1 files changed, 115 insertions, 0 deletions
diff --git a/lib/ui/tab.go b/lib/ui/tab.go
new file mode 100644
index 00000000..e6a8aa5f
--- /dev/null
+++ b/lib/ui/tab.go
@@ -0,0 +1,115 @@
+package ui
+
+import (
+	tb "github.com/nsf/termbox-go"
+)
+
+type Tabs struct {
+	Tabs       []*Tab
+	TabStrip   *TabStrip
+	TabContent *TabContent
+	Selected   int
+
+	onInvalidateStrip   func(d Drawable)
+	onInvalidateContent func(d Drawable)
+}
+
+type Tab struct {
+	Content Drawable
+	Name    string
+	invalid bool
+}
+
+type TabStrip Tabs
+type TabContent Tabs
+
+func NewTabs() *Tabs {
+	tabs := &Tabs{}
+	tabs.TabStrip = (*TabStrip)(tabs)
+	tabs.TabContent = (*TabContent)(tabs)
+	return tabs
+}
+
+func (tabs *Tabs) Add(content Drawable, name string) {
+	tabs.Tabs = append(tabs.Tabs, &Tab{
+		Content: content,
+		Name:    name,
+	})
+	tabs.TabStrip.Invalidate()
+	content.OnInvalidate(tabs.invalidateChild)
+}
+
+func (tabs *Tabs) invalidateChild(d Drawable) {
+	for i, tab := range tabs.Tabs {
+		if tab.Content == d {
+			if i == tabs.Selected {
+				tabs.TabContent.Invalidate()
+			}
+			return
+		}
+	}
+}
+
+func (tabs *Tabs) Remove(content Drawable) {
+	for i, tab := range tabs.Tabs {
+		if tab.Content == content {
+			tabs.Tabs = append(tabs.Tabs[:i], tabs.Tabs[i+1:]...)
+			break
+		}
+	}
+	tabs.TabStrip.Invalidate()
+}
+
+func (tabs *Tabs) Select(index int) {
+	if tabs.Selected != index {
+		tabs.Selected = index
+		tabs.TabStrip.Invalidate()
+		tabs.TabContent.Invalidate()
+	}
+}
+
+// TODO: Color repository
+func (strip *TabStrip) Draw(ctx *Context) {
+	x := 0
+	for i, tab := range strip.Tabs {
+		cell := tb.Cell{
+			Fg: tb.ColorBlack,
+			Bg: tb.ColorWhite,
+		}
+		if strip.Selected == i {
+			cell.Fg = tb.ColorDefault
+			cell.Bg = tb.ColorDefault
+		}
+		x += ctx.Printf(x, 0, cell, " %s ", tab.Name)
+	}
+	cell := tb.Cell{
+		Fg: tb.ColorBlack,
+		Bg: tb.ColorWhite,
+	}
+	ctx.Fill(x, 0, ctx.Width()-x, 1, cell)
+}
+
+func (strip *TabStrip) Invalidate() {
+	if strip.onInvalidateStrip != nil {
+		strip.onInvalidateStrip(strip)
+	}
+}
+
+func (strip *TabStrip) OnInvalidate(onInvalidate func(d Drawable)) {
+	strip.onInvalidateStrip = onInvalidate
+}
+
+func (content *TabContent) Draw(ctx *Context) {
+	tab := content.Tabs[content.Selected]
+	tab.Content.Draw(ctx)
+}
+
+func (content *TabContent) Invalidate() {
+	if content.onInvalidateContent != nil {
+		content.onInvalidateContent(content)
+	}
+}
+
+func (content *TabContent) OnInvalidate(onInvalidate func(d Drawable)) {
+	content.onInvalidateContent = onInvalidate
+}