Add statusline widget

widgets/status.go

@@ -0,0 +1,91 @@
+package widgets
+
+import (
+	"time"
+
+	tb "github.com/nsf/termbox-go"
+
+	"git.sr.ht/~sircmpwn/aerc2/lib/ui"
+)
+
+type StatusLine struct {
+	stack    []*StatusMessage
+	fallback StatusMessage
+
+	onInvalidate func(d ui.Drawable)
+}
+
+type StatusMessage struct {
+	bg      tb.Attribute
+	fg      tb.Attribute
+	message string
+}
+
+func NewStatusLine() *StatusLine {
+	return &StatusLine{
+		fallback: StatusMessage{
+			bg:      tb.ColorWhite,
+			fg:      tb.ColorBlack,
+			message: "Idle",
+		},
+	}
+}
+
+func (status *StatusLine) OnInvalidate(onInvalidate func (d ui.Drawable)) {
+	status.onInvalidate = onInvalidate
+}
+
+func (status *StatusLine) Invalidate() {
+	if status.onInvalidate != nil {
+		status.onInvalidate(status)
+	}
+}
+
+func (status *StatusLine) Draw(ctx *ui.Context) {
+	line := &status.fallback
+	if len(status.stack) != 0 {
+		line = status.stack[len(status.stack)-1]
+	}
+	cell := tb.Cell{
+		Fg: line.fg,
+		Bg: line.bg,
+		Ch: ' ',
+	}
+	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), cell)
+	ctx.Printf(0, 0, cell, "%s", line.message)
+}
+
+func (status *StatusLine) Set(text string) *StatusMessage {
+	status.fallback = StatusMessage{
+		bg:      tb.ColorWhite,
+		fg:      tb.ColorBlack,
+		message: text,
+	}
+	status.Invalidate()
+	return &status.fallback
+}
+
+func (status *StatusLine) Push(text string, expiry time.Duration) *StatusMessage {
+	msg := &StatusMessage{
+		bg:      tb.ColorWhite,
+		fg:      tb.ColorBlack,
+		message: text,
+	}
+	status.stack = append(status.stack, msg)
+	go (func () {
+		time.Sleep(expiry)
+		for i, m := range status.stack {
+			if m == msg {
+				status.stack = append(status.stack[:i], status.stack[i+1:]...)
+				break
+			}
+		}
+		status.Invalidate()
+	})()
+	return msg
+}
+
+func (msg *StatusMessage) Color(bg tb.Attribute, fg tb.Attribute) {
+	msg.bg = bg
+	msg.fg = fg
+}