Added a generic Events struct in zntg (without ui.Context).

Refactored ui.Events to re-use zntg.Events.

events.go

@@ -0,0 +1,46 @@
+package zntg
+
+type EventFn func()
+
+type EventStateFn func(interface{})
+
+func NewEvents() *Events {
+	return &Events{events: map[uint]EventStateFn{}}
+}
+
+type Events struct {
+	nextID uint
+	events map[uint]EventStateFn
+}
+
+type EventHandler interface {
+	AddHandler(EventStateFn) uint
+	AddHandlerEmpty(EventFn) uint
+	RemoveHandler(uint)
+}
+
+func (e *Events) Notify(state interface{}) bool {
+	if e.events == nil {
+		return false
+	}
+	for _, handler := range e.events {
+		handler(state)
+	}
+	return len(e.events) > 0
+}
+
+func (e *Events) AddHandler(handler EventStateFn) uint {
+	if e.events == nil {
+		e.events = map[uint]EventStateFn{}
+	}
+	id := e.nextID
+	e.nextID++
+	e.events[id] = handler
+	return id
+}
+
+func (e *Events) AddHandlerEmpty(handler EventFn) uint {
+	return e.AddHandler(func(interface{}) { handler() })
+}
+
+func (e *Events) RemoveHandler(id uint) { delete(e.events, id) }

ui/controlbase.go

@@ -20,7 +20,7 @@ type ControlClickedEvents struct {
 }
 
 func (e *ControlClickedEvents) AddHandler(handler func(Context, ControlClickedArgs)) uint {
-	return e.Events.AddHandlerState(func(ctx Context, state interface{}) {
+	return e.Events.AddHandler(func(ctx Context, state interface{}) {
 		args := state.(ControlClickedArgs)
 		handler(ctx, args)
 	})
@@ -40,7 +40,7 @@ type DragEndedEvents struct {
 }
 
 func (e *DragEndedEvents) AddHandler(handler func(Context, DragEndedArgs)) uint {
-	return e.Events.AddHandlerState(func(ctx Context, state interface{}) {
+	return e.Events.AddHandler(func(ctx Context, state interface{}) {
 		args := state.(DragEndedArgs)
 		handler(ctx, args)
 	})
@@ -60,7 +60,7 @@ type DragMovedEvents struct {
 }
 
 func (e *DragMovedEvents) AddHandler(handler func(Context, DragMovedArgs)) uint {
-	return e.Events.AddHandlerState(func(ctx Context, state interface{}) {
+	return e.Events.AddHandler(func(ctx Context, state interface{}) {
 		args := state.(DragMovedArgs)
 		handler(ctx, args)
 	})
@@ -79,7 +79,7 @@ type DragStartedEvents struct {
 }
 
 func (e *DragStartedEvents) AddHandler(handler func(Context, DragStartedArgs)) uint {
-	return e.Events.AddHandlerState(func(ctx Context, state interface{}) {
+	return e.Events.AddHandler(func(ctx Context, state interface{}) {
 		args := state.(DragStartedArgs)
 		handler(ctx, args)
 	})

ui/events.go

@@ -1,46 +1,37 @@
 package ui
 
-type EventFn func(Context) bool
+import "opslag.de/schobers/zntg"
+
+type EventFn func(Context)
 
 type EventStateFn func(Context, interface{})
 
-func NewEvents() *Events {
-	return &Events{events: map[uint]EventStateFn{}}
+type EventArgs struct {
+	Context Context
+	State   interface{}
 }
 
 type Events struct {
-	nextID uint
-	events map[uint]EventStateFn
+	zntg.Events
 }
 
 type EventHandler interface {
-	AddHandler(EventFn) uint
-	AddHandlerState(EventStateFn) uint
+	AddHandler(EventStateFn) uint
+	AddHandlerEmpty(EventFn) uint
 	RemoveHandler(uint)
 }
 
 func (e *Events) Notify(ctx Context, state interface{}) bool {
-	if e.events == nil {
-		return false
-	}
-	for _, handler := range e.events {
-		handler(ctx, state)
-	}
-	return len(e.events) > 0
+	return e.Events.Notify(EventArgs{Context: ctx, State: state})
 }
 
-func (e *Events) AddHandler(handler EventFn) uint {
-	return e.AddHandlerState(func(ctx Context, _ interface{}) { handler(ctx) })
+func (e *Events) AddHandler(handler EventStateFn) uint {
+	return e.Events.AddHandler(func(state interface{}) {
+		args := state.(EventArgs)
+		handler(args.Context, args.State)
+	})
 }
 
-func (e *Events) AddHandlerState(handler EventStateFn) uint {
-	if e.events == nil {
-		e.events = map[uint]EventStateFn{}
-	}
-	id := e.nextID
-	e.nextID++
-	e.events[id] = handler
-	return id
+func (e *Events) AddHandlerEmpty(handler EventFn) uint {
+	return e.AddHandler(func(ctx Context, _ interface{}) { handler(ctx) })
 }
-
-func (e *Events) RemoveHandler(id uint) { delete(e.events, id) }