Curses::Widgets::TextField - Text Field Widgets

  use Curses::Widgets::TextField;

  $tf = Curses::Widgets::TextField->new({
    CAPTION     => 'Name',
    CAPTIONCOL  => 'yellow',
    COLUMNS     => 10,
    MAXLENGTH   => 255,
    MASK        => undef,
    VALUE       => '',
    INPUTFUNC   => \&scankey,
    FOREGROUND  => undef,
    BACKGROUND  => 'black',
    BORDER      => 1,
    BORDERCOL   => 'red',
    FOCUSSWITCH => "\t\n",
    CURSORPOS   => 0,
    TEXTSTART   => 0,
    PASSWORD    => 0,
    X           => 1,
    Y           => 1,
    READONLY    => 0,
    });

  $tf->draw($mwh, 1);

  See the Curses::Widgets pod for other methods.

  $tf = Curses::Widgets::TextField->new({
    CAPTION     => 'Name',
    CAPTIONCOL  => 'yellow',
    COLUMNS     => 10,
    MAXLENGTH   => 255,
    MASK        => undef,
    VALUE       => '',
    INPUTFUNC   => \&scankey,
    FOREGROUND  => undef,
    BACKGROUND  => 'black',
    BORDER      => 1,
    BORDERCOL   => 'red',
    FOCUSSWITCH => "\t\n",
    CURSORPOS   => 0,
    TEXTSTART   => 0,
    PASSWORD    => 0,
    X           => 1,
    Y           => 1,
    READONLY    => 0,
    });

  Key         Default   Description
  ============================================================
  CAPTION       undef   Caption superimposed on border
  CAPTIONCOL    undef   Foreground colour for caption text
  COLUMNS          10   Number of columns displayed
  MAXLENGTH       255   Maximum string length allowed
  MASK          undef   Not yet implemented
  VALUE            ''   Current field text
  INPUTFUNC \&scankey   Function to use to scan for keystrokes
  FOREGROUND    undef   Default foreground colour
  BACKGROUND    undef   Default background colour
  BORDER            1   Display a border around the field
  BORDERCOL     undef   Foreground colour for border
  FOCUSSWITCH  "\t\n"   Characters which signify end of input
  CURSORPOS         0   Starting position of the cursor
  TEXTSTART         0   Position in string to start displaying
  PASSWORD          0   Subsitutes '*' instead of characters
  READONLY          0   Prevents alteration to content

  $tf->draw($mwh, 1);

# Curses::Widgets::TextField.pm -- Text Field Widgets
#
# (c) 2001, Arthur Corliss <corliss@digitalmages.com>
#
# $Id: TextField.pm,v 1.103 2002/11/04 00:35:44 corliss Exp corliss $
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
#####################################################################

#####################################################################
#
# Environment definitions
#
#####################################################################

package Curses::Widgets::TextField;

use strict;
use vars qw($VERSION @ISA);
use Carp;
use Curses;
use Curses::Widgets;

($VERSION) = (q$Revision: 1.103 $ =~ /(\d+(?:\.(\d+))+)/);
@ISA = qw(Curses::Widgets);

#####################################################################
#
# Module code follows
#
#####################################################################

sub _conf {
  # Validates and initialises the new TextField object.
  #
  # Usage:  $self->_conf(%conf);

  my $self = shift;
  my %conf = ( 
    CAPTION     => undef,
    COLUMNS     => 10,
    LINES       => 1,
    MAXLENGTH   => 255,
    MASK        => undef,
    VALUE       => '',
    INPUTFUNC   => \&scankey,
    BORDER      => 1,
    FOCUSSWITCH => "\t\n",
    CURSORPOS   => 0,
    TEXTSTART   => 0,
    PASSWORD    => 0,
    READONLY    => 0,
    @_ 
    );
  my @required = qw(X Y);
  my $err = 0;

