Fix T62016: Outliner visibility icons drag behaviour broken

We are mixing bool and fancy 3-in-1 func-set buttons in the outliner.
So they would return different pushed state in
ui_drag_toggle_but_pushed_state().

We now have a callback function that allows the button to set its own
pushed_button_state callback function.

Note: This is a bit of overkill since we are planning to change the
3-in-1 outliner buttons. That said, it may be nice to have, since in the
future we can mix those buttons for other things.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D4434

1 files changed, 12 insertions, 7 deletions

diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index 507e0581020..498e2f07ea4 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -1240,13 +1240,18 @@ static bool ui_drag_toggle_but_is_supported(const uiBut *but)
 
 /* Button pushed state to compare if other buttons match. Can be more
  * then just true or false for toggle buttons with more than 2 states. */
-static int ui_drag_toggle_but_pushed_state(uiBut *but)
+static int ui_drag_toggle_but_pushed_state(bContext *C, uiBut *but)
 {
 	if (but->rnapoin.data == NULL && but->poin == NULL && but->icon) {
-		/* Assume icon identifies a unique state, for buttons that
-		 * work though functions callbacks and don't have an boolean
-		 * value that indicates the state. */
-		return but->icon + but->iconadd;
+		if (but->pushed_state_func) {
+			return but->pushed_state_func(C, but->pushed_state_arg);
+		}
+		else {
+			/* Assume icon identifies a unique state, for buttons that
+			* work though functions callbacks and don't have an boolean
+			* value that indicates the state. */
+			return but->icon + but->iconadd;
+		}
 	}
 	else if (ui_but_is_bool(but)) {
 		return ui_but_is_pushed(but);
@@ -1295,7 +1300,7 @@ static bool ui_drag_toggle_set_xy_xy(
 					/* execute the button */
 					if (ui_drag_toggle_but_is_supported(but)) {
 						/* is it pressed? */
-						int pushed_state_but = ui_drag_toggle_but_pushed_state(but);
+						int pushed_state_but = ui_drag_toggle_but_pushed_state(C, but);
 						if (pushed_state_but != pushed_state) {
 							UI_but_execute(C, but);
 							if (do_check) {
@@ -1754,7 +1759,7 @@ static bool ui_but_drag_init(
 			 * typically 'button_activate_exit()' handles this */
 			ui_apply_but_autokey(C, but);
 
-			drag_info->pushed_state = ui_drag_toggle_but_pushed_state(but);
+			drag_info->pushed_state = ui_drag_toggle_but_pushed_state(C, but);
 			drag_info->but_cent_start[0] = BLI_rctf_cent_x(&but->rect);
 			drag_info->but_cent_start[1] = BLI_rctf_cent_y(&but->rect);
 			copy_v2_v2_int(drag_info->xy_init, &event->x);