1 files changed, 178 insertions, 0 deletions
diff --git a/app/terminal.go b/app/terminal.go
new file mode 100644
index 00000000..1b177f3e
--- /dev/null
+++ b/app/terminal.go
@@ -0,0 +1,178 @@
+package app
+
+import (
+	"os/exec"
+	"sync/atomic"
+
+	"git.sr.ht/~rjarry/aerc/config"
+	"git.sr.ht/~rjarry/aerc/lib/ui"
+	"git.sr.ht/~rjarry/aerc/log"
+	tcellterm "git.sr.ht/~rockorager/tcell-term"
+
+	"github.com/gdamore/tcell/v2"
+)
+
+type Terminal struct {
+	closed  int32
+	cmd     *exec.Cmd
+	ctx     *ui.Context
+	focus   bool
+	visible bool
+	vterm   *tcellterm.VT
+	running bool
+
+	OnClose func(err error)
+	OnEvent func(event tcell.Event) bool
+	OnStart func()
+	OnTitle func(title string)
+}
+
+func NewTerminal(cmd *exec.Cmd) (*Terminal, error) {
+	term := &Terminal{
+		cmd:     cmd,
+		vterm:   tcellterm.New(),
+		visible: true,
+	}
+	term.vterm.OSC8 = config.General.EnableOSC8
+	term.vterm.TERM = config.General.Term
+	return term, nil
+}
+
+func (term *Terminal) Close() {
+	term.closeErr(nil)
+}
+
+// TODO: replace with atomic.Bool when min go version will have it (1.19+)
+const closed int32 = 1
+
+func (term *Terminal) isClosed() bool {
+	return atomic.LoadInt32(&term.closed) == closed
+}
+
+func (term *Terminal) closeErr(err error) {
+	if atomic.SwapInt32(&term.closed, closed) == closed {
+		return
+	}
+	if term.vterm != nil {
+		// Stop receiving events
+		term.vterm.Detach()
+		term.vterm.Close()
+	}
+	if term.OnClose != nil {
+		term.OnClose(err)
+	}
+	ui.Invalidate()
+}
+
+func (term *Terminal) Destroy() {
+	// If we destroy, we don't want to call the OnClose callback
+	term.OnClose = nil
+	term.closeErr(nil)
+}
+
+func (term *Terminal) Invalidate() {
+	ui.Invalidate()
+}
+
+func (term *Terminal) Draw(ctx *ui.Context) {
+	term.vterm.SetSurface(ctx.View())
+
+	w, h := ctx.View().Size()
+	if !term.isClosed() && term.ctx != nil {
+		ow, oh := term.ctx.View().Size()
+		if w != ow || h != oh {
+			term.vterm.Resize(w, h)
+		}
+	}
+	term.ctx = ctx
+	if !term.running && term.cmd != nil {
+		term.vterm.Attach(term.HandleEvent)
+		if err := term.vterm.Start(term.cmd); err != nil {
+			log.Errorf("error running terminal: %v", err)
+			term.closeErr(err)
+			return
+		}
+		term.running = true
+		if term.OnStart != nil {
+			term.OnStart()
+		}
+	}
+	term.vterm.Draw()
+	if term.focus {
+		y, x, style, vis := term.vterm.Cursor()
+		if vis && !term.isClosed() {
+			ctx.SetCursor(x, y)
+			ctx.SetCursorStyle(style)
+		} else {
+			ctx.HideCursor()
+		}
+	}
+}
+
+func (term *Terminal) Show(visible bool) {
+	term.visible = visible
+}
+
+func (term *Terminal) MouseEvent(localX int, localY int, event tcell.Event) {
+	ev, ok := event.(*tcell.EventMouse)
+	if !ok {
+		return
+	}
+	if term.OnEvent != nil {
+		term.OnEvent(ev)
+	}
+	if term.isClosed() {
+		return
+	}
+	e := tcell.NewEventMouse(localX, localY, ev.Buttons(), ev.Modifiers())
+	term.vterm.HandleEvent(e)
+}
+
+func (term *Terminal) Focus(focus bool) {
+	if term.isClosed() {
+		return
+	}
+	term.focus = focus
+	if term.ctx != nil {
+		if !term.focus {
+			term.ctx.HideCursor()
+		} else {
+			y, x, style, _ := term.vterm.Cursor()
+			term.ctx.SetCursor(x, y)
+			term.ctx.SetCursorStyle(style)
+			term.Invalidate()
+		}
+	}
+}
+
+// HandleEvent is used to watch the underlying terminal events
+func (term *Terminal) HandleEvent(ev tcell.Event) {
+	if term.isClosed() {
+		return
+	}
+	switch ev := ev.(type) {
+	case *tcellterm.EventRedraw:
+		if term.visible {
+			ui.Invalidate()
+		}
+	case *tcellterm.EventTitle:
+		if term.OnTitle != nil {
+			term.OnTitle(ev.Title())
+		}
+	case *tcellterm.EventClosed:
+		term.Close()
+		ui.Invalidate()
+	}
+}
+
+func (term *Terminal) Event(event tcell.Event) bool {
+	if term.OnEvent != nil {
+		if term.OnEvent(event) {
+			return true
+		}
+	}
+	if term.isClosed() {
+		return false
+	}
+	return term.vterm.HandleEvent(event)
+}