[WINTCL] "Dynamic" Combobox

[Mark A J. <maj...@ra...>]

All,

I have created a "DYNAMIC" (command history)  combobox. However, the
behavior of the UP ARROW is not what I want. I created a combobox which
contains a history of commands entered by the user. It starts out as an
empty list. As the user enters commands in the combobox, the NEW command is
added to the bottom of the combobox command list. The combobox contains a
UNIQUE list of commands (i.e., a command ONLY appears in the combobox once)
if the user enters a command (or selects a command) that is already in the
combobox, that command is moved to the bottom of the list. The UP ARROW can
be used by the user to reselect a command already in the combobox or to
modify a previously entered command.

The behavior I see is as follows:

In the combobox entry widget enter the following ...
 1<cr>
 2<cr>
 3<cr>
 4<cr>
 5<cr>
 UP ARROW        (5 appears in the combobox entry widget)
 UP ARROW        (4 appears in the combobox entry widget)
 UP ARROW        (3 appears in the combobox entry widget)
   333<cr>

the result is a command list in the combobox  of ... 1  2  3  4  5  333

UP ARROW        (2 appears in the combobox entry widget, I WANT 333 to
appear since that was the last command entered)

The behavior I want is for "333" to appear first in the combobox when the
UP ARROW is selected in the sequence above since "333" was the last command
entered (successive UP ARROWS should result in 5, 4, 3, 2, 1 appearing in
the combobox after the 333 appears).  Once a command is entered in the
combobox entry widget, I want the UP ARROW to bring up the LAST COMMAND
entered and then move UP the command history in the combobox.

The behavior I see is that the combobox widget "remembers" the position of
where it was in the STACK of commands from the previous UP ARROW selection,
which results in the next UP ARROW key displaying the previous command in
the combobox entry from the LAST REMEMBERED place in the stack, rather than
from the last command entered.

I expected the command ....

                "pathname" selection anchor end ...

which is in my code, would result in the last command being displayed in
the combobox entry the first time the UP ARROW is selected following the
<cr> or the <enter> key. Is there a way to obtain the results I am trying
to obtain by using the combobox widget or is ther some other widget that I
should be using ... like possibly the tixCombobox???

Any help would be greatly appreciated.

TIA,
Mark

=============================================

[BEGIN code snippet]
# include the Iwidgets package for use of the combobox function
package require Iwidgets;

################################################################################
##
##    Function Name:  close_dcb_combobox
##
##    Inputs:           none
##
##    Outputs:    none
##
##    Description:      Exits program
##
##
################################################################################
proc close_dcb_combobox {} {
   exit;
};

################################################################################
##
##    Function Name:  execute_combobox_Cmnd
##
##    Inputs:           commandString
##
##    Outputs:    none
##
##    Description:
##
##
################################################################################
proc execute_combobox_Cmnd {commandString} {

  global current_command_list

  set s1 "";                #string 1
  set s2 "";                #string 2
  set s3 "";                #string 3
  set matchFound 0;
  set len_current_command_list [ llength $current_command_list ];

#
# MAKE THE 'commandString' INTO CAPITAL LETTERS
#
  set commandString [ string toupper [ string trim $commandString ] ];

  if { ![ llength $commandString ] > 0 } {
# nothing was entered into the combobox before the RETURN or ENTER key was
selected
    return;
    };

# print the command entered by the user in the output text widget
  .dcb.output.text insert end "Command entered was ... $commandString\n";

# check to see if the command is already on the list
# if the command is NOT on the list ... put it at the bottom of the list
# if the command IS on the list ... move the command that is on the list
#   to the bottom of the list so that the last command is ALWAYS at the
#   bottom of the list and each command appears on the list ONLY ONCE!!!

  if { $len_current_command_list > 0 } {
    set i 0;
    while { ( $i < $len_current_command_list ) &&  $matchFound == 0 } {
      if { ( [ string compare $commandString \
                          [ lindex [ lrange $current_command_list $i $i ] 0
] ] == 0 ) } {
        set matchFound 1;
        set s1 [ lrange $current_command_list 0 [ expr $i -1 ] ];
        set s2 [ lrange $current_command_list [ expr $i +1 ] [ expr
$len_current_command_list -1 ]  ];
        set s3 [ list $commandString ];
        set current_command_list [concat $s1 $s2 $s3 ];
        }; #endof if '{ ( [ string compare $commandString ... ] ) }'
      incr i;
      }; #endof while
    }; #endof if '{ $len_current_command_list > 0 }'

  if { !$matchFound } {
    .dcb.input.curCommand insert list end $commandString;
    set current_command_list [ concat $current_command_list [ list
$commandString ] ];
    } else {
        .dcb.input.curCommand clear list;
        for { set knt 0 } { $knt < $len_current_command_list } { incr knt }
{
          .dcb.input.curCommand insert list end [ lindex
$current_command_list $knt];
        }; #endof for
      }; #endof if '{ !$matchFound }'

# set the selection to the end of the list
  .dcb.input.curCommand selection anchor end ;

# clear the entry window for the next command
  .dcb.input.curCommand clear entry;

# clear command string
  set commandString "";
};

################################################################################
##
##    main code starts here
##
################################################################################
wm title      . "Sample Combobox";
wm iconname   . "Combobox";
wm protocol   . WM_DELETE_WINDOW close_dcb_combobox;
wm resizable  . 0 0;

#################################################################################
# define the frames
#################################################################################
frame .dcb;
frame .dcb.input        -bg white;
frame .dcb.output;

#################################################################################
# end of frame definitions
#################################################################################

# <----- define the widgets ---->
# define the combobox widget
iwidgets::combobox .dcb.input.curCommand \
   -labeltext "Command:" \
   -width 30 \
   -unique true \
   -completion false \
   -listheight 5i \
   -textvariable currentCommand;
set CmndEntryField [.dcb.input.curCommand component entry];
bind $CmndEntryField <Return> { execute_combobox_Cmnd "$currentCommand" };

# define the output label widget
label .dcb.output.output_label \
   -text "Output:" \
   -anchor w \
   -justify left;

# define the output text area widget
text .dcb.output.text \
   -width 60 \
   -height 25 \
   -relief groove \
   -bd 2 \
   -wrap word \
   -yscrollcommand ".dcb.output.scroll set";

# define the scrollbar widget
scrollbar .dcb.output.scroll -relief raised \
   -command ".dcb.output.text yview";

#################################################################################
# pack everything
#################################################################################
pack .dcb.input.curCommand \
  -fill x;

pack .dcb.output.output_label \
  -anchor w \
  -pady 2;
pack .dcb.output.text \
     .dcb.output.scroll \
  -side left \
  -fill y;

pack .dcb.input \
     .dcb.output \
  -side top \
  -fill x ;

pack  .dcb;

#################################################################################
# Initializations
#################################################################################
set current_command_list "";

[END code snippet]