Our (research) projects with JavaFX are almost finished. We have awesome results and everything is production ready. The only drop of bitterness is the performance of JavaFX on desktops and mobile devices, but this can be improved by Oracle. It's not in our hands.

What do we have?

We have

• a complete JavaFX UI for JVx
• a custom application frame for mobile applications
• Live CSS manipulation of installed apps (needs debug build)
• Complete Project export for JavaFX mobile projects (JavaFXPorts based gradle project),
  integrated in upcoming VisionX 2.3
• Remote Work-screen loading (via VisionX)
• JVx server runs without limitations on mobile devices
• JVx client runs on mobile devices (for network clients)

How does it look like?

I have some screenshots from two applications. The first one is a standalone JVx application. The whole JVx framework runs on the mobile device. The app is a remote control for our eTV project (it's a brand new side project of our research team).

The app was inspired by MS Metro style ... Windows8 style ... Modern ... Universal ... Windows Store ... Windows apps.

The main screen has some buttons to control our eTV and some buttons open a "popup" with additional options:

eTV Dashboard		eTV Window view
eTV Gallery

The second app will be shown as Video, because we want to demonstrate how we use VisionX to create backoffice apps in under 5 minutes! The app itself isn't complex and does "nothing special", but the same mechanism works for complex applications like our Demo ERP system (read our Code once. Run anywhere post).

Our JavaFX mobile project was based on the great work of Gluon and their JavaFXPorts OpenSource project and also on RoboVM.

JavaFX mobile LIVE CSS hacking

(The video lasts 05:19 but it should be 07:30 because the build process takes 02:50. We shortened the build process because it's boring to wait.)

After one year of JavaFX development, we thought it's time to write about our experience.

We started in Nov. 2014 with our first bigger JavaFX tests. The idea was an UI implementation for JVx. We thought it should be an easy task because JavaFX is a desktop technology. We had another research project in 2012, but the result wasn't as expected. Sometimes it's a good idea to re-start from scratch!

JavaFX wasn't very popular and is still not a Superstar, but we love researching and we thought it might be a good idea to bet on JavaFX. Not only as pure desktop solution and Swing replacement, but also for mobile app development based on JavaFXPorts and for embedded devices, like Raspberry Pi. So we had this big picture in mind.
We thought it would be awesome to create a single JavaFX application, for all platforms and devices. Sure, some other companies tried to solve this problem as well, but we didn't try to do the same. Our idea was simple and based on JVx. We hade this awesome JVx application framework which enabled GUI and technology independent application development. So we tried to solve the GUI problem because all other things like persistence, remote communcation, i18n, ... were already solved by JVx.

We did different GUI implementations for JVx, before we started with JavaFX. Our first one was based on Swing, followed by QTJambi, GWT, GXT, a headless variant and - last but not least - vaadin. We also made some tests with Flex and Pivot, but we didn't create more than some simple PoC. To be clear: GUI technology know-how was not the problem!

We knew that JavaFX didn't have a solution for MDI and especially a DesktopPane was missing, but it wasn't a problem to create custom components/controls. We had some hard months of development because we found out that JavaFX wasn't a mature toolkit like Swing. We had to find many workarounds for very simple problems and had to create more custom components than expected. We solved most problems in our own code, but it wasn't possible to change some basic problems. We tried to get in contact with the developers, via JIRA, but it was hard to explain real-world use-cases to toolkit developers. Our developers at SIB Visions create custom products and projects together with customers for their needs. So we had many UI toolkit requirements from real users. Some issues were accepted but not all. Many bugs were fixed but we had big problems with Feature Requests. So far so good.

We finished our JavaFX UI implementation in April 2015 and it was a big success, because we had a fresh UI technology with lots new features and animations, transitions, web and media views, .... awesome.

We thought that JavaFX will be improved in 2015/2016 and it will be mature enough to use it for our customers.

Wait... what's the problem with JavaFX?

Performance, Memory, limited chances to modify standard controls

The performance is not good, if you have many controls (= nodes). It's different on Windows, Linux, MacOS. It's much better on MacOS than on any other supported OS. If you develop business/backoffice applications, the performance is very important. Sure, if you create simple form based applications, it doesn't really matter.

We use JVx to develop huge backoffice applications and currently, JavaFX should be used with care.

What do we mean with "performance is not good"?

• Large TableViews have scroll delays
• Layouting sometimes need some "extra repaints"
• Scrolling with many controls is not immediate
• Startup time of an application is too long, compared to e.g. Swing applications

The version number of JavaFX 8 is too high for it's maturity.

