88 lines
1.9 KiB
Go
88 lines
1.9 KiB
Go
package part
|
|
|
|
import (
|
|
"fmt"
|
|
mqtt "github.com/eclipse/paho.mqtt.golang"
|
|
"gocv.io/x/gocv"
|
|
"log"
|
|
"time"
|
|
)
|
|
|
|
func NewPart(client mqtt.Client, frameTopic string) *FramePart {
|
|
return &FramePart{
|
|
client: client,
|
|
frameTopic: frameTopic,
|
|
window: gocv.NewWindow(frameTopic),
|
|
img: gocv.NewMat(),
|
|
}
|
|
|
|
}
|
|
|
|
type FramePart struct {
|
|
client mqtt.Client
|
|
frameTopic string
|
|
window *gocv.Window
|
|
img gocv.Mat
|
|
}
|
|
|
|
func (p *FramePart) Start() error {
|
|
if err := p.registerCallbacks(); err != nil {
|
|
return fmt.Errorf("unable to start service: %v", err)
|
|
}
|
|
for {
|
|
time.Sleep(1 * time.Hour)
|
|
}
|
|
}
|
|
|
|
func (p *FramePart) Stop() {
|
|
defer func (){
|
|
err := p.img.Close()
|
|
if err != nil {
|
|
log.Printf("unable to close resource: %v", err)
|
|
}
|
|
}()
|
|
defer p.window.Close()
|
|
StopService("frame-display", p.client, p.frameTopic)
|
|
}
|
|
|
|
func (p *FramePart) onFrame(_ mqtt.Client, message mqtt.Message) {
|
|
img, err := gocv.IMDecode(message.Payload(), gocv.IMReadUnchanged)
|
|
if err != nil {
|
|
log.Printf("unable to decode image: %v", err)
|
|
return
|
|
}
|
|
defer img.Close()
|
|
img.CopyTo(&p.img)
|
|
p.window.IMShow(p.img)
|
|
p.window.WaitKey(1)
|
|
}
|
|
|
|
func (p *FramePart) registerCallbacks() error {
|
|
err := RegisterCallback(p.client, p.frameTopic, p.onFrame)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func StopService(name string, client mqtt.Client, topics ...string) {
|
|
log.Printf("Stop %s service", name)
|
|
token := client.Unsubscribe(topics...)
|
|
token.Wait()
|
|
if token.Error() != nil {
|
|
log.Printf("unable to unsubscribe service: %v", token.Error())
|
|
}
|
|
client.Disconnect(50)
|
|
}
|
|
|
|
func RegisterCallback(client mqtt.Client, topic string, callback mqtt.MessageHandler) error {
|
|
log.Printf("Register callback on topic %v", topic)
|
|
token := client.Subscribe(topic, 0, callback)
|
|
token.Wait()
|
|
if token.Error() != nil {
|
|
return fmt.Errorf("unable to register callback on topic %s: %v", topic, token.Error())
|
|
}
|
|
return nil
|
|
}
|