############################################################################
#
#	File:     interact.icn
#
#	Subject:  Procedures to support interactive applications
#
#	Author:   Ralph E. Griswold
#
#	Date:     August 7, 2001
#
############################################################################
#
#   This file is in the public domain.
#
############################################################################
#
#	edit_file(s)	launches an editor, default vi, for the file named
#			s.
#
#	edit_list(L)	provides edit dialog for the strings in the list L.
#
#	error_notice(i, x, s)
#			produces a notice dialog noting a run-time
#			error.  It can be used to handle procedure
#			errors by runerr := error_notice.
#
#	execute()	provides a dialog for specifying a command.
#
#	expose(win)	attempt to make win the active window for the
#			window manager.
#
#	load_file(s, n)	presents a standard open dialog with the caption s.
#			and suggest name n.
#
#			If the user specifies a file that can be opened,
#			dialog_value is set to it.  Otherwise, the dialog
#			is presented again.  The name of the selected
#			button is returned.
#
#	open_image(s)	presents a standard open dialog with the caption s.
#			If the user specifies a file that can be opened as
#			an image in a window, the window is opened.  Otherwise
#			the dialog is presented again.
#
#	ExitNotice(s[])	Notice() that exits.
#
#	FailNotice(s[])	Notice() that fails.
#
#	save_as(s, n)	presents a standard save dialog with the caption s
#			and suggested name n.  If the user specifies a file
#			that can be written, the file is assigned to
#			dialog_value.  Otherwise the dialog is presented
#			again.  save_as() fails if the user cancels.
#
#	save_file(s, n)	presents a standard save dialog with the caption s
#			and suggested name n.  If the user specifies a file
#			that can be written, the file is returned.
#			Otherwise, save_as() is called.  The name of
#			the selected button is returned.
#
#	save_list(s, L)	provides dialog for saving list items in a file.
#
#	select_dialog(s, L, d)	
#			provides a dialog for selecting from a list of
#			items.  d is the default selection.
#
#	snapshot(win, x, y, w, h, n)
#			writes an image file for the specified portion of
#			the window.  The name for the file is requested from
#			the user via a dialog box.  If there already is a
#			file by the specified name, the user is given the
#			option of overwriting it or selecting another name.
#			The procedure fails if the user cancels.  n sets
#			the width of the text-entry field.
#
#	unsupported()	provides Notice() for unsupported feature.
#
############################################################################
#
#  Links:  dsetup, exists, lists, strings
#
############################################################################
#
#  Requires:  Version 9 graphics
#
############################################################################

link dsetup
link io
link lists

procedure edit_file(name)			#: editor launch
   local editor

   TextDialog("Edit:", , name, 30) == "Okay" | fail

   editor := getenv("EDITOR") | "vi"

   return system(editor || " " || dialog_value[1])

end

procedure edit_list(lines)			#: edit lines dialog
   local insert, number, location, bounds, n
   static add_tbl, labels, buttons

   initial {
      add_tbl := table("")
      add_tbl["number"] := 1
      add_tbl["position"] := "after"

      labels := []
      every put(labels, right(1 to 50, 2))

      buttons := ["Okay", "Cancel", "Add", "Delete"]
      }

   repeat {
      case TextDialog("", labels[1 +: *lines], lines, 60, buttons) of {
         "Cancel":   fail
         "Okay":     return dialog_value
         "Delete":   {
            repeat {
               case TextDialog("Delete lines:", , , 60) of {
                  "Cancel":   break next
                  "Okay":     {
                     lines := ldelete(lines, dialog_value[1])
                     if *lines = 0 then {
                        Notice("List empty; creating one line")
                        lines := list(1)
                        }
                     break next
                     }
                  }
               }
            }
         "Add":      {
            repeat {
               add_tbl["location"] :=
                  if add_tbl["position"] == "after" then *lines else 0
               case add_dialog(add_tbl) of {
                  "Cancel":   break next
                  "Okay":     {
                     bounds := (if add_tbl["position"] == "after" then 0 else 1)
                     (0 <= (n := integer(add_tbl["location"] - bounds)) <=
                        (*lines)) | {
                           Notice("Invalid location")
                           add_tbl["location"] := if add_tbl["position"] ==
                              "after" then *lines else 0
                           next
                           }
                     (number := (0 <= integer(add_tbl["number"]))) | {
                           Notice("Invalid number")
                           add_tbl["number"] := 1
                           next
                           }
                     insert := list(number, add_tbl["value"])
                     if n = 0 then lines := insert ||| lines
                     else if n = *lines then lines |||:= insert
                     else lines := lines[1:n] ||| insert ||| lines[n:0]
                     break next
                     }
                  }
               }
            }
         }
      }

end

procedure error_notice(i, x, s)			#: error alert

   return Notice("Error " || i || " " || s,
      "Offending value: " || image(x))

end

procedure execute()				#: command-line launch
   local pipe, win, olist

   OpenDialog("Command line:") == "Okay"  | fail

   olist := []
   pipe := open(dialog_value, "p")

   every put(olist, !pipe)

   close(pipe)

   win := list_win(olist, "command") | fail

   Event(win)

