+ //resize canvas view if mouse is outside
+ int w = (int)(x()+dx) + width() + GRAPH_MARGIN;
+ int h = (int)(y()+dy) + height() + GRAPH_MARGIN;
+ if (canvas()->width() > w) w = canvas()->width();
+ if (canvas()->height() > h) h = canvas()->height();
+ if (canvas()->width() < w || canvas()->height() < h) canvas()->resize(w, h);