|By Phil Herold||
|August 10, 2005 11:00 AM EDT||
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.
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);
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.
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).
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.
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.
|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:
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|
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:
|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?
The cloud market growth today is largely in public clouds. While there is a lot of spend in IT departments in virtualization, these aren’t yet translating into a true “cloud” experience within the enterprise. What is stopping the growth of the “private cloud” market? In his general session at 18th Cloud Expo, Nara Rajagopalan, CEO of Accelerite, explored the challenges in deploying, managing, and getting adoption for a private cloud within an enterprise. What are the key differences between wh...
Jan. 19, 2017 01:15 AM EST Reads: 6,087
"Tintri was started in 2008 with the express purpose of building a storage appliance that is ideal for virtualized environments. We support a lot of different hypervisor platforms from VMware to OpenStack to Hyper-V," explained Dan Florea, Director of Product Management at Tintri, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Jan. 19, 2017 12:45 AM EST Reads: 4,630
The security needs of IoT environments require a strong, proven approach to maintain security, trust and privacy in their ecosystem. Assurance and protection of device identity, secure data encryption and authentication are the key security challenges organizations are trying to address when integrating IoT devices. This holds true for IoT applications in a wide range of industries, for example, healthcare, consumer devices, and manufacturing. In his session at @ThingsExpo, Lancen LaChance, vic...
Jan. 18, 2017 09:45 PM EST Reads: 6,513
WebRTC has had a real tough three or four years, and so have those working with it. Only a few short years ago, the development world were excited about WebRTC and proclaiming how awesome it was. You might have played with the technology a couple of years ago, only to find the extra infrastructure requirements were painful to implement and poorly documented. This probably left a bitter taste in your mouth, especially when things went wrong.
Jan. 18, 2017 09:30 PM EST Reads: 7,627
Big Data, cloud, analytics, contextual information, wearable tech, sensors, mobility, and WebRTC: together, these advances have created a perfect storm of technologies that are disrupting and transforming classic communications models and ecosystems. In his session at @ThingsExpo, Erik Perotti, Senior Manager of New Ventures on Plantronics’ Innovation team, provided an overview of this technological shift, including associated business and consumer communications impacts, and opportunities it m...
Jan. 18, 2017 09:30 PM EST Reads: 5,741
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...
Jan. 18, 2017 07:30 PM EST Reads: 3,146
WebRTC is bringing significant change to the communications landscape that will bridge the worlds of web and telephony, making the Internet the new standard for communications. Cloud9 took the road less traveled and used WebRTC to create a downloadable enterprise-grade communications platform that is changing the communication dynamic in the financial sector. In his session at @ThingsExpo, Leo Papadopoulos, CTO of Cloud9, discussed the importance of WebRTC and how it enables companies to focus o...
Jan. 18, 2017 06:15 PM EST Reads: 4,197
Big Data engines are powering a lot of service businesses right now. Data is collected from users from wearable technologies, web behaviors, purchase behavior as well as several arbitrary data points we’d never think of. The demand for faster and bigger engines to crunch and serve up the data to services is growing exponentially. You see a LOT of correlation between “Cloud” and “Big Data” but on Big Data and “Hybrid,” where hybrid hosting is the sanest approach to the Big Data Infrastructure pro...
Jan. 18, 2017 05:30 PM EST Reads: 4,885
In his General Session at 16th Cloud Expo, David Shacochis, host of The Hybrid IT Files podcast and Vice President at CenturyLink, investigated three key trends of the “gigabit economy" though the story of a Fortune 500 communications company in transformation. Narrating how multi-modal hybrid IT, service automation, and agile delivery all intersect, he will cover the role of storytelling and empathy in achieving strategic alignment between the enterprise and its information technology.
Jan. 18, 2017 04:45 PM EST Reads: 4,596
Buzzword alert: Microservices and IoT at a DevOps conference? What could possibly go wrong? In this Power Panel at DevOps Summit, moderated by Jason Bloomberg, the leading expert on architecting agility for the enterprise and president of Intellyx, panelists peeled away the buzz and discuss the important architectural principles behind implementing IoT solutions for the enterprise. As remote IoT devices and sensors become increasingly intelligent, they become part of our distributed cloud enviro...
Jan. 18, 2017 04:30 PM EST Reads: 4,801
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
Jan. 18, 2017 03:30 PM EST Reads: 3,688
"LinearHub provides smart video conferencing, which is the Roundee service, and we archive all the video conferences and we also provide the transcript," stated Sunghyuk Kim, CEO of LinearHub, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Jan. 18, 2017 02:45 PM EST Reads: 1,597
Things are changing so quickly in IoT that it would take a wizard to predict which ecosystem will gain the most traction. In order for IoT to reach its potential, smart devices must be able to work together. Today, there are a slew of interoperability standards being promoted by big names to make this happen: HomeKit, Brillo and Alljoyn. In his session at @ThingsExpo, Adam Justice, vice president and general manager of Grid Connect, will review what happens when smart devices don’t work togethe...
Jan. 18, 2017 02:00 PM EST Reads: 420
"There's a growing demand from users for things to be faster. When you think about all the transactions or interactions users will have with your product and everything that is between those transactions and interactions - what drives us at Catchpoint Systems is the idea to measure that and to analyze it," explained Leo Vasiliou, Director of Web Performance Engineering at Catchpoint Systems, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York Ci...
Jan. 18, 2017 01:00 PM EST Reads: 5,618
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
Jan. 18, 2017 01:00 PM EST Reads: 5,105
Discover top technologies and tools all under one roof at April 24–28, 2017, at the Westin San Diego in San Diego, CA. Explore the Mobile Dev + Test and IoT Dev + Test Expo and enjoy all of these unique opportunities: The latest solutions, technologies, and tools in mobile or IoT software development and testing. Meet one-on-one with representatives from some of today's most innovative organizations
Jan. 18, 2017 12:15 PM EST Reads: 1,552
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
Jan. 18, 2017 12:00 PM EST Reads: 1,962
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
Jan. 18, 2017 12:00 PM EST Reads: 4,235
SYS-CON Events announced today that Super Micro Computer, Inc., a global leader in Embedded and IoT solutions, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 7-9, 2017, at the Javits Center in New York City, NY. Supermicro (NASDAQ: SMCI), the leading innovator in high-performance, high-efficiency server technology, is a premier provider of advanced server Building Block Solutions® for Data Center, Cloud Computing, Enterprise IT, Hadoop/Big Data, HPC and E...
Jan. 18, 2017 12:00 PM EST Reads: 5,769
WebRTC is the future of browser-to-browser communications, and continues to make inroads into the traditional, difficult, plug-in web communications world. The 6th WebRTC Summit continues our tradition of delivering the latest and greatest presentations within the world of WebRTC. Topics include voice calling, video chat, P2P file sharing, and use cases that have already leveraged the power and convenience of WebRTC.
Jan. 18, 2017 10:30 AM EST Reads: 3,119