A context menu appears when the right mouse button is pressed within the drawing canvas. The context determines the items in the menu; it depends on the type of graph elements that are selected at the time the mouse is pressed.
When no graph elements are selected and the mouse click occurs at an empty place within the drawing canvas, the drawing canvas becomes the context.
When no graph elements are selected and the mouse click occurs on a graph element, the graph element becomes the context.
Note: The graph element gets automatically selected in that case.
Mouse Drag Gesture
A combination of a simple mouse click (left mouse button) and a drag gesture of the mouse where the drag is in-between the mouse button press and mouse button release.