feat: add option to enable displaying TM scope name in hover

org.eclipse.tm4e.ui/plugin.xml

@@ -37,7 +37,7 @@
              path="./themes/Eclipse-light.css" />
       <theme id="org.eclipse.tm4e.ui.themes.WtpXmlClassic"
              name="%Theme.WtpXmlClassic.name"
-             path="./themes/WTP-XML-Classic.css" />  
+             path="./themes/WTP-XML-Classic.css" />
       <!-- "Dark" themes -->
       <theme id="org.eclipse.tm4e.ui.themes.Dark"
              name="%Theme.Dark.name"
@@ -138,4 +138,10 @@
       <super type="org.eclipse.tm4e.ui.textmarker"/>
       <persistent value="true"/>
    </extension>
+
+   <extension point="org.eclipse.ui.genericeditor.hoverProviders">
+      <hoverProvider
+            class="org.eclipse.tm4e.ui.internal.hover.TMTokenTextHover"
+            contentType="org.eclipse.core.runtime.text" />
+   </extension>
 </plugin>

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/TMUIPlugin.java

@@ -43,6 +43,10 @@ public class TMUIPlugin extends AbstractUIPlugin {
 	@Nullable
 	private static volatile TMUIPlugin plugin;
 
+	public static boolean getPreference(final String key, final boolean defaultValue) {
+		return Platform.getPreferencesService().getBoolean(PLUGIN_ID, key, defaultValue, null /* = search in all available scopes */);
+	}
+
 	public static @Nullable String getPreference(final String key, final @Nullable String defaultValue) {
 		return Platform.getPreferencesService().getString(PLUGIN_ID, key, defaultValue, null /* = search in all available scopes */);
 	}

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/hover/TMTokenTextHover.java

@@ -0,0 +1,110 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Vegard IT GmbH and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Sebastian Thomschke (Vegard IT) - initial implementation
+ *******************************************************************************/
+package org.eclipse.tm4e.ui.internal.hover;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.DefaultInformationControl;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IInformationControl;
+import org.eclipse.jface.text.IInformationControlCreator;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextHover;
+import org.eclipse.jface.text.ITextHoverExtension;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.Region;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.tm4e.core.model.TMToken;
+import org.eclipse.tm4e.ui.internal.model.TMDocumentModel;
+import org.eclipse.tm4e.ui.internal.model.TMModelManager;
+import org.eclipse.tm4e.ui.internal.preferences.PreferenceHelper;
+import org.eclipse.ui.editors.text.EditorsUI;
+
+public class TMTokenTextHover implements ITextHover, ITextHoverExtension {
+
+	private static final class RegionWithTMToken extends Region {
+		final TMToken token;
+
+		RegionWithTMToken(final int offset, final int length, final TMToken token) {
+			super(offset, length);
+			this.token = token;
+		}
+	}
+
+	@Override
+	public IInformationControlCreator getHoverControlCreator() {
+		// setup a hover control that interprets basic HTML input
+		return new AbstractReusableInformationControlCreator() {
+			@Override
+			protected IInformationControl doCreateInformationControl(final @NonNullByDefault({}) Shell parent) {
+				return new DefaultInformationControl(parent, EditorsUI.getTooltipAffordanceString());
+			}
+		};
+	}
+
+	@Override
+	public @Nullable String getHoverInfo(final @NonNullByDefault({}) ITextViewer textViewer,
+			final @NonNullByDefault({}) IRegion hoverRegion) {
+		if (hoverRegion instanceof final RegionWithTMToken regionWithToken) {
+			return "<b>TextMate scope:</b> " + regionWithToken.token.type;
+		}
+		return null;
+	}
+
+	@Override
+	public @Nullable IRegion getHoverRegion(final @NonNullByDefault({}) ITextViewer textViewer, final int offset) {
+		if (!PreferenceHelper.isTMScopeHoverEnabled())
+			return null;
+
+		final @Nullable IDocument doc = textViewer.getDocument();
+		if (doc == null)
+			return null;
+
+		final TMDocumentModel model = TMModelManager.INSTANCE.getConnectedModel(doc);
+		if (model == null)
+			return null;
+
+		try {
+			// retrieve parsed TM tokens of the hovered line
+			final int lineIndex = doc.getLineOfOffset(offset);
+			final var tokens = model.getLineTokens(lineIndex);
+			if (tokens == null)
+				return null;
+
+			// find the TM token at the hover position
+			final int lineStartOffset = doc.getLineOffset(lineIndex);
+			TMToken hoveredToken = null;
+			TMToken nextToken = null;
+			for (final TMToken token : tokens) {
+				if (token.startIndex <= offset - lineStartOffset) {
+					hoveredToken = token;
+				} else {
+					nextToken = token;
+					break;
+				}
+			}
+			if (hoveredToken == null)
+				return null;
+
+			return new RegionWithTMToken(
+					lineStartOffset + hoveredToken.startIndex,
+					nextToken == null
+							? doc.getLineLength(lineIndex) - hoveredToken.startIndex
+							: nextToken.startIndex - hoveredToken.startIndex,
+					hoveredToken);
+		} catch (final BadLocationException e) {
+			return null;
+		}
+	}
+}

