gowinkey

Contents

• gowinkey
  • Contents
  • Installation
  • If you prefer using Java...
  • Getting started
  • Predicates
    • Example

Installation

To use gowinkey, you need to have Go installed and set up.

Now, you can get gowinkey by running

$ go get -u github.com/daspoet/gowinkey

and import it in your code:

import "github.com/daspoet/gowinkey"

If you prefer using Java...

... be sure to check out the Java version of this package.

Getting started

To start listening to key events, simply run gowinkey.Listen(). It returns a channel on which all key events will be sent, and a function that you can call whenever you want gowinkey to stop listening to events.

Note that calling this function will also close the channel.

Consider the following example:

package main

import (
	"fmt"
	"github.com/daspoet/gowinkey"
	"time"
)

func main() {
	events, stopFn := gowinkey.Listen()

	time.AfterFunc(time.Minute, func() {
		stopFn()
	})

	for e := range events {
		switch e.State {
		case gowinkey.KeyDown:
			fmt.Println("pressed", e)
		case gowinkey.KeyUp:
			fmt.Println("released", e)
		}
	}
}

Predicates

To help customise the way that Listen works, gowinkey uses Predicates. You can either supply your own, or use those that have already been created for you. You can find a collection of predefined predicates here.

Example

Suppose we don't want to get bombarded with key events. For instance, we could only be interested in events for the keys W, A, S and D, because we want to write some basic movement for a game, or something.

We can now alter the code from above just slightly by passing the predefined predicate Selective to Listen. Notice that Selective takes the keys we want to listen for and returns an appropriate predicate that will handle all the work for us.

Consider the following code snippet:

package main

import (
	"fmt"
	"github.com/daspoet/gowinkey"
	"time"
)

func main() {
	keys := []gowinkey.VirtualKey{
		gowinkey.VK_W,
		gowinkey.VK_A,
		gowinkey.VK_S,
		gowinkey.VK_D,
	}
	events, stopFn := gowinkey.Listen(gowinkey.Selective(keys...))

	time.AfterFunc(time.Minute, func() {
		stopFn()
	})

	for e := range events {
		switch e.State {
		case gowinkey.KeyDown:
			fmt.Println("pressed", e)
		case gowinkey.KeyUp:
			fmt.Println("released", e)
		}
	}
}