Gtk2::Ex::RecordsFilter 0.03

Gtk2::Ex::RecordsFilter is a high level widget to browse reasonably large amounts of relational data. This widget is inspired by the song browser of iTunes.

SYNOPSIS

use Gtk2 -init;
use Gtk2::Ex::RecordsFilter;

# Create a recordset
my $recordset = [
[Automobiles,Cars,Toyota,Camry],
[Automobiles,SUV,BMW,Xi],
[Automobiles,SUV,Toyota,Highlander],
[Automobiles,Cars,Mitsubishi,Lancer]
];

# Create the recordsfilter object
my $recordsfilter = Gtk2::Ex::RecordsFilter->new;

# Specify the headers for the columns
my $headers = [Category, Sub-Category, Brand, Model];
Gtk2::Ex::RecordsFilter->set_headers($headers);

# Inject data into the widget
Gtk2::Ex::RecordsFilter->set_data($recordset);

# Get a ref to its widget
my $recordsfilter_widget = $recordsfilter->get_widget();

# Create the root window
my $window = Gtk2::Window->new;
$window->signal_connect(destroy => sub { Gtk2->main_quit; });
$window->set_default_size(500, 300);

# Add the widget to the root window
$window->add($recordsfilter_widget);
$window->show_all;

Gtk2->main;

When working with large amounts of relational records (csv files, database records, music files index), a common task is to filter out a subset or records from a given set. For example, in a master-detail database design, the master recordset, which is typically smaller than the detail recordset, can be filtered out and the filtered subset of master records can then be used to perform additional tasks on the detail records that they point to.

A common example of this usage is the song browser in your own mp3 player application (for example, the iTunes application). This application will allow you to choose an mp3 file (the detail record) based on criteria such as Artist, Album, Song (the master record). Once the master record is choosen (i.e., the Artist, Album and Song) it then performs a task on the detail record (i.e., play the mp3 file).

This Gtk2::Ex::RecordsFilter widget is inspired by the iTunes song browser widget. But this widget carries certain functionality which is not present in the iTunes song browser. The iTunes song browser allows the user to choose one song (one master record) at a time and play it. However, a more general usage should allow the user to choose multiple master records at a time. One approach for such multiple selections is to enable the user to click on different records with the CTRL key pressed and then choose all the highlighted records in one shot. This widget takes a different approach, which I call the shopping cart approach. This is explained in the next section.