Using Rendering Mechanisms

The rendering mechanism is essentially a protocol that determines the contents of several fields in the DRAGITEM structure. These fields are:

  • ulItemID, which contains an application-specific value uniquely identifying the item being dragged.

  • hstrType, which contains a handle to a string defining the data type of the dragitem.

  • hstrRMF, which contains a handle to a string containing the names of all rendering mechanisms supported by the dragitem, and the data formats supported by those rendering mechanisms.

  • hstrContainerName, hstrSourceName and hstrTargetName, which contain handles to strings used by the DRM_OS2FILE rendering mechanism, and may be used by private rendering mechanisms to contain string data.

    The content of the hstrRMF field should obey a set of syntactical rules that are explained in the OS/2 2.0 Programming Guide Volume II. Other fields in the DRAGITEM structure may also be used by particular rendering mechanisms; their use is dependent upon the individual rendering mechanism in use at the time. Applications may use one of the standard rendering mechanisms DRM_PRINT, DRM_DISCARD, DRM_OS2FILE or DRM_DDE, or may define their own rendering mechanisms to support dragging and dropping of particular dragitems.


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