Click here to close now.

Welcome!

Java Authors: Carmen Gonzalez, Pat Romanski, Elizabeth White, Lori MacVittie, Kyle Samani

Related Topics: Java

Java: Article

GUI Design Patterns

Choosing data from long lists

Long lists of data present a problem for GUI development. This occurs when choosing records from large database tables or recipients from a long list of e-mail addresses, or any time a subset of data must be chosen from a long list or table.

Two issues arise when choosing from long lists of data. First, what is the best GUI for long lists so that the users understand how to navigate and manipulate their data? Second, if the list holds more than a few hundred items, performance become an issue.

In this article, simple examples show how to optimize usability for this common GUI design pattern. In a later article, more complex examples will show how to optimize performance for long lists.

GUI Design Patterns
In the late 1990s, a GUI design pattern emerged for choosing multiple objects from long lists. The book GUI Design Essentials by Susan Weinschenk, et al, called this the Selection Summary pattern. In "A Dual Listbox Selection Manager" by Steve Aube, it's also known as the Dual Listbox Selection interface. In "The Java Look and Feel Guidelines, Advanced Topics" by Sun Microsystems, it's called the Add-and-Remove idiom. Figure 1 shows an example of this GUI design pattern.

The Add-and-Remove design pattern has many variations. One common enhancement is to provide "Move Up" and "Move Down" buttons to reorder the chosen list. Sometimes the chosen list is displayed as a table (as in Figure 2) to show additional information.

This GUI design pattern has several advantages. By presenting the original and chosen lists in a symmetric layout, learning is simplified: once users learn one part of the GUI, the corresponding part works consistently. Also, because objects are moved from one location to another, directional icons and disabling can be used to guide the user.

The most important advantage of a standard GUI design like this is that because it is widely known, users will most likely have seen it before and therefore understand it quickly. A standard GUI design pattern is the simplest way to achieve usability.

Lay Out the Components
Listing 1 shows how this GUI design pattern can be implemented using the Swing components JList, JScrollPane, ImageIcon, and GridBagLayout. The GridBagLayout enables the alignment of unequal-sized components and provides good behavior on resizing. For a basic implementation, we need a grid with three columns and five rows. Lists, labels, and buttons are placed using GridBagConstraints so that when the component is resized, the lists grow or shrink while other components retain their original size (see Figure 3).

To support the Add-and-Remove pattern, the list contents must be mutable; i.e., the lists must dynamically change in response to the button presses. The DefaultListModel provides mutable storage that performs satisfactorily for lists of moderate size.

In Listing 1, the ActionListener interface connects the buttons to the lists. The actionPerformed method uses the button text to determine which of the four buttons was pressed.

The code in Listing 1 produces the GUI shown in Figure 4.

The DefaultListModel is not the default ListModel. By default, JLists use an internal ListModel that is immutable: you can't change its contents. This internal ListModel is efficient when applications only need to view a list because it doesn't carry the overhead of changing list contents.

To change list contents, as in the Add-and-Remove pattern, requires a mutable ListModel. Swing provides one in javax.swing.DefaultListModel, and it gives good performance for most applications. For long lists DefaultListModel is not particularly fast, and a later article will show how to improve on its performance.

Follow the Guidelines
"The Java Look and Feel Guidelines" specify precise spacings in multiples of six pixels between components. To follow these guidelines, EmptyBorders are added around the buttons and labels.

_originalLabel.setBorder(
  BorderFactory.createEmptyBorder( 0, 0, 6, 0 ));
_chosenLabel.setBorder(
  BorderFactory.createEmptyBorder( 0, 0, 6, 0 ));
_add.setBorder(
  BorderFactory.createCompoundBorder(
  BorderFactory.createEmptyBorder( 0, 11, 5, 11 ),
  _add.getBorder()));
_addAll.setBorder(
  BorderFactory.createCompoundBorder(
  BorderFactory.createEmptyBorder( 0, 11, 11, 11 ),
  _addAll.getBorder()));
_remove.setBorder(
  BorderFactory.createCompoundBorder(
  BorderFactory.createEmptyBorder( 0, 11, 5, 11 ),
  _remove.getBorder()));
_removeAll.setBorder(
  BorderFactory.createCompoundBorder(
  BorderFactory.createEmptyBorder( 0, 11, 0, 11 ),
  _removeAll.getBorder()));

The Guidelines also recommend mnemonics to support keyboard equivalents of mouse actions, as shown in the code below.

