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><H1
CLASS="SECT1"
><A
NAME="AEN995"
>Embedding applications</A
></H1
><P
>One may wish to embed an existing curses or simple text-based application
within a prettier frame-work, and/or add extra macro or session
functionality to simplify its use.</P
><P
>One such example of this is
the Crescendo application, which embeds the TinyFuge mud client
into a gnome-aware GUI application and provides some
point-and-click functionality.</P
><P
>This is very easy to do using the
ZvtTerm widget. All you have to do is instantiate the widget, and
then execute the controlled program in the appropriate
environment. The
and
functions are used for this purpose.
</P
><P
>Further information can be found in <A
HREF="zvtterm-input-output.html"
>the Section called <I
>Terminal input and output</I
></A
>
about how to interact with the subordinate application. </P
><BR
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CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1004"
>Creating an appropriate widget</A
></H2
><P
> Typically applications such
as these are designed to run in a 80x24 character-mode terminal,
you should use zvt_term_new_with_size() to create the initial
80x24 terminal.</P
><P
>You may also need to force the application window not to
be resized, if the embedded application cannot handle it.
This can be done using the normal GDK/GTK+ window hints
mechanism.</P
></DIV
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CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1008"
>Creating an appropriate execution environment</A
></H2
><P
>The function should be
used to create the child process required to execute the
program in. It works just like fork(2) with some additional
features.</P
><P
>This will setup the pseudo tty (pty) for the
subordinate program, and register the login session if required.
ZvtTerm uses a secure set-uid helper application to register
the session, so applications need not (and should not!) be run
as a privileged user to register login sessions.</P
><P
>The environment must also be setup appropriately if any
curses/nurses or similar application is to be run within the
terminal. The following environmental variables should be modified/set
as shown:</P
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="ENVAR"
>TERM</TT
></DT
><DD
><P
>Should be set to xterm, as the ZvtTerm widget
tries to emulate an xterm. vt100 or vt220 may also work if xterm
is not understood by the application.
</P
></DD
><DT
><TT
CLASS="ENVAR"
>COLORTERM</TT
></DT
><DD
><P
>Can be set to anything, including the name of the
application. Although it may be appropriate to set it
to the value "zterm". This will enable color rendering
in a modern color-capable curses, like ncurses.
</P
></DD
><DT
><TT
CLASS="ENVAR"
>COLUMNS</TT
> & <TT
CLASS="ENVAR"
>ROWS</TT
></DT
><DD
><P
>These variables should be removed from the
environment passed to the child process. However it may
be necessary to initialize it to the size of the
terminal, if it will not change. The terminal size is
always set properly on the pseudo-tty.
</P
></DD
></DL
></DIV
><P
>These should only be set in the child process (that
which received a 0 return value from zvt_term_forkpty()). The
program should then be executed using execle(2), execpe(2) or
similar. If these environment variables are not set, the
terminal will still function, but any embedded application may
not properly display.
</P
></DIV
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CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1032"
>Setting up an exit handler</A
></H2
><P
>The widget will generate a "child_died" signal when the
child process terminates. This signal should be caught if you
wish to detect when the subordinate process exits.</P
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>As a color output device</B
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>
distrib
>
Mandriva
>
2010.0
>
i586
>
media
>
contrib-release
>
by-pkgid
>
1bbf51ece72e40a5f40ad48678e7c5a5
>
files
>
724
