---

Inside Macintosh: More Macintosh Toolbox

Previous | Chapter Top | Chapter Contents | Next |

FindNextComponent

The FindNextComponent function returns the component identifier for the next registered component that meets the selection criteria specified by your application. You specify the selection criteria in a component description record.

Your application can use the component identifier returned by this function to get more information about the component or to open the component.

FUNCTION FindNextComponent (aComponent: Component;
                                          looking: ComponentDescription)
                                          : Component;


aComponent

The starting point for the search. Set this field to 0 to to start the search at the beginning of the component list. If you are continuing a search, you can specify a component identifier previously returned by the FindNextComponent function. The function then searches the remaining components.

looking

A component description record. Your application specifies the criteria for the component search in the fields of this record.

The Component Manager ignores fields in the component description record that are set to 0. For example, if you set all the fields to 0, all components meet the search criteria. In this case, your application can retrieve information about all of the components that are registered in the system by repeatedly calling FindNextComponent and GetComponentInfo until the search is complete. Similarly, if you set all fields to 0 except for the componentManufacturer field, the Component Manager searches all registered components for a component supplied by the manufacturer you specify. Note that the FindNextComponent function does not modify the contents of the component description record you supply. To retrieve detailed information about a component, you need to use the GetComponentInfo function to get the component description record for each returned component.

CountComponents

Your application can use the CountComponents function to determine the number of registered components that meet your selection criteria. You specify the selection criteria in a component description record. The CountComponents function returns the number of components that meet those search criteria.

FUNCTION CountComponents (looking: ComponentDescription): LongInt;


looking

A component description record. Your application specifies the criteria for the component search in the fields of this record.

The Component Manager ignores fields in the component description record that are set to 0. For example, if you set all the fields to 0, the Component Manager returns the number of components registered in the system. Similarly, if you set all fields to 0 except for the componentManufacturer field, the Component Manager returns the number of registered components supplied by the manufacturer you specify.

GetComponentListModSeed

The GetComponentListModSeed function allows you to determine if the list of registered components has changed. This function returns the value of the component registration seed number. By comparing this value to values previously returned by the this function, you can determine whether the list has changed. Your application may use this information to rebuild its internal component lists or to trigger other activity that is necessary whenever new components are available.

FUNCTION GetComponentListModSeed: LongInt;