keybinds: fix mouse wheel keysims on Hyprland and Mango

fixes #2683

core/internal/keybinds/providers/scroll.go

@@ -0,0 +1,74 @@
+package providers
+
+import "strings"
+
+// Scroll-wheel binds are captured by the shell as niri's keysym names
+// (WheelScrollUp/Down/Left/Right) regardless of the active compositor. Niri
+// consumes them natively; every other provider speaks a different dialect, so the
+// raw niri token must be translated on write and back again on read. Without this
+// the token is emitted verbatim and the compositor rejects the bind (issue #2683).
+
+var canonicalScrollKeys = map[string]string{
+	"wheelscrollup":    "WheelScrollUp",
+	"wheelscrolldown":  "WheelScrollDown",
+	"wheelscrollleft":  "WheelScrollLeft",
+	"wheelscrollright": "WheelScrollRight",
+}
+
+func isScrollKey(token string) bool {
+	_, ok := canonicalScrollKeys[strings.ToLower(token)]
+	return ok
+}
+
+// Hyprland binds the wheel inside a regular bind using mouse_up/down/left/right.
+var hyprlandScrollNative = map[string]string{
+	"wheelscrollup":    "mouse_up",
+	"wheelscrolldown":  "mouse_down",
+	"wheelscrollleft":  "mouse_left",
+	"wheelscrollright": "mouse_right",
+}
+
+var hyprlandScrollCanonical = map[string]string{
+	"mouse_up":    "WheelScrollUp",
+	"mouse_down":  "WheelScrollDown",
+	"mouse_left":  "WheelScrollLeft",
+	"mouse_right": "WheelScrollRight",
+}
+
+func hyprlandScrollToNative(token string) (string, bool) {
+	v, ok := hyprlandScrollNative[strings.ToLower(token)]
+	return v, ok
+}
+
+func hyprlandScrollToCanonical(token string) (string, bool) {
+	v, ok := hyprlandScrollCanonical[strings.ToLower(token)]
+	return v, ok
+}
+
+// MangoWC binds the wheel through a dedicated axisbind directive whose key field
+// is a direction (UP/DOWN/LEFT/RIGHT) rather than a keysym.
+const mangowcAxisBindPrefix = "axisbind"
+
+var mangowcScrollDirection = map[string]string{
+	"wheelscrollup":    "UP",
+	"wheelscrolldown":  "DOWN",
+	"wheelscrollleft":  "LEFT",
+	"wheelscrollright": "RIGHT",
+}
+
+var mangowcScrollCanonical = map[string]string{
+	"up":    "WheelScrollUp",
+	"down":  "WheelScrollDown",
+	"left":  "WheelScrollLeft",
+	"right": "WheelScrollRight",
+}
+
+func mangowcScrollToDirection(token string) (string, bool) {
+	v, ok := mangowcScrollDirection[strings.ToLower(token)]
+	return v, ok
+}
+
+func mangowcDirectionToScroll(direction string) (string, bool) {
+	v, ok := mangowcScrollCanonical[strings.ToLower(direction)]
+	return v, ok
+}