fix: Invoke colorizer when editor is cloned or splitted #827 (#870)

For new models the colorizer will be invoked after tokenization. For
reused models (e.g. when splitting an editor) this must be done
explicitly.

---------

Co-authored-by: Sebastian Thomschke <sebthom@users.noreply.github.com>

Author: oleosterhagen

org.eclipse.tm4e.ui.tests/src/main/java/org/eclipse/tm4e/ui/tests/TMinGenericEditorTest.java

@@ -19,6 +19,7 @@
 import org.eclipse.tm4e.ui.tests.support.TestUtils;
 import org.eclipse.ui.IEditorDescriptor;
 import org.eclipse.ui.IEditorPart;
+import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.ide.IDE;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -28,6 +29,7 @@ class TMinGenericEditorTest {
 
 	private IEditorDescriptor genericEditorDescr;
 	private IEditorPart editor;
+	private IEditorPart clonedEditor;
 
 	@BeforeEach
 	public void setup() throws Exception {
@@ -40,6 +42,9 @@ public void tearDown() throws Exception {
 		TestUtils.closeEditor(editor);
 		editor = null;
 
+		TestUtils.closeEditor(clonedEditor);
+		clonedEditor = null;
+
 		TestUtils.assertNoTM4EThreadsRunning();
 	}
 
@@ -72,6 +77,19 @@ void testTMHighlightInGenericEditorEdit() throws Exception {
 				() -> text.getStyleRanges().length > initialNumberOfRanges + 3);
 	}
 
+	@Test
+	void testTMHighlightInClonedGenericEditor() throws Exception {
+		final var f = TestUtils.createTempFile(".ts");
+		try (var fileOutputStream = new FileOutputStream(f)) {
+			fileOutputStream.write("let a = '';".getBytes());
+		}
+		editor = IDE.openEditor(UI.getActivePage(), f.toURI(), genericEditorDescr.getId(), true);
+		clonedEditor = UI.getActivePage().openEditor(editor.getEditorInput(), genericEditorDescr.getId(), true, IWorkbenchPage.MATCH_NONE);
+
+		final var text = (StyledText) clonedEditor.getAdapter(Control.class);
+		TestUtils.waitForAndAssertCondition(3_000, () -> text.getStyleRanges().length > 1);
+	}
+
 	@Test
 	void testReconcilierStartsAndDisposeThread() throws Exception {
 		testTMHighlightInGenericEditor();

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

@@ -217,12 +217,23 @@ public void inputDocumentChanged(final @Nullable IDocument oldDoc, final @Nullab
 						viewer.getTextWidget().getBackground().getRGB());
 			}
 
-			TMPresentationReconciler.this.colorizer = new Colorizer(viewer, theme, listeners);
+			final var colorizer = TMPresentationReconciler.this.colorizer = new Colorizer(viewer, theme, listeners);
+			final var isModelReused = TMModelManager.INSTANCE.isConnected(newDoc);
 
 			// connect a TextMate model to the new document
 			final var docModel = TMModelManager.INSTANCE.connect(newDoc);
 			docModel.setGrammar(newDocGrammar);
 			docModel.addModelTokensChangedListener(modelsTokensChangedListener);
+
+			// For new models the colorizer will be invoked after tokenization. For reused
+			// models (e.g. when splitting an editor) this must be done explicitly.
+			if (isModelReused) {
+				try {
+					colorizer.colorize(new Region(0, newDoc.getLength()), docModel);
+				} catch (final BadLocationException ex) {
+					TMUIPlugin.logError(ex);
+				}
+			}
 		}
 
 		@Override