hdmi-joystick.go

package main

//To avoid opening a console at application startup, use these compile flags:
//go build -ldflags -H=windowsgui

import (
	"github.com/0xcafed00d/joystick"
	"github.com/getlantern/systray"
	"github.com/getlantern/systray/example/icon"
	"log"
	"os"
	"os/exec"
	"strconv"
	"strings"
	"time"
)

//from winddcutil.exe capaboilities 0:  60( 11 12 0F)

var displayList = [...]int64{0xf, 0x11, 0x12}

func switchToDisplay(display int64) {
	//convert display to hex string
	displayHex := strconv.FormatInt(display, 16)
	cmd := exec.Command("c:\\apps\\winddcutil\\winddcutil.exe", "setvcp", "0", "60", displayHex)
	cmd.Run()
}

func getCurrentDisplay() int64 {
	cmd := exec.Command("c:\\apps\\winddcutil\\winddcutil.exe", "getvcp", "0", "60")
	out, _ := cmd.Output()
	//fmt.Printf("getvcp output: %s\n", out)
	//err is always not nill, we just ignore it
	//format is VCP <ID> <output>
	//split the output to get the last part
	split := strings.Split(string(out), " ")

	//convert the last part to an int (from hex)
	last := split[len(split)-1]
	//remove the newline
	last = strings.TrimSuffix(last, "\r\n")
	display, _ := strconv.ParseInt(last, 16, 32)
	return display
}

func handleButtonEvent(button int, pressed bool) {
	if pressed {
		log.Printf("Button %d pressed", button)
	} else {
		log.Printf("Button %d released", button)
		//fmt.Printf("get current display")
		currentDisplay := getCurrentDisplay()
		//fmt.Printf("current display is %d", currentDisplay)

		currentDisplayIndex := 0
		for i, display := range displayList {
			if display == currentDisplay {
				currentDisplayIndex = i
			}
		}
		if button%2 == 1 {
			currentDisplayIndex = (currentDisplayIndex + 1) % len(displayList)
		} else {
			currentDisplayIndex = (currentDisplayIndex - 1 + len(displayList)) % len(displayList)
		}
		switchToDisplay(displayList[currentDisplayIndex])

	}
}

func handleJoyStick() {
	log.Println("Opening joystick")
	jsid := 0
	js, err := joystick.Open(jsid)
	if err != nil {
		panic(err)
	}

	log.Printf("Joystick Name: %s", js.Name())
	log.Printf("   Axis Count: %d", js.AxisCount())
	log.Printf(" Button Count: %d", js.ButtonCount())

	buttons_state := make([]bool, js.ButtonCount())
	buttons_tmp := make([]bool, js.ButtonCount())

	state, err := js.Read()
	if err != nil {
		panic(err)
	}

	log.Printf("Axis Data: %v", state.AxisData)

	ticker := time.NewTicker(time.Millisecond * 40)
	for doQuit := false; !doQuit; {
		<-ticker.C
		state, err := js.Read()
		if err != nil {
			panic(err)
		}

		//fmt.Printf("Axis Data: %v", state.AxisData)
		copy(buttons_tmp, buttons_state)
		for button := 0; button < js.ButtonCount(); button++ {
			if state.Buttons&(1<<uint32(button)) != 0 {
				//fmt.Printf("Button %d pressed", button)
				buttons_state[button] = true
			} else {
				buttons_state[button] = false
			}
		}
		for button := 0; button < js.ButtonCount(); button++ {
			if buttons_state[button] != buttons_tmp[button] {
				handleButtonEvent(button, buttons_state[button])
			}
		}

	}
	js.Close()
}

func main() {
	f, err := os.OpenFile("c:\\apps\\winddcutil\\joystick.txt", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
	if err != nil {
		log.Fatalf("error opening file: %v", err)
	}
	defer f.Close()

	log.SetOutput(f)
	log.Println("This is a test log entry")
	systray.Run(onReady, onExit)

}

func onReady() {
	go handleJoyStick()
	log.Println("on Ready")
	systray.SetIcon(icon.Data)
	systray.SetTitle("Joystick display switcher")
	systray.SetTooltip("Switch display using joystick")
	mQuit := systray.AddMenuItem("Quit", "Quit the whole app")

	// Sets the icon of a menu item. Only available on Mac and Windows.
	mQuit.SetIcon(icon.Data)
	go func() {
		for {
			select {
			case <-mQuit.ClickedCh:
				systray.Quit()
			}
		}
	}()

}

func onExit() {
	// clean up here
}