Blurry preview when using JavaFX

When the characters in the preview look blurry, while the editor shows sharp characters.

Symptom

When the preview of the AsciiDoc Plugin (usually on the right) is blurry: While the characters in the editor on the left look sharp, the characters in the preview on the right look blurry.

The following JetBrains ticket contains examples: IDEA-213110

Environment

This only happens when using the JavaFX preview. The current combinations seems to be:

  • Operating System Windows 10,
    JavaFX preview
    a high-resolution display with a fractional scaling (for example 125% or 175%),
    IntelliJ running on OpenJDK 8 / JetBrains Runtime 8

or

  • Operating System Linux (for example Fedora 31 Wayland),
    JavaFX preview
    a high-resolution display with scaling-factor 200% or more,
    IntelliJ running on OpenJDK or JetBrains Runtime (any version)

How do I fix this?

Upgrade to IntelliJ 2020.3 which bundles JDK 11 as its runtime, and used the JCEF preview.

Change to JCEF preview

This JCEF preview embeds a Chromium based browser in the IDE. As it supports high-resolution displays and is the preview technology recommended by JetBrains, follow the instructions in the chapter ‘JCEF Preview’ to activate it.

Help, preview is still blurry!

To have the maintainers investigate the issue, open a GitHub issue.