JavaFX has big potential but we're not sure if it'll survive it's predecessor Swing.

And we're not alone with our opinion: Should Oracle Spring clean JavaFX

But there are also companies with JavaFX applications: JavaFX Real-world apps

There's more

The toolkit issues are one thing. Another big surprise was that Oracle stopped official ARM support in Jan 2015 which didn't mean that JavaFX doesn't run on ARM devices (RaspberryPi, ...), but it's not officially supported and Oracle doesn't fix bugs or implement improvements.
Thanks to Gluon it's still very easy to use JavaFX on ARM devices.

Another step backwards was the migration to Bugzilla. In 2014 (and earlier), JavaFX was a "newcomer" and announced as Swing replacement. The development process at Oracle was very open and you had a "direct connection" to the development team, or something like that. It was very simple to report issues and to get feedback from the developers. It was fantastic to see and feel the progress. This is different nowadays, because the ticketing system moved from JIRA to Bugzilla and it's more or less readonly for standard developers.

One problem with JavaFX is that Oracle doesn't tell us the strategy behind JavaFX. The investment of Oracle in JavaFX was high, but what will be the next step? It's hard to bet on JavaFX without definitive commitment from Oracle.

But we still hope that JavaFX will be the one and only UI toolkit for Java.

JavaFX for Android and iOS

In summer, we moved forward and tried to use JavaFXPorts. It makes it possible to use your JavaFX application as native Android and iOS apps. Our JavaFX UI worked with some smaller changes out-of-the-box. It was awesome to see our JVx on Android or iOS devices! It was a milestone.

But things have changed since summer because JavaFXPorts has a depency on RoboVM. It was an OpenSource project and was a big win for the community. But now it's a commercial tool (read more). This has no impact for us, but means that we can't offer an out-of-the-box OpenSource solution.

JavaFXPorts also works without RoboVM and there are plans for a JVM running on mobile devices, but this won't solve the problem that you need access to device features/APIs. But we'll see what happens in the next few months.

We had some fun in the last few weeks because we tuned our application frame for mobile devices. A mobile application has some specific characteristics and isn't a 1:1 desktop application. A desktop application usually has a menubar and a toolbar. The same app on a mobile device shouldn't use a menubar or toolbar. It should offer a hamburger button which offers a custom menu. Also the style of the controls should be different on mobile devices, e.g. Tabsets.

There are two interesting projects which offer custom mobile controls. The first is a commercial product, from Gluon and the second one is JFoenix and it's OpenSource (LGPL). We took JFoenix because it met our requirements and JVx is OpenSource.

We have some screenshots in older posts:

• Code once. Run anywhere
• Live CSS hacking

Resume

JavaFX has potential to rule the Java UI world, but it needs an official commitment/statement from Oracle. Now it's unclear if JavaFX is the right UI technology for the future.

We hope that JavaFX is the right toolkit, but we aren't sure. Our investment was risky and high, but no risk - no fun. The results are awesome!

Thanks to JVx the UI technology is not important for us, because if JavaFX won't make the race, we still have Swing or vaadin. It's important to be UI technology independent because it saves time and money and is future save.

Some weeks ago, Gluon released the first version of their Eclipse plugin for creating/building mobile applications with Java(FX).

We had some experience with their NetBeans plugin but our preferred IDE was Eclipse. So, an Eclipse plugin was good for us
The NetBeans version worked without bigger problems and we expected the same quality for the Eclipse plugin.

We followed the official installation instructions and didn't have any problem. But the problems started after we tried to create Android or iOS specific code. It wasn't possible to access javafxports, android or robovm classes, because the jar files weren't found. The classpath with NetBeans had references to all libraries, but the Eclipse project didn't have such references.

We tried to find some information in the documentation and found the NFC example application. The build file had additional dependencies for android and javafxports. We changed the build file of our Eclipse project:

and after some Gradle/Refresh Dependencies, Refresh All clicks, all Errors were fixed!
It was horrible, because after clicking Refresh Dependencies, nothing happened and after some more clicks, all errors were gone. Not sure if this was a Gradle project problem, or Gluon plugin problem.

Our full build script (without robovm):

• Enable developer options for your Android device
• Show log messages from your Android device: \platform-tools\adb logcat

I wrote a blog post about JavaFXPorts and Android some weeks ago.

At last Eclipse DemoCamp in Vienna, Tom Schindl asked me about the startup performance on iOS, because his experience with startup performance was horrible with early RoboVM versions. I had no answer because we didn't test our app with iOS and... the question didn't get ouf of my head. Sure, I knew that RoboVM was tuned in last two versions but didn't test it myself.

