This function adds a reference to the object in the list of objects to be drawn in the current pad or canvas. The canvas itself is a pad. You do not need to create a pad in case you want to get only one pad.
Pads are resizable and moveable areas in the canvas.
Pads in turn may contain other pads to build a hierarchy. In case a canvas or pad is resized, its contents are automatically redrawn. It simply adds a reference to object in the list of pad objects. For each object drawn, a TObjLink object is created. This TObjLink object contains a reference to object .