The splash screen size is updated after a while during startup and displayed incorrectly.

[MLausberg]

Steps to reproduce

From a fresh installation and clean workspace:

Adapt the *.ini file used to start the eclipse based application and add
-Dswt.autoScale.updateOnRuntime=false
-Dswt.autoScale=125

At the begining the splash screen is shown correctly, but after some seconds and shortly before the application is shown, the splash screenis redrawn and out of scope.

First

after a while

Splash Screen related

From Product Definition file

   <splash
      location="<obfuscated>" />

Tested under this environment:

Windows 11

Java Version

• IMPLEMENTOR="Eclipse Adoptium"
• IMPLEMENTOR_VERSION="Temurin-25.0.1+8"
• JAVA_RUNTIME_VERSION="25.0.1+8-LTS"
• JAVA_VERSION="25.0.1"
• JAVA_VERSION_DATE="2025-10-21"

Eclipse-RCP Back-End (2025-12)

• org.eclipse.equinox.simpleconfigurator.configUrl=file:org.eclipse.equinox.simpleconfigurator/bundles.info
• osgi.bundles=reference:file:org.eclipse.equinox.simpleconfigurator_1.5.700.v20251111-1031.jar@1:start
• osgi.bundles.defaultStartLevel=4
• osgi.framework=file:plugins/org.eclipse.osgi_3.24.0.v20251126-0427.jar
• osgi.framework.extensions=reference:file:org.eclipse.osgi.compatibility.state_1.3.0.v20251022-1724.jar
• osgi.splashPath=platform:/base/plugins/obfuscated

Community

• I understand reporting an issue to this OSS project does not mandate anyone to fix it. Other contributors may consider the issue, or not, at their own convenience. The most efficient way to get it fixed is that I fix it myself and contribute it back as a good quality patch to the project.

[vogella]

IIRC HDPI handing had a splash screen bug, try with 2026-06 should be fixed in latest release. Open if you still see it with latest release.

[MLausberg]

I am sorry, but the same problem exists within 2026-06

-startup
plugins/org.eclipse.equinox.launcher_1.7.100.v20251111-0406.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.3.0.v20260203-2149

• org.eclipse.equinox.simpleconfigurator.configUrl=file:org.eclipse.equinox.simpleconfigurator/bundles.info
• osgi.bundles=reference:file:org.eclipse.equinox.simpleconfigurator_1.5.700.v20251111-1031.jar@1:start
• osgi.bundles.defaultStartLevel=4
• osgi.framework=file:plugins/org.eclipse.osgi_3.24.200.v20260515-1403.jar
• osgi.framework.extensions=reference:file:org.eclipse.osgi.compatibility.state_1.3.0.v20251022-1724.jar

[MLausberg]

I can not re-open this Bug

[HeikoKlare]

Have you properly considered the information given in the news entries on this topic?

• https://eclipse.dev/eclipse/markdown/?f=news/4.39/platform_isv.md#monitor-specific-scaling-by-default-windows
• https://eclipse.dev/eclipse/markdown/?f=news/4.39/platform.md#equinox-launcher-scaling-defaults-windows-only

In particular, are you running the process with the correct/expected DPI awareness?

[MLausberg]

Have you properly considered the information given in the news entries on this topic?

• https://eclipse.dev/eclipse/markdown/?f=news/4.39/platform_isv.md#monitor-specific-scaling-by-default-windows
• https://eclipse.dev/eclipse/markdown/?f=news/4.39/platform.md#equinox-launcher-scaling-defaults-windows-only

In particular, are you running the process with the correct/expected DPI awareness?

The parameters I used were specified above.

• -Dswt.autoScale.updateOnRuntime=false
• -Dswt.autoScale=125

As a user, I would expect the splash screen to either be initially too large and not fully visible, or to be displayed correctly from the beginning.

However, the fact that the splash screen changes its layout during the startup procedure is unexpected and difficult for the user to configure via parameters.

From your point of view, is there a combination of parameters that corrects the initially described behavior?

[HeikoKlare]

It's not necessarily only about parameters passed via ini, but about the DPI awareness that your process is running. I do not know how you may have configured your product's executable regarding DPI awareness, but with Equinox default settings it is supposed to just work.

I have just tested with the parameters you have posted used in a current I-Build, and the splash screen works expected (rendered at 125% and preserves its size), so I cannot reproduce the issue you report.
I am not sure if you have fully moved to a 2026-06 release or just exchanged the Equinox launcher for testing. The latter will not work, because the Equinox launcher behavior and the Eclipse workbench behavior are tighly coupled with respect to the splash, as the splash handle is passed between them and their implementations thus need to align. So you would have to update the workbench to the 2026-06 state as well.

[MLausberg]

I started debugging the Startup process and the Splash-screen size changes after line
"Workbench.lambda$3(Display, WorkbenchAdvisor, int[]) line: 665"

if (createSplash) {                                                     
	AUTOSCALE_ADAPTATION.runWithInitialAutoScaleValue(splashCreation);  
}  

Before that line the SplashScreen is

after that line is executed the image changes to

The Code i am testing and looking at is from 2026-06

• org.eclipse.ui.workbench_3.139.0.v20260601-0955.jar

Is the behaviour related to missing/incosistent properties in simpleconfigurator *.xmi file or is this a Bug in the adaption logic?

[HeikoKlare]

As said, for me there is no bug at all. I have downloaded one of the latest Eclipse packages: https://www.eclipse.org/downloads/packages/
Then I have added to the ini file:

-Dswt.autoScale.updateOnRuntime=false
-Dswt.autoScale=125

And everything works as expected.

Since you seem to be referring to a runtime product started from an IDE, please be aware that no Equinox/application executable with proper DPI awareness is involved here, but the DPI awareness from your JVM process is used. Since all current JVMs default to "PerMonitorV2" (which is inconsistent with the Equinox executable behavior for swt.autoScale.updateOnRuntime set to false), you can experience changing splash screen sizes due to non-fitting DPI awareness of the process and for what Eclipse uses later on. But that is also explained in the already linked news: https://eclipse.dev/eclipse/markdown/?f=news/4.39/platform_isv.md#monitor-specific-scaling-by-default-windows

If you really want to have a splash screen behavior in your runtime application that conforms to the behavior you will see when using the final Equinox executable, you need to adapt your JVM's manifest to use "System" DPI awareness. But you should be aware that this discrepancy of DPI awareness modes has always existed for the last 10 years and the behavior became even more consistent (except for the splash screen size alignment in very specific configurations like yours) with the latest releases. The behavior of a runtime Eclipse instance and one started via Equinox executable was completely different in terms of DPI awareness / UI scaling until 2-3 releases ago.

You may also think about replacing a fixed auto-scale zoom with monitor-specific scaling in general, as that fixed-zoom auto-scaling mode is very badly tested and supported in general.