refactor: move ui code from game/state/handlers/menu.go to its own package in game/ui

game/state/handlers/menu.go

@@ -2,59 +2,39 @@ package handlers
 
 import (
 	"tetris/assets"
-	"tetris/engine/audio"
 	"tetris/engine/render"
 	"tetris/game"
 	"tetris/game/state"
+	"tetris/game/ui"
 
 	rl "github.com/gen2brain/raylib-go/raylib"
 )
 
-type entry struct {
-	label string
-	state string
+type MainMenu struct {
+	menu ui.Menu
 }
 
-type Menu struct {
-	selected int
-	entries  []entry
-}
-
-func NewMenu() *Menu {
-	return &Menu{
-		selected: 0,
-		entries: []entry{
-			{"Start", "gameplay"},
-			{"Quit", "quit"},
-		},
+func NewMainMenu(fsm state.Transitioner) *MainMenu {
+	return &MainMenu{
+		menu: ui.NewMenu([]ui.Widget{
+			ui.NewButton("Start", func() { fsm.Switch("gameplay") }),
+			ui.NewButton("Quit", func() { fsm.Switch("quit") }),
+		}),
 	}
 }
 
-func (menu *Menu) Enter() {
-	menu.selected = 0
+func (main *MainMenu) Enter() {
+	main.menu.Select(0)
 }
 
-func (Menu) Exit() {
+func (MainMenu) Exit() {
 }
 
-func (menu *Menu) Update(fsm state.Transitioner, delta float32) {
-	if rl.IsKeyPressed(rl.KeyEnter) {
-		fsm.Switch(menu.entries[menu.selected].state)
-		audio.Play(assets.SFX_MENU_ENTER)
-	} else if rl.IsKeyPressed(rl.KeyDown) {
-		if menu.selected+1 < len(menu.entries) {
-			menu.selected = menu.selected + 1
-			audio.Play(assets.SFX_MENU_SELECT)
-		}
-	} else if rl.IsKeyPressed(rl.KeyUp) {
-		if menu.selected-1 >= 0 {
-			menu.selected = menu.selected - 1
-			audio.Play(assets.SFX_MENU_SELECT)
-		}
-	}
+func (menu *MainMenu) Update(fsm state.Transitioner, delta float32) {
+	menu.menu.HandleInput()
 }
 
-func (Menu) renderLogo(offset_x, offset_y int32) {
+func (MainMenu) renderLogo(offset_x, offset_y int32) {
 	for y := range assets.LOGO_HEIGHT {
 		for x := range assets.LOGO_STRIDE {
 			index := assets.Logo[x+(y*assets.LOGO_STRIDE)]
@@ -76,20 +56,15 @@ func (Menu) renderLogo(offset_x, offset_y int32) {
 	}
 }
 
-func (menu Menu) renderEntries(offset_x, offset_y int32) {
+func (menu MainMenu) renderEntries(offset_x, offset_y int32) {
 	y := offset_y
-	for i, entry := range menu.entries {
-
-		col := rl.White
-		if i == menu.selected {
-			col = rl.Red
-		}
-		render.DrawTextCenter(offset_x, y, 32, entry.label, col)
+	for i, entry := range menu.menu.Entries() {
+		entry.Draw(offset_x, y, menu.menu.IsSelected(i))
 		y += 40
 	}
 }
 
-func (menu Menu) Render() {
+func (menu MainMenu) Render() {
 	render.Begin(rl.Black)
 
 	menu.renderLogo(20, 150)

game/ui/button.go

@@ -0,0 +1,33 @@
+package ui
+
+import (
+	"tetris/engine/render"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+type Button struct {
+	Text   string
+	Action func()
+}
+
+func NewButton(text string, action func()) Button {
+	return Button{
+		Text:   text,
+		Action: action,
+	}
+}
+
+func (b Button) HandleInput() {
+	if rl.IsKeyPressed(rl.KeyEnter) {
+		b.Action()
+	}
+}
+
+func (b Button) Draw(x, y int32, selected bool) {
+	col := rl.White
+	if selected {
+		col = rl.Red
+	}
+	render.DrawTextCenter(x, y, 32, b.Text, col)
+}

game/ui/menu.go

@@ -0,0 +1,59 @@
+package ui
+
+import (
+	"tetris/assets"
+	"tetris/engine/audio"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+type Menu struct {
+	selected int
+	entries  []Widget
+}
+
+func NewMenu(entries []Widget) Menu {
+	return Menu{
+		entries: entries,
+	}
+}
+
+func (menu Menu) Entries() []Widget {
+	return menu.entries
+}
+
+func (menu *Menu) Select(index int) {
+	menu.selected = min(index, len(menu.entries)-1)
+}
+
+func (menu Menu) Selected() Widget {
+	return menu.entries[menu.selected]
+}
+
+func (menu Menu) IsSelected(index int) bool {
+	return menu.selected == index
+}
+
+func (menu *Menu) Next() {
+	if menu.selected+1 < len(menu.entries) {
+		menu.selected = menu.selected + 1
+		audio.Play(assets.SFX_MENU_SELECT)
+	}
+}
+
+func (menu *Menu) Previous() {
+	if menu.selected-1 >= 0 {
+		menu.selected = menu.selected - 1
+		audio.Play(assets.SFX_MENU_SELECT)
+	}
+}
+
+func (menu *Menu) HandleInput() {
+	if rl.IsKeyPressed(rl.KeyDown) {
+		menu.Next()
+	} else if rl.IsKeyPressed(rl.KeyUp) {
+		menu.Previous()
+	} else {
+		menu.Selected().HandleInput()
+	}
+}

game/ui/widget.go

@@ -0,0 +1,6 @@
+package ui
+
+type Widget interface {
+	HandleInput()
+	Draw(x, y int32, selected bool)
+}

tetris.go

@@ -41,7 +41,7 @@ func main() {
 
 	// Setup state machine.
 	fsm := machine.New()
-	fsm.Register("menu", handlers.NewMenu())
+	fsm.Register("menu", handlers.NewMainMenu(fsm))
 	fsm.Register("gameover", &handlers.GameOver{})
 	fsm.Register("gameplay", handlers.NewGamePlay())
 	fsm.Start("menu")