NAME

Term::Choose - Choose items from a list interactively.

SYNOPSIS

use Term::Choose :choose;

my @list = <one two three four five>;


# Functional interface:
 
my $chosen = choose( @list, :2layout );


# OO interface:
 
my $tc = Term::Choose.new( :1mouse, :0order );

$chosen = $tc.choose( @list, :1layout, :2default );

DESCRIPTION

Choose interactively from a list of items.

For choose, choose-multi and pause the first argument holds the list of the available choices.

The different options can be passed as key-values pairs. See OPTIONS to find the available options.

The return values are described in Routines

USAGE

To browse through the available list-elements use the keys described below.

If the items of the list don't fit on the screen, the user can scroll to the next (previous) page(s).

If the window size is changed, the screen is rewritten as soon as a key is pressed.

How to choose the items is described in ROUTINES.

Keys

• the Arrow keys (or h,j,k,l) to move up and down or to move to the right and to the left,

• the Tab key (or Ctrl-I) to move forward, the BackSpace key (or Ctrl-H) to move backward,

• the PageUp key (or Ctrl-P) to go to the previous page, the PageDown key (or Ctrl-N) to go to the next page,

• the Insert key to go back 10 pages, the Delete key to go forward 10 pages,

• the Home key (or Ctrl-A) to jump to the beginning of the list, the End key (or Ctrl-E) to jump to the end of the list.

For the usage of SpaceBar, Ctrl-SpaceBar, Return and the q-key see choose, choose-multi and pause.

With mouse enabled use the the left mouse key instead the Return key and the right mouse key instead of the SpaceBar key. Instead of PageUp and PageDown it can be used the mouse wheel. See mouse

Pressing the Ctrl-F allows one to enter a regular expression so that only the items that match the regular expression are displayed. When going back to the unfiltered menu (Return) the item highlighted in the filtered menu keeps the highlighting. Also (in list context) marked items retain there markings. The Raku function prompt is used to read the regular expression if Readline is not available. See option search.

CONSTRUCTOR

The constructor method new can be called with named arguments. For the valid options see OPTIONS. Setting the options in new overwrites the default values for the instance.

ROUTINES

choose

choose allows the user to choose one item from a list: the highlighted item is returned when Return is pressed.

choose returns nothing if the q or Ctrl-Q is pressed.

choose-multi

The user can choose many items.

To choose an item mark the item with the SpaceBar. When Return is pressed choose-multi then returns the marked items as an Array. If the option include-highlighted is set to 1, the highlighted item is also returned.

If Return is pressed with no marked items and include-highlighted is set to 2, the highlighted item is returned.

Ctrl-SpaceBar (or Ctrl-@) inverts the choices: marked items are unmarked and unmarked items are marked.

choose-multi returns nothing if the q or Ctrl-Q is pressed.

pause

Nothing can be chosen, nothing is returned but the user can move around and read the output until closed with Return, q or Ctrl-Q.

OUTPUT

For the output on the screen the elements of the list are copied and then modified. Chosen elements are returned as they were passed without modifications.

Modifications:

• If an element is not defined the value from the option undef is assigned to the element.

• If an element holds an empty string the value from the option empty is assigned to the element.

• Tab characters in elements are replaces with a space.

  $element =~ s/\t/ /g;

• Vertical spaces in elements are squashed to two spaces.

  $element =~ s/\v+/\ \ /g;

• Code points from the ranges of control, surrogate and noncharacter are removed.

  $element =~ s/[\p{Cc}\p{Noncharacter_Code_Point}\p{Cs}]//g;

• If the length (print columns) of an element is greater than the width of the screen the element is cut and three dots are attached.

OPTIONS

Options which expect a number as their value expect integers.

alignment

0 - elements ordered in columns are aligned to the left (default)

1 - elements ordered in columns are aligned to the right

2 - elements ordered in columns are centered

beep

0 - off (default)

1 - on

clear-screen

0 - off

1 - clears the screen before printing the choices (default)

color

If enabled, SRG ANSI escape sequences can be used to color the screen output.

0 - off (default)

1 - on (current selected element not colored)

2 - on (current selected element colored)

default

With the option default it can be selected an element, which will be highlighted as the default instead of the first element.

default expects a zero indexed value, so e.g. to highlight the third element the value would be 2.

