Initializing
and Terminating the Callback Context
Before the
default queue callback routine can be used, either by specifying it as the
callback routine when committing a file queue, or by calling it from a custom
callback routine, it must be initialized.
The SetupInitDefaultQueueCallback function builds the context
structure that is used by the default queue callback routine. It returns a void
pointer to that structure. This structure is essential for the default callback
routine s operation and must be passed to the callback
routine. You do can this either by specifying the void pointer as the context
in a call to SetupCommitFileQueue, or by specifying the void pointer as the
context parameter when calling SetupDefaultQueueCallback from a custom callback
routine. This context structure must not be altered or referenced by the setup
application.
The SetupInitDefaultQueueCallbackEx function also initializes a
context for the default queue callback routine, but it specifies a second
window to receive a caller-specified progress message each time the queue sends
a notification. This enables you to use the default disk prompting and error
dialog boxes, and to also embed a progress bar in a second window, for example,
in a page of an installation wizard.
Regardless of
whether you initialized the context used by the default queue callback routine
with SetupInitDefaultQueueCallback or SetupInitDefaultQueueCallbackEx,
after the queued operations have finished processing, call SetupTermDefaultQueueCallback
to release the resources allocated in initializing the context structure.