How to send a 'ESC' to a native program

Question

Dear,
I'm calling a native program using: Runtime.getRuntime().exec(cmd);
This command opens cmd.exe.
I use the outputstream to move to the right directory and open the desired program.
The program executes properly but when it finishes, it asks to push the escape button to continue.
How can I simulate the 'pressing of the escape button' via the outputstream?
I already tried to send the entire ascii table(1 by 1) but the program doesn't terminate.
Also tried the Robot class without success.
Does someone knows how to handle this?
Kind regards,
Steven

Answer 1

My life needs a "rewind/erase" button...
camickr wrote:
Either way, I'm afraid the Robot class does simulate events only in the current JVM. No, the Robot generates OS level events (is that the correct terminology), so the events are displatched to the application that has focusSorry, I made an unbacked assumption.
OK so the problem may be to give the focus to the correct application.
Here you have me a little confused (...) process.getInputStream() returns an InputStream, from the point of view of the launched native pogram, it's an OutputStream. The java program receives information via process.getInputStream().Yes, sorry, sorry, and sorry again. I wrote off memory without bothering a glance to the API, and I was absolutely wrong!
I remember thinking "Remember that there's a trap in the naming of the methods..." :o)
I'll try to remember as well "...and it is not what you thought!" :op
The program that I'm calling does not have a GUI and it expects the pressing of the ESC-button on the keyboard.
The program does not respond to the keyboard if the window is not active.That probably means the program does not read 'ESC' on its stdin, but merely listens for a "graphical" event indicating "key ESC pressed".
In this case, as per camickr correction, Robot might generate this native event, but the app (or its launching window) will not receive it if it doesn't have the focus.
One not-so-nice way could be to display the app window or terminal (using xterm -e /path/to/real/app on Unices, start \path\to\real\app on Windows, with various options to handle titles and pathes), and the user would have to click on this window and then type the 'ESC' key.
A few words on the drawback:
- how to automate giving the focus to the app terminal, so that the user doesn't have to click on it?
Of course it depends on your application: is it general purpose app running on general purpose desktops, or worse portable across different OS? Then you're most probably stuck.
I"ve had to work on constrained environments where our app were almost the only one to run, and managed the whole screen. When launching an external app from the main Java launcher, for some dedicated task, the main Java app would simply hide or iconify itself, and the forked app was the only active one.
- how to automate typing the ESC key?
See camickr reply about Robot being able to send a native event to the current focused app.
- how to control (more or less) how the app terminal displays?
Give up any hope of portability. But there are system-specific ways to fix a terminal's look (in the sense of "windowing-system-specific", two window managers on Linux will support different options).
- how to pipe the launched app output to the Java window?
First, that may not be necessary once you and the user have accepted that the native console will indeed show up. If you still want the app output, for display of to parse it from the Java launcher, then again look around system-specific options. e.g.:
{code}xterm -l -lc <filename> -e /path/to/app{code}
Edited by: jduprez on Jul 8, 2009 9:08 AM - fixed typo