How to set the linenumber of an IMarker for a ICompilationUnit?

Question

I want to create a marker with a message and colored code line (like EclEmma does) at a given linenumber. I have a ICompilationUnit and its resource to create the marker like this:

IMarker marker = resource.createMarker("org.epitest.mutationmarker");
marker.setAttribute(IMarker.MESSAGE, "statusDescription");
marker.setAttribute(IMarker.LINE_NUMBER, 5);
marker.setAttribute(IMarker.CHAR_START, 10);
marker.setAttribute(IMarker.CHAR_END, 20);

Unfortunatly the line number is ignored and the marker is placed at the first line.

What went wrong? How can i solve this?

Answer 1

CHAR_START and CHAR_END are offsets from the start of the document and are being used in preference to LINE_NUMBER. The position display code only uses the line number if neither of the char start and end attributes is specified.

You can use IDocument.getLineOffset(line) to get a line offset if you have the IDocument.

If you are using a text editor you can get the IDocument from that, otherwise you can construct an instance of the Document class.

Note: Line numbers in IDocument are 0 based, line numbers in IMarker are 1 based.