NAME

       Tk::HistEntry - Entry widget with history capability

SYNOPSIS

           use Tk::HistEntry;

           $hist1 = $top->HistEntry(-textvariable => \$var1);
           $hist2 = $top->SimpleHistEntry(-textvariable => \$var2);

DESCRIPTION

       "Tk::HistEntry" defines entry widgets with history capabilities. The widgets come in two
       flavours:

       "HistEntry" (in package "Tk::HistEntry::Browse") - with associated browse entry
       "SimpleHistEntry" (in package "Tk::HistEntry::Simple") - plain widget without browse entry

       The user may browse with the Up and Down keys through the history list.  New history
       entries may be added either manually by binding the Return key to historyAdd() or
       automatically by setting the -command option.

OPTIONS

       HistEntry is an descendant of BrowseEntry and thus supports all of its standard options.

       SimpleHistEntry is an descendant of Entry and supports all of the Entry options.

       In addition, the widgets support following specific options:

       -textvariable or -variable
           Variable which is tied to the HistEntry widget. Either -textvariable (like in Entry)
           or -variable (like in BrowseEntry) may be used.

       -command
           Specifies a callback, which is executed when the Return key was pressed or the invoke
           method is called. The callback reveives three arguments: the reference to the
           HistEntry widget, the current textvariable value and a boolean value, which tells
           whether the string was added to the history list (e.g. duplicates and empty values are
           not added to the history list).

       -dup
           Specifies whether duplicate entries are allowed in the history list. Defaults to true.

       -bell
           If set to true, rings the bell if the user tries to move off of the history or if a
           search was not successful. Defaults to true.

       -limit
           Limits the number of history entries. Defaults to unlimited.

       -match
           Turns auto-completion on.

       -case
           If set to true a true value, then be case sensitive on auto-completion. Defaults to 1.

METHODS

       historyAdd([string])
           Adds string (or the current textvariable value if not set) manually to the history
           list. addhistory is an alias for historyAdd. Returns the added string or undef if no
           addition was made.

       invoke([string])
           Invokes the command specified with -command.

       history([arrayref])
           Without argument, returns the current history list. With argument (a reference to an
           array), replaces the history list.

       historySave(file)
           Save the history list to the named file.

       historyMergeFromFile(file)
           Merge the history list from the named file to the end of the current history list of
           the widget.

       historyReset
           Remove all entries from the history list.

KEY BINDINGS

       Up, Control-p
           Selects the previous history entry.

       Down, Control-n
           Selects the next history entry.

       Meta-<, Alt-<
           Selects first entry.

       Meta->, Alt->
           Selects last entry.

       Control-r
           The current content of the widget is searched backward in the history.

       Control-s
           The current content of the widget is searched forward in the history.

       Return
           If -command is set, adds current content to the history list and executes the
           associated callback.

EXAMPLE

       This is an simple example for Tk::HistEntry. More examples can be found in the t and
       examples directories of the source distribution.

           use Tk;
           use Tk::HistEntry;

           $top = new MainWindow;
           $he = $top->HistEntry(-textvariable => \$foo,
                                 -command => sub {
                                     # automatically adds $foo to history
                                     print STDERR "Do something with $foo\n";
                                 })->pack;
           $b = $top->Button(-text => 'Do it',
                             -command => sub { $he->invoke })->pack;
           MainLoop;

       If you like to not depend on the installation of Tk::HistEntry, you can write something
       like this:

           $Entry = "Entry"; # default Entry widget
           eval {
               # try loading the module, otherwise $Entry is left to the value "Entry"
               require Tk::HistEntry;
               $Entry = "SimpleHistEntry";
           };
           $entry = $mw->$Entry(-textvariable => \$res)->pack;
           $entry->bind("<Return>" => sub {
                                          # check whether the historyAdd method is
                                          # known to the widget
                                          if ($entry->can('historyAdd')) {
                                              $entry->historyAdd;
                                          }
                                      });

       In this approach the history lives in an array variable. Here the entry widget does not
       need to be permanent, that is, it is possible to destroy the containing window and restore
       the history again:

           $Entry = "Entry";
           eval {
               require Tk::HistEntry;
               $Entry = "HistEntry";
           };
           $entry = $mw->$Entry(-textvariable => \$res)->pack;
           if ($entry->can('history') && @history) {
               $entry->history(\@history);
           }

           # Later, after clicking on a hypothetical "Ok" button:
           if ($res ne "" && $entry->can('historyAdd')) {
               $entry->historyAdd($res);
               @history = $entry->history;
           }

BUGS/TODO

        - C-s/C-r do not work as nice as in gnu readline
        - use -browsecmd from Tk::BrowseEntry
        - use Tie::Array if present

AUTHOR

       Slaven Rezic <slaven@rezic.de>

CREDITS

       Thanks for Jason Smith <smithj4@rpi.edu> and Benny Khoo <kkhoo1@penang.intel.com> for
       their suggestions. The auto-completion code is stolen from Tk::IntEntry by Dave Collins
       <Dave.Collins@tiuk.ti.com>.

COPYRIGHT

       Copyright (c) 1997, 2000, 2001, 2003, 2008, 2016, 2017 Slaven Rezic. All rights reserved.
       This package is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.