  # Check for required arguments
  foreach (@required) { $err = 1 unless exists $conf{$_} };

  # Make sure no errors are returned by the parent method
  $err = 1 unless $self->SUPER::_conf(%conf);

  return $err == 0 ? 1 : 0;
}

sub _content {
  my $self = shift;
  my $dwh = shift;
  my $cursor = shift;
  my $conf = $self->{CONF};
  my ($pos, $ts, $value, $border, $col) = 
    @$conf{qw(CURSORPOS TEXTSTART VALUE BORDER COLUMNS)};
  my $seg;

  # Trim the value if it exceeds the maximum length
  $value = substr($value, 0, $$conf{MAXLENGTH}) if $$conf{MAXLENGTH};

  # Turn on underlining (terminal-dependent) if no border is used
  $dwh->attron(A_UNDERLINE) unless $border;

  # Adjust the cursor position and text start if it's out of whack
  if ($pos > length($value)) {
    $pos = length($value);
  } elsif ($pos < 0) {
    $pos = 0;
  }
  if ($pos > $ts + $$conf{COLUMNS} - 1) {
    $ts = $pos + 1 - $$conf{COLUMNS};
  } elsif ($pos < $ts) {
    $ts = $pos;
  }
  $ts = 0 if $ts < 0;

  # Write the widget value (adjusting for horizontal scrolling)
  $seg = substr($value, $ts, $$conf{COLUMNS});
  $seg = '*' x length($seg) if $$conf{PASSWORD};
  $seg .= ' ' x ($$conf{COLUMNS} - length($seg));
  $dwh->addstr(0, 0, $seg);
  $dwh->attroff(A_BOLD);

  # Underline the field if no border is used
  $dwh->chgat(0, 0, $col, A_UNDERLINE, 
    select_colour(@$conf{qw(FOREGROUND BACKGROUND)}), 0) unless $border;

  # Save the textstart, cursorpos, and value in case it was tweaked
  @$conf{qw(TEXTSTART CURSORPOS VALUE)} = ($ts, $pos, $value);
}

sub _cursor {
  my $self = shift;
  my $dwh = shift;
  my $conf = $self->{CONF};

  # Display the cursor
  $dwh->chgat(0, $$conf{CURSORPOS} - $$conf{TEXTSTART}, 1, A_STANDOUT, 
    select_colour(@$conf{qw(FOREGROUND BACKGROUND)}), 0)
    unless $$conf{READONLY};

  # Restore the default settings
  $self->_restore($dwh);
}

sub input_key {
  # Process input a keystroke at a time.
  #
  # Usage:  $self->input_key($key);

  my $self = shift;
  my $in = shift;
  my $conf = $self->{CONF};
  my $mask = $$conf{MASK};
  my ($value, $pos, $max, $ro) = 
    @$conf{qw(VALUE CURSORPOS MAXLENGTH READONLY)};
  my @string = split(//, $value);

  # Process special keys
  if ($in eq KEY_BACKSPACE) {
    return if $ro;
    if ($pos > 0) {
      splice(@string, $pos - 1, 1);
      $value = join('', @string);
      --$pos;
    } else {
      beep;
    }
  } elsif ($in eq KEY_RIGHT) {
    $pos < length($value) ? ++$pos : beep;
  } elsif ($in eq KEY_LEFT) {
    $pos > 0 ? --$pos : beep;
  } elsif ($in eq KEY_HOME) {
    $pos = 0;
  } elsif ($in eq KEY_END) {
    $pos = length($value);

  # Process other keys
  } else {

    return if $ro || $in !~ /^[[:print:]]$/;

    # Exit if it's a non-printing character
    return unless $in =~ /^[\w\W]$/;

    # Reject if we're already at the max length
    if (defined $max && length($value) == $max) {
      beep;
      return;

    # Append to the end if the cursor's at the end
    } elsif ($pos == length($value)) {
      $value .= $in;

    # Insert the character at the cursor's position
    } elsif ($pos > 0) {
      @string = (@string[0..($pos - 1)], $in, @string[$pos..$#string]);
      $value = join('', @string);

    # Insert the character at the beginning of the string
    } else {
      $value = "$in$value";
    }

    # Increment the cursor's position
    ++$pos;
  }

  # Save the changes
  @$conf{qw(VALUE CURSORPOS)} = ($value, $pos);
}

1;