Add select and deselect actions

Close #2358

src/options.go

@@ -839,6 +839,8 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 				appendAction(actDeleteChar)
 			case "delete-char/eof":
 				appendAction(actDeleteCharEOF)
+			case "deselect":
+				appendAction(actDeselect)
 			case "end-of-line":
 				appendAction(actEndOfLine)
 			case "cancel":
@@ -879,6 +881,8 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 				appendAction(actToggleAll)
 			case "toggle-search":
 				appendAction(actToggleSearch)
+			case "select":
+				appendAction(actSelect)
 			case "select-all":
 				appendAction(actSelectAll)
 			case "deselect-all":

src/terminal.go

@@ -276,6 +276,8 @@ const (
 	actReload
 	actDisableSearch
 	actEnableSearch
+	actSelect
+	actDeselect
 )
 
 type placeholderFlags struct {
@@ -1785,11 +1787,26 @@ func (t *Terminal) selectItem(item *Item) bool {
 	return true
 }
 
+func (t *Terminal) selectItemChanged(item *Item) bool {
+	if _, found := t.selected[item.Index()]; found {
+		return false
+	}
+	return t.selectItem(item)
+}
+
 func (t *Terminal) deselectItem(item *Item) {
 	delete(t.selected, item.Index())
 	t.version++
 }
 
+func (t *Terminal) deselectItemChanged(item *Item) bool {
+	if _, found := t.selected[item.Index()]; found {
+		t.deselectItem(item)
+		return true
+	}
+	return false
+}
+
 func (t *Terminal) toggleItem(item *Item) bool {
 	if _, found := t.selected[item.Index()]; !found {
 		return t.selectItem(item)
@@ -2341,6 +2358,16 @@ func (t *Terminal) Loop() {
 				} else {
 					req(reqQuit)
 				}
+			case actSelect:
+				current := t.currentItem()
+				if t.multi > 0 && current != nil && t.selectItemChanged(current) {
+					req(reqList, reqInfo)
+				}
+			case actDeselect:
+				current := t.currentItem()
+				if t.multi > 0 && current != nil && t.deselectItemChanged(current) {
+					req(reqList, reqInfo)
+				}
 			case actToggle:
 				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
 					req(reqList)