Weird swing heavyweight & lightweight mixing problem - java

We have a problem in our swing based application since we've upgraded our java version from 6u5 to 6u18 (The application runs over WinXP).
Our application contains a Canvas object which resides in a JFrame. The application draws things on the canvas.
Every time we drag a lightweight swing object (popup or another frame) over the canvas, it has a refresh problem.
It blinks - becomes black. The problem only resolves after we move the swing component away from the canvas and click on it again.
We think this problem is related to the fact the the canvas is a heavyweight object.
And we know there were changes done in the new versions of java on the mixing of heavyweight and lightweight objects issue.
Some more details:
1) Our problem reproduces in java 6u14 and 6u16.
2) Everything works fine in java 6u5.
Another strange thing:
We have 2 types of stations running our application.
The first type has a ATI FireGL7100 PCI-E graphics card. The second type has a Matrox G450 PCI graphic card.
The problem does not reproduce on the Matrox based station in any java version.
One more thing:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6829858 - looks similar to our problem.
Is our problem familiar?
Do you have any suggestions (workarounds, ideas how the difference in graphics cards is connected to this problem)
Hope I was clear enough,
Yoav

The article Mixing heavy and light components describes how support for this changed in JDK 6 update 12. The two video cards may handle Z-order differently. Any chance your code has a workaround that's no longer needed?

We had problems w/ HW/LW mixing from 6u14+ (the fixes that breaks everything is in 14). Our problem was in a thirdy part library (JIDE) and they ended up fixing the problem on their end.
My suggestion is avoid HW where ever you can. You can get very decent performance out of LW if done correclty. What are you drawing that needs to be HW?

I don't know if this is relevant to anyone else, but we've found a workaround/fix for our problem.
We've set the system properties sun.awt.noerasebackground and sun.java2d.noddraw both to true. That eliminated our issue.
The only problem is that I'm not sure what other problems might rise from setting those system properties.

Related

Java 3D Object Rendering with Yaw/Pitch/Roll

Im looking for a way of displaying a 3D Rectangle, which could be moved by the values a gyrosensor delivers from my arduino.
I just don't know where to start with the Implementation of the 3D Space, the communication works fine.
I did not find any useful information online, however, I just need a Window (Don't know, is JFrame enough for this) with a model that I can set x/y/z and yaw/pitch/roll etc.
Are there libraries or code-examples?
I did see one integration with JavaFX which I have never used yet, or the implementations were in other languages.
Unity worked out for this, even though i was getting buggy behaviour.
Therefore i tried out Processing, which turned out to work fine. There are some snippets online where you can pass in the values of your arduino and it just works out.
I cannot provide more details since the project was abandoned.

JavaFX sporadic rendering issue - disappearing buttons / controls

I have a Java/JavaFX application deployed as a native install for Windows and Mac. The bundled runtime is currently 8.121. You can find the installers and the Java code here: George download
I have been using this application in the classroom weekly (with 20 children) for the last 15 months, and right from the start I have seen the following problem:
From time to time, buttons disappear. That is to say, they are simply rendered as a white rectangle, making them effectively almost invisible. Both the background and label/text disappear.
This mainly happens on mouse-over, but then does not correct itself.
The buttons are still there, and clickable.
It only happens sporadically, but it seems to recur on certain machines more than others. Windows 10 now, but used to the same happened on tiny Windows 7 machines previously.
I am not able to reproduce it myself and have never seen it on a Mac, I think.
It now also happens sometimes with other widgets/controls, and even before any user interaction.
Is there some known issue around this?
Has anyone else described something similar?
Might it have something to do with certain minor operating system adjustments?
Any thoughts or ideas would be much appreciated.
Update (2018-11-06)
Just started testing my application in Java 8 in VirtualBox with Windows 10, and I now get the rendering error myself. Hurra!
Looking into the -Dprism.xxx options, I found this article:
http://werner.yellowcouch.org/log/javafx-8-command-line-options/
Testing with -Dprism.threadcheck=true, I get a lot of
"ERROR: PrismPen / FX threads co-running: DIRTY: false" with stack traces.
Setting -Dprism.dirtopts=falsedoes not solve it for me, though.
But running with -Dprism.order=sw does. But this is not a good solution for an application that may do some demanding rendering (Turtle Geometry).
Will keep digging.
I've been having the same issue, I tried updating to Java 10 but the issue remained. I then edited the properties on java.exe and on the 'Compatibility' tab I set 'Override high DPI scaling behavior' to 'System (enhanced)' and the problem seems to have gone away (or at least it hasn't happened again yet).
I observed the same thing: Visually disappearing (but still functional) buttons and other controls (except labels) especially in areas outside the original size of the window after I have resized it manually)
In my case -Dprism.dirtopts=false reduced the problem but also didn't solve it (and was not really a satisfying solution anyway).
Additionally I observed that some TextField controls also showed rendering glitches (looked like the same text was rendered twice with a little offset). That finally put me on the right track:
It turned out to be just a missing Platform.runLater(...) around some calls to TextField.setText(...) (from another thread) for exactly these TextField controls, which was causing this (even for e.g. a Button which is at a totally different place - also in the widget hierarchy).
I know, this is probably not the answer in all cases, but hopefully it helps at least some others facing the same problem (took me a full day to find out).

