MATLAB Function Reference (Volume 2: Graphics)

Light Propertiessets the current figure colormap to hsv whenever you create a light object.MATLAB executes this routine after setting all light properties. Setting thisproperty on an existing light object has no effect.The handle of the object whose CreateFcn is being executed is accessible onlythrough the root CallbackObject property, which you can query using gcbo.DeleteFcnstringDelete light callback routine. A callback routine that executes when you deletethe light object (i.e., when you issue a delete command or clear the axes orfigure containing the light). MATLAB executes the routine before destroyingthe object’s properties so these values are available to the callback routine.The handle of the object whose DeleteFcn is being executed is accessible onlythrough the root CallbackObject property, which you can query using gcbo.HandleVisibility {on} | callback | offControl access to object’s handle by command-line users and GUIs. Thisproperty determines when an object’s handle is visible in its parent’s list ofchildren. HandleVisibility is useful for preventing command-line users fromaccidentally drawing into or deleting a figure that contains only user interfacedevices (such as a dialog box).Handles are always visible when HandleVisibility is on.Setting HandleVisibility to callback causes handles to be visible fromwithin callback routines or functions invoked by callback routines, but not fromwithin functions invoked from the command line. This provides a means toprotect GUIs from command-line users, while allowing callback routines tohave complete access to object handles.Setting HandleVisibility to off makes handles invisible at all times. Thismay be necessary when a callback routine invokes a function that mightpotentially damage the GUI (such as evaling a user-typed string), and sotemporarily hides its own handles during the execution of that function.When a handle is not visible in its parent’s list of children, it cannot be returnedby functions that obtain handles by searching the object hierarchy or queryinghandle properties. This includes get, findobj, gca, gcf, gco, newplot, cla, clf,and close.2-266