fix: light TM themes don't have light background in Eclipse dark mode

org.eclipse.tm4e.ui.tests/src/main/java/org/eclipse/tm4e/ui/tests/themes/TMEditorColorTest.java

@@ -73,9 +73,10 @@ void systemDefaultEditorColorTest() throws IOException, PartInitException {
 		assertNull(theme.getEditorSelectionBackground(), "System default selection background should be null");
 		assertNull(theme.getEditorSelectionForeground(), "System default selection foreground should be null");
 
-		final Color lineHighlight = ColorManager.getInstance().getPreferenceEditorColor(EDITOR_CURRENTLINE_HIGHLIGHT);
-		assertNotNull(theme.getEditorCurrentLineHighlight(), "Highlight shouldn't be a null");
-		assertNotEquals(lineHighlight, theme.getEditorCurrentLineHighlight(), "Default Line highlight should be from TM theme");
+		final Color eclipseLineHighlight = ColorManager.getInstance().getPreferenceEditorColor(EDITOR_CURRENTLINE_HIGHLIGHT);
+		final Color themeLineHighlight = theme.getEditorCurrentLineHighlight();
+		assertNotNull(themeLineHighlight, "Highlight shouldn't be a null");
+		assertNotEquals(eclipseLineHighlight, themeLineHighlight, "Default Line highlight should be from TM theme");
 	}
 
 	@Test

org.eclipse.tm4e.ui/META-INF/MANIFEST.MF

@@ -11,6 +11,7 @@ Require-Bundle: org.eclipse.core.expressions,
  org.eclipse.core.runtime,
  org.eclipse.jface.text,
  org.eclipse.ui,
+ org.eclipse.ui.editors,
  org.eclipse.ui.ide;resolution:=optional,
  org.eclipse.ui.trace;resolution:=optional,
  org.eclipse.ui.workbench.texteditor,

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/menus/ThemeContribution.java

@@ -23,7 +23,7 @@
 import org.eclipse.tm4e.core.grammar.IGrammar;
 import org.eclipse.tm4e.registry.ITMScope;
 import org.eclipse.tm4e.ui.TMUIPlugin;
-import org.eclipse.tm4e.ui.internal.utils.PreferenceUtils;
+import org.eclipse.tm4e.ui.internal.utils.UI;
 import org.eclipse.tm4e.ui.text.TMPresentationReconciler;
 import org.eclipse.tm4e.ui.themes.ITheme;
 import org.eclipse.tm4e.ui.themes.IThemeManager;
@@ -59,7 +59,7 @@ protected IContributionItem[] getContributionItems() {
 					final IGrammar grammar = presentationReconciler.getGrammar();
 					if (grammar != null) {
 						final IThemeManager manager = TMUIPlugin.getThemeManager();
-						final boolean dark = PreferenceUtils.isDarkEclipseTheme();
+						final boolean dark = UI.isDarkEclipseTheme();
 						final String scopeName = ITMScope.parse(grammar.getScopeName()).getName();
 						final ITheme selectedTheme = manager.getThemeForScope(scopeName, dark);
 						for (final ITheme theme : manager.getThemes()) {

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/preferences/PreferenceConstants.java

@@ -22,13 +22,9 @@ public final class PreferenceConstants {
 
 	public static final String THEME_ASSOCIATIONS = "org.eclipse.tm4e.ui.themeAssociations";
 
-	public static final String E4_THEME_ID = "themeid";
-
 	public static final String DEFAULT_DARK_THEME = "org.eclipse.tm4e.ui.themes.defaultDarkTheme";
 	public static final String DEFAULT_LIGHT_THEME = "org.eclipse.tm4e.ui.themes.defaultLightTheme";
 
-	public static final String EDITOR_CURRENTLINE_HIGHLIGHT = "currentLineColor";
-
 	private PreferenceConstants() {
 	}
 }

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/themes/AbstractThemeManager.java

@@ -20,7 +20,7 @@
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.tm4e.registry.ITMScope;
-import org.eclipse.tm4e.ui.internal.utils.PreferenceUtils;
+import org.eclipse.tm4e.ui.internal.utils.UI;
 import org.eclipse.tm4e.ui.themes.ITheme;
 import org.eclipse.tm4e.ui.themes.IThemeAssociation;
 import org.eclipse.tm4e.ui.themes.IThemeManager;
@@ -54,7 +54,7 @@ public ITheme[] getThemes() {
 
 	@Override
 	public ITheme getDefaultTheme() {
-		return getDefaultTheme(PreferenceUtils.isDarkEclipseTheme());
+		return getDefaultTheme(UI.isDarkEclipseTheme());
 	}
 
 	@Override
@@ -87,7 +87,7 @@ public ITheme[] getThemes(final boolean dark) {
 
 	@Override
 	public ITheme getThemeForScope(final String scopeName) {
-		return getThemeForScope(scopeName, PreferenceUtils.isDarkEclipseTheme());
+		return getThemeForScope(scopeName, UI.isDarkEclipseTheme());
 	}
 
