Using Taskpads

This section discusses how to implement snap-in taskpads. For more information and an overview of taskpads, see Using Different Result Pane View Types.

Snap-in taskpads are introduced in MMC 1.1. In MMC 1.2, use console taskpads rather than snap-in taskpads. This section discusses how to implement snap-in taskpads in snap-ins that must be backward compatible. Be aware that in the discussion the term "taskpad" is used in place of "snap-in taskpad."

The MMC SDK specifies a number of interfaces and other constructs for working with taskpads. MMC calls the snap-in's implementation of IComponent::GetResultViewType to display the result pane for a particular scope item. The snap-in uses the method to provide MMC with the address of a string that contains the resource path to the taskpad template or HTML file and a group name that identifies the taskpad.

The IExtendTaskPad interface enables the snap-in to set up a taskpad and receive notifications from the taskpad. When the taskpad DHTML page is loaded, the MMCCtrl control on that page calls methods in MMC. In turn, MMC attempts to get the IExtendTaskPad interface from the IComponent object and calls the methods required to provide the MMCCtrl control with the data required to render the taskpad's general elements: title text, banner image, and background image.

If the taskpad is a list view taskpad, MMC calls IExtendTaskPad::GetListPadInfo to get the title text for the list control, text for an optional button, and the command ID passed to IExtendTaskPad::TaskNotify when the button is clicked.

MMC calls the IExtendTaskPad::EnumTasks method to get a pointer to the IEnumTASK interface of an object that specifies the tasks the snap-in must add to the taskpad.

The IEnumTASK::Next method enables MMC to retrieve the next task in the snap-in's list of tasks. MMC calls this method until it returns S_FALSE to indicate there are no more tasks for the snap-in to add to the taskpad. The IEnumTASK::Reset method enables MMC to reset the enumeration to the beginning of the snap-in's task list.

MMC calls the IExtendTaskPad::TaskNotify method to notify the snap-in when the user clicks a task or a list view button. The list view button applies only to list view taskpads.

The IEnumTASK::Skip and IEnumTASK::Clone methods are included in the MMC SDK for completeness, but are not used by MMC. Snap-ins can simply return E_NOTIMPL in their implementation of these two methods.