java applet using Next-generation plug-in

I have a web application (struts 1.3, Weblogic 10.3.0, Toplink, Oracle) that has a Java applet which isn’t working in the browser (IE7/8) when the Next-Generation Plug-in setting is enabled in the Java control panel but works fine when it’s disabled. The trouble is that this setting is set to disappear in an upcoming Java release meaning that my users would have to keep using Java 1.6_xx on their workstations as they are currently. I have little influence over which version they use because they are all governed by their local IT departments across the country. So, either I have to find a simple fix to allow the Next-Generation setting to work, or we have to look at replacing/rewriting the applet with something else (but would be a last resort due to funding constraints), most likely something AJAX-friendly so as to avoid the need for a plugin. This application is quite old, written around 2001 before AJAX was really around.
The main window has a left, right, and top frame (JSP’s), as well as a center frame which is where the applet is. The applet has a main content area in the middle and a lower panel at the bottom which has some buttons. The buttons tell the content area (which is basically a treegrid) what to do (Save, Copy, change status, etc ). When I press one of the buttons the entire window (surrounding frames plus the applet itself) repeat inside the area where the applet is. It’s like a kaleidoscope or like a repeating fractal pattern kind of thing, or like when you take a picture of yourself in the mirror and you see the room repeated over and over in the mirror. In this case it repeats for each button press and the repeated set gets smaller each time. Weird!!
So, based on my research, the Java Next-Generation plugin works differently by allowing more than one process or thread whereas the classic plugin only uses a single thread. So my suspicion is that a new process is being spawned for each button press. I tried using the “separate_jvm” applet parameter but it made no difference whether it was set to true or false. I don’t see any other applet parameters which seem to be relevant.
Another idea I had is that maybe it’s something to do with the JSP frameset, maybe something like “target=_top” needs to be added somewhere…but I’m not sure how this relates to applet threads if at all.
Anyone have any suggestions, ideas or experiences that might help?
you can use velocity to handle these type of problem and it will also help you for future enhancement also.
The problem is not related to version of IE but rather to version of Java. Below excerpt from letter of certificate provider (they took it from some forum, so direct link to source cannot be provided):
For JDK version higher than 1.6.0 and below 1.6_15, you can just
clear all kinds of cache in web browser, java console and java control
panel. Then it should works fine!
For JDK version between 1.6_15 and 1.6_30, you should disable the "next-generation java" option in java control panel.
For JDK version higher than 1.6_30, you should turn on "next-generation java" option in java control panel.

Fixed size swing GUI changes when using different resolution

I have a small java application with a swing gui. I have set a fixed size for the window and everything works really well. But when using the GUI on different screens, the objects seem to have moved slightly. (Labels not showing their entire text etc,...) I think the difference lies in the aspect ratio of the screen but is there any way to counter this?
The way to counter it is to not used fixed size windows.
I agree with Bryan. There are many reasons - the screen resolution, localization (if you do so), different look-and-feels and rendering depending on the platform and/or JVM version. Swing's layouts are flexible enough to do everything you want without fixing the frame size. Otherwise you are going to implement your rendering engine to calculate everything which is rendered.

Java Applet, AWT Refresh, issue on Mac OS X 10.4

We have a Java Applet built using AWT. This applet lets you select pictures from your hard drive and upload them to a server. The applet includes a scrollable list of pictures, which works fine in Windows, Linux and Mac OS X 10.5. We launch this applet via Java Web Start or within a web page.
Our applet does not behave properly in Mac OS X 10.4, regardless of the version of Java (1.4 or 1.5). You can find a screenshot of the incorrect behaviour, when scrolling, here:
http://www.lavablast.com/tmp/ui_error.png
Simply put, sometimes when scrolling the pictures end up overlapping the header or footer of the application. This behaviour does not occur on other platforms. On Mac OS X 10.4, it shows the pictures in the incorrect location when scrolling, which would not be so bad if it refreshed the screen after painting the image at that location. However, it does not appear that the application knows it painted it incorrectly and thus does not refresh.
If the window is minimized, resized or even moved, the application is refreshed and the incorrectly positioned elements vanish and the application resumes normally. I spent quite some time trying to force a refresh of the background image unsuccessfully. (the repaint the image directly, repaint all children of a few panels, etc. ) Thus, I am looking for any tips that would help me resolve this problem under Mac OS X 10.4 or, in the worst case, simply simulate a full applet refresh.
Until recently, everything was compatible with Java 1.1 but this has changed in a few locations which now require 1.4. I don't feel these changes created the issue, I am just providing this as extra information. If you are interested in implementation details of the scroll panel, I will investigate, but I am assuming this is a common platform bug for which workarounds must be known.
To replicate the problem, open the following Java Web Start application:
http://www.lavablast.com/tmp/opal-webstart.php.jnlp
Select a folder containing lots of images and play with the scrollbar. At some point (fairly quickly), you should get the refresh problem.
Edit: I followed the first suggestion here and replaced all my controls that feature background images with a Swing equivalent and the issue is still there. (Plus, there are numerous other fixes I would need to do to do a complete change). Any other ideas? A simple one line of code that forces a full refresh would be great :)
Edit2: The main thread creates the panels and launches X threads. Using an observer/notifier pattern, the threads complete and notify the main control, which adds a panel to the page. This is done via an EventQueue.invokeLater which, unless I am mistaken, should run on the right thread. The issue is at its most severe when scrolling even if no extra threads are running (as during the loading).
It does look like mixing lightweight (usually Swing) and heavyweight (AWT) components together. Moving to Swing you need to replace every last AWT component Swing equivalents (hint: avoid import java.awt.*).
Threading is often a potential problem for odd bugs. Swing components must always be used on the EDT (use java.awt.EventQueue.invokeLater). AWT is thread-safe is theory, but not in practice - also restrict usage to the EDT.
As you already require Java 1.4 you should consider some small changes to take into use SWING GUI instead, it solved our Applet refresh issues with AWT. (Mac, Linux etc)
If you have e.g. Panel, you need to replace it with JPanel etc.
You need this:
import javax.swing.*;

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