event-manager.go

package paunch

// EventManager triggers methods with the On- prefix when appropriate given the
// objects supplied to it.
type EventManager struct {
	Objects []interface{}
}

// NewEventManager creates a new EventManager.
func NewEventManager() *EventManager {

	return &EventManager{make([]interface{}, 0)}
}

// RunKeyEvent simulates a key event, triggering the expected response from
// the EventManager's objects.
func (eventManager *EventManager) RunKeyEvent(key Key, action Action) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(KeyboardEventResponder); ok {
			val.OnKeyboard(key, action)
		}
	}
}

// RunMouseButtonEvent simulates a mouse button event, triggering the
// expected response from the EventManager's objects.
func (eventManager *EventManager) RunMouseButtonEvent(button MouseButton, action Action, x, y float64) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(MouseButtonEventResponder); ok {
			val.OnMouseButton(button, action, x, y)
		}
	}
}

// RunMousePositionEvent simulates a mouse position event, triggering the
// expected response from the EventManager's objects.
func (eventManager *EventManager) RunMousePositionEvent(x, y float64) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(MousePositionEventResponder); ok {
			val.OnMousePosition(x, y)
		}
	}
}

// RunMouseEnterWindowEvent simulates a mouse enter window event, triggering
// the expected response from the EventManager's objects.
func (eventManager *EventManager) RunMouseEnterWindowEvent(x, y float64, entered bool) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(MouseEnterWindowResponder); ok {
			val.OnMouseEnterWindow(x, y, entered)
		}
	}
}

func (eventManager *EventManager) RunScrollEvent(xOffset, yOffset float64) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(ScrollResponder); ok {
			val.OnScroll(xOffset, yOffset)
		}
	}
}

// RunWindowFocusEvent simulates a window focus event, triggering the
// expected response from the EventManager's objects.
func (eventManager *EventManager) RunWindowFocusEvent(focused bool) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(WindowFocusEventResponder); ok {
			val.OnWindowFocus(focused)
		}
	}
}

// RunWindowResizeEvent simulates a window resize event, triggering the
// expected response from the EventManager's objects.
func (eventManager *EventManager) RunWindowResizeEvent(width, height int) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(WindowResizeEventResponder); ok {
			val.OnWindowResize(width, height)
		}
	}
}

// RunJoystickButtonEvent simulates a joystick button event, triggering the
// expected response from the EventManager's objects.
func (eventManager *EventManager) RunJoystickButtonEvent(button int, action Action) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(JoystickButtonEventResponder); ok {
			val.OnJoystickButton(button, action)
		}
	}
}

// RunJoystickAxisEvent simulates a joystick axis event, triggering the
// expected response from the EventManager's objects.
func (eventManager *EventManager) RunJoystickAxisEvent(device int, value float64) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(JoystickAxisEventResponder); ok {
			val.OnJoystickAxis(device, value)
		}
	}
}

// RunCollisionEvent checks for collisions between the EventManager's objects
// and triggers appropriate methods.
func (eventManager *EventManager) RunCollisionEvent() {

	for i := range eventManager.Objects {
		actorCollider, ok := eventManager.Objects[i].(CollisionEventResponder)
		if !ok {
			continue
		}
		colliders1 := actorCollider.GetColliders()

		for _, val := range eventManager.Objects {
			if eventManager.Objects[i] == val {
				continue
			}

			actorCollider2, ok2 := val.(CollisionEventResponder)
			if !ok2 {
				continue
			}
			colliders2 := actorCollider2.GetColliders()

			for _, col1 := range colliders1 {
				for _, col2 := range colliders2 {
					if Collides(col1, col2) {
						actorCollider.OnCollision(col1, col2, val)
					}
				}
			}
		}
	}
}

// RunCharacterEvent simulates a character event, triggering the expected
// response from the EventManager's objects.
func (eventManager *EventManager) RunCharacterEvent(character rune) {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(CharacterEventResponder); ok {
			val.OnCharacter(character)
		}
	}
}

// RunTickEvent runs a tick event, triggering the expected response from
// the EventManager's objects.
func (eventManager *EventManager) RunTickEvent() {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(TickEventResponder); ok {
			val.OnTick()
		}
	}
}

// RunDrawEvent runs a draw event, triggering the expected response from
// the EventManager's objects.
func (eventManager *EventManager) RunDrawEvent() {

	for i := range eventManager.Objects {
		if val, ok := eventManager.Objects[i].(DrawEventResponder); ok {
			val.OnDraw()
		}
	}
}

// Collides checks if the supplied Collider collides with any of the
// EventManager's objects.
func (eventManager *EventManager) Collides(collider Collider) bool {

	for i := range eventManager.Objects {
		actorCollider, ok := eventManager.Objects[i].(CollisionEventResponder)
		if !ok {
			continue
		}

		collisions := actorCollider.GetColliders()
		for _, val := range collisions {
			if Collides(collider, val) {
				return true
			}
		}
	}

	return false
}

// GetUserEvents sets whether or not the EventManager object should be
// recieving user events. The default value is false.
func (eventManager *EventManager) GetUserEvents(getting bool) {

	if getting {
		for _, val := range paunchWindow.eventManagers {
			if val == eventManager {
				return
			}
		}
		paunchWindow.eventManagers = append(paunchWindow.eventManagers, eventManager)
	} else {
		for i, val := range paunchWindow.eventManagers {
			if val == eventManager {
				if len(paunchWindow.eventManagers) == 1 {
					paunchWindow.eventManagers = make([]*EventManager, 0)
				} else if i == 0 {
					paunchWindow.eventManagers = paunchWindow.eventManagers[i+1 : len(paunchWindow.eventManagers)]
				} else if i == len(paunchWindow.eventManagers)-1 {
					paunchWindow.eventManagers = paunchWindow.eventManagers[0:i]
				} else {
					paunchWindow.eventManagers = append(paunchWindow.eventManagers[0:i],
						paunchWindow.eventManagers[i+1:len(paunchWindow.eventManagers)]...)
				}
			}
		}
	}
}