Welcome!

Java IoT Authors: Elizabeth White, Yeshim Deniz, Tim Hinds, Douglas Lyon, Stackify Blog

Related Topics: Java IoT

Java IoT: Article

FrameResizer

Resizing windows

This article presents a Java/Swing component implementation of a feature that is ubiquitous in nearly all desktop applications, particularly Windows applications - an area in the lower right portion of a window (Frame) that can be used to resize the window.

Of course, a window can be re-sized with most desktop managers by dragging the lower-right edge - the additional component simply serves as a visual indicator of the resize capability, and also increases the margin of error for the mouse drag.

Typically this component is placed in a status or message area at the bottom of a window. I demonstrate my solution in the context of a very simple (and barely func-tional) Web browser. I also introduce a technique in which a Frame/JFrame/JInternalFrame can exhibit "continuous layout" behavior as it is resized.

Details
The component is called Frame-Resizer. It subclasses JComponent and has two main jobs that it performs. First, it draws itself and, second, it handles mouse events so that it can both change the mouse cursor (on mouse enter/leave) and resize the window (on mouse press/drag/release). FrameResizer can be used to resize a Frame, JFrame, or JInternalFrame, each of which has a common ancestor of java.awt.Container in the component class hierarchy. So constructors for FrameResizer take a Container argument as follows:

public FrameResizer(Container parent);
public FrameResizer(Container parent, boolean useContinuousLayout);

Rendering
Figure 1 shows the FrameResizer in its typical context, at the lower right edge of a window, as part of a status/message area.

FrameResizer draws itself in the paintComponent() method as shown in Listing 1. There are seven "ribs" that make up the component.

A rib is one of the raised "bumps" in the component visual; it's actually just two 2x2 pixel rectangles drawn in different colors offset slightly from each other. You can see this in the exploded view of the FrameResizer in Figure 2.

Resizing
Much of the interesting FrameResizer code is in the MouseInputListener inner class that the component adds to itself. In the mouseEntered() and mouseExited() methods, the cursor is changed to Cursor.NW_RESIZE_CURSOR and the default Cursor, respectively. In the mousePressed() method (see Listing 2), the mouse location is converted to actual screen coordinates, and the relative location from edge of the window (the Point mouseAdjust) is calculated.

In the mouseDragged() method (see Listing 3), the current mouse position is again converted to absolute screen position, and the new bounds of the parent Container (Frame/InternalFrame) are recalculated based on the original mouse location.

The mouseReleased() method calls mouseDragged() for a final calculation, and then "validates" the parent container. Since FrameResizer supports either an external Frame or a JInternalFrame, the validate() method does the appropriate validation and invokes the repaint() method (see Listing 4). This needs to be done at the end of the AWT EventDispatchThread (thus the use of SwingUtilities.invokeLater()). This method is declared static so it can be re-used for the "continuous layout" functionality (see below).

Continuous Layout
This concept is familiar to Swing developers who use JSplitPane - it's the ability to have internal components validate and repaint as the container is resized (in real time). Unfortunately, when a top-level Java desktop window is resized, this doesn't happen, as the validate/repaint messages are not sent to the underlying Container until resizing (via mouse dragging) is complete. Figure 3 is a capture of our browser window during the mouse drag. You can see how the contents of the window are not "stretched' to fit the bounds of the Frame - this is done when the mouse is released.

Ideally you want the contents of the window to stretch to the frame bounds during resizing. This capability is evident in most non-Java top-level desktop windows.

The trick to doing this in Java is to use a Timer to periodically check the current bounds of the window (Frame), and if it has changed since the last interval, send the validate/repaint messages to the Frame. You can see how this is done in Listing 5. I coded it as a static method in FrameResizer so this functionality can be used independently of the component.

The code uses a static HashMap (continuousLayoutWindows) so it can be used for multiple windows in a multi-frame application. It lazily initializes this HashMap. In the map it stores the current Container bounds keyed by the Container. If the current bounds are different than what is in the map, the current bounds are saved and the validate and repaint messages are sent to the Container (our static validate() method from before). That's all there is to it. I use 100 milliseconds (hard-coded) as my timer interval - feel free to experiment with this number (or parameterize it).

You can specify whether or not "continuous layout" is used by the FrameResizer in its constructor (the default is true). Note that one drawback to "continuous layout" in this context is the flicker that occurs during the repaint. This is unfortunately unavoidable. Also note that the continuous layout behavior is not required if you are using the FrameResizer in the context of a JInternalFrame.

Summary
In this article I presented a custom Swing component that can be used to help provide a customary look and feel to a Frame or JInternalFrame. I've also introduced the concept of "continuous layout" to top-level Java desktop windows and shown how this can be implemented. The source code for this article can be downloaded from http://jdj.sys-con.com.

More Stories By Phil Herold

Phil Herold is VP and CTO of PocketScience LLC in Research Triangle Park, NC. He has over 24 years of experience in software engineering, and has been working with Java client technologies since 1996.

Comments (4) 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
Phil Herold 09/28/05 10:43:13 AM EDT

The link for the code to this article has been fixed. Here's the direct link:

http://res.sys-con.com/story/aug05/117759/FrameResizer.zip

This contains a jar file with both source and class files. If your run the jar with javaw, it will run the "Lame Browser" window that is shown in the article.