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/hover/package-info.java

@@ -0,0 +1,4 @@
+@NonNullByDefault
+package org.eclipse.tm4e.ui.internal.hover;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;

org.eclipse.tm4e.ui/src/main/java/org/eclipse/tm4e/ui/internal/model/TMModelManager.java

@@ -16,6 +16,7 @@
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.tm4e.ui.model.ITMModelManager;
 
@@ -44,6 +45,10 @@ public void disconnect(final IDocument document) {
 		}
 	}
 
+	public @Nullable TMDocumentModel getConnectedModel(final IDocument document) {
+		return models.get(document);
+	}
+
 	@Override
 	public boolean isConnected(final IDocument document) {
 		return models.containsKey(document);

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

@@ -22,7 +22,7 @@ public abstract class AbstractPreferencePage extends PreferencePage implements I
 
 	private final @Nullable String title;
 
-	protected AbstractPreferencePage(final @Nullable String title, final String description) {
+	protected AbstractPreferencePage(final @Nullable String title, final @Nullable String description) {
 		this.title = title;
 		setDescription(description);
 	}

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

@@ -25,6 +25,8 @@ public final class PreferenceConstants {
 	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 TMSCOPE_HOVER_ENABLED = "org.eclipse.tm4e.ui.tmScopeHoverEnabled";
+
 	private PreferenceConstants() {
 	}
 }

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

@@ -110,6 +110,16 @@ public static void saveMarkerConfigs(final Set<MarkerConfig> markerConfigs) thro
 		prefs.flush();
 	}
 
+	public static boolean isTMScopeHoverEnabled() {
+		return TMUIPlugin.getPreference(PreferenceConstants.TMSCOPE_HOVER_ENABLED, false);
+	}
+
+	public static void saveTMScopeHoverEnabled(boolean enableTMScopeHover) throws BackingStoreException {
+		final var prefs = InstanceScope.INSTANCE.getNode(TMUIPlugin.PLUGIN_ID);
+		prefs.putBoolean(PreferenceConstants.TMSCOPE_HOVER_ENABLED, enableTMScopeHover);
+		prefs.flush();
+	}
+
 	private PreferenceHelper() {
 	}
 }

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

@@ -11,63 +11,96 @@
  */
 package org.eclipse.tm4e.ui.internal.preferences;
 
+import static org.eclipse.tm4e.core.internal.utils.NullSafetyHelper.lazyNonNull;
+
 import org.eclipse.core.runtime.Platform;
-import org.eclipse.jdt.annotation.Nullable;
-import org.eclipse.jface.preference.PreferencePage;
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jface.layout.GridLayoutFactory;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.layout.GridData;
-import org.eclipse.swt.layout.GridLayout;
+import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Label;
+import org.eclipse.tm4e.ui.TMUIPlugin;
 import org.eclipse.tm4e.ui.internal.TMUIMessages;
 import org.eclipse.ui.IWorkbench;
-import org.eclipse.ui.IWorkbenchPreferencePage;
 import org.eclipse.ui.dialogs.PreferenceLinkArea;
 import org.eclipse.ui.preferences.IWorkbenchPreferenceContainer;
+import org.osgi.service.prefs.BackingStoreException;
 
