fold: add an option to toggle folding

Add a toggle option (-t) to :fold/:unfold commands to allow for
switching the folding status of a thread.

Changelog-Added: Toggle folding with `:fold -t`.
Signed-Off-By: inwit <inwit@sindominio.net>
Acked-by: Robin Jarry <robin@jarry.cc>
Tested-by: Jason Cox <me@jasoncarloscox.com>

5 files changed, 37 insertions, 18 deletions

diff --git a/commands/msg/fold.go b/commands/msg/fold.go
index 06e933d7..f3f55871 100644
--- a/commands/msg/fold.go
+++ b/commands/msg/fold.go
@@ -7,7 +7,9 @@ import (
 	"git.sr.ht/~rjarry/aerc/lib/ui"
 )
 
-type Fold struct{}
+type Fold struct {
+	Toggle bool `opt:"-t" aliases:"fold,unfold"`
+}
 
 func init() {
 	register(Fold{})
@@ -17,7 +19,7 @@ func (Fold) Aliases() []string {
 	return []string{"fold", "unfold"}
 }
 
-func (Fold) Execute(args []string) error {
+func (f Fold) Execute(args []string) error {
 	h := newHelper()
 	store, err := h.store()
 	if err != nil {
@@ -31,9 +33,9 @@ func (Fold) Execute(args []string) error {
 
 	switch strings.ToLower(args[0]) {
 	case "fold":
-		err = store.Fold(msg.Uid)
+		err = store.Fold(msg.Uid, f.Toggle)
 	case "unfold":
-		err = store.Unfold(msg.Uid)
+		err = store.Unfold(msg.Uid, f.Toggle)
 	}
 	ui.Invalidate()
 	return err
diff --git a/config/binds.conf b/config/binds.conf
index c0e28af9..a38795d5 100644
--- a/config/binds.conf
+++ b/config/binds.conf
@@ -44,6 +44,7 @@ V = :mark -v<Enter>
 T = :toggle-threads<Enter>
 zc = :fold<Enter>
 zo = :unfold<Enter>
+<tab> = :fold -t<Enter>
 
 <Enter> = :view<Enter>
 d = :prompt 'Really delete this message?' 'delete-message'<Enter>
diff --git a/doc/aerc.1.scd b/doc/aerc.1.scd
index 2d53dca3..c34b3e7f 100644
--- a/doc/aerc.1.scd
+++ b/doc/aerc.1.scd
@@ -529,10 +529,11 @@ message list, the message in the message viewer, etc).
 *:toggle-threads*
 	Toggles between message threading and the normal message list.
 
-*:fold*++
-*:unfold*
+*:fold* [*-t*]++
+*:unfold* [*-t*]
 	Collapse or un-collapse the thread children of the selected message.
-	Folded threads can be identified by _{{.Thread\*}}_ template attributes
+	If the toggle flag *-t* is set, the folded status is changed. Folded
+	threads can be identified by _{{.Thread\*}}_ template attributes
 	in *[ui].index-columns*. See *aerc-config*(5) and *aerc-templates*(7)
 	for more details.
 
diff --git a/lib/msgstore.go b/lib/msgstore.go
index ca5f16d9..e54c2565 100644
--- a/lib/msgstore.go
+++ b/lib/msgstore.go
@@ -509,29 +509,44 @@ func (store *MessageStore) SelectedThread() (*types.Thread, error) {
 	return store.Thread(store.SelectedUid())
 }
 
-func (store *MessageStore) Fold(uid uint32) error {
-	return store.doThreadFolding(uid, true)
+func (store *MessageStore) Fold(uid uint32, toggle bool) error {
+	return store.doThreadFolding(uid, true, toggle)
 }
 
-func (store *MessageStore) Unfold(uid uint32) error {
-	return store.doThreadFolding(uid, false)
+func (store *MessageStore) Unfold(uid uint32, toggle bool) error {
+	return store.doThreadFolding(uid, false, toggle)
 }
 
-func (store *MessageStore) doThreadFolding(uid uint32, hide bool) error {
+func (store *MessageStore) doThreadFolding(uid uint32, hide bool, toggle bool) error {
 	thread, err := store.Thread(uid)
 	if err != nil {
 		return err
 	}
-	if hide && thread.FirstChild.Hidden > 0 {
+	if len(thread.Uids()) == 1 {
+		return nil
+	}
+	folded := thread.FirstChild.Hidden > 0
+	if !toggle && hide && folded {
 		return nil
 	}
 	err = thread.Walk(func(t *types.Thread, _ int, __ error) error {
 		if t.Uid != uid {
-			if hide {
-				t.Hidden++ //increase fold level
-			} else if t.Hidden > 1 {
+			switch {
+			case toggle:
+				if folded {
+					if t.Hidden > 1 {
+						t.Hidden--
+					} else {
+						t.Hidden = 0
+					}
+				} else {
+					t.Hidden++
+				}
+			case hide:
+				t.Hidden++
+			case t.Hidden > 1:
 				t.Hidden--
-			} else {
+			default:
 				t.Hidden = 0
 			}
 		}
diff --git a/worker/types/thread.go b/worker/types/thread.go
index b4f5ac5f..fdd2a8e6 100644
--- a/worker/types/thread.go
+++ b/worker/types/thread.go
@@ -15,7 +15,7 @@ type Thread struct {
 	NextSibling *Thread
 	FirstChild  *Thread
 
-	Hidden  int // if this flag is not zero the message isn't rendered in the UI
+	Hidden  int  // if this flag is not zero the message isn't rendered in the UI
 	Deleted bool // if this flag is set the message was deleted
 
 	// Context indicates the message doesn't match the mailbox / query but