Scaling Handled Differently in Java and Eclipse Framework - eclipse-plugin

We have a problem using Paperclips (printing library for SWT) on scaled monitors, but I don't think it has anything to do with the framework and all with the Eclipse environment.
Let's see an example:
Left is the print with no scaling (or 100%), right is the same print started on a monitor with 175% scaling. I know what you are thinking: the monitor and its resolution / scaling should have no influence on a print. Right, should.
While that's sad and all, it would not be much of a problem. But there comes the kicker: The above prints were generated by a JUnit test case run as plug-in test. If I run them as a regular unit test both work.
Clearly something in the Eclipse environment works differently when started in an OSGi context, and I'm trying to find out what it is (so I can maybe prevent it).
And I think that's a nice puzzle.
If you need a hint for what SWT class might be the , I narrowed it down to this file ScalePrint.java for the table (i.e if I remove the instance of ScalePrint from my demo, the table is displayed correctly; the header is still wrong, though).
I can confirm the error exists only in Eclipse 4.6, and not 4.5 or 3.7 (which is not entirely surprising, since 4.6 is the first version to support scaling). And if I add -Dswt.autoScale=100 to the VM options to disable scaling, it works as expected, too.
I could append my test case, but as I said, I don't really think it has anything to do with Paperclips per se.
So... what could break the scaling when the entire Eclipse framework is started compared to running the same code in a plain Java application?

The Problem is the use of the class Transform, which itself uses the static field DPIUtil.deviceZoom (in the form of DPIUtil.autoScaleUp(float dx)).
Since DPIUtil.deviceZoom is a static field everything fails when used with a primary monitor that has scaling (since printers don't).

Related

java.util.Lists in Gwt super dev mode debugger

We recently decided to integrate Material Design into our mature GWT application and this has finally forced our hand on moving from Legacy dev Mode to Super dev mode. We have this working fairly well using Chrome and Intellij IDE, 2016.2. One lingering problem though is viewing Java containers (Lists, Maps, etc.) in the debugger. In the screenshot below, the two expanded supportingCopyWidgetPresenters and supportingCopyEventPageBlockContentElements are both declared as java.util.Lists:
In case this is hard to read, the debugger is showing both lists values to be:
array = Internal error: com.google.gson.JsonParseException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 1386
Is there a special argument I need to pass to super dev mode to have it interpret Lists (and Maps, for that matter) correctly in the debugger? Is this a matter of telling super dev mode to use a different JSON parser?
Any help is greatly appreciated!
This was an issue with the version of Intellij. This was answered in the GWT google group.

Visual Studio 2012 adds numbers to my double values if I enter them in vb.net

A very strange, presumably meant to be helpfull behaviour of Visual Studio 2012.
When I enter a double in vb.net like:
Dim myD as Double = 1.4
When I hit enter of move my focus another way, the formatting kicks in and changes the above to:
Dim myD as Double = 1.39999999999999998
or 1.6 as
Dim myD as Double = 1.6000000000000001
This behaviour does not appear to happen for all doubles. 1.3, 1.5, 1.7 and 1.8
See this youtube movie for the behaviour in action:
http://youtu.be/afw4jg58-aU
Why, and more important, how can I prevent this?
Edit:
Extensions installed are:
Second Edit
The behaviour seems to have gone away. I do not know what has caused this so for future reference this is useless to anyone, but for now, I'm happy that I don't have to go troubleshooting as suggested.
The exact same issue is also reported in this question. Which applied to VS2010, otherwise without a usable answer.
This is an environmental problem, code is getting loaded into Visual Studio that messes with the FPU control word on your machine. It is a processor register that determines how floating point operations work, it looks like this:
The Rounding Control bits are a good source of trouble like this, they determine how the internal 80-bits precision floating point value is truncated to 64-bits. Options are round-up, round-down and round-to-nearest. The Precision Control bits are also a good candidate, options are full 64-bit precision, 53 and 24 bits.
Both VS2012 and the .NET Framework rely on the operating system default, with the expectation that this will not change afterwards. Pretty hard to diagnose trouble arises when code actually does change it, your observation strongly fits the pattern. The most common troublemakers are:
code that uses DirectX without the D3DCREATE_FPU_PRESERVE option. DirectX reprograms the precision and rounding control bits to squeeze out a bit more perf.
code that was written in an older Borland language product. Its runtime library initializes the FPU control word in a non-standard way. Otherwise a generic problem with software that relies on old runtime library or an old legacy initialization that was carried through in later releases.
in general, any code that uses a media codec or media api. Such code tends to reprogram the FPU to squeeze out perf for the same reasons that DirectX does. Especially notorious in a product I worked on which uses such codecs heavily. The codebase was peppered with calls that reset the FPU control word after making a call into external code.
Finding and eliminating such code can be very difficult. DLLs get injected into another process by a large variety of well-intended malware. The SysInternals' Autoruns utility can be very useful, it shows all the possible ways code can be injected with an easy way to disable it. Be prepared to be shocked at what you see and readily disable stuff that doesn't carry a Microsoft copyright.
For dynamic injection, you'll need a debugger to see what is loaded into VS. Start VS again and use Tools + Attach to Process to attach to the first one, selecting the unmanaged debugger. Debug + Windows + Modules shows you what DLLs are loaded. Do beware that the DLL can be transient, a shell dialog like File + Open + File will dynamically load shell extensions into VS and unload them again afterwards. Good luck with it, you'll need it and sometimes the only fix is a rather drastic one.
I had the exact same issue with Visual Studio 2012.
The "solution" if it happens to you is:
write your number in your code
let VS screw it up, e.g. when you move to another line
CTRL-Z to revert VS mess
continue writing your code

Using JFace ProjectionViewer in Standalone App

I've been trying to use the JFace ProjectionViewer to implement folding in a standalone Java app. I got the idea from this article:
http://www.eclipse.org/articles/Article-Folding-in-Eclipse-Text-Editors/folding.html
However the source code provided with the article is for an Eclipse plug-in, not for a standalone.
The particular problem I'm having is that I can't get the VerticalRuler to respond and cause folding/unfolding.
Since I get the expected results, i.e. line numbers in the ruler, when I change from using a VerticalRuler to a LineNumberRuler while leaving everything else the same, I think my problem is specific to the implementation of the relationship among the ProjectionViewer, the VerticalRuler, and the Annotations.
My exact question is whether anyone has gotten this to work in a stand-alone code and, if so, how?

