--- name: "UI::Dialog::Screen::Menu" section: "3pm" platform: "linux" package: "libui-dialog-perl" version: "1.21-0.1" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/UI::Dialog::Screen::Menu" --- # UI::Dialog::Screen::Menu(3pm) wrapper to screen dialogs. ## NAME UI::Dialog::Screen::Menu - wrapper to screen dialogs. ## SYNOPSIS ``` use UI::Dialog::Screen::Menu; # $d is an existing instance of UI::Dialog my $screen = new UI::Dialog::Screen::Menu ( dialog => $d ); $screen->add_menu_item("This is the label", sub { print "Hello\n"; }); # $rv is 0 if the user canceled, 1 if any menu item was selected. my $rv = $screen->run(); ``` ## ABSTRACT UI::Dialog::Screen::Menu is a helper class which enables a clean and modular code flow for menu driven applications using UI::Dialog. Using callbacks assigned to menu items, a reactionary model to scripting with UI::Dialog becomes rapidly easy. ## DESCRIPTION UI::Dialog::Screen::Menu is actually "external" to the UI::Dialog core usage. The class simply wraps around an existing UI::Dialog instance for rendering a menu-driven flow of screens. Using this class, you define a number of screen instances and assign callbacks to each of the menu items. Once defined, simply call ***run()*** (or ***loop()*** to execute ***run()*** indefinitely). When a user selects one of the menu items, the assigned function will be executed. From within those functions, simply call other UI::Dialog::Screen::Menu instances and that's how you branch your user's experience from one screen to the next. See the **EXAMPLES** ## EXPORT None ## INHERITS None ## CONSTRUCTOR ### new( %options ) - EXAMPLE ``` # Have UI::Dialog::Screen::Menu use an existing UI::Dialog instance # to render the user interface. my $s = new( dialog => $d ); # Also accepts UI::Dialog constructor arguments, so that it can create # it's own instance of UI::Dialog if none is provided. my $s = new( title => 'Default Title', backtitle => 'Backtitle', width => 65, height => 20, listheight => 5, order => [ 'zenity', 'xdialog', 'gdialog' ] ); ``` - DESCRIPTION This is the Class Constructor method. It accepts a list of key =\> value pairs and uses them as the defaults when interacting with the various widgets. - RETURNS A blessed object reference of the UI::Dialog::Screen::Menu class. - OPTIONS The (...)'s after each option indicate the default for the option. An \* denotes support by all the widget methods on a per-use policy defaulting to the values decided during object creation. - **dialog = UI::Dialog** (undef) - **debug = 0,1,2** (0) - **order = \[ zenity, xdialog, gdialog, kdialog, cdialog, whiptail, ascii \]** (as indicated) - **PATH = \[ /bin, /usr/bin, /usr/local/bin, /opt/bin \]** (as indicated) - **backtitle = "backtitle"** ('') \* - **title = "title"** ('') \* - **beepbefore = 0,1** (0) \* - **beepafter = 0,1** (0) \* - **height = \\d+** (20) \* - **width = \\d+** (65) \* - **listheight = \\d+** (5) \* ## STATE METHODS ### run( ) - EXAMPLE ``` my $rv = $s->run(); ``` - DESCRIPTION Render the screen menu immediately. This method blocks until the user input has been received and acted upon. - RETURNS TRUE if the user selected an item from the menu, FALSE otherwise. ### loop( ) - EXAMPLE ``` $s->loop(); ``` - DESCRIPTION Calls the ***run()*** method immediately. Once ***run()*** completes it's execution, the ***loop()*** decides whether or not to display again. If the return value of *run()* is TRUE, the ***loop()*** will continue. If the use pressed Cancel (or Escape) or any other action other than one of the menu items; the ***loop()*** will end. The ***loop()*** will also end if the ***break\_loop()*** method is called. - RETURNS TRUE if the user selected an item from the menu, FALSE otherwise. ### is\_looping( ) - EXAMPLE ``` if ($s->is_looping()) { print "Currently in a UI::Dialog::Screen::Menu loop\n"; } ``` - DESCRIPTION Returns TRUE if the given screen is in a menu ***loop()***, FALSE otherwise. - RETURNS a single SCALAR. ### break\_loop( ) - EXAMPLE ``` $s->break_loop(); ``` - DESCRIPTION Flags the screen menu to stop looping. This does not close or otherwise clear the screen. This simply flags the loop to exit at the end of it's current run. - RETURNS None. ## SCREEN METHODS ### add\_menu\_item( ) - EXAMPLE ``` my $index = $s->add_menu_item( "Menu Item Label", \%some_function ); ``` - DESCRIPTION Append a new item to the menu list. - RETURNS Returns the list index (starting from 0) of the item that was just appended to the list. ### get\_menu\_items( ) - EXAMPLE ``` my @items = $s->get_menu_items(); ``` - DESCRIPTION Returns an array of hashrefs. Each hash contains a "label" and "func" key/value pairs. - RETURNS An ARRAY. ### del\_menu\_item( ) - EXAMPLE ``` my $old_item = $d->del_menu_item( $index ); ``` - DESCRIPTION Remove a specific item from the menu, addressed by it's list index (starting from 0), and return the menu item as a hashref. - RETURNS A HASH containing the 'label' and 'func' of the menu item that was just removed from the menu list. ### set\_menu\_item( ) - EXAMPLE ``` # Modify the 'label' and 'func' for a specific menu item my $original_item = $s->set_menu_item( $index, $label, $func ); # Modify just the label of a menu item my $original_item = $s->set_menu_item( $index, $label, undef ); # Modify just the func of a menu item my $original_item = $s->set_menu_item( $index, undef, $func ); # Effectively do nothing my $original_item = $s->set_menu_item( $index, undef, undef ); ``` - DESCRIPTION Modify the menu item addressed by the given index (starting from 0). If the 'label' and/or 'func' arguments are undef then the previous value is kept. - RETURNS A HASH of the original values for the modified menu item. ## EXAMPLE USAGE The below example assumed that `$d` is an instances of UI::Dialog. ``` # Create our first screen my $s1 = new UI::Dialog::Screen::Menu ( dialog => $d ); $s1->add_menu_item( "Just an option", \&some_function ); # Add a menu item that updates it's own label every time # it is selected. our $counter = 0; $s1->add_menu_item ( "Counter: ".$counter, sub { my ($self,$dialog,$index) = @_; $counter++; $self->set_menu_item($index,"Counter: ".$counter, undef); } ); # Create a second screen my $s2 = new UI::Dialog::Screen::Menu ( dialog => $d ); $s2->add_menu_item( "Another item", \&another_function ); # Link the second screen to an option of the first $s1->add_menu_item( "Goto Screen 2", sub { $s2->loop(); } ); # Start a menu loop and actually display the first screen $s1->loop(); ``` Users can get to second menu from selecting the third item on the first menu screen. As long as the user continues to select items from the second menu, it will continue to loop. If the user cancels the second screen, the will return to the first which will itself continue to loop. ## SEE ALSO - PERLDOC ``` UI::Dialog UI::Dialog::GNOME UI::Dialog::KDE UI::Dialog::Console UI::Dialog::Screen::Druid UI::Dialog::Backend UI::Dialog::Backend::ASCII UI::Dialog::Backend::CDialog UI::Dialog::Backend::GDialog UI::Dialog::Backend::KDialog UI::Dialog::Backend::Nautilus UI::Dialog::Backend::Whiptail UI::Dialog::Backend::XDialog UI::Dialog::Backend::XOSD UI::Dialog::Backend::Zenity ``` - MAN FILES ``` dialog(1), whiptail(1), zenity(1), gdialog(1), Xdialog(1), osd_cat(1), kdialog(1) and nautilus(1) ``` ## BUGS Please email the author with any bug reports. Include the name of the module in the subject line. ## AUTHOR Kevin C. Krinke, \ ## COPYRIGHT AND LICENSE ``` Copyright (C) 2004-2016 Kevin C. Krinke This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ```