Semantic Tokens: Do not use default theme

Fix for #1028 - we requested the default theme if no TM mapping for the editor, but
this calls syncExec. Reconciler threads mustn't block on the UI thread as it is possible for the UI thread to be blocked
waiting for reconciliation; this deadlock was indeed observed.

org.eclipse.lsp4e.test/fragment.xml

@@ -43,6 +43,10 @@
  contentType="org.eclipse.lsp4e.test.content-type"
  id="org.eclipse.lsp4e.test.server">
  </contentTypeMapping>
+ <contentTypeMapping
+ contentType="org.eclipse.lsp4e.test.content-type.tm"
+ id="org.eclipse.lsp4e.test.server">
+ </contentTypeMapping>
  <contentTypeMapping
  contentType="org.eclipse.lsp4e.test.content-type-multi-ls"
  id="org.eclipse.lsp4e.test.server">
@@ -125,6 +129,13 @@
  id="org.eclipse.lsp4e.test.content-type"
  name="Test Content Type"
  priority="normal">
+ </content-type>
+ <content-type
+ base-type="org.eclipse.core.runtime.text"
+ file-extensions="lsptm"
+ id="org.eclipse.lsp4e.test.content-type.tm"
+ name="Test Content Type With TM Grammar"
+ priority="normal">
  </content-type>
  <content-type
  base-type="org.eclipse.core.runtime.text"
@@ -277,4 +288,23 @@
  class="org.eclipse.lsp4e.test.references.FindReferencesTest$UiFreezeEventLogger">
  </logger>
  </extension>
+
+ <extension
+ point="org.eclipse.tm4e.registry.grammars">
+ <grammar
+ path="org/eclipse/lsp4e/test/semanticTokens/rust.tmLanguage.json"
+ scopeName="source.lsptm">
+ </grammar>
+ <scopeNameContentTypeBinding
+ contentTypeId="org.eclipse.lsp4e.test.content-type.tm"
+ scopeName="source.lsptm">
+ </scopeNameContentTypeBinding>
+ </extension>
+ <extension
+ point="org.eclipse.ui.genericeditor.presentationReconcilers">
+ <presentationReconciler
+ class="org.eclipse.tm4e.ui.text.TMPresentationReconciler"
+ contentType="org.eclipse.lsp4e.test.content-type.tm">
+ </presentationReconciler>
+ </extension> 
 </fragment>

org.eclipse.lsp4e.test/src/org/eclipse/lsp4e/test/semanticTokens/SemanticHighlightReconcilerStrategyTest.java

@@ -49,7 +49,7 @@ public void testKeyword() throws CoreException {
 
  MockLanguageServer.INSTANCE.getTextDocumentService().setSemanticTokens(semanticTokens);
 
- IFile file = TestUtils.createUniqueTestFile(project, "lspt", SemanticTokensTestUtil.keywordText);
+ IFile file = TestUtils.createUniqueTestFile(project, "lsptm", SemanticTokensTestUtil.keywordText);
  ITextViewer textViewer = TestUtils.openTextViewer(file);
 
  Display display = shell.getDisplay();
@@ -58,18 +58,30 @@ public void testKeyword() throws CoreException {
  StyleRange[] styleRanges = textViewer.getTextWidget().getStyleRanges();
  var backgroundColor = textViewer.getTextWidget().getBackground();
 
- assertEquals(3, styleRanges.length);
+ assertEquals(6, styleRanges.length);
 
  assertEquals(0, styleRanges[0].start);
  assertEquals(4, styleRanges[0].length);
  assertNotEquals(styleRanges[0].foreground, backgroundColor);
 
- assertEquals(15, styleRanges[1].start);
- assertEquals(4, styleRanges[1].length);
+ assertEquals(4, styleRanges[1].start);
+ assertEquals(11, styleRanges[1].length);
  assertNotEquals(styleRanges[1].foreground, backgroundColor);
 
- assertEquals(24, styleRanges[2].start);
- assertEquals(7, styleRanges[2].length);
+ assertEquals(15, styleRanges[2].start);
+ assertEquals(4, styleRanges[2].length);
  assertNotEquals(styleRanges[2].foreground, backgroundColor);
+
+ assertEquals(19, styleRanges[3].start);
+ assertEquals(5, styleRanges[3].length);
+ assertNotEquals(styleRanges[3].foreground, backgroundColor);
+
+ assertEquals(24, styleRanges[4].start);
+ assertEquals(7, styleRanges[4].length);
+ assertNotEquals(styleRanges[4].foreground, backgroundColor);
+
+ assertEquals(31, styleRanges[5].start);
+ assertEquals(11, styleRanges[5].length);
+ assertNotEquals(styleRanges[5].foreground, backgroundColor);
  }
 }