_add.setMnemonic( 'A' );
_addAll.setMnemonic( 'l' );
_remove.setMnemonic( 'R' );
_removeAll.setMnemonic( 'v' );

Note the difference between Figures 4 and 5. By following the guidelines, the GUI appearance is improved.

This example uses the guidelines for the Java ("Metal") Look and Feel. If you target a different platform the guidelines will be different. For example, Windows Guidelines specify different spacings between the components.

Whatever the target platform, the reason for following guidelines is to make life easier for the user. When your application looks and works the way the users expect, they have less to learn.

Help the Users Learn
"The Java Look and Feel Guidelines, Advanced Topics" by Sun recommends the use of icons in the buttons. If icons are stored with the ListChooser class, they can be assigned with the following code.

_add.setIcon( new ImageIcon(
  ListSelector.class.getResource( "images/add.gif" )));
_add.setHorizontalTextPosition( SwingConstants.LEFT );
_addAll.setIcon( new ImageIcon(
  ListSelector.class.getResource( "images/addAll.gif" )));
_addAll.setHorizontalTextPosition( SwingConstants.LEFT );
_remove.setIcon( new ImageIcon(
  ListSelector.class.getResource( "images/remove.gif" )));
_remove.setHorizontalTextPosition( SwingConstants.RIGHT );
_removeAll.setIcon( new ImageIcon(
  ListSelector.class.getResource( "images/removeAll.gif")));
_removeAll.setHorizontalTextPosition( SwingConstants.RIGHT );

These simple icons transform the buttons into a diagram of information flow through the GUI. The icons make the users' possible actions clear before they read the buttons' text, enabling new users to understand the buttons' functions at a glance.

The icons in Figure 6 are chosen because they're familiar to most users; similar icons appear on most tape and disk players. "The Java Look and Feel Guidelines, Advanced Topics" illustrate other icons specific to the Java look and feel. Whatever icons are chosen, the program should provide equal margins on the left and right to ensure consistent spacing between the icons and the button text. A slight margin below the icon, as shown in Figure 7, can improve vertical alignment.

Prevent User Errors
One of the best ways to improve usability is to prevent the user from making a mistake. The authors of GUI Design Essentials recommend disabling unavailable actions. This technique guides users through the GUI, preventing them from taking actions that make no sense.

This effective GUI design pattern is trivially easy to code. The ActionListener interface enables the "Add All" and "Remove All" buttons when the lists contain objects, and disables them when the lists are empty.

public void actionPerformed(
  ActionEvent e )
{    .
    .
    .
  _addAll.setEnabled(
   originalModel.getSize() > 0 );
  _removeAll.setEnabled(
   chosenModel.getSize() > 0 );
}

The ListSelectionListener interface enables the "Add" and "Remove" buttons when objects are selected, and disables them when no objects are selected.

public void valueChanged(
   ListSelectionEvent e )
{ _add.setEnabled( _originalList.
   getSelectedValues().length > 0 );
  _remove.setEnabled( _chosenList.
   getSelectedValues().length > 0 );
}

As shown in Listing 1, the ListChooser registers itself as an ActionListener to receive events when buttons are pressed. To receive events when list contents are selected, the ListChooser registers itself as a ListSelectionListener. Also, at the end of the constructor, two dummy events are initiated to set the default enabled states.

public ListChooser(
  Object[] original, Object[] chosen )
{     .
     .
     .
  _originalList.
   addListSelectionListener( this );
  _chosenList.
   addListSelectionListener( this );
  actionPerformed(
   new ActionEvent( this, 0, "" ));
  valueChanged(
   new ListSelectionEvent(
   this, 0, 0, false ));
}

The effect of this code is shown in Figure 8. Rather than trying to deal with the user pressing the wrong button, the program uses disabling to prevent the mistake from occurring. Disabling unavailable actions is one of the simplest and most effective GUI design patterns.

GUI Variations
All of the GUI design patterns described above apply to tables as well as lists. Listing 2 shows an implementation using JTable and TableModel instead of JList and ListModel. "The Java Look and Feel Guidelines" recommend only one table column in the original list and multiple columns in the chosen list. As shown in Listing 2, this can be done by disabling the header and grid lines in the original table, and by assigning the preferred viewport size based on TableColumn widths.

