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
IDocument clippedDoc= (IDocument)fViewer.getInput();
		try {
			IRegion unclippedLineInfo= unclippedDocument.getLineInformation(fCommentLineCount + textSelection.getStartLine());
			IRegion clippedLineInfo= clippedDoc.getLineInformation(textSelection.getStartLine());
			int removedIndentation= unclippedLineInfo.getLength() - clippedLineInfo.getLength();
			int relativeLineOffset= textSelection.getOffset() - clippedLineInfo.getOffset();
			return unclippedLineInfo.getOffset() + removedIndentation + relativeLineOffset ;
		} catch (BadLocationException ex) {
			return -1;
		}
	}
	
	/*
	 * @see AbstractInfoView#internalDispose()
	 */
	protected void internalDispose() {
		fViewer= null;
		JFaceResources.getFontRegistry().removeListener(fFontPropertyChangeListener);
	}
	/*
	 * @see org.eclipse.ui.part.WorkbenchPart#setFocus()
	 */
	public void setFocus() {
		fViewer.getTextWidget().setFocus();
	}
	
	/*
	 * @see AbstractInfoView#setInput(Object)
	 */
	protected boolean setInput(Object input) {