 	@Override
@@ -109,9 +109,7 @@ public ITheme getThemeForScope(String scopeName, final boolean dark) {
 
 	@Override
 	public ITheme getThemeForScope(final String scopeName, final RGB background) {
-		return getThemeForScope(scopeName, 0.299 * background.red
-				+ 0.587 * background.green
-				+ 0.114 * background.blue < 128);
+		return getThemeForScope(scopeName, UI.isDarkColor(background));
 	}
 
 	@Override

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/themes/ThemeManager.java

@@ -65,7 +65,7 @@ public static ThemeManager getInstance() {
 	 */
 	public static void addPreferenceChangeListener(final IPreferenceChangeListener themeChangeListener) {
 		// Observe change of Eclipse E4 Theme
-		var prefs = PreferenceUtils.getE4PreferenceStore();
+		var prefs = PreferenceUtils.getE4ThemesPreferenceStore();
 		if (prefs != null) {
 			prefs.addPreferenceChangeListener(themeChangeListener);
 		}
@@ -84,7 +84,7 @@ public static void addPreferenceChangeListener(final IPreferenceChangeListener t
 	 */
 	public static void removePreferenceChangeListener(final IPreferenceChangeListener themeChangeListener) {
 		// Observe change of Eclipse E4 Theme
-		var prefs = PreferenceUtils.getE4PreferenceStore();
+		var prefs = PreferenceUtils.getE4ThemesPreferenceStore();
 		if (prefs != null) {
 			prefs.removePreferenceChangeListener(themeChangeListener);
 		}

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/utils/PreferenceUtils.java

@@ -16,25 +16,21 @@
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.tm4e.ui.TMUIPlugin;
-import org.eclipse.tm4e.ui.internal.preferences.PreferenceConstants;
+import org.eclipse.ui.editors.text.EditorsUI;
 
 public final class PreferenceUtils {
 
+	/** see {@link org.eclipse.e4.ui.css.swt.internal.theme.ThemeEngine#THEMEID_KEY} */
+	@SuppressWarnings({ "restriction", "javadoc" })
+	public static final String E4_THEME_ID = "themeid";
+
+	/** see {@link org.eclipse.e4.ui.css.swt.internal.theme.ThemeEngine#THEME_PLUGIN_ID} */
+	@SuppressWarnings({ "restriction" })
 	private static final String E4_CSS_PREFERENCE_NAME = "org.eclipse.e4.ui.css.swt.theme";
-	private static final String EDITORS_PREFERENCE_NAME = "org.eclipse.ui.editors";
 
 	private static @Nullable Boolean isDebugGenerateTest;
 	private static @Nullable Boolean isDebugThrowError;
 
-	/**
-	 * @return if Eclipse is currently using a dark UI theme
-	 */
-	public static boolean isDarkEclipseTheme() {
-		final IEclipsePreferences prefs = getE4PreferenceStore();
-		final String eclipseThemeId = prefs == null ? null : prefs.get(PreferenceConstants.E4_THEME_ID, null);
-		return eclipseThemeId != null && eclipseThemeId.toLowerCase().contains("dark");
-	}
-
 	public static boolean isDebugGenerateTest() {
 		var isDebugGenerateTest = PreferenceUtils.isDebugGenerateTest;
 		if (isDebugGenerateTest == null)
@@ -52,12 +48,12 @@ public static boolean isDebugThrowError() {
 	}
 
 	/**
-	 * Get e4 preferences store
+	 * Get e4 themes preferences store
 	 *
 	 * @return preferences store
 	 */
 	@Nullable
-	public static IEclipsePreferences getE4PreferenceStore() {
+	public static IEclipsePreferences getE4ThemesPreferenceStore() {
 		return InstanceScope.INSTANCE.getNode(E4_CSS_PREFERENCE_NAME);
 	}
 
@@ -68,7 +64,7 @@ public static IEclipsePreferences getE4PreferenceStore() {
 	 */
 	@Nullable
 	public static IEclipsePreferences getEditorsPreferenceStore() {
-		return InstanceScope.INSTANCE.getNode(EDITORS_PREFERENCE_NAME);
+		return InstanceScope.INSTANCE.getNode(EditorsUI.PLUGIN_ID);
 	}
 
 	private PreferenceUtils() {

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/utils/UI.java

@@ -19,8 +19,10 @@
 import org.eclipse.jface.viewers.TableViewer;
 import org.eclipse.swt.events.ModifyEvent;
 import org.eclipse.swt.events.ModifyListener;
+import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.FontMetrics;
 import org.eclipse.swt.graphics.GC;
+import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IWorkbenchPage;
@@ -151,6 +153,29 @@ public static int getTextWidth(final String string) {
 		}
 	}
 
