of the filename text widget.
                   directoryname: "", $   ; The current contents of the directory text widget.
                   frame: 0L, $           ; A flag to indicate a frame around the compound widget.
                   filter: Ptr_New(), $   ; The current file filter used in file selection.
                   labelfont: "", $       ; The font for the label widgets.
                   labelname: "", $       ; The VALUE of the file name label widget.
                   labelsize: 0L, $       ; The X screen size fo the label widgets.
                   mustexist: 0L, $       ; If this field is 1, the user can only select files that exist.
                   nomaxsize: 0L, $       ; This widget sizes itself to the largest widget in the base, unless this is set.
                   read: 0L, $            ; Set this keyword to select a file for reading.
                   selectdir: "", $       ; The inital directory used for file selection.
                   selectfont: "", $      ; The font used for the Browse buttons.
                   selecttitle: "", $     ; The text on the Dialog_Pickfile widget.
                   textfont: "", $        ; The font used in the text widgets.
                   uvalue: Ptr_New(), $   ; The user's user value. Unused by the program.
                   write: 0L, $           ; Set this keyword to select a file for writing.
                   xsize: 0L $            ; The X size of the text widgets.
                 }

END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect_Set_Value, id, filename

; This function sets the filename of the widget, using the
; traditional "Widget_Control, fieldID, Set_Value=filename" syntax.
; The directory will be stripped off the filename, if required.

firstChild = Widget_Info(id, /Child)
Widget_Control, firstChild, Get_UValue=self
self->SetFilename,filename
END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect_Get_Value, id

; This function returns the filename of the widget, using the
; traditional "Widget_Control, fieldID, Get_Value=filename" syntax.

firstChild = Widget_Info(id, /Child)
Widget_Control, firstChild, Get_UValue=self
RETURN, self->GetFilename()
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO CW_FileSelect__Define

; The event structure definition. This is the event structure returned by the compound widget.

   eventStructure = { CW_FileSelect, $     ; The name of the event structure.
                      ID: 0L,  $           ; The ID of the top-level base of the compound widget.
                      TOP: 0L, $           ; The ID of the top-level base.
                      HANDLER: 0L, $       ; The ID of the event handler widget.
                      Filename: "", $      ; The fully qualified file name.
                      Basename: "", $      ; The base file name without directory attached.
                      Directory: "" }      ; The file directory.
END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect_Event_Handler, event

; The main event handler for the compound widget. It reacts
; to "messages" in the UValues of widgets that generate events.
; The messages indicate which object method to call. A message
; consists of an object method and the self object reference.

Widget_Control, event.ID, Get_UValue=theMessage

Call_Method, theMessage.method, theMessage.object, event

   ; Events will be sent only if there is an assigned event handler.

self = theMessage.object
self->GetProperty, Filename=filename, DirectoryName=directory, $
   Event_Pro=event_pro, Event_Func=event_func
IF event_pro NE "" OR event_func NE "" THEN BEGIN

    pseudoevent = {CW_FileSelect, self->GetTLB(), event.top, 0L, $
      Filepath(Root_Dir=directory, filename),  filename, directory}

    ; Don't return events from text widgets, unless the user has typed
    ; a cariage return.
    eventName = Tag_Names(event, /Structure_Name)
    IF eventName NE "" THEN BEGIN

       IF StrMid(eventName, 0, 11) EQ 'WIDGET_TEXT' THEN BEGIN
          IF (eventName EQ 'WIDGET_TEXT_CH') THEN BEGIN
            IF (event.ch EQ 10) THEN RETURN, pseudoevent ELSE RETURN, 0
          ENDIF ELSE RETURN, 0
       ENDIF
    ENDIF
    RETURN, pseudoevent
ENDIF ELSE RETURN, 0
END ;-----------------------------------------------------------------------------------------------------------------------------


PRO FSC_FileSelect_Notify_Realize, labelID

; When the compound widget is realized, make sure sizes are correct.

Widget_Control, labelID, Get_UValue=self
IF self->GetNoMaxSize() THEN RETURN
self->Matchsize
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO FSC_FileSelect_Kill_Notify, labelID

; When the compound widget dies, destroy the self object.

Widget_Control, labelID, Get_UValue=self
Obj_Destroy, self
END ;-----------------------------------------------------------------------------------------------------------------------------



FUNCTION FSC_FileSelect, $
   parent, $                       ; The parent widget ID of the compound widget.
   Event_Pro=event_pro, $          ; The event handler procedure for this compound widget.By default: "".
   Event_Func=event_func, $        ; The event handler function for this compound widget. By default: "".
   DirectoryName=dirname, $        ; The initial name of the directory. By defaut: current directory.
   Filename=filename, $            ; The initial file name in the filename text widget.
   Filter=filter, $                ; The file filter. By default: "*".
   Frame=frame, $                  ; Set this keyword for a frame around the compound widget.
   LabelFont=labelfont, $          ; The font for the label widget. By default: "".
   LabelName=labelname, $          ; The text on the label widgt. By default: "Filename: ".
   LabelSize=labelsize, $          ; The X screen size of the label widget. By default: 0.
   MustExist=mustexist, $          ; A flag that indicates selected files must exist. By default: 0.
   NoMaxSize=nomaxsize, $          ; A flag to prohibit automatica text widget sizing. By default: 0.
   ObjectRef=objectref, $          ; An output keyword containing the object reference.
   Read=read, $                    ; Set this keyword to have file selection for reading a file. By default: 1.
   SelectDirectory=selectdir, $    ; The default directory for file selection.
   SelectFont=selectfont, $        ; The font for the "Browse" button. By default: "".
   SelectTitle=selecttitle, $      ; The title bar text on the file selection dialog. By default: "Select a File...".
   TextFont=textfont, $            ; The font for the filename text widget. By default: "".
   UValue=uvalue, $                ; User value for any purpose.
   Write=write, $                  ; Set this keyword to open a file for writing. By default: 0.
   XSize=xsize                     ; The X size of the text widget holding the filename. By default: StrLen(filename) * 1.5 > 40.

