aerc: add quake-mode terminal

Add a drop-down (quake-mode) terminal which is a persistent terminal
session that overlays aerc at the top and can be toggled on or off.

Enable quake mode by setting [General].enable-quake-mode=true.

The height of the drop-down terminal can be set with
[ui].quake-terminal-height (default: 20).

Toggling is hardcoded to the F1 key. Note that this key should not be
used in your key bindings when you enable Quake mode.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Tested-by: Inwit <inwit@sindominio.net>
Acked-by: Robin Jarry <robin@jarry.cc>

4 files changed, 271 insertions, 15 deletions

diff --git a/app/aerc.go b/app/aerc.go
index beef6328..107fc1f3 100644
--- a/app/aerc.go
+++ b/app/aerc.go
@@ -190,16 +190,15 @@ func (aerc *Aerc) Draw(ctx *ui.Context) {
 	}
 	aerc.grid.Draw(ctx)
 	if aerc.dialog != nil {
-		if w, h := ctx.Width(), ctx.Height(); w > 8 && h > 4 {
-			if d, ok := aerc.dialog.(Dialog); ok {
-				xstart, width := d.ContextWidth()
-				ystart, height := d.ContextHeight()
-				aerc.dialog.Draw(
-					ctx.Subcontext(xstart(w), ystart(h),
-						width(w), height(h)))
-			} else {
-				aerc.dialog.Draw(ctx.Subcontext(4, h/2-2, w-8, 4))
-			}
+		w, h := ctx.Width(), ctx.Height()
+		if d, ok := aerc.dialog.(Dialog); ok {
+			xstart, width := d.ContextWidth()
+			ystart, height := d.ContextHeight()
+			aerc.dialog.Draw(
+				ctx.Subcontext(xstart(w), ystart(h),
+					width(w), height(h)))
+		} else if w > 8 && h > 4 {
+			aerc.dialog.Draw(ctx.Subcontext(4, h/2-2, w-8, 4))
 		}
 	}
 }
@@ -329,6 +328,13 @@ func (aerc *Aerc) simulate(strokes []config.KeyStroke) {
 }
 
 func (aerc *Aerc) Event(event vaxis.Event) bool {
+	if config.General.QuakeMode {
+		if e, ok := event.(vaxis.Key); ok && e.MatchString("F1") {
+			ToggleQuake()
+			return true
+		}
+	}
+
 	if aerc.dialog != nil {
 		return aerc.dialog.Event(event)
 	}
diff --git a/app/dialog.go b/app/dialog.go
index fba0fd7b..64dbf125 100644
--- a/app/dialog.go
+++ b/app/dialog.go
@@ -30,7 +30,7 @@ func NewDialog(
 	d ui.DrawableInteractive,
 	x func(int) int, y func(int) int,
 	w func(int) int, h func(int) int,
-) Dialog {
+) *dialog {
 	return &dialog{DrawableInteractive: d, x: x, y: y, w: w, h: h}
 }
 
