Curses::Widgets::TextMemo - Text Memo Widgets

CursesWidgets documentation Contained in the CursesWidgets distribution.

Index

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NAME

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Curses::Widgets::TextMemo - Text Memo Widgets

MODULE VERSION

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$Id: TextMemo.pm,v 1.104 2002/11/14 01:27:31 corliss Exp corliss $

SYNOPSIS

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  use Curses::Widgets::TextMemo;

  $tm = Curses::Widgets::TextMemo->new({
    CAPTION       => 'Memo',
    CAPTIONCOL    => 'blue',
    COLUMNS       => 10,
    MAXLENGTH     => undef,
    LINES         => 3,
    MASK          => undef,
    VALUE         => '',
    INPUTFUNC     => \&scankey,
    FOREGROUND    => 'white',
    BACKGROUND    => 'black',
    BORDER        => 1,
    BORDERCOL     => 'red',
    FOCUSSWITCH   => "\t",
    CURSORPOS     => 0,
    TEXTSTART     => 0,
    PASSWORD      => 0,
    X             => 1,
    Y             => 1,
    READONLY      => 0,
    });

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

  See the Curses::Widgets pod for other methods.

REQUIREMENTS

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Curses
Curses::Widgets

DESCRIPTION

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Curses::Widgets::TextMemo provides simplified OO access to Curses-based single line text fields. Each object maintains its own state information.

METHODS

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new (inherited from Curses::Widgets)

  $tm = Curses::Widgets::TextMemo->new({
    CAPTION       => 'Memo',
    CAPTIONCOL    => 'blue',
    COLUMNS       => 10,
    MAXLENGTH     => undef,
    LINES         => 3,
    MASK          => undef,
    VALUE         => '',
    INPUTFUNC     => \&scankey,
    FOREGROUND    => 'white',
    BACKGROUND    => 'black',
    BORDER        => 1,
    BORDERCOL     => 'red',
    FOCUSSWITCH   => "\t",
    CURSORPOS     => 0,
    TEXTSTART     => 0,
    PASSWORD      => 0,
    X             => 1,
    Y             => 1,
    READONLY      => 0,
    });

The new method instantiates a new TextMemo object. The only mandatory key/value pairs in the configuration hash are X and Y. All others have the following defaults:

  Key           Default   Description
  ============================================================
  CAPTION         undef   Caption superimposed on border
  CAPTIONCOL      undef   Foreground colour for caption text
  COLUMNS            10   Number of columns displayed
  MAXLENGTH       undef   Maximum string length allowed
  LINES               3   Number of lines in the window
  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"   Characters which signify end of input
  CURSORPOS           0   Starting position of the cursor
  TEXTSTART           0   Line number of string to start 
                          displaying
  PASSWORD            0   Subsitutes '*' instead of characters
  READONLY            0   Prevents alteration to content

The CAPTION is only valid when the BORDER is enabled. If the border is disabled, the field will be underlined, provided the terminal supports it. The MAXLENGTH has no effect if left undefined.

draw

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

The draw method renders the text memo in its current state. This requires a valid handle to a curses window in which it will render itself. The optional second argument, if true, will cause the field's text cursor to be rendered as well.

HISTORY

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1999/12/29 -- Original text field widget in functional model
2001/07/05 -- First incarnation in OO architecture

AUTHOR/COPYRIGHT

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(c) 2001 Arthur Corliss (corliss@digitalmages.com)

CursesWidgets documentation Contained in the CursesWidgets distribution. 
# Curses::Widgets::TextMemo.pm -- Text Memo Widgets
#
# (c) 2001, Arthur Corliss <corliss@digitalmages.com>
#
# $Id: TextMemo.pm,v 1.104 2002/11/14 01:27:31 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::TextMemo;

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

($VERSION) = (q$Revision: 1.104 $ =~ /(\d+(?:\.(\d+))+)/);
@ISA = qw(Curses::Widgets);

