Bug 17365 Text Editor: icons in vert. ruler disappear for partial top line
- open Java text editor on file that is larger as view (so that you can scroll) - generate any kind of icon in vertical ruler (e.g. a breakpoint) - use the thumb to carefully scroll pixel wise so that a top line is half visible - now scroll with the scrollbar buttons (not the thumb!) until a line with an icon is at the top (half visible) Observe: as soon as a line is only partially visible its icon is no longer drawn.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/ProblemPainter.java
public ProblemPainter(ITextEditor textEditor, ISourceViewer sourceViewer) {
		fTextEditor= textEditor;
		fSourceViewer= sourceViewer;
		fTextWidget= sourceViewer.getTextWidget();
	}
	
	private boolean hasProblems() {
		return !fProblemPositions.isEmpty();
	}	
	
	private void enablePainting() {
		if (!fIsPainting && hasProblems()) {
			fIsPainting= true;
			fTextWidget.addPaintListener(this);
			handleDrawRequest(null);
		}
	}
	
	private void disablePainting(boolean redraw) {
		if (fIsPainting) {
			fIsPainting= false;
			fTextWidget.removePaintListener(this);
			if (redraw && hasProblems())
				handleDrawRequest(null);
		}
	}
	
	private void setModel(IAnnotationModel model) {