Windows: SWTException "Invalid image" when rasterizing SVG at size 0 after moving Eclipse window between monitors (DPI change)

[oberlehner]

Describe the bug
On Windows, after a DPI/scaling change (e.g., moving an Eclipse/SWT application window between monitors with different scaling, or in VM/RDP-like setups), UI painting can throw an unhandled event loop exception. SWT attempts to rasterize an SVG image for a requested size where the computed width or height becomes 0 (or negative). The SVG rasterizer rejects this and throws IllegalArgumentException, which bubbles up as org.eclipse.swt.SWTException: Invalid image, disrupting painting and sometimes leaving the UI in a broken state.

To Reproduce

1. Start an Eclipse-based app that uses SVG icons and renders scaled images during paint (common in editors/views, including those using Draw2D/GEF).

2)Open a view/editor that triggers frequent repaints (e.g., zoomable canvas, thumbnail/overview, outline, etc.).

3)Move the application window between monitors with different DPI scaling (e.g., 100% ↔ 150%/200%), or change scaling while the app is running.

4)Trigger repaint (open/activate editor, zoom, resize window).

5)Observe exception.

Environment:

• App: 4diac IDE 3.1.0.qualifier
• Eclipse Release Train: 2026-03 (Platform 4.39)
• SWT: 4.39 (org.eclipse.swt ~3.133.0… in 4.39 stream)
• Java: 21 (required)
• VM args: -Dswt.autoScale=quarter
• OS: Windows (see stack trace shows Win32 DPI utils)

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]

[HeikoKlare]

Thank you for reporting this issue. It definitely looks like something that should be fixed soon.

Unfortunately, I have never this seen this exception yet and cannot reproduce it either. Can you provide a standalone reproducer? It does not need to be a plain SWT reproducer but, e.g., a concrete GEF diagram with an according image and a workflow to produce the issue would be helpful.

From the stack trace, it looks as if the target size of the image-to-be-drawn becomes too small (because of any involved scaling such as UI, diagram and the like). This is something that did probably not occur so far because images were not "prescaled" but just used in an existing size (such as their 100% representation) and the scaled by the Windows GDI drawing operation. But it does obviously not make any sense to request an image handle of size 0. So what what seems reasonable to me is that we either just not draw anything in case the target size of the image becomes 0 (which might have side effects and unintentionally changes behavior, or we ensure that either the size passed to the executeOnImageHandleAtBestFittingSize() is at least 1 or the method itself provides a handle of at least size 1 (as consumers need to be able to deal with the actual handle having any other available size anyway).

I will propose a PR for one of the solutions. Would be great to also have a reproducer to test it then (or at least to have you test the proposed solution with your scenarios).

[HeikoKlare]

@oberlehner I have created a PR that hopefully resolves the described issue. Are you able to test if the PR resolves the issue for you?

• Avoid attempt to draw images with target width/height of 0 #3079