Why's a simple change to rt.jar causing the Java Runtime Environment to crash silently?

This is what I'm doing:
extract contents of my JRE's rt.jar
extract src.zip of my JDK (same version)
Now, if I copy Runtime.java from the extracted src folder and compile it using javac.exe without any modifications and then put it in the extracted rt folder to finally put everything back in a jar file using jar.exe, everything works as expected. The JRE runs fine.
However, if I make the slightest change to Runtime.java and compile it and put it in rt.jar, the JRE crashes whenever I attempt to start it. This is an example of a slight change that causes the silent crash:
/** Don't let anyone else instantiate this class */
private Runtime() {
System.out.println("This is a test.");
}
Instead of:
/** Don't let anyone else instantiate this class */
private Runtime() {}
Could anyone tell me why this is causing my JRE to crash?
Thanks in advance.
It's possible that System.out has not been initialised at the time that the Runtime() constructor runs. Usually console output is not considered a "slight" change, but at the wrong time it can invoke way too much stuff that may not be set up at all yet.
You're doing this all wrong. You can't distribute that modified JRE for a start, so it is only useful inside your organization . Install a SecurityManager and don't grant your codebase any of the RuntimePermissions you're trying to protect against.
#Tom - I advise you NOT to try to do this:
You cannot distribute the modified rt.jar file without violating the Sun binary license.
Even if you did, you would not be allowed to call it Java.
As you are finding, there are lots of complications that arise when you make changes, particularly when those changes might interfere with the JVM's behind the scenes initialization. And when things blow up during initialization, the JVM often cannot report the problem in an intelligible way.
If you do succeed in making the modified rt.jar work for one JRE, there is no guarantee that the same hacks will work for a different version.
Nobody in their right mind would knowingly use a modified JVM (especially one modified by a third-party) in a production app.
EDIT : judging from your other questions, I guess you are trying to reverse engineer or modify some third party Java application with a custom launcher. If you provided more information on what you were really trying to do, we might be able to suggest the right way to do it ... rather than using "desperate measures" such as modifying the JRE.
That's pretty strange, as I did the same trick with many classes in rt.jar in past.
Can you provide us with the crashed process output?

What causes difference in VB6 app testing result when running from Dev machine vs installed?

I'm new to VB6 but i'm currently in charge of maintaining a horror of editor like tool with plenty of forms, classes, modules and 3rd party tools all chunk together like the skin faces on that guy in the texas chainsaw massacre...
What i don't understand is why i get different results when i run the app in debugging mode, vs when i compiled it and run it on my devevelopment pc vs when i installed it on a different pc.
Yes i know i'm dumb, so please direct me to where i can find out more about this. I'm hoping to find out something like different linking, registry related etc connection that i'm simply not getting right now, i.e. something like wax on, wax off :P
The main pain in the neck is when i'm trying to debug some errors from my QA and i need to find a spare pc to test this on plus i can't directly debug because i don't know where the code is if i do it that manner.
Thanks.
i run the app in debugging mode vs when i compiled it and run it on my
devevelopment pc
When you compile you have the option of compiling to native code or pcode. The debugger runs using pcode only. Under rare circumstances when you compile to native code there will be a change in behavior. This particular is really rare. I used VB6 since it's release and I may get it once or twice a year. My application is a complex CAD/CAM creating shapes and running metal cutting machine and has two dozen DLLs. Not a typical situation. At home with my hobby software I never ran into this problem.
There are another class of errors that result from event sequencing problems. While VB6 isn't truly multi-tasking it has the ability to jump out of the current code block to process a event. If it re-enters the same block for the new event interesting things (to say the least) can result. I think this is the likely source of your problems as you software is an editor which is a highly interactive type of software.
In general the problem is fixed by reordering the effected areas. You find the effected area by inserting MsgBox or write to a text file to log where you are. I recommend logging to a text file as MsgBox tend to alter behavior that are timing or multi-tasking related.
Remember if a event fire while VB6 in the middle of a code block and there a DoEvents floating around then it will leave the code block process the event and return to the original code block. If it re-enters the same code block and you didn't mean for this to happen then you will have problems. And you will have different problems on different computers as the timing will be different for each.
The easiest way to deal with this type of issues is create some flag variables. In multi-tasking parlance they are known as semaphores or mutexes. WHen you enter a critical section of code, you set it true. When you leave the routine you set it to false. If it is already true when you enter that section of code you don't execute it.
when i installed it on a different pc.
These are usually the result of the wrong DLL installed. Most likely you have an older version while the target has a newer version. I would download the free Virtual PC and create a clean Window XP install to double check this.
If your problem is event timing this too can be different on different computers. This is found by logging (not MsgBox) suspect regions.
If you can display a screen shot or the text of your specific errors then I can help better.
The first thing to check would be the versions of all the dlls that your app depends on - including the service pack version of the VB6 dll.
Have you any more specific details about what's behaving differently?