Unhandled event loop exception

[oberlehner]

4diac IDE version: 3.1.0.qualifier

Session ID: c142afc8-9559-463a-a6c4-5f5a99481170

Stack trace

org.eclipse.swt.SWTException: Invalid image (java.lang.IllegalArgumentException: Argument not valid [Cannot rasterize SVG for width or height <= 0])
	at org.eclipse.swt.SWT.error(SWT.java:4950)
	at org.eclipse.swt.SWT.error(SWT.java:4865)
	at org.eclipse.swt.internal.image.FileFormat.loadFromStreamBySize(FileFormat.java:140)
	at org.eclipse.swt.internal.image.FileFormat.load(FileFormat.java:167)
	at org.eclipse.swt.internal.NativeImageLoader.load(NativeImageLoader.java:30)
	at org.eclipse.swt.graphics.ImageLoader.loadBySize(ImageLoader.java:169)
	at org.eclipse.swt.graphics.ImageLoader.loadBySize(ImageLoader.java:215)
	at org.eclipse.swt.graphics.ImageDataLoader.loadBySize(ImageDataLoader.java:75)
	at org.eclipse.swt.graphics.Image$ImageFileNameProviderWrapper.loadImageDataAtExactSize(Image.java:2737)
	at org.eclipse.swt.graphics.Image$HandleAtSize.createHandleAtExactSize(Image.java:239)
	at org.eclipse.swt.graphics.Image$HandleAtSize.refresh(Image.java:224)
	at org.eclipse.swt.graphics.Image.executeOnImageHandleAtBestFittingSize(Image.java:949)
	at org.eclipse.swt.graphics.GC$DrawScaledImageOperation.draw(GC.java:1294)
	at org.eclipse.swt.graphics.GC$DrawScaledImageOperation.apply(GC.java:1283)
	at org.eclipse.swt.graphics.GC.storeAndApplyOperationForExistingHandle(GC.java:6089)
	at org.eclipse.swt.graphics.GC.drawImage(GC.java:1185)
	at org.eclipse.swt.graphics.GC.drawImage(GC.java:1052)
	at org.eclipse.draw2d.SWTGraphics.drawImage(SWTGraphics.java:444)
	at org.eclipse.draw2d.Label.paintFigure(Label.java:498)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1274)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1359)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.IScalablePane$IScalablePaneHelper.paintClientArea(IScalablePane.java:109)
	at org.eclipse.draw2d.ScalableFreeformLayeredPane.paintClientArea(ScalableFreeformLayeredPane.java:77)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.Figure.paintChildren(Figure.java:1322)
	at org.eclipse.draw2d.Figure.paintClientArea(Figure.java:1355)
	at org.eclipse.draw2d.Figure.paint(Figure.java:1276)
	at org.eclipse.draw2d.parts.Thumbnail$ThumbnailUpdater.run(Thumbnail.java:197)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4134)
	at org.eclipse.swt.widgets.Display.lambda$3(Display.java:3483)
	at org.eclipse.swt.internal.Win32DPIUtils.runWithProperDPIAwareness(Win32DPIUtils.java:94)
	at org.eclipse.swt.widgets.Display.msgFilterProc(Display.java:3481)
	at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
	at org.eclipse.swt.widgets.Shell.callWindowProc(Shell.java:509)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:5075)
	at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:336)
	at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1499)
	at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:2432)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:5129)
	at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
	at org.eclipse.swt.widgets.Shell.callWindowProc(Shell.java:509)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:5075)
	at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:336)
	at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1499)
	at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:2432)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:5129)
	at org.eclipse.swt.internal.win32.OS.DispatchMessage(Native Method)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3745)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1160)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1051)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:684)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:583)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:185)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:219)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:149)
[truncated]

I moved my 4diac from my smaller notebookscreen to a larger monitor with different resolution

[oberlehner]

the margin between the pins also looks strange

[azoitl]

Can you forward that exception to the SWT repository. I guess they would be really interested in that problem.

[vikash1703]

Hi @azoitl , I’m interested in contributing to the GSoC project. Could you please guide me on how to start and what I should focus on to get my proposal accepted.

