Gtk read current keyboard state - keyboard

Is there a function similar to glfwGetKey in GTK-3? That is, given a scancode, is it possible to retrieve its state outside a keyboard event handler (which literally tells you what has changed).

I don't believe there is. This sounds like something that would be more likely to be part of a game programming toolkit or something similar.

Related

How does the Ctrl + Z keyboard shortcut actually work in general?

I mean, its not about some code or something, but how does that shortcut work in general, like when I am working on a something and accidentally, I delete a chunk of text, how does the shortcut, revert it back on to the screen, don't give me the code or something, but take instances of elements in the coding world like whiles, ifs etc. How did the creator get the idea that something like this should even exist?
There are multiple ways this can be achieved, the decision how, is up to the developer to decide.
One way is to make use of a stack, where the where the state of this program is stored in such a structure.
Another way is use a design pattern called the command pattern which is often used to implement undo redo functionality, this is very similar to a stack, but instead of storing the program state, you save the action done to the program together with a similar action to undo the executed one.

How to run a function when a key is pressed?

I've been searching on how to do it without pygame, but I haven't found a way.
Basically all I want to do is to press a key and play a sound, but I do not know how to register keystrokes in python.
edit: Forgot to mention, for Windows.
It (getting keypresses and playing sounds) is probably operating system specific, and you might want to use some widget toolkit (interfaced to Python). So consider using one of PyGTK, PyQt, PySDL2 or some other suitable toolkit. I guess that for a game, PySDL2 should be the most suitable.
You might focus on the WinAPI only and follow this.

Computer keyboard into piano keyboard with AutoHotkey

I want to be able to use my computer keyboard as a piano keyboard, however the default version of AutoHotkey only supports one "voice" at a time. I tried running an instance for each note, but that doesn't fix it if I press the same note repeatedly.
I found this thread on how this might be solved with the BASS library, but I'm pretty green when it comes to coding and so I'm not certain how to incorporate the library into my simple code.
Here's another similar forum that might solve things, but it has a delay and the overlapping solution doesn't really solve my issue.
This is such a simple idea (play sound when a button is pressed), but somehow it's way out of my depth. Currently my code looks like this:
~1::
SoundPlay, C:\Users\Fires\Downloads\2489__jobro__piano-ff\39187__jobro__piano-ff-040.wav
for each note
Edit:
~a::
FileDelete, %A_ScriptDIR%\Sound1.AHK
FileAppend,
(
SoundPlay, C:\Users\Fires\Desktop\New folder (4)\043.wav, Wait
), %A_ScriptDir%\Sound1.AHK
Run, %A_ScriptDIR%\Sound1.AHK
Return
is what I am using now, but it's still iffy when two are pressed at the same time.
Its likely due to the "Wait". according to the documentation:
https://autohotkey.com/docs/commands/SoundPlay.htm
"If a file is playing and the current script plays a second file, the first file will be stopped so that the second one can play. On some systems, certain file types might stop playing even when an entirely separate script plays a new file."
It looks like this is an "issue" with AutoHotKey. And its not possible to open multiple "voices" or simultaneous sounds. it is completely possible to make a C# program that does the same thing, I've done it before. and i have bits of the code now still (it plays midi sounds, instead of wavs, but same concept play notes asynchronously).

References for keyboard input parsing algorithm?

I am working on software for an embedded system where I need to parse the values of a USB device which is recognized by the Linux OS as a keyboard. The issue is that I need to convert the various keyboard events to actual text.
To me this seems like a fairly common task that should exist out there somewhere. Is there any projects or references that explain a good algorithm for implementing this? Stuff like when modifier keys are pressed, what the values become and stuff like that.
If it matters I am using Golang but implementations or references in other languages would be fine too.
I think this tool can solve your problem: termbox

How do I tell if a button is being held down in OpenGL/Glut? (linux)

This is a similar problem: Link
Which was solved by calling GetAsyncKeyState(). While all fine and dandy, I need a Linux alternative. I need to know if a button is being held down, not just being pressed (because of the keyboard buffer delay). Does anything like this exist in the OpenGL/Glut libraries, or will I have to look elsewhere?
I have never used Glut, but I know that many people will say SDL is better. I have used SDL and I like it a lot. It does everything Glut does and a lot more. In SDL, you can use SDL_PollEvent() to get key state without the keyboard buffer delay.
Edit: I know almost nothing about Glut, but it looks like you can use glutKeyboardFunc to detect normal keys, and glutSpecialFunc for keys that do not generate ASCII characters (such as shift). I'm not sure if there is a better way, as this doesn't seem very nice.
You can detect when a keypress event occurs, record that state, and then listen for a key release event.
As said, you will have to make your own state machine, which is easy. But you also need to use this callback method I think.
http://pyopengl.sourceforge.net/documentation/manual/glutKeyboardUpFunc.3GLUT.xml

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