The GridBagLayout code is omitted from Listing 2 as it is similar to the simpler variation of Listing 1. If "Move Up" and "Move Down" buttons are provided, the GridBagLayout contains seven rows instead of five. Following "The Java Look and Feel Guidelines," the spacing between these optional buttons is six pixels greater than between the "Add" and "Remove" buttons.

The ActionListener implementation is slightly different in Listing 2 because of the use of TableModels instead of ListModels. The code in Listing 2 produces the GUI shown in Figure 2.

Details of the JTable and TableModel can be found in The JFC Swing Tutorial (by Kathy Walrath and Mary Campione), along with descriptions of the JList and ListModel. The JTable is more complex than the JList, but when displaying long lists they share many of the same performance issues. A future article will discuss these issues and how to optimize performance for this common GUI design pattern.

Conclusion
The Add-and-Remove pattern enables users to choose multiple objects from long lists. This standard GUI design pattern improves usability by easing the user's learning curve. Standard spacing, directional icons, and button disabling all reduce the users' efforts, enabling them to accomplish their tasks easily in a professional user interface.

Resources

  • Aube, S. (2000). "A Dual Listbox Selection Manager": www.codeguru.com/Cpp/controls/listbox/article.php/c4755
  • Walrath, K., and Campione, M. (2004). The JFC Swing Tutorial: A Guide to Constructing GUIs. Addison-Wesley Professional: java.sun.com/docs/books/tutorial/uiswing/components/
  • "Official Guidelines for User Interface Developers and Designers." Microsoft Inc. (2004): msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwue/html/welcome.asp
  • Sun Microsystems Inc. (2001). Java Look and Feel Design Guidelines, Second Edition. Addison-Wesley Professional: java.sun.com/products/jlf/ed2/book/HIG.Misc.html
  • Sun MicroSystems Inc. (2002). Java Look and Feel Design Guidelines: Advanced Topics. Addison-Wesley Professional: java.sun.com/products/jlf/at/book/Idioms6.html
  • Weinschenk, S., Jamar, P., and Yeo, S. (1997). GUI Design Essentials. John Wiley & Sons.
  • More Stories By Heman Robinson

    Heman Robinson is a senior developer with SAS Institute in Cary, N.C. He holds a BS in mathematics from the University of North Carolina and an MS in computer science from the University of Southern California. He has specialized in GUI design and development for 15 years and has been a Java developer since 1996.

    Comments (1) View Comments

    Share your thoughts on this story.

    Add your comment
    You must be signed in to add a comment. Sign-in | Register

    In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


    Most Recent Comments
    steve 02/14/05 07:04:05 PM EST

    Does anyone have code that accomplishes this for VB.NET?

