Help Me Grow the Go userbase

toddmcleod · December 22, 2015, 9:03pm

Hello Everyone,

Lynda.com has hired me to do the “code clinic” using Go.

I’ve nailed 4 of the 5 challenges, but this one is stumping me.

Do you have any ideas on how to capture mouse X,Y position?

The lynda.com “code clinic” includes a challenge to have your mouse control sound, and I’d like to figure out how best to do it, eg, easiest, most explainable, most appealing, showcases Go.

Here are the specs of the challenge:
– mouse click means on
– up/down = increase / decrease volume
– left/right = decrease / increase pitch

Thank you for your help brainstorming on this!

elithrar · December 23, 2015, 5:30am

This will be entirely driven by the OS you need to do it on, and you’ll need to do it using the OS API. Which OS is this for?

If anything this is also not a ‘great’ fit for Go—talking with the (e.g.) Win32 API isn’t a great example of Go as a language.

toddmcleod · December 23, 2015, 8:01am

Hi Matt,

Yes, I was thinking the OS package, also.

I was wondering if there was some way to switch the Stdin to the mouse instead of the keyboard.

I will be creating this for
Mac OS X
10.10.5

Thank you for any suggestions you can provide!

Ganners · December 28, 2015, 1:15pm

Probably the most straightforward answer is to leverage work that has been done in C. Look at SDL2 and therefore the go bindings https://github.com/veandco/go-sdl2. It looks like there exist examples for everything you need to do.

toddmcleod · December 29, 2015, 2:29am

Thank you. I’m looking into this!

toddmcleod · December 29, 2015, 4:56am

Thank you, Mark. I just ran some of the examples and captured mouse X,Y in an open window, and another one which produced sound.

I wish there was some way to do this natively in Go without binding to C.

I want to showcase Go, not some binding.

Any other thoughts?

I was thinking about https://godoc.org/syscall#pkg-constants which has a lot of constants which I don’t understand. I saw a cool program using that in Ivo Balbaert’s book:

github.com

GoesToEleven/thewaytogo/blob/master/code_examples/chapter_9/reboot.go

// reboot.go
// compile errors (Windows):
//undefined: syscall.SYS_REBOOT
// reboot.go:13: not enough arguments in call to syscall.Syscall
// Linux: compileert, uitvoeren met sudo ./6.out --> systeem herstart
package main

import (
	"syscall"
)

const LINUX_REBOOT_MAGIC1 uintptr = 0xfee1dead
const LINUX_REBOOT_MAGIC2 uintptr = 672274793
const LINUX_REBOOT_CMD_RESTART uintptr = 0x1234567

func main() {
	syscall.Syscall(syscall.SYS_REBOOT,
		LINUX_REBOOT_MAGIC1,
		LINUX_REBOOT_MAGIC2,
		LINUX_REBOOT_CMD_RESTART)

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elithrar · December 29, 2015, 5:11am

https://github.com/nsf/termbox-go will allow you to write a terminal application in Go that can use the mouse (no sound though).

If you want to create a GUI application you will definitely need to use some kind of C-bindings because there doesn’t exist (to my knowledge) a bridge between Go and OS X’s windowing server.

Creating a GUI app isn’t one of Go’s strong points right now, and GUI bindings in most languages are a bit of work to get going.

system · March 28, 2016, 5:11am

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