I've started working on a little project in Lua that involves making a text-based interface that updates constantly, and allows keyboard input for interaction.
I need a way to get keyboard input, but I also need it to either not block, or have some kind of timeout (which can be set to a fraction of a second, preferably). I've done research myself, but I found nothing that worked for me.
I need something that works with Lua 5.1.5 and Linux. Windows compatibility would be nice, but is not a requirement as I'm also doing things that require an ANSI terminal.
As stated in the comments of my post by hyde, I can use a Lua wrapper for ncurses to get input. In addition to this, I can use its features for some other parts of my code that I was going to program myself anyways.
I'm doing this in Lua 5.1 with Luasocket and opening two separate Lua processes. I have two Lua console windows- "INPUT WINDOW" AND "OUTPUT WINDOW". INPUT WINDOW sends keypresses over localhost. OUTPUT WINDOW reads the localhost socket I'm using for this. It's non-blocking; you can set a very quick timeout on the udp receive. It's ugly, but it's the most vanilla solution I've found. That said, input data from INPUT window doesn't appear on the OUTPUT window (unless I want it to), which can be nice for a console-based UI.
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Motivation: I'm trying to write scripts which send keystrokes to the currently focused window. Right now I use xdotool, which lets me send raw keystrokes. However, I want the exact keystrokes to be a function of the current text around the input caret in the focused window.
Problem: Is there a generic way of reading the state of the text input caret -- both its current position as well as the text around it? Intuitively, I want the content of the current "text box" as well as the location of the cursor within that text box. Perhaps this is not possible in the general case, but is there a way of doing it which would work for emacs and firefox? I'm running Ubuntu Linux
Further motivation: due to a bad case of RSI I control my computer by voice rather than typing. This works by setting up voice-activated scripts that are triggered by saying different phrases. When dictating English prose, it would be helpful to automatically capitalize words at the beginning of sentences. This automatic capitalization can be accomplished by reading the characters immediately before the input caret, checking if they contain a period, and if so, capitalizing the start of the next phrase that I dictate by voice.
Thanks so much! If anybody can help me here, it would greatly increase my day-to-day accessibility.
Since there is no standard widget toolkit for X11, but only a buch of independently developed arbitrary toolkits, there is no generic way to implement this.
As far as X11 and tools operating on its level (like xdotool) is concerned, there's only windows of either the InputOutput variety (i.e. visible windows, that receive events and one can draw to) or the just Input which are invisible and only receive events. There are no further refined "widgets" so to speak. You get a pixel grid, which you can draw to.
Accessibility interfaces are the burden of the toolkits (or if you don't use a toolkit – then you're a badass – you, the developer), to implement: https://www.freedesktop.org/wiki/Accessibility/
The absolute generic way would be to take a screenshot of the currently focused window, employ a computer vision / machine learning based solution to identify the caret, then OCR the line of text around it. And to be honest, IMHO doing it that way would probably be a lot more reliable than hoping for the accessibility interfaces to be properly implemented.
I'm trying to send keystrokes of regular keyboard input from 'a-z' which may or may not include the directional arrow keys to a running game process, however i'm confused at the pywinauto documentation:
I've already connected the existing process via pid by:
from pywinauto.application import Application
from pywinauto.keyboard import SendKeys
app = Application().connect(process=1234)
#app.SendKeys('a')? Doesn't seem to work
I've read some other answers on this but it's not very clear as to what the next step is on the documentation, there aren't any real examples.
I've also read from some other answers that SendKeys auto focuses the windows, which isn't want I want, if possible would it be possible to send keystrokes to the process silently?
There are few moments. If the game process has its own window with native handle, you may try the following:
app.window(title="Window title").send_keystrokes("something")
app.window(title="Window title").send_chars("something")
It should work even for minimized window. The difference may appear for special symbols which may not work for some of these methods or even for both. But arrows should probably work with send_keystrokes.
If it's DirectX game, sending keys might be more complicated task. A while ago I found some references about potential implementation of this: https://github.com/pywinauto/pywinauto/issues/469 Though I had no chance to try it yet.