    @ThingsExpo Stories
    SYS-CON Events announced today that Akana, formerly SOA Software, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Akana’s comprehensive suite of API Management, API Security, Integrated SOA Governance, and Cloud Integration solutions helps businesses accelerate digital transformation by securely extending their reach across multiple channels – mobile, cloud and Internet of Things. Akana enables enterprises to share data as APIs, connect and integrate applications, drive part...
    After making a doctor’s appointment via your mobile device, you receive a calendar invite. The day of your appointment, you get a reminder with the doctor’s location and contact information. As you enter the doctor’s exam room, the medical team is equipped with the latest tablet containing your medical history – he or she makes real time updates to your medical file. At the end of your visit, you receive an electronic prescription to your preferred pharmacy and can schedule your next appointment.
    The WebRTC Summit 2014 New York, to be held June 9-11, 2015, at the Javits Center in New York, NY, announces that its Call for Papers is open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 16th International Cloud Expo, @ThingsExpo, Big Data Expo, and DevOps Summit.
    SYS-CON Events announced today that Solgenia will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Solgenia is the global market leader in Cloud Collaboration and Cloud Infrastructure software solutions. Designed to “Bridge the Gap” between Personal and Professional Social, Mobile and Cloud user experiences, our solutions help large and medium-sized organizations dr...
    SYS-CON Events announced today that Liaison Technologies, a leading provider of data management and integration cloud services and solutions, has been named "Silver Sponsor" of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York, NY. Liaison Technologies is a recognized market leader in providing cloud-enabled data integration and data management solutions to break down complex information barriers, enabling enterprises to make smarter decisions, faster.
    The 3rd International Internet of @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that its Call for Papers is open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
    SYS-CON Events announced today that CommVault has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. A singular vision – a belief in a better way to address current and future data management needs – guides CommVault in the development of Singular Information Management® solutions for high-performance data protection, universal availability and sim...
    Cloud is not a commodity. And no matter what you call it, computing doesn’t come out of the sky. It comes from physical hardware inside brick and mortar facilities connected by hundreds of miles of networking cable. And no two clouds are built the same way. SoftLayer gives you the highest performing cloud infrastructure available. One platform that takes data centers around the world that are full of the widest range of cloud computing options, and then integrates and automates everything. Join SoftLayer on June 9 at 16th Cloud Expo to learn about IBM Cloud's SoftLayer platform, explore se...
    The list of ‘new paradigm’ technologies that now surrounds us appears to be at an all time high. From cloud computing and Big Data analytics to Bring Your Own Device (BYOD) and the Internet of Things (IoT), today we have to deal with what the industry likes to call ‘paradigm shifts’ at every level of IT. This is disruption; of course, we understand that – change is almost always disruptive.
    SYS-CON Media announced today that 9 out of 10 " most read" DevOps articles are published by @DevOpsSummit Blog. Launched in October 2014, @DevOpsSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development cycles that produce softw...
    Wearable technology was dominant at this year’s International Consumer Electronics Show (CES) , and MWC was no exception to this trend. New versions of favorites, such as the Samsung Gear (three new products were released: the Gear 2, the Gear 2 Neo and the Gear Fit), shared the limelight with new wearables like Pebble Time Steel (the new premium version of the company’s previously released smartwatch) and the LG Watch Urbane. The most dramatic difference at MWC was an emphasis on presenting wearables as fashion accessories and moving away from the original clunky technology associated with t...
    The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on Twitter at @MicroservicesE
    SYS-CON Events announced today that Site24x7, the cloud infrastructure monitoring service, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Site24x7 is a cloud infrastructure monitoring service that helps monitor the uptime and performance of websites, online applications, servers, mobile websites and custom APIs. The monitoring is done from 50+ locations across the world and from various wireless carriers, thus providing a global perspective of the end-user experience. Site24x7 supports monitoring H...
    SYS-CON Events announced today that SafeLogic has been named “Bag Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. SafeLogic provides security products for applications in mobile and server/appliance environments. SafeLogic’s flagship product CryptoComply is a FIPS 140-2 validated cryptographic engine designed to secure data on servers, workstations, appliances, mobile devices, and in the Cloud.
    @ThingsExpo has been named the Top 5 Most Influential M2M Brand by Onalytica in the ‘Machine to Machine: Top 100 Influencers and Brands.' Onalytica analyzed the online debate on M2M by looking at over 85,000 tweets to provide the most influential individuals and brands that drive the discussion. According to Onalytica the "analysis showed a very engaged community with a lot of interactive tweets. The M2M discussion seems to be more fragmented and driven by some of the major brands present in the M2M space. This really allows some room for influential individuals to create more high value inter...
    SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Raspberry Pi, BeagleBone, Spark and Intel Edison. You will also get an overview of cloud technologies s...
    Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
    SOA Software has changed its name to Akana. With roots in Web Services and SOA Governance, Akana has established itself as a leader in API Management and is expanding into cloud integration as an alternative to the traditional heavyweight enterprise service bus (ESB). The company recently announced that it achieved more than 90% year-over-year growth. As Akana, the company now addresses the evolution and diversification of SOA, unifying security, management, and DevOps across SOA, APIs, microservices, and more.
    The Open Compute Project is a collective effort by Facebook and a number of players in the datacenter industry to bring lessons learned from the social media giant's giant IT deployment to the rest of the world. Datacenters account for 3% of global electricity consumption – about the same as all of Switzerland or the Czech Republic -- according to people I met at the recent Open Compute Summit in San Jose. With increasing mobility at the edge of the cloud and vast new dataflows being predicted with the growth of the Internet of Things (and The Coming Age of Many Zettabytes) in the near...
    GENBAND has announced that SageNet is leveraging the Nuvia platform to deliver Unified Communications as a Service (UCaaS) to its large base of retail and enterprise customers. Nuvia’s cloud-based solution provides SageNet’s customers with a full suite of business communications and collaboration tools. Two large national SageNet retail customers have recently signed up to deploy the Nuvia platform and the company will continue to sell the service to new and existing customers. Nuvia’s capabilities include HD voice, video, multimedia messaging, mobility, conferencing, Web collaboration, deskt...