 /**
  * TextMate Global preferences page.
- *
  */
-public final class TextMatePreferencePage extends PreferencePage implements IWorkbenchPreferencePage {
+public final class TextMatePreferencePage extends AbstractPreferencePage {
+
+	private Button enableTMScopeHover = lazyNonNull();
+
+	public TextMatePreferencePage() {
+		super(null, null);
+	}
 
 	@Override
-	protected Control createContents(@Nullable final Composite parent) {
+	protected Control createContents(final @NonNullByDefault({}) Composite parent) {
 		final var composite = new Composite(parent, SWT.NONE);
-		final var layout = new GridLayout(1, false);
-		layout.marginHeight = layout.marginWidth = 0;
-		composite.setLayout(layout);
+		composite.setLayout(GridLayoutFactory.fillDefaults().create());
+
+		addRelatedLinks(composite);
+
+		new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL)
+				.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));
+
+		enableTMScopeHover = new Button(composite, SWT.CHECK);
+		enableTMScopeHover.setText("Show TextMate scope name in hovers.");
+		enableTMScopeHover.setSelection(PreferenceHelper.isTMScopeHoverEnabled());
+
+		applyDialogFont(composite);
+		return composite;
+	}
 
+	private void addRelatedLinks(final Composite parent) {
 		// Add link to grammar preference page
-		addRelatedLink(composite, GrammarPreferencePage.PAGE_ID, TMUIMessages.TextMatePreferencePage_GrammarRelatedLink);
+		addRelatedLink(parent, GrammarPreferencePage.PAGE_ID, TMUIMessages.TextMatePreferencePage_GrammarRelatedLink);
 
 		// Add link to language configuration preference page
-		if (Platform.getBundle("org.eclipse.tm4e.languageconfiguration") != null) { //$NON-NLS-1$
-			addRelatedLink(composite,
-					"org.eclipse.tm4e.languageconfiguration.preferences.LanguageConfigurationPreferencePage", //$NON-NLS-1$
+		if (Platform.getBundle("org.eclipse.tm4e.languageconfiguration") != null) {
+			addRelatedLink(parent,
+					"org.eclipse.tm4e.languageconfiguration.preferences.LanguageConfigurationPreferencePage",
 					TMUIMessages.TextMatePreferencePage_LanguageConfigurationRelatedLink);
 		}
 
 		// Add link to task tags preference page
-		addRelatedLink(composite, TaskTagsPreferencePage.PAGE_ID, TMUIMessages.TextMatePreferencePage_TaskTagsRelatedLink);
+		addRelatedLink(parent, TaskTagsPreferencePage.PAGE_ID, TMUIMessages.TextMatePreferencePage_TaskTagsRelatedLink);
 
 		// Add link to theme preference page
-		addRelatedLink(composite, ThemePreferencePage.PAGE_ID, TMUIMessages.TextMatePreferencePage_ThemeRelatedLink);
-
-		applyDialogFont(composite);
-		return composite;
-
+		addRelatedLink(parent, ThemePreferencePage.PAGE_ID, TMUIMessages.TextMatePreferencePage_ThemeRelatedLink);
 	}
 
 	private void addRelatedLink(final Composite parent, final String pageId, final String message) {
 		final var contentTypeArea = new PreferenceLinkArea(parent, SWT.NONE, pageId, message,
 				(IWorkbenchPreferenceContainer) getContainer(), null);
 
-		final var data = new GridData(GridData.FILL_HORIZONTAL | GridData.GRAB_HORIZONTAL);
-		contentTypeArea.getControl().setLayoutData(data);
+		contentTypeArea.getControl()
+				.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.GRAB_HORIZONTAL));
 	}
 
 	@Override
-	public void init(@Nullable final IWorkbench workbench) {
+	public void init(final @NonNullByDefault({}) IWorkbench workbench) {
+	}
+
+	@Override
+	protected void performDefaults() {
+		enableTMScopeHover.setSelection(PreferenceHelper.isTMScopeHoverEnabled());
+	}
+
+	@Override
+	public boolean performOk() {
+		try {
+			PreferenceHelper.saveTMScopeHoverEnabled(enableTMScopeHover.getSelection());
+		} catch (final BackingStoreException ex) {
+			TMUIPlugin.logError(ex);
+			return false;
+		}
+		return super.performOk();
 	}
 }