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


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

  my $self = shift;
  my %conf = ( 
    COLUMNS       => 10,
    MAXLENGTH     => undef,
    LINES         => 3,
    VALUE         => '',
    INPUTFUNC     => \&scankey,
    BORDER        => 1,
    UNDERLINE     => 1,
    FOCUSSWITCH   => "\t",
    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 _border {
  my $self = shift;
  my $dwh = shift;
  my $conf = $self->{CONF};
  my ($border, $ts, $pos, $value, $lines) = 
    @$conf{qw(BORDER TEXTSTART CURSORPOS VALUE LINES)};
  my (@lines, $v, $i, $y, $x);

  # Massage the value as needed, and split the result
  $value = '' unless defined $value;
  $value = substr($value, 0, $$conf{MAXLENGTH}) if
    defined $$conf{MAXLENGTH};
  @lines = textwrap($value, $$conf{COLUMNS} - 1);

  # Adjust the cursor position and text start line if they're out of whack
  $pos = $pos < 0 ? 0 : ($pos > length($value) ? $pos = length($value) :
    $pos);
  $ts = $#lines if $ts > $#lines;
  $ts = 0 if $ts < 0;
  if ($ts > 0 && $pos < length(join('', @lines[0..($ts - 1)]))) {
    $v = length(join('', @lines[0..($ts - 1)]));
    $i = $ts - 1;
    until ($v <= $pos) {
      $v -= length($lines[$i]);
      --$i;
    }
    $ts = $i > 0 ? $i : 0;
    ++$ts unless $pos < length($lines[0]);
  } elsif ($ts + $lines - 1 < $#lines && 
    $pos >= length(join('', @lines[0..($ts + $lines - 1)]))) {
    $v = length(join('', @lines[0..($ts + $lines - 1)]));
    $i = $ts + $lines;
    until ($v >= $pos) {
      $v += length($lines[$i]);
      ++$i;
    }
    $ts = $i - $lines;
    ++$ts if $pos == $v;
  }
  ++$ts if $pos == length($value) and $ts + $lines == @lines;

  # Save the adjust values
  @$conf{qw(TEXTSTART CURSORPOS VALUE)} = ($ts, $pos, $value);
  $self->{SPLIT} = [@lines];

  # Render the border
  if ($border) {

    # Call the parent method
    $self->SUPER::_border($dwh);

    # Place the arrows
    $dwh->getmaxyx($y, $x);
    $dwh->addch(0, $x - 2, ACS_UARROW) if $ts > 0;
    $dwh->addch($y - 1, $x - 2, ACS_DARROW)
      if $#lines - $ts > $lines;
  }
}

sub _content {
  my $self = shift;
  my $dwh = shift;
  my $conf = $self->{CONF};
  my ($border, $ts, $pos, $lines, $cols) = 
    @$conf{qw(BORDER TEXTSTART CURSORPOS LINES COLUMNS)};
  my @lines = @{$self->{SPLIT}};
  my ($i, $j);

  # Print the lines
  $j = 0;
  for ($i = $ts; $i < $ts + $lines; $i++) {
    unless ($i > $#lines) {
      $$conf{PASSWORD} ? 
        $dwh->addstr($j, 0, '*' x length($lines[$i])) :
        $dwh->addstr($j, 0, $lines[$i]) ;
    }

    # Underline each line if there's no border
    $dwh->chgat($j, 0, $cols, A_UNDERLINE, 
      select_colour(@$conf{qw(FOREGROUND BACKGROUND)}), 0) unless $border;

    $j++;
  }
}

sub _cursor {
  my $self = shift;
  my $dwh = shift;
  my $conf = $self->{CONF};
  my ($pos, $ts) = @$conf{qw(CURSORPOS TEXTSTART)};
  my @lines = @{$self->{SPLIT}};
  my $i = 0;
  my $v = 0;
  my $seg;

