binds: remove duplicated and empty bindings

Add keybindings filtering, so if the context binding is defined, the
parent one is removed and is not shown in the list at all.

Also add keybinding removing, so if the context defines an empty
binding, both this and parent one are removed from the list. This way
you can disable and hide specific bindings in contexts.

Changelog-added: Disable parent context bindings by declaring them empty.
Signed-off-by: Vitaly Ovchinnikov <v@ovch.ru>
Acked-by: Robin Jarry <robin@jarry.cc>

2 files changed, 61 insertions, 0 deletions

diff --git a/config/binds.go b/config/binds.go
index 1b2799f2..4552030d 100644
--- a/config/binds.go
+++ b/config/binds.go
@@ -272,6 +272,53 @@ func NewKeyBindings() *KeyBindings {
 	}
 }
 
+func areBindingsInputsEqual(a, b *Binding) bool {
+	if len(a.Input) != len(b.Input) {
+		return false
+	}
+
+	for idx := range a.Input {
+		if a.Input[idx] != b.Input[idx] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// this scans the bindings slice for copies and leaves just the first ones
+// it also removes empty bindings, the ones that do nothing, so you can
+// override and erase parent bindings with the context ones
+func filterAndCleanBindings(bindings []*Binding) []*Binding {
+	// 1. remove a binding if we already have one with the same input
+	res1 := []*Binding{}
+	for _, b := range bindings {
+		// do we already have one here?
+		found := false
+		for _, r := range res1 {
+			if areBindingsInputsEqual(b, r) {
+				found = true
+				break
+			}
+		}
+
+		// add it if we don't
+		if !found {
+			res1 = append(res1, b)
+		}
+	}
+
+	// 2. clean up the empty bindings
+	res2 := []*Binding{}
+	for _, b := range res1 {
+		if len(b.Output) > 0 {
+			res2 = append(res2, b)
+		}
+	}
+
+	return res2
+}
+
 func MergeBindings(bindings ...*KeyBindings) *KeyBindings {
 	merged := NewKeyBindings()
 	for _, b := range bindings {
@@ -280,6 +327,7 @@ func MergeBindings(bindings ...*KeyBindings) *KeyBindings {
 			break
 		}
 	}
+	merged.Bindings = filterAndCleanBindings(merged.Bindings)
 	merged.ExKey = bindings[0].ExKey
 	merged.Globals = bindings[0].Globals
 	return merged
diff --git a/doc/aerc-binds.5.scd b/doc/aerc-binds.5.scd
index 8ce59cf0..f3e44574 100644
--- a/doc/aerc-binds.5.scd
+++ b/doc/aerc-binds.5.scd
@@ -87,6 +87,19 @@ gi = :cf Inbox<Enter>
 You may also configure global keybindings by placing them at the beginning of
 the file, before specifying any context-specific sections.
 
+Parent keybindings can be erased in the context ones by specifying an "empty"
+binding:
+
+```
+[compose::review]
+a = :attach<space>
+d = :deatch<space>
+
+[compose::review:account=no-attachments]
+a =
+d =
+```
+
 # SPECIAL OPTIONS
 
 In addition of user defined key sequences, the following special options are