From ef93665838bd8fee51606ebcd95c84a82a3a1520 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@spreadspace.org>
Date: Mon, 11 Feb 2019 20:41:12 +0100
Subject: subscribing to controller events works now

---
 pkg/controller/controller.go | 62 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 57 insertions(+), 5 deletions(-)

(limited to 'pkg/controller')

diff --git a/pkg/controller/controller.go b/pkg/controller/controller.go
index ab04fcc..01e36cd 100644
--- a/pkg/controller/controller.go
+++ b/pkg/controller/controller.go
@@ -23,9 +23,10 @@
 package controller
 
 import (
+	"container/list"
 	"errors"
 	"fmt"
-	"log"
+	//	"log"
 	"strings"
 
 	"github.com/scgolang/midi"
@@ -47,8 +48,32 @@ const (
 	LED_BLINK_MAX   = byte(0x7f)
 )
 
+type EventType int
+
+const (
+	ButtonPressed EventType = iota
+	ButtonReleased
+)
+
+func (e EventType) String() string {
+	switch e {
+	case ButtonPressed:
+		return "button pressed"
+	case ButtonReleased:
+		return "button released"
+	default:
+		return "unknown"
+	}
+}
+
+type Event struct {
+	Button byte
+	Type   EventType
+}
+
 type Controller struct {
-	Dev *midi.Device
+	Dev         *midi.Device
+	subscribers list.List
 }
 
 func openDevice(devices []*midi.Device, prefix string) (d *midi.Device, err error) {
@@ -78,17 +103,39 @@ func NewController(c Config) (*Controller, error) {
 	return ctrl, nil
 }
 
+func (c *Controller) sendEvent(ev Event) {
+	var next *list.Element
+	for sub := c.subscribers.Front(); sub != nil; sub = next {
+		next = sub.Next()
+
+		ch, ok := (sub.Value).(chan<- Event)
+		if !ok {
+			panic(fmt.Sprintf("controller: subscriber list element value has wrong type: %T", sub.Value))
+		}
+
+		select {
+		case ch <- ev:
+		default:
+			// subscriber is not respoding...
+			// log.Printf("controller: removing subscriber '%v', because it is not responding", ch)
+			close(ch)
+			c.subscribers.Remove(sub)
+		}
+	}
+}
+
 func (c *Controller) handleMidiPacket(p midi.Packet) {
-	num := p.Data[1]
+	ev := Event{Button: p.Data[1]}
 	switch p.Data[0] {
 	case BUTTON_ON:
-		log.Printf("controller: button %d pressed", num)
+		ev.Type = ButtonPressed
 	case BUTTON_OFF:
-		log.Printf("controller: button %d released", num)
+		ev.Type = ButtonReleased
 	default:
 		// ignore all other events
 		return
 	}
+	c.sendEvent(ev)
 }
 
 func (c *Controller) Init() error {
@@ -149,3 +196,8 @@ func (c *Controller) LedBlink(num, wait byte) error {
 	}
 	return c.setLed(num, wait+LED_BLINK_MIN)
 }
+
+func (c *Controller) Subscribe(out chan<- Event) {
+	// log.Printf("controller: subscribing '%v' to events", out)
+	c.subscribers.PushBack(out)
+}
-- 
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