If the passed value is greater than the index of the last array element, the first element is highlighted.

Allowed values: 0 or greater

(default: 0)

empty

Sets the string displayed on the screen instead of an empty string.

(default: "")

footer

Add a string in the bottom line.

If a footer string is passed with this option, the option page is automatically set to 2.

(default: undefined)

hide-cursor

0 - keep the terminals highlighting of the cursor position

1 - hide the terminals highlighting of the cursor position (default)

index

0 - off (default)

1 - return the indices of the chosen elements instead of the chosen elements.

This option has no meaning for pause.

info

Expects as its value a string. The string is printed above the prompt string.

keep

keep prevents that all the terminal rows are used by the prompt lines.

Setting keep ensures that at least keep terminal rows are available for printing "list"-rows.

If the terminal height is less than keep, keep is set to the terminal height.

Allowed values: 1 or greater

(default: 5)

layout

From broad to narrow: 0 > 1 > 2

• 0 - layout off

  .-------------------.   .-------------------.   .-------------------.   .-------------------.
  | .. .. .. .. .. .. |   | .. .. .. .. .. .. |   | .. .. .. .. .. .. |   | .. .. .. .. .. .. |
  |                   |   | .. .. .. .. .. .. |   | .. .. .. .. .. .. |   | .. .. .. .. .. .. |
  |                   |   |                   |   | .. .. .. ..       |   | .. .. .. .. .. .. |
  |                   |   |                   |   |                   |   | .. .. .. .. .. .. |
  |                   |   |                   |   |                   |   | .. .. .. .. .. .. |
  |                   |   |                   |   |                   |   | .. .. .. .. .. .. |
  '-------------------'   '--- ---------------'   '-------------------'   '-------------------'

• 1 - (default)

  .-------------------.   .-------------------.   .-------------------.   .-------------------.
  | .. .. .. .. .. .. |   | .. .. .. ..       |   | .. .. .. .. ..    |   | .. .. .. .. .. .. |
  |                   |   | .. .. .. ..       |   | .. .. .. .. ..    |   | .. .. .. .. .. .. |
  |                   |   | .. ..             |   | .. .. .. .. ..    |   | .. .. .. .. .. .. |
  |                   |   |                   |   | .. .. .. .. ..    |   | .. .. .. .. .. .. |
  |                   |   |                   |   | .. .. ..          |   | .. .. .. .. .. .. |
  |                   |   |                   |   |                   |   | .. .. .. .. .. .. |
  '-------------------'   '-------------------'   '-------------------'   '-------------------'

• 2 - all in a single column

  .-------------------.   .-------------------.   .-------------------.   .-------------------.
  | ..                |   | ..                |   | ..                |   | ..                |
  | ..                |   | ..                |   | ..                |   | ..                |
  | ..                |   | ..                |   | ..                |   | ..                |
  |                   |   | ..                |   | ..                |   | ..                |
  |                   |   |                   |   | ..                |   | ..                |
  |                   |   |                   |   |                   |   | ..                |
  '-------------------'   '-------------------'   '-------------------'   '-------------------'

margin

The option margin allows one to set a margin on all four sides.

margin expects a list of four elements in the following order:

• top margin (number of terminal lines)

• right margin (number of terminal columns)

• botton margin (number of terminal lines)

• left margin (number of terminal columns)

margin does not affect the info and prompt string. To add margins to the info and prompt string see tabs-info and tabs-prompt.

Allowed values: 0 or greater. Elements beyond the fourth are ignored.

(default: undefined)

max-cols

Limit the number of item columns to max-cols.

Allowed values: 1 or greater

(default: undefined)

max-height

If defined sets the maximal number of rows used for printing list items.

If the available height is less than max-height, max-height is set to the available height.

Height in this context means number of print rows.

max-height overwrites keep if max-height is set to a value less than keep.

Allowed values: 1 or greater

(default: undefined)

max-width

If defined, sets the maximal output width to max-width if the terminal width is greater than max-width.

To prevent the "auto-format" to use a width less than max-width set layout to 0.

Width refers here to the number of print columns.

