Add 'zero' event

Close #3263

src/options.go

@@ -632,6 +632,8 @@ func parseKeyChordsImpl(str string, message string, exit func(string)) map[tui.E
 			add(tui.Focus)
 		case "one":
 			add(tui.One)
+		case "zero":
+			add(tui.Zero)
 		case "alt-enter", "alt-return":
 			chords[tui.CtrlAltKey('m')] = key
 		case "alt-space":

src/terminal.go

@@ -956,10 +956,18 @@ func (t *Terminal) UpdateList(merger *Merger, reset bool) {
 			t.cy = count - util.Min(count, t.maxItems()) + pos
 		}
 	}
-	if !t.reading && t.merger.Length() == 1 {
-		one := tui.One.AsEvent()
-		if _, prs := t.keymap[one]; prs {
-			t.eventChan <- one
+	if !t.reading {
+		switch t.merger.Length() {
+		case 0:
+			zero := tui.Zero.AsEvent()
+			if _, prs := t.keymap[zero]; prs {
+				t.eventChan <- zero
+			}
+		case 1:
+			one := tui.One.AsEvent()
+			if _, prs := t.keymap[one]; prs {
+				t.eventChan <- one
+			}
 		}
 	}
 	t.mutex.Unlock()
@@ -2854,7 +2862,7 @@ func (t *Terminal) Loop() {
 			}
 			select {
 			case event = <-t.eventChan:
-				needBarrier = event != tui.Load.AsEvent()
+				needBarrier = !event.Is(tui.Load, tui.One, tui.Zero)
 			case actions = <-t.serverChan:
 				event = tui.Invalid.AsEvent()
 				needBarrier = false

src/tui/tui.go

@@ -94,6 +94,7 @@ const (
 	Load
 	Focus
 	One
+	Zero
 
 	AltBS
 
@@ -283,6 +284,15 @@ type Event struct {
 	MouseEvent *MouseEvent
 }
 
+func (e Event) Is(types ...EventType) bool {
+	for _, t := range types {
+		if e.Type == t {
+			return true
+		}
+	}
+	return false
+}
+
 type MouseEvent struct {
 	Y      int
 	X      int