Implemented scene events and callback handlers for those events. Manager defaults also added.

manager.go

@@ -25,8 +25,10 @@ type GameInfo struct {
 type Manager struct {
 	Info           GameInfo
 	currentScene   Scene
-	currentSceneId int
+	currentSceneId uint
+	nextSceneId    uint
 	scenes         []Scene
+	EventMap       map[SceneEvent]func()
 }
 
 // can be used to create default manager instance
@@ -37,9 +39,11 @@ func NewManager() Manager {
 			Version: "1.0",
 			Dimension: Area{
 				Width:  defaultWidth,
-				Height: defaultHeight},
+				Height: defaultHeight,
+			},
 		},
 		currentSceneId: 0,
+		nextSceneId:    1,
 	}
 }
 
@@ -50,29 +54,13 @@ func (m *Manager) Update() error {
 		return nil
 	}
 
-	m.CheckTransitions()
-	m.CheckExit()
-
 	//call the current scene's update method
 	return m.currentScene.Update()
 
 }
 
-// check for exit condition
-func (m *Manager) CheckExit() {
-	if m.currentSceneId >= len(m.scenes) {
-		os.Exit(0)
-	}
-}
-
-// check for scene completion and if reached, set up next scene (if available)
-func (m *Manager) CheckTransitions() {
-	if m.currentScene.Completed() {
-		m.currentSceneId++
-		if m.currentSceneId < len(m.scenes) {
-			m.currentScene = m.scenes[m.currentSceneId]
-		}
-	}
+func (m *Manager) Quit() {
+	os.Exit(0)
 }
 
 // calls current scene's draw method if the currentscene is valid
@@ -89,18 +77,57 @@ func (m *Manager) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHe
 
 // appends scene to the managed scenes
 func (m *Manager) AddScene(s Scene) {
+	setDefaultHandlers(m, s)
 	m.scenes = append(m.scenes, s)
 }
 
-// sets the current scene, based on sceneindex
-func (m *Manager) SetCurrentScene(sceneId int) {
-	if sceneId >= 0 && sceneId < len(m.scenes) {
-		m.currentSceneId = sceneId
-		m.currentScene = m.scenes[m.currentSceneId]
-	}
+// sets the default callback handlers for a given scene within manager
+// Default Handling behaviours:
+//
+//	reset: sets (scene, nextscene) to {0, 1}
+//	scene completion: sets (scene, nextscene) to {nextscene, nextscene+1}
+//	end game: shutdown groovy
+//
+//	note: NOOP and RELOAD are purposefully not mapped; they are scene
+//	specific and should be mapped to by user of groovy
+func setDefaultHandlers(m *Manager, s Scene) {
+	s.SetEventHandler(RESET, func() { m.ResetScenes() })
+	s.SetEventHandler(COMPLETED, func() { m.TransitionScene() })
+	s.SetEventHandler(ENDGAME, func() { m.Quit() })
 }
 
-// check for exit condition
+// we're going to reset the scene to the first one
+func (m *Manager) ResetScenes() {
+	m.currentSceneId = 0
+	m.nextSceneId = 1
+	m.SetCurrentScene(0)
+}
+
+// sets the current scene, based on sceneindex n
+// n > scenelist, quit
+// otherwise, scene = n
+func (m *Manager) SetCurrentScene(sceneId uint) {
+	if sceneId >= uint(len(m.scenes)) {
+		m.Quit()
+	}
+	m.currentSceneId = sceneId
+	m.currentScene = m.scenes[sceneId]
+}
+
+func (m *Manager) TransitionScene() {
+	m.SetCurrentScene(m.nextSceneId)
+}
+
+func (m *Manager) SetNextScene(sceneId uint) {
+	m.nextSceneId = sceneId
+}
+
+// sets sene dimensions
 func (m *Manager) SetDimensions(a Area) {
 	m.Info.Dimension = a
 }
+
+// report number of total scenes
+func (m *Manager) SceneCount() uint {
+	return uint(len(m.scenes))
+}