Phil Herold 09/26/05 09:59:47 AM EDT

Michael,

Someone in a private e-mail pointed out that Toolkit.setDynamicLayout() will accomplish the same thing as the timer/validate-paint technique used in my article. I haven't tried it, but you might look at that as well.

Michael Bushe 08/12/05 08:05:03 PM EDT

Brilliant!!! I've been writing fancy Swing apps for a long time and never even considered that there was a way around the gray-screen-as-you-resize problem. Very slick, very thorough. An icon for this was meticulously created by Jonathan Simon here:
http://today.java.net/pub/a/today/2005/06/07/pixelpushing.html

Bill Winspur 08/12/05 06:10:43 PM EDT

Very interesting article - unfortunately I cant find a link to the source code in the article, or on http://jdj.sys-con.com . Can somebody provide it?

@ThingsExpo Stories
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
Nordstrom is transforming the way that they do business and the cloud is the key to enabling speed and hyper personalized customer experiences. In his session at 21st Cloud Expo, Ken Schow, VP of Engineering at Nordstrom, discussed some of the key learnings and common pitfalls of large enterprises moving to the cloud. This includes strategies around choosing a cloud provider(s), architecture, and lessons learned. In addition, he covered some of the best practices for structured team migration an...
Product connectivity goes hand and hand these days with increased use of personal data. New IoT devices are becoming more personalized than ever before. In his session at 22nd Cloud Expo | DXWorld Expo, Nicolas Fierro, CEO of MIMIR Blockchain Solutions, will discuss how in order to protect your data and privacy, IoT applications need to embrace Blockchain technology for a new level of product security never before seen - or needed.
Imagine if you will, a retail floor so densely packed with sensors that they can pick up the movements of insects scurrying across a store aisle. Or a component of a piece of factory equipment so well-instrumented that its digital twin provides resolution down to the micrometer.
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settle...
BnkToTheFuture.com is the largest online investment platform for investing in FinTech, Bitcoin and Blockchain companies. We believe the future of finance looks very different from the past and we aim to invest and provide trading opportunities for qualifying investors that want to build a portfolio in the sector in compliance with international financial regulations.
No hype cycles or predictions of a gazillion things here. IoT is here. You get it. You know your business and have great ideas for a business transformation strategy. What comes next? Time to make it happen. In his session at @ThingsExpo, Jay Mason, an Associate Partner of Analytics, IoT & Cybersecurity at M&S Consulting, presented a step-by-step plan to develop your technology implementation strategy. He also discussed the evaluation of communication standards and IoT messaging protocols, data...
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
In his session at 21st Cloud Expo, Raju Shreewastava, founder of Big Data Trunk, provided a fun and simple way to introduce Machine Leaning to anyone and everyone. He solved a machine learning problem and demonstrated an easy way to be able to do machine learning without even coding. Raju Shreewastava is the founder of Big Data Trunk (www.BigDataTrunk.com), a Big Data Training and consulting firm with offices in the United States. He previously led the data warehouse/business intelligence and B...
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
When shopping for a new data processing platform for IoT solutions, many development teams want to be able to test-drive options before making a choice. Yet when evaluating an IoT solution, it’s simply not feasible to do so at scale with physical devices. Building a sensor simulator is the next best choice; however, generating a realistic simulation at very high TPS with ease of configurability is a formidable challenge. When dealing with multiple application or transport protocols, you would be...
Smart cities have the potential to change our lives at so many levels for citizens: less pollution, reduced parking obstacles, better health, education and more energy savings. Real-time data streaming and the Internet of Things (IoT) possess the power to turn this vision into a reality. However, most organizations today are building their data infrastructure to focus solely on addressing immediate business needs vs. a platform capable of quickly adapting emerging technologies to address future ...
We are given a desktop platform with Java 8 or Java 9 installed and seek to find a way to deploy high-performance Java applications that use Java 3D and/or Jogl without having to run an installer. We are subject to the constraint that the applications be signed and deployed so that they can be run in a trusted environment (i.e., outside of the sandbox). Further, we seek to do this in a way that does not depend on bundling a JRE with our applications, as this makes downloads and installations rat...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
DX World EXPO, LLC, a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
In this strange new world where more and more power is drawn from business technology, companies are effectively straddling two paths on the road to innovation and transformation into digital enterprises. The first path is the heritage trail – with “legacy” technology forming the background. Here, extant technologies are transformed by core IT teams to provide more API-driven approaches. Legacy systems can restrict companies that are transitioning into digital enterprises. To truly become a lead...
Digital Transformation (DX) is not a "one-size-fits all" strategy. Each organization needs to develop its own unique, long-term DX plan. It must do so by realizing that we now live in a data-driven age, and that technologies such as Cloud Computing, Big Data, the IoT, Cognitive Computing, and Blockchain are only tools. In her general session at 21st Cloud Expo, Rebecca Wanta explained how the strategy must focus on DX and include a commitment from top management to create great IT jobs, monitor ...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
The IoT Will Grow: In what might be the most obvious prediction of the decade, the IoT will continue to expand next year, with more and more devices coming online every single day. What isn’t so obvious about this prediction: where that growth will occur. The retail, healthcare, and industrial/supply chain industries will likely see the greatest growth. Forrester Research has predicted the IoT will become “the backbone” of customer value as it continues to grow. It is no surprise that retail is ...