| 摘要 |
A video framework for use in a data processing system provides parallel hierarchies of video device drivers and video device handles, which are created by video device driver objects, and a hierarchy of data encapsulators contained by a subclass of the hierarchy of video device handles to encapsulate configuration information describing the functionality of a display connected to a data processing system. Applications access video device drivers through ones of the video device handles at respective levels of the video device handle hierarchy. When a change of configuration is made or requested in for the data processing system or any display connected thereto, corresponding video display handles issue a signal to lock down drawing tasks before video handles are created or altered to carry out the display devices without loss of information displayed to a user and maintains a default functionality of displays connected to the data processing system.
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