Initial commit

implemented the game of life variation with hexagonal grid

ui/event_bus.go

@@ -0,0 +1,58 @@
+package ui
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/nmoniz/gubgub"
+)
+
+var eventBusGetter = sync.OnceValue(func() *eventBus {
+	return NewSyncEventBus()
+})
+
+func EventBus() *eventBus {
+	return eventBusGetter()
+}
+
+type Event interface {
+	Name() string
+	Data() any
+}
+
+type eventBus struct {
+	topics map[string]gubgub.Topic[Event]
+}
+
+func NewSyncEventBus() *eventBus {
+	return &eventBus{
+		topics: make(map[string]gubgub.Topic[Event]),
+	}
+}
+
+func (eb *eventBus) Emit(e Event) error {
+	topic, ok := eb.topics[e.Name()]
+	if !ok {
+		return nil
+	}
+	err := topic.Publish(e)
+	if err != nil {
+		return fmt.Errorf("emit event: %w", err)
+	}
+	return nil
+}
+
+func (eb *eventBus) Listen(name string, handler func(Event)) error {
+	topic, ok := eb.topics[name]
+	if !ok {
+		topic = gubgub.NewSyncTopic[Event]()
+		eb.topics[name] = topic
+	}
+
+	err := topic.Subscribe(gubgub.Forever(handler))
+	if err != nil {
+		return fmt.Errorf("listen for event: %w", err)
+	}
+
+	return nil
+}