Allowed values: 2 or greater

(default: undefined)

mouse

0 - no mouse (default)

1 - mouse enabled

order

If the output has more than one row and more than one column:

0 - elements are ordered horizontally

1 - elements are ordered vertically (default)

pad

Sets the number of whitespaces between columns. (default: 2)

Allowed values: 0 or greater

page

0 - off

1 - print the page number on the bottom of the screen. If all the choices fit into one page, the page number is not displayed. (default)

2 - the page number is always displayed even with only one page. Setting page to 2 automatically enables the option clear-screen.

prompt

If prompt is undefined, a default prompt-string will be shown.

If the prompt value is an empty string (""), no prompt-line will be shown.

(default: undefined)

save-screen

0 - off (default)

1 - use the alternate screen

search

Set the behavior of Ctrl-F.

0 - off

1 - case-insensitive search (default)

2 - case-sensitive search

tabs-info

The option tabs-info allows one to insert spaces at beginning and the end of info lines.

tabs-info expects a list with one to three elements:

• the first element (initial tab) sets the number of spaces inserted at beginning of paragraphs

• the second element (subsequent tab) sets the number of spaces inserted at the beginning of all broken lines apart from the beginning of paragraphs

• the third element sets the number of spaces used as a right margin.

Allowed values: 0 or greater. Elements beyond the third are ignored.

default: If margin is set, the initial-tab and the subsequent-tab are set to left-margin and the right margin is set to right-margin. If margin is not defined, the default is undefined.

tabs-prompt

The option tabs-prompt allows one to insert spaces at beginning and the end of prompt lines.

tabs-prompt expects a list with one to three elements:

• the first element (initial tab) sets the number of spaces inserted at beginning of paragraphs

• the second element (subsequent tab) sets the number of spaces inserted at the beginning of all broken lines apart from the beginning of paragraphs

• the third element sets the number of spaces used as a right margin.

Allowed values: 0 or greater. Elements beyond the third are ignored.

default: If margin is set, the initial-tab and the subsequent-tab are set to left-margin and the right margin is set to right-margin. If margin is not defined, the default is undefined.

undef

Sets the string displayed on the screen instead of an undefined element.

(default: "")

options choose-multi

include-highlighted

0 - choose-multi returns the items marked with the SpaceBar. (default)

1 - choose-multi returns the items marked with the SpaceBar plus the highlighted item.

2 - choose-multi returns the items marked with the SpaceBar. If no items are marked with the SpaceBar, the highlighted item is returned.

mark

mark expects as its value a list of indexes (integers). choose-multi preselects the list-elements correlating to these indexes.

(default: undefined)

meta-items

meta-items expects as its value a list of indexes (integers). List-elements correlating to these indexes can not be marked with the SpaceBar or with the right mouse key but if one of these elements is the highlighted item it is added to the chosen items when Return is pressed.

Elements greater than the last index of the list are ignored.

(default: undefined)

no-spacebar

no-spacebar expects as its value an list. The elements of the list are indexes of choices which should not be markable with the SpaceBar or with the right mouse key. If an element is preselected with the option mark and also marked as not selectable with the option no-spacebar, the user can not remove the preselection of this element.

(default: undefined)

MULTITHREADING

Term::Choose uses multithreading when preparing the list for the output; the number of threads to use can be set with the environment variable TC_NUM_THREADS.

REQUIREMENTS

Escape sequences

The control of the cursor location, the highlighting of the cursor position and the marked elements and other options on the terminal is done via escape sequences.

By default Term::Choose uses tput to get the appropriate escape sequences. If the environment variable TC_ANSI_ESCAPES is set to a true value, hardcoded ANSI escape sequences are used directly without calling tput.

The escape sequences to enable the mouse mode and the escape sequence to get the cursor position are always hardcoded.

If the environment variable TERM is not set to a true value, vt100 is used instead as the terminal type for tput.

Monospaced font

It is required a terminal that uses a monospaced font which supports the printed characters.

Ambiguous width characters

By default ambiguous width characters are treated as half width. If the environment variable TC_AMBIGUOUS_WIDE is set to a true value, ambiguous width characters are treated as full width.

AUTHOR

Matthäus Kiem [email protected]

CREDITS

Based on the choose function from the Term::Clui module.

Thanks to the people from Perl-Community.de, from stackoverflow and from #perl6 on irc.freenode.net for the help.

LICENSE AND COPYRIGHT

Copyright (C) 2016-2022 Matthäus Kiem.

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.