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Exploring Tk::JComboBox Perl module contains a tutorial for usage of the Tk::JComboBox widget.

Overview

This tutorial assumes a familiarity with basic Perl/Tk concepts. It is meant to be used alongside the JComboBox class reference.

What is it and what is it good for?

JComboBox is yet another combo box implementation for use with the Perl/Tk Toolkit. A combo box is a widget that can activate a popup (or dropdown) listbox with a number of selectable items. After an item is selected, the listbox disappears and that item appears on the widget. This is a space-saving alternative to having a full list in the interface, or having a very long Frame or Menu full of radio buttons. In addition to providing a way of selecting one item from a list of options, a Combo Box can also allow a user to add an entry that does not necessarily appear within the list.

This implementation is named for the JComboBox component in the Java Swing classes, and those familiar with that component should have no problem using this because both share several superficial similarities including method names and general behavior -- its a passing resemblance at best.

When compared to other similar Perl/Tk widgets, JComboBox is probably the most bloated or to put it another way, feature-rich. It has a slightly larger overhead associated with it than any of the others. Simply put, there is more code required to support the extra options and methods it offers. In applications I have used it in, Ive found that the cost is negligible and that the benefits outweigh the cost, but since requirements and constraints vary, its probably best to determine this for yourself, and to check out the alternatives.

Two Modes of Operation

Like other Combo Box implementations, the JComboBox has more than one mode of operation: uneditable and editable. The mode can only be set once, at creation time. To better distinguish the two modes, the uneditable mode is called readonly. Unlike other similar Combo box implementations, each mode is distinctive and like having two different Widgets bundled as one. Each mode has a separate default visual appearance, and can affect how options are processed. This is done to emphasize the differences between the two. The basic question is why should an element that looks like a text field, not be editable like a text field and vice versa? So, when a JComboBox is editable it resembles a text field. A user can edit it directly like other text fields, or select one of the items from the list of choices. In readonly mode, the JComboBox resembles a Button, that displays the selected item on its face.

OpenPlay is a cross-platform network abstraction layer. OpenPlay is designed to simplify the task of creating programs which communicate across multiple computers and has been used in dozens of commercial products. Includes NetSprocket API compatability.
Getting Started With OpenPlay
There are currently a few sample applications available to help you understand the workings of OpenPlay/NetSprocket:
OPExample1 is the best place to start. This example is a complete mini-game for multiple players and demonstrates how to host and join games, as well as sending, receiving data and how to handle various chores related to networking with OpenPlay. This example has both a Protocol and NetSprocket networking example, and can server as a decent learning tool for the APIs as well as a good starting point for your own game. The networking code (nsp_network or op_network) was designed to be fairly easy to bring to another app, so although it is not 100% application independent it should be easy enough to figure out how to make it work in yours.
OpenPlayTest is a small application that allows you to explore the basic features of OpenPlay, including setting up a client/server connection via the cross-platform GUI, enumerating through a list of available hosts, sending packets and streams between processes, and so forth. The code can be a bit daunting to newcomers, however.
OPMiniDemo is a stripped down "bare metal" example of the lowest elements of OpenPlay, using a crude text-based menu to drive a fixed single-connection client/server topology. Its severely limited functionality helps reveal the core workings of an OpenPlay application, however. MiniPlay is meant to be learning tool, not a foundation on which to build your application.
OPEnumTest is a simple app focusing on OpenPlays enumeration routines -functions for creating a list of games currently on the network and joining based on that.
NSpTestApp is a small application that allows you to explore and test the NetSprocket component of OpenPlay. You can do pretty much anything in the API here via lists of commands, so its a good way to orient yourself with the workings of NSp. In the Documentation folder, youll find a step by step list of commands to run to ensure NetSprocket is working properly.
Enhancements:
- fixed missing functions in export files

The Mono Live CD is a way for you to try out Linux, the Mono Framework 1.1.7, and the newest desktop applications without modifying your current computing environment.
Main features:
- Develop, compile and run software with MonoDevelop.
- Listen to your music collection in style with Muine.
- Take notes with Tomboy.
- Manage your photos with F-Spot.
- Search music, photos, chats, and documents with Beagle.
- Explore web applications such as ASP.NET Forums, IBuySpy, and mojoPortal.
This CD also contains the files necessary to install Mono on Windows computers. This allows you to expore the framework without installing a Linux desktop, and begin developing cross-platform applications with Mono and Gtk# today.