Catch, theError
;theError = 0
IF theError NE 0 THEN BEGIN
   ok = Error_Message()
   RETURN, 0
ENDIF

   ; Need a parent parameter.

IF N_Elements(parent) EQ 0 THEN BEGIN
   ok = Dialog_Message('FSC_FILESELECT: A parent parameter is required.')
   RETURN, -1
ENDIF

   ; Check keyword arguments.

IF N_Elements(dirname) EQ 0 THEN CD, Current=dirname
dirname = StrJoin( StrSplit(dirname, '\\', /Regex, /Extract, /Preserve_Null), '/')
IF N_Elements(event_pro) EQ 0 THEN event_pro = ""
IF N_Elements(event_func) EQ 0 THEN event_func = ""
IF N_Elements(filename) EQ 0 THEN filename = ""
IF N_Elements(filter) EQ 0 THEN filter = '*'
IF N_Elements(Frame) EQ 0 THEN Frame = 0
IF N_Elements(labelfont) EQ 0 THEN labelfont = ""
IF N_Elements(labelname) EQ 0 THEN labelname = "Filename: "
IF N_Elements(labelsize) EQ 0 THEN labelsize = 0
IF N_Elements(mustexist) EQ 0 THEN mustexist = 0
IF N_Elements(nomaxsize) EQ 0 THEN nomaxsize = 0
IF N_Elements(read) EQ 0 THEN read = 0
IF N_Elements(selectdir) EQ 0 THEN selectdir = dirname
IF N_Elements(selectfont) EQ 0 THEN selectfont = ""
IF Keyword_Set(read) EQ 0 AND Keyword_Set(write) EQ 0 AND $
   N_Elements(selecttitle) EQ 0 THEN selecttitle = "Select a File..." ELSE selecttitle = ""
IF N_Elements(textfont) EQ 0 THEN textfont = ""
IF N_Elements(uvalue) EQ 0 THEN uvalue = ""
IF N_Elements(write) EQ 0 THEN write = 0
IF N_Elements(xsize) EQ 0 THEN xsize = Long(StrLen(dirname) * 1.20 > 40)

   ; Create the underlying structure.

objectref = Obj_New('FSC_FileSelect', $
   parent, $
   DirectoryName=dirname, $
   Event_Pro=event_pro, $
   Event_Func=event_func, $
   Filename=filename, $
   Filter=filter, $
   Frame=frame, $
   LabelFont=labelfont, $
   LabelName=labelname, $
   LabelSize=labelsize, $
   MustExist=mustexist, $
   NoMaxSize=nomaxsize, $
   Read=read, $
   Scr_XSize=scr_xsize, $
   SelectFont=selectfont, $
   SelectTitle=selecttitle, $
   Selectdir=selectdir, $
   TextFont=textfont, $
   UValue=uvalue, $
   Write=write, $
   XSize=xsize )

   ; Return the ID of the top-level base of the compound widget.

  RETURN, objectref->GetTLB()
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO Example_Set_Size, event
Widget_Control, event.top, Get_UValue=theObject
theObject->MatchSize
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO Example_Set_Filter, event
Widget_Control, event.top, Get_UValue=theObject
theObject->SetProperty, Filter='*.pro', Filename='cyclone.pro'
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO Example_Set_Filename, event
Widget_Control, event.top, Get_UValue=theObject
filename = Filepath(Subdir=['examples', 'data'], 'worldelv.dat')
theObject->SetFilename, filename
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO Example_Shrink, event
Widget_Control, event.top, Get_UValue=theObject
theObject->SetProperty, XSize=40
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO Example_Print_Filename, event
Widget_Control, event.top, Get_UValue=theObject
Print, theObject->GetFilename()
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO Example_Quit, event
Widget_Control, event.top, /Destroy
END ;-----------------------------------------------------------------------------------------------------------------------------



PRO Example, theObject

tlb = Widget_Base(Title='Exercise FSC_FILESELECT...', Column=1)
button = Widget_Button(tlb, Value='Make Compound Widget As Big As Me', $
   Event_Pro='Example_Set_Size', Scr_XSize=500)
button = Widget_Button(tlb, Value='Set Filename to worldelv.data in Data Directory', $
   Event_Pro='Example_Set_Filename')
button = Widget_Button(tlb, Value='Print Filename', $
   Event_Pro='Example_Print_Filename')
button = Widget_Button(tlb, Value="Shrink the Text Fields", $
   Event_Pro='Example_Shrink')
CD, Current=thisDir
filenameID = FSC_FileSelect(tlb, Directory=thisDir, Filename='fileselect.pro', $
   /NoMaxSize, ObjectRef=theObject)
button = Widget_Button(tlb, Value='Quit', Event_Pro='Example_Quit')
Widget_Control, tlb, /Realize, Set_UValue=theObject
XManager, 'example', tlb, /No_Block
END ;-----------------------------------------------------------------------------------------------------------------------------