  $v = length(join('', @lines[0..($ts - 1)])) if $ts > 0;
  while ($ts + $i < $#lines && $v + length($lines[$ts + $i]) <= $pos) {
    $v += length($lines[$ts + $i]);
    ++$i;
  }
  $v = $pos - $v;
  #$i-- if $i > 0 and substr($$conf{VALUE}, $pos - 1, 1) eq "\n";
  if ($pos == length($$conf{VALUE}) && substr($$conf{VALUE}, $pos - 1, 1) eq
    "\n") {
    ++$i;
    $v = 0;
  }

  $dwh->chgat($i, $v, 1, A_STANDOUT, 
    select_colour(@$conf{qw(FOREGROUND BACKGROUND)}), 0);

  $self->_restore($dwh);
}

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

  my $self = shift;
  my $in = shift;
  my $conf = $self->{CONF};
  my ($value, $pos, $max, $ro, $ts) = 
    @$conf{qw(VALUE CURSORPOS MAXLENGTH READONLY TEXTSTART)};
  my @string = split(//, $value);
  my @lines = @{$self->{SPLIT}};
  my ($snippet, $i, $lpos, $l);

  # 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_UP || $in eq KEY_DOWN ||
    $in eq KEY_NPAGE || $in eq KEY_PPAGE) {

    # Exit early if there's no text
    unless (length($value) > 0) {
      beep;
      return;
    }

    # Get the text length up to the displayed window
    $snippet = $ts == 0 ? 0 : length(join('', @lines[0..($ts - 1)]));

    # Get the position of the cursor relative to the line it's on,
    # as well as the line index
    if ($pos == length($value)) {
      $l = $#lines;
      $lpos = length($lines[$#lines]);
    } else {
      $i = 0;
      while ($snippet + length($lines[$ts + $i]) <= $pos) {
        $snippet += length($lines[$ts + $i]);
        ++$i;
      }
      $l = $ts + $i;
      $lpos = $pos - $snippet;
    }

    # Process according to the key
    if ($in eq KEY_UP) {
      if ($l > 0) {
        if (length($lines[$l - 1]) >= $lpos) {
          $pos -= length($lines[$l - 1]);
        } else {
          $pos -= ($lpos + 1);
        }
      } else {
        beep;
      }
    } elsif ($in eq KEY_DOWN) {
      if ($l < $#lines) {
        if (length($lines[$l + 1]) >= $lpos) {
          $pos += length($lines[$l]);
        } else {
          $pos += ((length($lines[$l]) - $lpos) + 
            length($lines[$l + 1]) - 1);
        }
      } else {
        beep;
      }
    } elsif ($in eq KEY_PPAGE) {
      if ($l >= $$conf{LINES}) {
        $pos -= length(join('', 
          @lines[(1 + $l - $$conf{LINES})..($l - 1)]));
        if (length($lines[$l - $$conf{LINES}]) > $lpos) {
          $pos -= length($lines[$l - $$conf{LINES}]);
        } else {
          $pos -= ($lpos + 1);
        }
      } elsif ($l > 0) {
        if ($lpos > length($lines[0])) {
          $pos = length($lines[0]) - 1;
        } else {
          $pos = $lpos;
        }
      } else {
        beep;
      }
    } elsif ($in eq KEY_NPAGE) {
      if ($l <= $#lines - $$conf{LINES}) {
        $pos += length(join('', 
          @lines[($l + 1) ..($l + $$conf{LINES} - 1)]));
        if (length($lines[$l + $$conf{LINES}]) >= $lpos) {
          $pos += (length($lines[$l + $$conf{LINES}]) + 1);
        } else {
          $pos += ((length($lines[$l]) - $lpos) + 
            length($lines[$l + $$conf{LINES}]) - 1);
        }
      } elsif ($l < $#lines) {
        if (length($lines[$#lines]) > $lpos) {
          $pos = length($value) - (length($lines[$#lines]) -
            $lpos);
        } else {
          $pos = length($value);
        }
      } else {
        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
  @$conf{qw(VALUE CURSORPOS TEXTSTART)} = ($value, $pos, $ts);
}

1;