[Xcb] Advisable in this situation to swap Xlib with Xcb?

[Christian Linhart]

Hello Dieter,

XCB will not give you any different functionality than Xlib.
XCB is just another mechanism to access the functionality 
that is provided by the XServer via the X-protocol.

If you want to emulate user-input to X-Applications you could use 
xdotool which is a commandline application for that purpose,
to be used from shellscripts.
or libxdo which is the underlying library of xdotool.

I didn't use xdotool myself but the description looks good:
    http://www.semicomplete.com/projects/xdotool/

If xdotool is not suitable, you may also look at the XTest extension.

In any case you cannot send keyboard-input to applications other than emulating
key-presses. xdotool makes this just more convenient.

There is an exception: If an application has an extra API for doing that... 
Maybe tcl/tk offers something in that direction. Since your receiving
app seems to use tcl/tk, you might want to look at the tcl/tk docs,
or ask in a tcl/tk forum.

Hope this helps,

Chris

On 09/07/14 11:40, H. Dieter Wilhelm wrote:
> Hello List,
> 
> my aim is to send script snippets (i. e. ASCII text from the Emacs
> editor) to another input window (of an interpreter application called
> ANSYS Classics in an tcl/tk window frame).  I'm a beginner of X
> programming and my naive solution is to store text in Emacs into the
> clipboard and using xlib calls to send the interpreter window the
> "ctrl+v" key-combo.
> 
> Though working in principle, it is not very practical, mainly from the
> fact, that I have to send an additional "Return" key so that the Ansys
> interpreter is finally digesting its input.  Unfortunately I couldn't
> yet solve this with one xlib program: One program has to send the
> "Ctrl+v" combination, then Emacs must wait some 150 milli seconds,
> otherwise the "Return" key is arriving before the clipboard content
> before calling my other executable for sending the "Return" key!  This
> is causing an annoying interruption and flickering, since both
> executables have to give the other window temporarily the input focus.
>                       
> 1) Do you think it would be better here to switch to XCB, would it be
> possible with XCB to receive a notification when the clipboard content
> has been pasted and thus being able to do it in one executable?
> 
> 2) Or do you know a more elegant way of sending data to an input window
> without using simulated key-presses?  Would you do it in a totally
> different way?
> 
> I'm totally stuck, googling since 2 weeks, enquired the Xlib and Emacs
> mailing lists -- in vain, could you please give me a hint?  Thanks for
> your help!