is_item_at

[control H <control h gmail com>]

dear list,

I have made a line-item subclass of GOO_TYPE_CANVAS_ITEM_SIMPLE. This
subclass is (so far) only drawing 1 line. I overrule the is_item_at
function:

static gboolean
goo_line_item_is_item_at (GooCanvasItemSimple *simple,
                          gdouble              x,
                          gdouble              y,
                          cairo_t             *cr,
                          gboolean             is_pointer_event)
{
  GooLineItem *line=(GooLineItem*)simple;
  gboolean r,r2;
  GooCanvasPointerEvents pointer_events = GOO_CANVAS_EVENTS_ALL;
  gdouble width;

  g_object_get (G_OBJECT(line),"line-width", &width,NULL);

  cairo_move_to(cr,0,0);
  cairo_line_to(cr,line->dx,line->dy);
  cairo_set_line_width(cr,width+4.0);
  cairo_set_source_rgb(cr,1,0,0);

  r2=goo_canvas_item_simple_check_in_path(simple,x,y,cr,pointer_events);
  r=cairo_in_stroke (cr, x, y);
  printf(", r: %d, r2: %d\n",r,r2);

  return r;
}

struct _GooLineItem
{
  GooCanvasItemSimple parent_object;

  gdouble dx,dy;
  gboolean dragging;
};

When I put some goolineitem objects on the canvas, the
goo_line_item_is_item_at() returns only seldom TRUE. Both r and r2 are
FALSE when they should be TRUE. What I am doing wrong?

I use gtk 3.0.2 and goocanvas 2.0.0.

notes:
* I use line-width + 4.0 to make it easier to pick up thin lines.
* I want to use cairo_in_stroke() instead of
goo_canvas_item_simple_check_in_path() so that dashed lines can be
picked up anywhere