Preliminary support for dartdoc hovers. Future CLs will give us richer hover information and styl...

editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartTextHover.java

Index: editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartTextHover.java
===================================================================
--- editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartTextHover.java	(revision 0)
+++ editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartTextHover.java	(revision 0)
@@ -0,0 +1,61 @@
+package com.google.dart.tools.ui.internal.text.editor;
+
+import com.google.dart.compiler.ast.DartUnit;
+import com.google.dart.tools.core.model.CompilationUnit;
+import com.google.dart.tools.core.model.DartModelException;
+import com.google.dart.tools.core.utilities.dartdoc.DartDocUtilities;
+import com.google.dart.tools.ui.text.DartSourceViewerConfiguration;
+
+import org.eclipse.jface.text.DefaultTextHover;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.source.Annotation;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.ui.texteditor.ITextEditor;
+
+/**
+ * An implementation of ITextHover for Dart documentation.
+ */
+public class DartTextHover extends DefaultTextHover {
+  private CompilationUnitEditor editor;
+  private DartSourceViewerConfiguration sourceViewerConfiguration;
+
+  public DartTextHover(ITextEditor editor, ISourceViewer sourceViewer,
+      DartSourceViewerConfiguration sourceViewerConfiguration) {
+    super(sourceViewer);
+
+    if (editor instanceof CompilationUnitEditor) {
+      this.editor = (CompilationUnitEditor) editor;
+    }
+
+    this.sourceViewerConfiguration = sourceViewerConfiguration;
+  }
+
+  @Override
+  public String getHoverInfo(ITextViewer textViewer, IRegion region) {
+    String annotationHover = super.getHoverInfo(textViewer, region);
+
+    if (annotationHover != null) {
+      return annotationHover;
+    }
+
+    if (editor == null) {
+      return null;
+    }
+
+    DartUnit unit = editor.getAST();
+
+    try {
+      return DartDocUtilities.getDartDoc((CompilationUnit) editor.getInputDartElement(), unit,
+          region.getOffset(), region.getOffset() + region.getLength());
+    } catch (DartModelException e) {
+      return null;
+    }
+  }
+
+  @Override
+  protected boolean isIncluded(Annotation annotation) {
+    return sourceViewerConfiguration.isShownInText(annotation);
+  }
+
+}