   WClose(win)

   return

end

procedure list_win(lst, label)			#: window for list of strings
   local win

   win := WOpen("canvas=hidden", "label=" || label, "lines=" || *lst + 2,
      "columns=" || maxlen(lst) + 2) | fail

   WWrite(win)
   every WWrite(win, " ", !lst)
   WAttrib(win, "canvas=normal")

   return win

end

procedure expose(win)				#: expose window

#  For some window managers, this can be use to make a window active

#  WAttrib(\win, "canvas=hidden") | fail
#  WAttrib(win, "canvas=normal")

#  However, this should work without the fidgets:

   Raise(win)

   return

end

procedure load_file(caption, n)			#: load dialog
   local button

   repeat {
      (button := OpenDialog(caption, n)) == "Okay" | return button
      dialog_value := open(dialog_value) | {
         Notice("Can't open " || dialog_value)
         next
         }
      return button
      }

end

procedure open_image(caption, atts[])		#: open image
   local button, win

   repeat {
      (button := OpenDialog(caption)) == "Okay" | fail
      put(atts, "image=" || dialog_value)
      win := (WOpen ! atts) | {
         Notice("Can't open " || dialog_value)
         pull(atts)
         next
         }
      return win
      }

end

procedure ExitNotice(s[])			#: notice dialog that fails

   Notice ! s

   exit()

end

procedure FailNotice(s[])			#: notice dialog that fails

   Notice ! s

   fail

end

procedure save_as(caption, name, n)		#: save-as dialog
   local button, file

   repeat {
      if (button :=  SaveDialog(caption, name, n)) == "Yes" then {
         file := dialog_value
         if exists(file) then {
            if TextDialog("Overwrite existing file?") == "Cancel" then next
            }
         dialog_value := open(file, "w") | {
            Notice("Can't write " || dialog_value)
            next
            }
         }
      return button
      }

end

procedure save_file(caption, name, n)		#: save dialog
   local button

   (button := SaveDialog(caption, name, n)) == "Yes" | return button
   dialog_value := open(dialog_value, "w") | {
      Notice("Can't write file")
      return save_as("Save:", dialog_value, n)
      }

   return button

end

procedure save_list(caption, lst)		#: save list dialog
   local output

   OpenDialog(caption, , 30) == "Okay" | fail
   if dialog_value == "-" then output := &output	# "-" means &output
   else output := open(dialog_value, "w") |
      return FailNotice("Cannot open " || dialog_value)

   every write(output, !lst)

   close(output)

   return

end

#  This procedure handles selection from long lists by producing
#  a succession of dialogs to the user's choice of "More".

$define Choices 30		# maximum choices per dialog

procedure select_dialog(caption, lst, dflt)	#: select dialog for many items
   static buttons

   initial buttons := ["Okay", "More", "Cancel"]

   if *lst = 0 then {
      Notice("No selections available")
      fail
      }
   until *lst <= Choices do {
      case SelectDialog(caption, lst[1+:Choices], dflt, buttons) of {
            "Cancel":  fail
            "Okay":    return
            "More":    lst := lst[Choices + 1:0]
            }
      }

   if *lst > 0 then {
      SelectDialog(caption, lst, dflt) == "Okay" | fail
      return dialog_value
      }

   else fail

end

procedure snapshot(win, x, y, w, h, n)		#: snapshot dialog
   local name, fg, bg

   if type(win) ~== "window" then {
      win :=: x :=: y :=: w :=: h
      win := &window
      }

   fg := Fg(win)
   bg := Bg(win)
   Fg(win, "black")
   Bg(win, "light gray")

   repeat {
      if OpenDialog(win, "Image file name", , n) == "Okay" then {
         name := dialog_value
         if exists(dialog_value) then {
            if TextDialog("Overwrite existing file?") == "Cancel"
            then next
            }
         Fg(win, fg)
         Bg(win, bg)
         WriteImage(win, name, x, y, w, h) | {
            Notice("Cannot write image")
            next
            }
         return
         }
      else fail
      }
      
end

procedure unsupported()				#: unsupported feature alert

   return FailNotice("Unsupported feature")

end

#===<<vib:begin>>===	modify using vib; do not remove this marker line
procedure add_dialog(win, deftbl)
static dstate
initial dstate := dsetup(win,
   ["add_dialog:Sizer::1:0,0,531,182:add",],
   ["add:Label:::12,14,70,13:Add lines:",],
   ["cancel:Button:regular::76,150,49,20:Cancel",],
   ["location:Text::2:12,43,87,19:location:\\=",],
   ["number:Text::2:12,72,87,19:number:  \\=",],
   ["okay:Button:regular:-1:12,150,49,20:Okay",],
   ["position:Choice::2:117,50,71,42:",,
      ["after","before"]],
   ["value:Text::60:12,103,493,19:value:   \\=",],
   )
return dpopup(win, deftbl, dstate)
end
#===<<vib:end>>===	end of section maintained by vib