[PATCH weston] desktop-shell: use binding_modifier for zoom

[Ian Ray]

Support for kiosk-style use cases where binding modififer is `none':

 - Use binding modifier instead of hard-coded MODIFIER_SUPER for zoom.
 - Disable opacity zoom if there is no binding modifier.

Signed-off-by: Ian Ray <ian.ray at ge.com>
---
 desktop-shell/shell.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index 415da19..1f99efe 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -4860,12 +4860,6 @@ shell_add_bindings(struct weston_compositor *ec, struct desktop_shell *shell)
 	weston_compositor_add_touch_binding(ec, 0,
 					    touch_to_activate_binding,
 					    shell);
-	weston_compositor_add_axis_binding(ec, WL_POINTER_AXIS_VERTICAL_SCROLL,
-				           MODIFIER_SUPER | MODIFIER_ALT,
-				           surface_opacity_binding, NULL);
-	weston_compositor_add_axis_binding(ec, WL_POINTER_AXIS_VERTICAL_SCROLL,
-					   MODIFIER_SUPER, zoom_axis_binding,
-					   NULL);
 	weston_compositor_add_key_binding(ec, KEY_BRIGHTNESSDOWN, 0,
 				          backlight_binding, ec);
 	weston_compositor_add_key_binding(ec, KEY_BRIGHTNESSUP, 0,
@@ -4880,6 +4874,16 @@ shell_add_bindings(struct weston_compositor *ec, struct desktop_shell *shell)
 	if (!mod)
 		return;
 
+	/* This binding is not configurable, but is only enabled if there is a
+	 * valid binding modifier. */
+	weston_compositor_add_axis_binding(ec, WL_POINTER_AXIS_VERTICAL_SCROLL,
+				           MODIFIER_SUPER | MODIFIER_ALT,
+				           surface_opacity_binding, NULL);
+
+	weston_compositor_add_axis_binding(ec, WL_POINTER_AXIS_VERTICAL_SCROLL,
+					   mod, zoom_axis_binding,
+					   NULL);
+
 	weston_compositor_add_key_binding(ec, KEY_PAGEUP, mod,
 					  zoom_key_binding, NULL);
 	weston_compositor_add_key_binding(ec, KEY_PAGEDOWN, mod,
-- 
2.7.4