Plugin for toggling syntax highlighting in the current file (same as built-in "Highlighting level" slider in the inspector popup)

plugin.kts

import com.intellij.codeInsight.daemon.DaemonCodeAnalyzer
import com.intellij.codeInsight.daemon.impl.analysis.FileHighlightingSetting
import com.intellij.codeInsight.daemon.impl.analysis.HighlightLevelUtil
import com.intellij.codeInsight.daemon.impl.analysis.HighlightingLevelManager
import com.intellij.lang.injection.InjectedLanguageManager
import com.intellij.openapi.project.Project
import liveplugin.PluginUtil
import liveplugin.currentFile
import liveplugin.registerAction
import liveplugin.show

registerAction("Toggle Highlighting", "ctrl shift H") { event ->
  toggleCurrentEditorHightlighting(event.project)
}

if (!isIdeStartup) show("Reloaded 'Toggle Highlighting'")

fun toggleCurrentEditorHightlighting(project: Project?) {
  if (project == null) return
  val virtualFile = project.currentFile ?: return
  val psiFile = PluginUtil.psiFile(virtualFile, project) ?: return
  val manager = HighlightingLevelManager.getInstance(project)
  val isSyntaxHighlightingEnabled = manager.shouldHighlight(psiFile)
  val isInspectionsHighlightingEnabled = manager.shouldInspect(psiFile)

  if (isSyntaxHighlightingEnabled && isInspectionsHighlightingEnabled) {
    HighlightLevelUtil.forceRootHighlighting(psiFile, FileHighlightingSetting.SKIP_HIGHLIGHTING)
  } else {
    HighlightLevelUtil.forceRootHighlighting(psiFile, FileHighlightingSetting.FORCE_HIGHLIGHTING)
  }
  InjectedLanguageManager.getInstance(project).dropFileCaches(psiFile)
  DaemonCodeAnalyzer.getInstance(project).restart()
}