Content Listing Framework API: API Description

Content Listing Framework provides information about media files - such as images and videos. For example, Content Listing Framework can read artist name, song title and album name information from music files.

The Content Listing Framework API is a normal method call interface. The interface uses local objects for Content Listing Engine and List Model that provide methods for retrieving and modifying the media content listing.

Client applications can use Content Listing Framework to list media files stored on the device. The media file listing provided by Content Listing Engine is updated into CLF List Model. The item listing can be modified in the List Model by sorting, filtering and grouping the list items. In addition, it is also possible to create customized tools for further manipulating the List Model.

Content Listing Framework API can be used in different kinds of applications that need information about media files. For example, the application could be a music player that uses CLF to create a play lists from music files or image viewer, video player or some other application that needs to work with media files.

Use Cases

The main use cases of the Content Listing Framework API are:

• Getting lists of media files
  • All files stored on the device or list of specific media type(s)
• Getting media file details
  • Metadata fields etc.
• Manipulating the media file lists by
  • Sorting
  • Filtering
  • Grouping
• Getting notifications of new or changed media files

API class structure

Content Listing Framework API contains a number of classes providing functionality of the interface. In the following class diagrams, API classes are grouped together according to their roles and functionality.

Class diagram in the Figure 1 represents the part of the interface that is used for instantiating a Content Listing Engine and a List Model. ContentListingFactory is a factory for MCLFContentListingEngine, MCLFModifiableItem and MCLFSortingStyle classes. MCLFModifiableItem is used for grouping files (see Figure 2). MCLFChangedItemObserver observes if there are new or changed files in the file system and reports changes to its Content Listing Engine by sending a changed item event. MCLFProcessObserver is used for monitoring starting and stopping of CLF server update operations. MCLFItemListModel contains a list of requested media items where one MCLFItem object represents one media item.

Class diagram in Figure 2 shows the List Model part of the interface. MCLFSortingStyle is used for sorting the List Model and MCLFPostFilter can be used for creating custom filters for filtering items from the model. MCLFCustomSorter and MCLFCustomGrouper can be used for creating customized sorting and grouping tools for the List Model.