Information Preview Popup API: API description

Information Preview Popup API can be used by all GUI applications. It is a library API that provides an interface for construction and using the Preview Popup UI component. The interface contains only method calls that can be used for creating local objects of provided interface classes and then using these objects.

Use cases

The most important use cases of Information Preview Popup API are illustrated in Figure 1.

The use cases are as follows:

Creating popup

• Create controller for the popup
• Set content for the popup, or provide interface for asynchronous content building.
• Set properties and timeouts for the popup.

Showing popup

• Set the position for the popup.
• Request popup to be shown after specified timeout.

Hiding popup

• Request the popup to be hidden immediately.

Deleting popup

• Release the resources reserved for the popup.

API class structure

The class structure for Information Preview Popup API consists of three classes: CAknPreviewPopUpController, MAknPreviewPopUpObserver, and MAknPreviewPopUpContentProvider. The API class structure is shown in Figure 2 below.

The CAknPreviewPopUpController class provides an interface for controlling preview popups. A separate instance of this class is required for each preview popup.

The client application using preview popup, must realize the MAknPreviewPopUpObserver interface. This interface is used as a callback hook between the actual popup and the client application. The client application receives notifications through this interface when popup is shown or hidden.

The content for the preview popup can be provided either synchronously or asynchronously. When synchronous contend building is used, the client application sets the content for the popup when the popup up is constructed. Alternatively, the MAknPreviewPopUpContentProvider interface can be used for utilizing asynchronous content building for the preview popup. In this case, the client application has to provide realization for the interface, which builds the content when requested by the interface, and then notifies the popup when content has been build.