Bug 40780 [plan item] Improve context views
Declaration View and Javadoc View should compute their contents in background Both should provide a context menu containing at least Copy and F3 (where available).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/infoviews/SourceView.java
}
			i= reader.getOffset();
			reader.close();
		} catch (IOException ex) {
			i= 0;
		} finally {
			try {
				if (reader != null)
					reader.close();
			} catch (IOException ex) {
				JavaPlugin.log(ex);
			}
		}
		try {
			fCommentLineCount= document.getLineOfOffset(i);
		} catch (BadLocationException e) {
			fCommentLineCount= 0;
		}
		if (i < 0)
			return source;
		return source.substring(i);
	}
	/**
	 * Sets the font for this viewer sustaining selection and scroll position.
	 */
	private void setViewerFont() {
		Font font= JFaceResources.getFont(SYMBOLIC_FONT_NAME);
		if (fViewer.getDocument() != null) {
			Point selection= fViewer.getSelectedRange();
			int topIndex= fViewer.getTopIndex();