+	/**
+	 * @return 0-255
+	 */
+	private static int getBrightness(final int red, final int green, final int blue) {
+		// https://www.w3.org/TR/AERT/#color-contrast
+		return (int) (0.299 * red + 0.587 * green + 0.114 * blue);
+	}
+
+	public static boolean isDarkColor(final RGB color) {
+		return getBrightness(color.red, color.green, color.blue) < 128;
+	}
+
+	public static boolean isDarkColor(final Color color) {
+		return getBrightness(color.getRed(), color.getGreen(), color.getBlue()) < 128;
+	}
+
+	public static boolean isDarkEclipseTheme() {
+		final var shell = getActiveShell();
+		if (shell == null)
+			throw new IllegalStateException("No active shell found!");
+		return isDarkColor(shell.getBackground());
+	}
+
 	private UI() {
 	}
 }

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/text/TMPresentationReconciler.java

@@ -128,7 +128,7 @@ public class TMPresentationReconciler implements IPresentationReconciler {
 			return;
 
 		switch (event.getKey()) {
-			case PreferenceConstants.E4_THEME_ID, //
+			case PreferenceUtils.E4_THEME_ID, //
 					PreferenceConstants.THEME_ASSOCIATIONS, //
 					PreferenceConstants.DEFAULT_DARK_THEME, //
 					PreferenceConstants.DEFAULT_LIGHT_THEME:

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/themes/Theme.java

@@ -22,9 +22,10 @@
 import org.eclipse.tm4e.registry.TMResource;
 import org.eclipse.tm4e.registry.XMLConstants;
 import org.eclipse.tm4e.ui.TMUIPlugin;
-import org.eclipse.tm4e.ui.internal.preferences.PreferenceConstants;
+import org.eclipse.tm4e.ui.internal.utils.UI;
 import org.eclipse.tm4e.ui.themes.css.CSSTokenProvider;
 import org.eclipse.ui.texteditor.AbstractTextEditor;
+import org.eclipse.ui.texteditor.AbstractDecoratedTextEditorPreferenceConstants;
 
 /**
  * {@link ITheme} implementation.
@@ -87,40 +88,47 @@ public IToken getToken(final String type) {
 		return provider == null ? ITokenProvider.DEFAULT_TOKEN : provider.getToken(type);
 	}
 
+	private @Nullable Color getPriorityColor(final @Nullable Color themeColor, final String prefStoreKey) {
+		// if the theme is light but Eclipse is in dark mode (or vice versa) we cannot use the pref settings and always use the theme colors
+		return UI.isDarkEclipseTheme() == isDark()
+				? ColorManager.getInstance().getPriorityColor(themeColor, prefStoreKey)
+				: themeColor;
+	}
+
 	@Nullable
 	@Override
 	public Color getEditorForeground() {
 		final ITokenProvider provider = getTokenProvider();
-		final Color themeColor = provider != null ? provider.getEditorForeground() : null;
-		return ColorManager.getInstance()
-				.getPriorityColor(themeColor, AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND);
+		return getPriorityColor(
+				provider != null ? provider.getEditorForeground() : null,
+				AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND);
 	}
 
 	@Nullable
 	@Override
 	public Color getEditorBackground() {
 		final ITokenProvider provider = getTokenProvider();
-		final Color themeColor = provider != null ? provider.getEditorBackground() : null;
-		return ColorManager.getInstance()
-				.getPriorityColor(themeColor, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
+		return getPriorityColor(
+				provider != null ? provider.getEditorBackground() : null,
+				AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
 	}
 
 	@Nullable
 	@Override
 	public Color getEditorSelectionForeground() {
 		final ITokenProvider provider = getTokenProvider();
-		final Color themeColor = provider != null ? provider.getEditorSelectionForeground() : null;
-		return ColorManager.getInstance()
-				.getPriorityColor(themeColor, AbstractTextEditor.PREFERENCE_COLOR_SELECTION_FOREGROUND);
+		return getPriorityColor(
+				provider != null ? provider.getEditorSelectionForeground() : null,
+				AbstractTextEditor.PREFERENCE_COLOR_SELECTION_FOREGROUND);
 	}
 
 	@Nullable
 	@Override
 	public Color getEditorSelectionBackground() {
 		final ITokenProvider provider = getTokenProvider();
-		final Color themeColor = provider != null ? provider.getEditorSelectionBackground() : null;
-		return ColorManager.getInstance()
-				.getPriorityColor(themeColor, AbstractTextEditor.PREFERENCE_COLOR_SELECTION_BACKGROUND);
+		return getPriorityColor(
+				provider != null ? provider.getEditorSelectionBackground() : null,
+				AbstractTextEditor.PREFERENCE_COLOR_SELECTION_BACKGROUND);
 	}
 
 	@Nullable
@@ -130,7 +138,7 @@ public Color getEditorCurrentLineHighlight() {
 		final Color themeColor = provider != null ? provider.getEditorCurrentLineHighlight() : null;
 		final ColorManager manager = ColorManager.getInstance();
 		return manager.isColorUserDefined(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND)
-				? manager.getPreferenceEditorColor(PreferenceConstants.EDITOR_CURRENTLINE_HIGHLIGHT)
+				? manager.getPreferenceEditorColor(AbstractDecoratedTextEditorPreferenceConstants.EDITOR_CURRENT_LINE_COLOR)
 				: themeColor;
 	}