Product Information > JADE Encyclopaedia of Classes – Volume 3 > Chapter 2 - Window Classes > MultiMedia Class

MultiMedia Class

The MultiMedia control provides the ability to play sound and video files. It also allows the control of devices such as audio compact discs (CDs), image scanners, and MIDI sequencers. The MultiMedia control is a wrapper for the standard Microsoft Video for Windows MCIWnd window class.

The MultiMedia control provides options that enable the file to be played in its window with or without a playbar, title bar, and controlling popup menus. The playbar enables a user to start or stop the playback. (For details about the file types that can be handled by this control, see "MultiMedia File Types", later in this section.) The control also provides the ability to:

To control the device in a more complex fashion, the sendString method enables commands to be issued. For examples of the commands that are available in a Windows GUI environment, see the "Multimedia Command Strings" section under "Reference", in the Microsoft Developer Network product documentation.

Not all commands issued by the sendString method are valid and available for all device types; for example, changing the volume is not valid for a device that has no sound. Check the device documentation for compliance. (For details about the device types that can be accessed from the MultiMedia class, see "MultiMedia Device Types", later in this section.)

If the medium name is set at development time and involves a file, that file is copied into the database. As JADE handles only binary data that has a length less than the maximum database cache size, an attempt to store large files in the database may fail. To cover situations where the data is copied by logic, ensure that only files of a size less than half the cache size are stored.

Transparent sibling controls are always painted before a MultiMedia control, regardless of their zOrder settings. It is not possible to handle the painting of transparent controls in the correct zOrder when some controls are directly painted by JADE and others are painted by Windows separately.

The MultiMedia control provides notify events that inform JADE logic of changes of media, operating mode, and playback position. For details about using a MultiMedia control, see "Using MultiMedia Controls", in the following subsection.

For a summary of the constants, properties, methods, and events defined in the MultiMedia class, see "MultiMedia Class Constants", "MultiMedia Properties", "MultiMedia Methods", and "MultiMedia Events", later in this section.