diff --git a/app/quake.go b/app/quake.go
new file mode 100644
index 00000000..9ceb6457
--- /dev/null
+++ b/app/quake.go
@@ -0,0 +1,243 @@
+package app
+
+import (
+	"os/exec"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"git.sr.ht/~rjarry/aerc/config"
+	"git.sr.ht/~rjarry/aerc/lib/log"
+	"git.sr.ht/~rjarry/aerc/lib/ui"
+	"git.sr.ht/~rockorager/vaxis"
+	"github.com/riywo/loginshell"
+)
+
+var qt quakeTerminal
+
+type quakeTerminal struct {
+	mu      sync.Mutex
+	rolling int32
+	visible bool
+	term    *Terminal
+}
+
+func ToggleQuake() {
+	handleErr := func(err error) {
+		log.Errorf("quake-terminal: %v", err)
+	}
+	if !qt.HasTerm() {
+		shell, err := loginshell.Shell()
+		if err != nil {
+			handleErr(err)
+			return
+		}
+		args := []string{shell}
+		cmd := exec.Command(args[0], args[1:]...)
+		term, err := NewTerminal(cmd)
+		if err != nil {
+			handleErr(err)
+			return
+		}
+		term.OnClose = func(err error) {
+			if err != nil {
+				aerc.PushError(err.Error())
+			}
+			qt.Hide()
+			qt.SetTerm(nil)
+		}
+		qt.SetTerm(term)
+	}
+
+	if qt.Rolling() {
+		return
+	}
+
+	if qt.Visible() {
+		qt.Hide()
+	} else {
+		qt.Show()
+	}
+}
+
+func (q *quakeTerminal) Rolling() bool {
+	return atomic.LoadInt32(&q.rolling) > 0
+}
+
+func (q *quakeTerminal) SetTerm(t *Terminal) {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	q.term = t
+}
+
+func (q *quakeTerminal) HasTerm() bool {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	return q.term != nil
+}
+
+func (q *quakeTerminal) Visible() bool {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	return q.visible
+}
+
+// inputReturn is helper function to create dialog boxes.
+func inputReturn() func(int) int {
+	return func(x int) int { return x }
+}
+
+// fixReturn is helper function to create dialog boxes.
+func fixReturn(x int) func(int) int {
+	return func(_ int) int { return x }
+}
+
+func (q *quakeTerminal) Show() {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	if q.term == nil {
+		return
+	}
+
+	uiConfig := SelectedAccountUiConfig()
+	h := uiConfig.QuakeHeight
+
+	termBox := NewDialog(
+		ui.NewBox(q.term, "", "", uiConfig),
+		fixReturn(0),
+		fixReturn(0),
+		inputReturn(),
+		fixReturn(h),
+	)
+
+	f := Roller{
+		span: 100 * time.Millisecond,
+		done: func() {
+			log.Tracef("restore after show")
+			atomic.StoreInt32(&q.rolling, 0)
+			ui.QueueFunc(func() {
+				CloseDialog()
+				AddDialog(termBox)
+			})
+		},
+	}
+
+	atomic.StoreInt32(&q.rolling, 1)
+	emptyBox := NewDialog(
+		ui.NewBox(&EmptyInteractive{}, "", "", uiConfig),
+		fixReturn(0),
+		fixReturn(0),
+		inputReturn(),
+		f.Roll(1, h),
+	)
+
+	q.visible = true
+	if q.term != nil {
+		q.term.Show(q.visible)
+		q.term.Focus(q.visible)
+	}
+
+	CloseDialog()
+	AddDialog(emptyBox)
+}
+
+func (q *quakeTerminal) Hide() {
+	uiConfig := SelectedAccountUiConfig()
+	f := Roller{
+		span: 100 * time.Millisecond,
+		done: func() {
+			atomic.StoreInt32(&q.rolling, 0)
+			ui.QueueFunc(CloseDialog)
+			log.Tracef("restore after hide")
+		},
+	}
+
+	atomic.StoreInt32(&q.rolling, 1)
+	emptyBox := NewDialog(
+		ui.NewBox(&EmptyInteractive{}, "", "", uiConfig),
+		fixReturn(0),
+		fixReturn(0),
+		inputReturn(),
+		f.Roll(uiConfig.QuakeHeight, 2),
+	)
+
+	q.mu.Lock()
+	q.visible = false
+	if q.term != nil {
+		q.term.Focus(q.visible)
+		q.term.Show(q.visible)
+	}
+	q.mu.Unlock()
+
+	ui.QueueFunc(func() {
+		CloseDialog()
+		AddDialog(emptyBox)
+	})
+}
+
+type EmptyInteractive struct{}
+
+func (e *EmptyInteractive) Draw(ctx *ui.Context) {
+	w := ctx.Width()
+	h := ctx.Height()
+	if w == 0 || h == 0 {
+		return
+	}
+	style := SelectedAccountUiConfig().GetStyle(config.STYLE_DEFAULT)
+	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', style)
+}
+
+func (e *EmptyInteractive) Invalidate() {
+}
+
+func (e *EmptyInteractive) MouseEvent(_ int, _ int, _ vaxis.Event) {
+}
+
+func (e *EmptyInteractive) Event(_ vaxis.Event) bool {
+	return true
+}
+
+func (e *EmptyInteractive) Focus(_ bool) {
+}
+
+type Roller struct {
+	span  time.Duration
+	done  func()
+	value int64
+}
+
+func (f *Roller) Roll(start, end int) func(int) int {
+	nsteps := end - start
+
+	var step int64 = 1
+	if end < start {
+		step = -1
+		nsteps = -nsteps
+	}
+
+	span := f.span.Milliseconds() / int64(nsteps)
+	refresh := time.Duration(span) * time.Millisecond
+
+	atomic.StoreInt64(&f.value, int64(start))
+
+	go func() {
+		defer log.PanicHandler()
+		for i := 0; i < int(nsteps); i++ {
+			aerc.Invalidate()
+			time.Sleep(refresh)
+			atomic.AddInt64(&f.value, step)
+		}
+		if f.done != nil {
+			ui.QueueFunc(f.done)
+		}
+	}()
+
+	return func(_ int) int {
+		log.Tracef("in roller")
+		return int(atomic.LoadInt64(&f.value))
+	}
+}
diff --git a/app/terminal.go b/app/terminal.go
index a3109321..9bf4f869 100644
--- a/app/terminal.go
+++ b/app/terminal.go
@@ -17,10 +17,10 @@ type HasTerminal interface {
 
 type Terminal struct {
 	closed  int32
+	visible int32 // visible if >0
 	cmd     *exec.Cmd
 	ctx     *ui.Context
 	focus   bool
-	visible bool
 	vterm   *term.Model
 	running bool
 
@@ -34,7 +34,7 @@ func NewTerminal(cmd *exec.Cmd) (*Terminal, error) {
 	term := &Terminal{
 		cmd:     cmd,
 		vterm:   term.New(),
-		visible: true,
+		visible: 1,
 	}
 	term.vterm.OSC8 = config.General.EnableOSC8
 	term.vterm.TERM = config.General.Term
@@ -81,6 +81,9 @@ func (term *Terminal) Invalidate() {
 }
 
 func (term *Terminal) Draw(ctx *ui.Context) {
+	if ctx.Width() == 0 || ctx.Height() == 0 {
+		return
+	}
 	term.ctx = ctx
 	if !term.running && term.cmd != nil {
 		term.vterm.Attach(term.HandleEvent)
@@ -99,7 +102,11 @@ func (term *Terminal) Draw(ctx *ui.Context) {
 }
 
 func (term *Terminal) Show(visible bool) {
-	term.visible = visible
+	if visible {
+		atomic.StoreInt32(&term.visible, 1)
+	} else {
+		atomic.StoreInt32(&term.visible, 0)
+	}
 }
 
 func (term *Terminal) Terminal() *Terminal {
@@ -141,7 +148,7 @@ func (t *Terminal) HandleEvent(ev vaxis.Event) {
 	}
 	switch ev := ev.(type) {
 	case vaxis.Redraw:
-		if t.visible {
+		if atomic.LoadInt32(&t.visible) > 0 {
 			ui.Invalidate()
 		}
 	case term.EventTitle: