From c91f70ac38c658dd0cdc98350870c487191649e4 Mon Sep 17 00:00:00 2001
From: Brian Buller <brbuller@gmail.com>
Date: Fri, 12 Jul 2019 11:27:52 -0500
Subject: [PATCH] Windows loop

---
 screen.go         |   1 +
 screen_windows.go | 187 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 188 insertions(+)
 create mode 100644 screen_windows.go

diff --git a/screen.go b/screen.go
index 74b28a9..34448e0 100644
--- a/screen.go
+++ b/screen.go
@@ -1,3 +1,4 @@
+// +build !windows
 package termboxScreen
 
 import (
diff --git a/screen_windows.go b/screen_windows.go
new file mode 100644
index 0000000..350390e
--- /dev/null
+++ b/screen_windows.go
@@ -0,0 +1,187 @@
+// +build windows
+package termboxScreen
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	termbox "github.com/nsf/termbox-go"
+)
+
+const (
+	NoRefresh = 0
+)
+
+type Screen interface {
+	Id() int
+	Initialize(Bundle) error
+	HandleKeyEvent(termbox.Event) int
+	HandleNoneEvent(termbox.Event) int
+	DrawScreen()
+	ResizeScreen()
+}
+
+type Manager struct {
+	defaultFg termbox.Attribute
+	defaultBg termbox.Attribute
+
+	screens         map[int]Screen
+	displayScreenId int
+	events          chan termbox.Event
+
+	running     bool
+	refreshRate time.Duration
+}
+
+func NewManager() *Manager {
+	m := Manager{
+		defaultFg:   termbox.ColorWhite,
+		defaultBg:   termbox.ColorBlack,
+		events:      make(chan termbox.Event),
+		screens:     make(map[int]Screen),
+		refreshRate: NoRefresh,
+	}
+	if err := termbox.Init(); err != nil {
+		fmt.Println("Error initializing termbox")
+		return nil
+	}
+	termbox.SetOutputMode(termbox.Output256)
+	return &m
+}
+
+func (m *Manager) SetDefaultFg(c termbox.Attribute) { m.defaultFg = c }
+func (m *Manager) SetDefaultBg(c termbox.Attribute) { m.defaultBg = c }
+
+// AddScreen adds a screen to the screens map, they're indexed by the value
+// returned from the screen's Id() function
+func (m *Manager) AddScreen(s Screen) {
+	m.screens[s.Id()] = s
+	// If this is the only screen we've added, set it to active
+	if len(m.screens) == 1 {
+		m.SetDisplayScreen(s.Id())
+	}
+}
+
+// AddAndInitializeScreen adds a screen just like AddScreen, but then
+// calls it's 'Initialize' function with a blank bundle
+func (m *Manager) AddAndInitializeScreen(s Screen) error {
+	m.AddScreen(s)
+	return m.InitializeScreen(s.Id(), Bundle{})
+}
+
+func (m *Manager) GetScreens() map[int]Screen {
+	return m.screens
+}
+
+func (m *Manager) SetDisplayScreen(id int) error {
+	if id == m.displayScreenId {
+		return nil
+	}
+	var ok bool
+	if _, ok = m.screens[id]; !ok {
+		return errors.New("Invalid Screen Id")
+	}
+	m.displayScreenId = id
+	return nil
+}
+
+func (m *Manager) InitializeScreen(id int, b Bundle) error {
+	var ok bool
+	if _, ok = m.screens[id]; !ok {
+		return errors.New("Invalid screen id")
+	}
+	return m.screens[id].Initialize(b)
+}
+
+func (m *Manager) Loop() error {
+	if len(m.screens) == 0 {
+		return errors.New("Loop cannot run without screens")
+	}
+	m.running = true
+	go m.pollUserEvents()
+	// We always start display the first screen added
+	m.layoutAndDrawScreen()
+	for {
+		event := <-m.events
+		if event.Type == termbox.EventKey {
+			if event.Key == termbox.KeyCtrlC {
+				break
+			} else {
+				newScreenIndex := m.handleKeyEvent(event)
+				if err := m.SetDisplayScreen(newScreenIndex); err != nil {
+					break
+				}
+				m.layoutAndDrawScreen()
+			}
+		} else if event.Type == termbox.EventNone {
+			// Type = EventNone is how we can trigger automatic events
+			newScreenIndex := m.handleNoneEvent(event)
+			if err := m.SetDisplayScreen(newScreenIndex); err != nil {
+				break
+			}
+			m.layoutAndDrawScreen()
+		} else if event.Type == termbox.EventResize {
+			m.resizeScreen()
+			m.layoutAndDrawScreen()
+		}
+	}
+	m.running = false
+	close(m.events)
+	m.Close()
+	return nil
+}
+
+func (m *Manager) SendNoneEvent() {
+	m.SendEvent(termbox.Event{Type: termbox.EventNone})
+}
+
+func (m *Manager) SendEvent(t termbox.Event) {
+	m.events <- t
+}
+
+func (m *Manager) Close() {
+	termbox.Close()
+}
+
+func (m *Manager) pollUserEvents() {
+	for m.running {
+		m.SendEvent(termbox.PollEvent())
+	}
+}
+
+func (m *Manager) SetRefreshRate(t time.Duration) {
+	m.refreshRate = t
+	go m.pollRefreshEvents()
+}
+
+func (m *Manager) pollRefreshEvents() {
+	if m.refreshRate > time.Microsecond {
+		for m.running {
+			time.Sleep(m.refreshRate)
+			m.SendNoneEvent()
+		}
+	}
+}
+
+func (m *Manager) handleKeyEvent(event termbox.Event) int {
+	return m.screens[m.displayScreenId].HandleKeyEvent(event)
+}
+
+func (m *Manager) handleNoneEvent(event termbox.Event) int {
+	return m.screens[m.displayScreenId].HandleNoneEvent(event)
+}
+
+func (m *Manager) resizeScreen() {
+	m.screens[m.displayScreenId].ResizeScreen()
+}
+
+func (m *Manager) drawBackground() {
+	termbox.Clear(0, m.defaultBg)
+}
+
+func (m *Manager) layoutAndDrawScreen() {
+	m.drawBackground()
+	m.screens[m.displayScreenId].DrawScreen()
+	termbox.Flush()
+}