So, yesterday I had the time to test it out and... Startup and overall performance was same as on Android device!
The iOS device was an iPad Air2 and Android device was Nexus9. The performance may be worse on older devices.
Performance? Application start was finished after touch event (< 1 sec).

My test wasn't as simple as expected because RoboVM has some specifics and iOS needs code signing in order to run an app on real hardware. Also my JVx library (jvx.jar) wasn't usable because it contained SwingUI and one class of it was accessing a member of a parent class:

The listenerList is a member of JComponent:

But the member is not available in RoboVM' phantom class. The solution was easy: Removing SwingUI from jar.
A nice feature for RoboVM would be an ignore list of classes/packages.

Here's a picture of our DemoERP application on iOS:

It's working but still, a Desktop application 1:1 on a tablet isn't the best idea, e.g. the device type (iPad) or WLAN icon is over the application menu. The iOS port has some problems with TextFields, but we'll report an issue.

Thanks to JavaFXports the creation and deployment of our JavaFX app was super easy!

A few hours ago, we published a screenshot from our Demo ERP application running on Nexus 9 (an Android tablet).
It wasn't a fake!

Before we'll show you more screenshots, we want say that we've reached a long awaited goal!

Use JVx and write an application for all polpular platforms and devices.
This is real "write once run anywhere".

Create an application for Windows, Linux, Mac, iOS, or Android, PS4, OUYA or WiiU. Run it as desktop application, as html5 application in web browsers, as native iOS or Android application or as JavaFX application on Android and iOS devices. There's nothing like JVx in the world - not with only one framework with such a small footprint as JVx and certainly not Open Source!

Here are the screenshots:

Maximized frame with charts

Frame with tree

Also in portrait mode:

Portrait mode

And now a very strange one. It's the application with our styled stage. It's crazy because you can drag the window around (makes no sense, but it just works):

Styled stage

Sure, the application wasn't optimized for mobile devices. It has the same style as the desktop application. The mobile version should have bigger frame buttons and a bigger frame header To be honest - MDI on mobile devices? We were positively surprised about the usability. But, whatever. You have the option and decide what's best for your application (but please don't use MDI for smartphones).

Are you interested in some details?

We've used Netbeans IDE because there's a very useful plugin from gluon. We're Eclipse users but it was easier to use a preconfigured environment without doing everything manually. It was simple to configure Netbeans with gluon plugin and there's a video for your first steps. A "bigger" problem was gradle because the project was a gradle project and we've never used gradle. We love using ant.

We had a bad start with Hello World application because it didn't work. There were different problems: Missing ANDROID_HOME or DEX compiler problems. After reading the documentation it was possible to start compilation. The DEX problem was very strange because we had JVM 1.8 u31 and JVM 1.8 u40 configured in Netbeans, but Netbeans didn't use our configured JVM 1.8 u40. We removed the JVM 1.8 u31 from Netbeans and after that we successfully compiled our Hello World application. Very strange!

The next step was using JVx as library dependency for our project, but how did this work with gradle? We had the library in the libs directory of the project, in the file system. We didn't use a maven lib because it was easier to replace the library after recreation. We tried to find a solution in the official gradle documentation and found Chapter 51. C'mon gradle is a build tool and not a programming language! So much documentation means: complexity. Sure, ant wasn't the holy grale but it it's simple to understand and doesn't hide anything.

Our current gradle script:

It's short but we ddin't know what happened behind the scenes without additional research. But if it works it's good enough for many developers.

The integration of JVx was simple because JVx was compiled with JVM 1.6. The Dalvik VM or DART do support 1.6 and 1.7 syntax. It was cool to see that JVx and especially the communication worked without problems - Great job from Johan Vos and all people behind JavaFXPorts!

Our next step was the integration of additional dependencies like our JavaFX UI. It was based on JVM 1.8 u40 and heavily used lambdas. But lambda expressions weren't supported from Dalvik or ART. We thought that gluon plugin solves the problem for us, but it didn't. It contains retrolambda but only for project source files and it doesn't touch your dependencies. There was no additional gradle build task for that, so we had to convert the libs manually. Not a problem but you must be aware of it.

After we solved all dependency problems, we had the first version of our desktop ERP running on our android device. But don't think everything was trouble-free. We had problems with method references, Java Preferences because of write problems, new Date API, forEach calls, scene size and much more. We did solve most problems but not all - yet.