[gimp] app: update the item visibility lock logics.

[Jehan <jehanp src gnome org>]

commit 50496b8fb1d7ceb538c6bd7cec950920530054b0
Author: Jehan <jehan girinstud io>
Date:   Tue Feb 15 21:08:07 2022 +0100

    app: update the item visibility lock logics.
    
    Unlike other locks, visibility lock is less useful for locking a whole
    hierarchy of item and their children. On the other hand, being able to
    lock a group visibility while editing the children visibility is quite
    useful.

 app/core/gimpitem-exclusive.c | 10 +++++-----
 app/core/gimpitem.c           | 22 +++++++++++++---------
 app/core/gimpitem.h           |  6 ++++--
 3 files changed, 22 insertions(+), 16 deletions(-)
---
diff --git a/app/core/gimpitem-exclusive.c b/app/core/gimpitem-exclusive.c
index d449922c1c..301f2d9074 100644
--- a/app/core/gimpitem-exclusive.c
+++ b/app/core/gimpitem-exclusive.c
@@ -60,7 +60,7 @@ gimp_item_toggle_exclusive_visible (GimpItem    *item,
                               (GimpItemIsEnabledFunc) gimp_item_is_visible,
                               (GimpItemSetFunc)       gimp_item_set_visible,
                               NULL,
-                              (GimpItemIsPropLocked)  gimp_item_is_visibility_locked,
+                              (GimpItemIsPropLocked)  gimp_item_get_lock_visibility,
                               (GimpItemUndoPush)      gimp_image_undo_push_item_visibility,
                               _("Set Item Exclusive Visibility"),
                               GIMP_UNDO_GROUP_ITEM_VISIBILITY,
@@ -79,10 +79,10 @@ gimp_item_toggle_exclusive (GimpItem               *item,
                             gboolean                only_selected,
                             GimpContext            *context)
 {
-  GList       *ancestry;
-  GList       *on;
-  GList       *off;
-  GList       *list;
+  GList *ancestry;
+  GList *on;
+  GList *off;
+  GList *list;
 
   g_return_if_fail (GIMP_IS_ITEM (item));
   g_return_if_fail (gimp_item_is_attached (item));
diff --git a/app/core/gimpitem.c b/app/core/gimpitem.c
index 6918d3cb54..d2f4f016be 100644
--- a/app/core/gimpitem.c
+++ b/app/core/gimpitem.c
@@ -130,7 +130,8 @@ static gboolean   gimp_item_real_is_content_locked  (GimpItem       *item,
 static gboolean   gimp_item_real_is_position_locked (GimpItem       *item,
                                                      GimpItem      **locked_item,
                                                      gboolean        check_children);
-static gboolean   gimp_item_real_is_visibility_locked (GimpItem       *item);
+static gboolean gimp_item_real_is_visibility_locked (GimpItem       *item,
+                                                     GimpItem      **locked_item);
 static gboolean   gimp_item_real_bounds             (GimpItem       *item,
                                                      gdouble        *x,
                                                      gdouble        *y,
@@ -514,13 +515,15 @@ gimp_item_real_is_position_locked (GimpItem  *item,
 }
 
 static gboolean
-gimp_item_real_is_visibility_locked (GimpItem *item)
+gimp_item_real_is_visibility_locked (GimpItem  *item,
+                                     GimpItem **locked_item)
 {
-  GimpItem *parent = gimp_item_get_parent (item);
+  /* Unlike other locks, the visibility lock does not propagate from
+   * parents or children.
+   */
 
-  /* Locking visibility of a group item locks all child items. */
-  if (parent && gimp_item_is_visibility_locked (parent))
-    return TRUE;
+  if (GET_PRIVATE (item)->lock_visibility && locked_item)
+    *locked_item = item;
 
   return GET_PRIVATE (item)->lock_visibility;
 }
@@ -2320,7 +2323,7 @@ gimp_item_set_visible (GimpItem *item,
 
   if (gimp_item_get_visible (item) != visible)
     {
-      if (gimp_item_is_visibility_locked (item))
+      if (gimp_item_is_visibility_locked (item, NULL))
         {
           return FALSE;
         }
@@ -2591,11 +2594,12 @@ gimp_item_can_lock_visibility (GimpItem *item)
 }
 
 gboolean
-gimp_item_is_visibility_locked (GimpItem *item)
+gimp_item_is_visibility_locked (GimpItem  *item,
+                                GimpItem **locked_item)
 {
   g_return_val_if_fail (GIMP_IS_ITEM (item), FALSE);
 
-  return GIMP_ITEM_GET_CLASS (item)->is_visibility_locked (item);
+  return GIMP_ITEM_GET_CLASS (item)->is_visibility_locked (item, locked_item);
 }
 
 gboolean
diff --git a/app/core/gimpitem.h b/app/core/gimpitem.h
index ef66e14893..2be9a355bf 100644
--- a/app/core/gimpitem.h
+++ b/app/core/gimpitem.h
@@ -57,7 +57,8 @@ struct _GimpItemClass
   gboolean        (* is_position_locked) (GimpItem               *item,
                                           GimpItem              **locked_item,
                                           gboolean                checking_children);
-  gboolean        (* is_visibility_locked) (GimpItem               *item);
+  gboolean        (* is_visibility_locked) (GimpItem               *item,
+                                            GimpItem              **locked_item);
   GimpItemTree  * (* get_tree)           (GimpItem               *item);
   gboolean        (* bounds)             (GimpItem               *item,
                                           gdouble                *x,
@@ -392,7 +393,8 @@ void            gimp_item_set_lock_visibility  (GimpItem        *item,
                                                 gboolean         push_undo);
 gboolean        gimp_item_get_lock_visibility  (GimpItem        *item);
 gboolean        gimp_item_can_lock_visibility  (GimpItem        *item);
-gboolean        gimp_item_is_visibility_locked (GimpItem        *item);
+gboolean        gimp_item_is_visibility_locked (GimpItem        *item,
+                                                GimpItem       **locked_item);
 
 gboolean        gimp_item_mask_bounds        (GimpItem           *item,
                                               gint               *x1,