Syntax
'CONTEXT'(num)
Description
The 'CONTEXT' mnemonic sets the current context ID to num.
Each graphical window created with the SYSGUI device must have its own
context. With a device context, SYSGUI can be used to communicate with
multiple windows simultaneously. The SYSGUI device maintains a current
context and is used to specify which window is being referenced.
While some operations require that a context be specified as a parameter,
most operate on the current context.
The context ID is an integer from 0 to 32767. When SYSGUI is first opened,
the current context ID is 0, (empty, or no window in this context). All
contexts are initially empty and context 0 is selected as current. The
CTRL() and FIN() functions can be used to report the current context,
the number of an unused context, and the number of active contexts.
If only one graphical window is created at a time, the context does not
need to be set. However, to create multiple windows and manipulate them
simultaneously, contexts must be switched. Set the current context by
issuing 'CONTEXT'(num) to the
SYSGUI channel.
|
Parameter |
Description |
|
num |
Context ID number. It must be an integer between 0 and 32767. |