Split UI library and widgets

1 files changed, 79 insertions, 0 deletions

diff --git a/lib/ui/ui.go b/lib/ui/ui.go
new file mode 100644
index 00000000..9ea037c3
--- /dev/null
+++ b/lib/ui/ui.go
@@ -0,0 +1,79 @@
+package ui
+
+import (
+	tb "github.com/nsf/termbox-go"
+
+	"git.sr.ht/~sircmpwn/aerc2/config"
+)
+
+type UI struct {
+	Exit    bool
+	Content Drawable
+	ctx     *Context
+
+	interactive []Interactive
+
+	tbEvents      chan tb.Event
+	invalidations chan interface{}
+}
+
+func Initialize(conf *config.AercConfig, content Drawable) (*UI, error) {
+	if err := tb.Init(); err != nil {
+		return nil, err
+	}
+	width, height := tb.Size()
+	state := UI{
+		Content: content,
+		ctx:     NewContext(width, height),
+
+		tbEvents:      make(chan tb.Event, 10),
+		invalidations: make(chan interface{}),
+	}
+	tb.SetInputMode(tb.InputEsc | tb.InputMouse)
+	tb.SetOutputMode(tb.Output256)
+	go (func() {
+		for !state.Exit {
+			state.tbEvents <- tb.PollEvent()
+		}
+	})()
+	go (func() { state.invalidations <- nil })()
+	content.OnInvalidate(func(_ Drawable) {
+		go (func() { state.invalidations <- nil })()
+	})
+	return &state, nil
+}
+
+func (state *UI) Close() {
+	tb.Close()
+}
+
+func (state *UI) Tick() bool {
+	select {
+	case event := <-state.tbEvents:
+		switch event.Type {
+		case tb.EventKey:
+			if event.Key == tb.KeyEsc {
+				state.Exit = true
+			}
+		case tb.EventResize:
+			tb.Clear(tb.ColorDefault, tb.ColorDefault)
+			state.ctx = NewContext(event.Width, event.Height)
+			state.Content.Invalidate()
+		}
+		if state.interactive != nil {
+			for _, i := range state.interactive {
+				i.Event(event)
+			}
+		}
+	case <-state.invalidations:
+		state.Content.Draw(state.ctx)
+		tb.Flush()
+	default:
+		return false
+	}
+	return true
+}
+
+func (state *UI) AddInteractive(i Interactive) {
+	state.interactive = append(state.interactive, i)
+}