AT&T UNIX™PC Unix System V Users Manual - tenox

TAM (3T) (AT&T UNIX PC only ) TAM(3T)
window as large as the screen and every time it receives the
SIGWIND signal it resets its window to the top and as large as
the screen, the user is effectively blocked from running any other
applications.
The major difference between the remote and UNIX PC terminals
from the application point of view is the lack of kernel level window
support for remote terminals. TAM supports windows transparently
within a given process, but knows nothing about windows
created by other processes. Remote terminals can display
multiple windows but, unlike the UNIX PC terminal, only one
application owne the screen at a time. TAM simulates the kernel
window functions for a particular application by maintaining a
screen image, as well as those portions of windows that are overlayed.
Each process controls the entire screen, and windows
created by other processes are erased when the new process issues
a winit() call.
TAM uses the insert and delete line functions on remote terminals
for scrolling whenever the window is as wide as the screen. This
applies to windows with or without borders. Application programmers
who are concerned with making their programs run
efficiently on remote terminals should use windows of full screen
width if planning on scrolling the window.
If an application creates a child process that writes to the screen,
then after the child process dies, the application must issue a special
wrefresh{} call to restore its screen image. For remote terminals,
TAM provides window ID's, instead of file descriptors, for
accessing windows. Other differences from the bit-mapped terminal
are that the tty modes cannot be independently set and child
processes do not inherit windows.
TAM supports an optional mouse input device. Initially, mouse
reports are disabled, so applications that don't use the mouse
don't need to worry about it. When mouse reports are turned on
by the application, they are returned to the application as a special
8-bit input code (or 7-bit input escape sequence) in the input
stream.
In the default enabled state, a mouse report is inserted in the
input stream on each change of the button state (whether each of
the three buttons is up or down). Thus, these reports are buffered
and are in sequence with any keyboard input.
The mouse report contains the mouse button state and the mouse
cursor coordinates. This mouse report can be read and parsed by
the application, or the application can use the wgetmouse() call,
which reads the information from the input stream and returns it
in a structure.
After being enabled, the mouse reports initially return only
changes in mouse buttons. Optionally, mouse reports can tell if
the mouse cursor goes outside (or inside) a specified rectangle. In
the case of the remote terminal, mouse reports are never received,
and the mouse related subroutine calls are ignored.
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