I am trying to write a C program that uses Linux system calls to emulate the behaviour of the more command in the Linux terminal. Since the users might enter commands such as q to finish the execution, I am trying to find a way in which to read keystrokes from the standard inout without using read(...), as I don't want the pressed key to appear on the standard output.
In other words, I want to be able to detect pressed keys without them being written.
I have read that ioctl() and the termios struct can somehow be used for this purpose, but I am not sure how they are used (I find the man pages somewhat cryptic).
I have found a few answers to the use of those functions, but all of them seem too complicated. There must be an easier way to detect simple keystrokes, isn't there?
man 3 termios, tcsetattr, disable ECHO on stdin.
For a longer explanation see: Hide password input on terminal
Alternatively, you could go through below termios abstraction, use input layer, /dev/input/*, but I think you'll need to disable forwarding events from your input devices to upper layers then.
I'm a beginning programmer and i need a way to get python to recognize a keyboard event. So far i can only find these methods in vPython or tkinter, and i want to simply use the normal python shell. if anyone can help me with a module name/where i could download a module for free that would be very helpful. or simply the code if there is no need for a module.Thanks
There is no generic "keyboard event", they all depend on what your environment is.
In a terminal there are no keyboard events at all, you simply get sent text on stdin. In Windows you need to use the Win32, on Unix you need to use the X11 API and on Mac you have to use whatever OS X uses is it Cocoa?). wxPython and tkinter all work on all these platforms to provide an API that works on all of them. And the same goes for other GUI toolkits of the same sort like KDE and GTK. So you should use one of those. Which one is a matter of taste, but since tkinter is included in Python, that seems the obvious choice.
You can call the respective API's for the respective platforms directly, but it's generally not worth the trouble.
I am working on a project where I need to run Google chromium over Linux FrameBuffer, I need to run it without any windowing system dependency ( It should draw on the buffer we provide it to draw, this will make its porting to any embedded system very easy) , I do not need its multi-tab GUI, I just need its renderer window in the buffer, has any body ever tried this? Any help on what approach should I use for this?
If you need to have some direct control of the window functions, or want to poke around in the DOM data, then the right way to solve this problem is to probably look at embedding webkit directly. This will be much faster and cleaner than what I am about to suggest.
Now, let's suppose you don't need all that fancy control and that you are really lazy. An ancient, low tech solution to your problem could be to create a virtual frame buffer and then read its contents directly. To do this, you can set up xvfb on your server:
http://www.x.org/releases/X11R7.6/doc/man/man1/Xvfb.1.xhtml
xvfb is an old unix tool that lets you create a virtual x-server with whatever type of configuration you want. More importantly, it can be configured to write the contents of its X server's screen directly to a memory mapped file! You can also set it up to use shared memory, which is a bit faster though also more complicated.
I guess you will have better luck with uzbl and GTK/DirectFB. Same engine, and works with javascripts. For the facebook chat issue, I think you just have to change the user-agent string.
There is the Origyn Web Browser, which is supposed to be an embedded WebKit-based browser that looks portable and does not depend on "heavy" libraries (like GTK). Their web page is http://www.sand-labs.org/owb but it looks like their database crashed, which is a little worrying maybe.
try to port webkit engine to the netsurf framebuffer-based code.
HTH
You could buy one of the remaining 10 (or so) OGD1 boards.
http://en.wikipedia.org/wiki/Open_Graphics_Project
Then you can talk directly to hardware using libpci.
However you will still need code that draws a picture into a memory buffer.
I realize this answer is more a shameless plug.
But people who are interested in your question might want such a board.
I already have a board like this and it would help a lot if it got more exposure.
This project:
http://code.google.com/p/wkhtmltopdf/
Achieves that. It runs Webkit on a virtual display and captures the rendered output in form of PDF. You can customize that do do something else.
OR you can create a display with tigthvnc, and set DISPLAY variable so that Chrome renders in that display.
I suggest using the webkit2pdf package (which is available for many different Linux distributions). Then use fbgs which is a wrapper for the fbi frame buffer program, that displays PDF files right on the frame buffer.