[oberlehner]

Hi @azoitl , I’m interested in contributing to the GSoC project. Could you please guide me on how to start and what I should focus on to get my proposal accepted.

i think this issue is the wrong place to ask about GSoC

[oberlehner]

Can you forward that exception to the SWT repository. I guess they would be really interested in that problem.

eclipse-platform/eclipse.platform.swt#3078

[azoitl]

Can you forward that exception to the SWT repository. I guess they would be really interested in that problem.

eclipse-platform/eclipse.platform.swt#3078

Thx

[HeikoKlare]

SWT has been updated to hopefully avoid the kind of reported exception:

• Avoid attempt to draw images with target width/height of 0 eclipse-platform/eclipse.platform.swt#3079

Unfortunately the reported issue was not reproducible for me and there is nothing suspicious in the screenshot, so the fix was only based on stack trace analysis. In case you experience such an issue again, please raise an issue at SWT again or ping me here.

[azoitl]

@HeikoKlare we did some further tests today. We it happens when the following things are shown:

• An outline view showing an outline of a GEF Diagram using ScrollabelThumbnail
• at least one if the images shown in the diagram is an SVG image

For 4diac IDE we currently only have one SVG image therefore it happens not all the time. I now have the impression that we are maybe creating or providing the image wrong.

This specific image is shown as icon of an Draw2D Label. We use the default setIcon() method to set the icon. For managing the icons we use the JFaceResources.getImageRegistry where we ad an ImageDescriptor:

final URL fileLocation = getImageURL(name);
final ImageDescriptor id = ImageDescriptor.createFromURL(fileLocation);
JFaceResources.getImageRegistry().put(name, id);

Not really special. Anything that we did miss?

[HeikoKlare]

we did some further tests today.

So did you test with the SWT fix already included? And you do then experience the exact same stack trace as reported in the original issue post? I am just asking because I would currently not understand how the stack trace can occur with that fix at all.

Not really special. Anything that we did miss?

Doesn't look special to me as well. For the given stack trace, I don't think it can matter how the image is created but the problem is with zero values passed as width/height to the draw operation.

Is there any easy way how I could reproduce the issue? Can I set up 4diac-ide and open some example or the like?

[azoitl]

we did some further tests today.

So did you test with the SWT fix already included? And you do then experience the exact same stack trace as reported in the original issue post? I am just asking because I would currently not understand how the stack trace can occur with that fix at all.

No not yet. Sorry. The main reason I wrote was that I wanted to be sure if we are using SWT correct or if there is an issue in Draw2d. That leads to 0 size figures.

Not really special. Anything that we did miss?

Doesn't look special to me as well. For the given stack trace, I don't think it can matter how the image is created but the problem is with zero values passed as width/height to the draw operation.

That is already good to know.

Is there any easy way how I could reproduce the issue? Can I set up 4diac-ide and open some example or the like?

I fear not. And I definitely do not want to bother you with setting up 4diac IDE dev infra.

[HeikoKlare]

No not yet. Sorry. The main reason I wrote was that I wanted to be sure if we are using SWT correct or if there is an issue in Draw2d. That leads to 0 size figures.

My guess is that some figure drawn by Draw2d becomes so small in its drawing context (zooming out in a diagram, becoming very small in the outline view or the like) that its calculated target size becomes 0. That's something that SWT would have gracefully handled before, as it did not have the capability of dynamically providing an image at a required size but just used the image at its default size and then had it scaled to the target size by the OS-native rendering engine (which then reduced the size of the image to 0 in such a case). As we have now added the capability of providing an image already in the target size (in particular to be sharply rendered when having an SVG source), the 0 size is not (gracefully) processed by the OS-native rendering engine anymore but produced the mentioned failure when rasterizing an SVG at that invalid size. This scenario has been fixed by the SWT change.

The remaining question is whether it's correct that some piece of code tries to render an image at size 0 or if there is anything else wrong in the consumer (in you case it seems to be the ThumbnailUpdater. Maybe this was unnoticed until now as the OS-native rendering gracefully accepted the size of 0. That's something you could maybe check by setting a breakpoint at the code line where the exception is thrown, triggering it, and the looking who/where/why the image is drawn at size 0 to evaluate if that's somehow intended (like a very low scale factor leading to a calculated target size of 0) of is there is anything else wrong.

[azoitl]

@HeikoKlare thx for the long explanation. Yes in the thumbnailer we have very small images. See here an example for a small diagram that we show in the outline:

In each of the blocks there is one image. For largers this gets even smaller. With the getAbsoluteScale() fix I did for SWTGraphics my next steps will be to do some LoD aware drawing for Draw2d and 4diac IDE. This will not only give us more drawing performance but also cleaner thumbnails. Hope to have something early in the next simrel cycle.

[HeikoKlare]

Thank you for sharing the example. That supports my guess that images may get a target size of 0 in that use case and makes me more confident that the SWT fix resolves the reported issue for you.

Having an LoD-aware drawing for such cases definitely sounds like a great improvement.