UI: support alt+wheel for expanded enums

1 files changed, 72 insertions, 0 deletions

diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index 5527d375f70..d9023b94e19 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -114,6 +114,7 @@
 static void ui_but_smart_controller_add(bContext *C, uiBut *from, uiBut *to);
 static void ui_but_link_add(bContext *C, uiBut *from, uiBut *to);
 static int ui_do_but_EXIT(bContext *C, uiBut *but, struct uiHandleButtonData *data, const wmEvent *event);
+static bool ui_but_find_select_in_enum__cmp(const uiBut *but_a, const uiBut *but_b);
 
 #ifdef USE_KEYNAV_LIMIT
 static void ui_mouse_motion_keynav_init(struct uiKeyNavLock *keynav, const wmEvent *event);
@@ -3348,6 +3349,38 @@ static int ui_do_but_TOG(bContext *C, uiBut *but, uiHandleButtonData *data, cons
 			button_activate_state(C, but, BUTTON_STATE_EXIT);
 			return WM_UI_HANDLER_BREAK;
 		}
+		else if (ELEM(event->type, WHEELDOWNMOUSE, WHEELUPMOUSE) && event->alt) {
+			/* Support alt+wheel on expanded enum rows */
+			if (but->type == UI_BTYPE_ROW) {
+				const int direction = (event->type == WHEELDOWNMOUSE) ? -1 : 1;
+				uiBut *but_select = ui_but_find_select_in_enum(but, direction);
+				if (but_select) {
+					uiBut *but_other = (direction == -1) ? but_select->next : but_select->prev;
+					if (but_other && ui_but_find_select_in_enum__cmp(but, but_other)) {
+						ARegion *ar = data->region;
+
+						data->cancel = true;
+						button_activate_exit(C, but, data, false, false);
+
+						/* Activate the text button. */
+						button_activate_init(C, ar, but_other, BUTTON_ACTIVATE_OVER);
+						data = but_other->active;
+						if (data) {
+							ui_apply_but(C, but->block, but_other, but_other->active, true);
+							button_activate_exit(C, but_other, data, false, false);
+
+							/* restore active button */
+							button_activate_init(C, ar, but, BUTTON_ACTIVATE_OVER);
+						}
+						else {
+							/* shouldn't happen */
+							BLI_assert(0);
+						}
+					}
+				}
+				return WM_UI_HANDLER_BREAK;
+			}
+		}
 	}
 	return WM_UI_HANDLER_CONTINUE;
 }
@@ -6597,6 +6630,45 @@ static bool ui_but_isect_pie_seg(uiBlock *block, uiBut *but)
 	return false;
 }
 
+static bool ui_but_find_select_in_enum__cmp(const uiBut *but_a, const uiBut *but_b)
+{
+	return ((but_a->type == but_b->type) &&
+	        (but_a->alignnr == but_b->alignnr) &&
+	        (but_a->poin == but_b->poin) &&
+	        (but_a->rnapoin.type == but_b->rnapoin.type) &&
+	        (but_a->rnaprop == but_b->rnaprop));
+}
+
+/**
+ * Finds the pressed button in an aligned row (typically an expanded enum).
+ *
+ * \param direction  Use when there may be multiple buttons pressed.
+ */
+uiBut *ui_but_find_select_in_enum(uiBut *but, int direction)
+{
+	uiBut *but_iter = but;
+	uiBut *but_found = NULL;
+	BLI_assert(ELEM(direction, -1, 1));
+
+	while ((but_iter->prev) &&
+	       ui_but_find_select_in_enum__cmp(but_iter->prev, but))
+	{
+		but_iter = but_iter->prev;
+	}
+
+	while (but_iter && ui_but_find_select_in_enum__cmp(but_iter, but)) {
+		if (but_iter->flag & UI_SELECT) {
+			but_found = but_iter;
+			if (direction == 1) {
+				break;
+			}
+		}
+		but_iter = but_iter->next;
+	}
+
+	return but_found;
+}
+
 uiBut *ui_but_find_active_in_region(ARegion *ar)
 {
 	uiBlock *block;