terminal: draw even if underlying command has died

After the command running in the terminal has exited, the tcell-term
buffer still contains the last status of its virtual tty. If a virtual
terminal is visible, draw it even after its command has exited. Calling
tcellterm.VT.Draw() does not interact with the underlying process at
all, it only accesses the screen buffer.

This should fix incomplete drawing of message parts when using a pager
that exits after printing contents (e.g. `less -F`). Also, it should fix
redrawing of such message part contents after switching tabs back and
forth.

Reported-by: Julio B <julio.bacel@gmail.com>
Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Julio B <julio.bacel@gmail.com>

1 files changed, 11 insertions, 24 deletions

diff --git a/widgets/terminal.go b/widgets/terminal.go
index 47bf0e7a..96919515 100644
--- a/widgets/terminal.go
+++ b/widgets/terminal.go
@@ -53,7 +53,7 @@ func (term *Terminal) closeErr(err error) {
 	if atomic.SwapInt32(&term.closed, closed) == closed {
 		return
 	}
-	if term.vterm != nil && err == nil {
+	if term.vterm != nil {
 		// Stop receiving events
 		term.vterm.Detach()
 		term.vterm.Close()
@@ -61,9 +61,6 @@ func (term *Terminal) closeErr(err error) {
 	if term.OnClose != nil {
 		term.OnClose(err)
 	}
-	if term.ctx != nil {
-		term.ctx.HideCursor()
-	}
 	ui.Invalidate()
 }
 
@@ -78,13 +75,10 @@ func (term *Terminal) Invalidate() {
 }
 
 func (term *Terminal) Draw(ctx *ui.Context) {
-	if term.isClosed() {
-		return
-	}
 	term.vterm.SetSurface(ctx.View())
 
 	w, h := ctx.View().Size()
-	if term.ctx != nil {
+	if !term.isClosed() && term.ctx != nil {
 		ow, oh := term.ctx.View().Size()
 		if w != ow || h != oh {
 			term.vterm.Resize(w, h)
@@ -103,29 +97,22 @@ func (term *Terminal) Draw(ctx *ui.Context) {
 			term.OnStart()
 		}
 	}
-	term.draw()
-}
-
-func (term *Terminal) Show(visible bool) {
-	term.visible = visible
-}
-
-func (term *Terminal) draw() {
-	if term.isClosed() {
-		return
-	}
 	term.vterm.Draw()
-	if term.focus && term.ctx != nil {
+	if term.focus {
 		y, x, style, vis := term.vterm.Cursor()
-		if vis {
-			term.ctx.SetCursor(x, y)
-			term.ctx.SetCursorStyle(style)
+		if vis && !term.isClosed() {
+			ctx.SetCursor(x, y)
+			ctx.SetCursorStyle(style)
 		} else {
-			term.ctx.HideCursor()
+			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 {