[gimp] Add API to determine whether "lock" properties can ba changed

[Michael Natterer <mitch src gnome org>]

commit d52d7e77b3c58385cd2914fe518bf0b5050743c3
Author: Michael Natterer <mitch gimp org>
Date:   Sun Aug 23 18:44:05 2009 +0200

    Add API to determine whether "lock" properties can ba changed
    
    Add gimp_item_can_lock_content() and gimp_layer_can_lock_alpha() which
    return TRUE unless the item is a grop (has children), because group
    items will be considered to have lock_content always TRUE and
    lock_alpha always FALSE.

 app/core/gimpitem.c  |   11 +++++++++++
 app/core/gimpitem.h  |    1 +
 app/core/gimplayer.c |   11 +++++++++++
 app/core/gimplayer.h |    1 +
 4 files changed, 24 insertions(+), 0 deletions(-)
---
diff --git a/app/core/gimpitem.c b/app/core/gimpitem.c
index 8205b50..9a71966 100644
--- a/app/core/gimpitem.c
+++ b/app/core/gimpitem.c
@@ -1643,6 +1643,17 @@ gimp_item_get_lock_content (const GimpItem *item)
 }
 
 gboolean
+gimp_item_can_lock_content (const GimpItem *item)
+{
+  g_return_val_if_fail (GIMP_IS_ITEM (item), FALSE);
+
+  if (gimp_viewable_get_children (GIMP_VIEWABLE (item)))
+    return FALSE;
+
+  return TRUE;
+}
+
+gboolean
 gimp_item_is_in_set (GimpItem    *item,
                      GimpItemSet  set)
 {
diff --git a/app/core/gimpitem.h b/app/core/gimpitem.h
index 49ae46b..1e36ec4 100644
--- a/app/core/gimpitem.h
+++ b/app/core/gimpitem.h
@@ -277,6 +277,7 @@ void            gimp_item_set_lock_content   (GimpItem           *item,
                                               gboolean            lock_content,
                                               gboolean            push_undo);
 gboolean        gimp_item_get_lock_content   (const GimpItem     *item);
+gboolean        gimp_item_can_lock_content   (const GimpItem     *item);
 
 gboolean        gimp_item_is_in_set          (GimpItem           *item,
                                               GimpItemSet         set);
diff --git a/app/core/gimplayer.c b/app/core/gimplayer.c
index ce1bf23..bb79e02 100644
--- a/app/core/gimplayer.c
+++ b/app/core/gimplayer.c
@@ -2055,3 +2055,14 @@ gimp_layer_get_lock_alpha (const GimpLayer *layer)
 
   return layer->lock_alpha;
 }
+
+gboolean
+gimp_layer_can_lock_alpha (const GimpLayer *layer)
+{
+  g_return_val_if_fail (GIMP_IS_LAYER (layer), FALSE);
+
+  if (gimp_viewable_get_children (GIMP_VIEWABLE (layer)))
+    return FALSE;
+
+  return TRUE;
+}
diff --git a/app/core/gimplayer.h b/app/core/gimplayer.h
index b092b82..c45d245 100644
--- a/app/core/gimplayer.h
+++ b/app/core/gimplayer.h
@@ -136,6 +136,7 @@ void            gimp_layer_set_lock_alpha      (GimpLayer            *layer,
                                                 gboolean              lock_alpha,
                                                 gboolean              push_undo);
 gboolean        gimp_layer_get_lock_alpha      (const GimpLayer      *layer);
+gboolean        gimp_layer_can_lock_alpha      (const GimpLayer      *layer);
 
 
 #endif /* __GIMP_LAYER_H__ */