Iterate over all an image's items recursively

Use gimp_image_get_layer,channel,vectors_list() instead of
gimp_image_get_layer,channel,vectors_iter(). As a side-effect,
simplified some code that was making sure we don't modify the list
returned by the old functions (the new functions return newly
allocated lists so we can safely remove items from the image while
iterating it). Some places will need adjusting once we really have
item trees.

app/core/gimpimage-convert.c

@@ -766,6 +766,7 @@ gimp_image_convert (GimpImage               *image,
 {
   QuantizeObj       *quantobj = NULL;
   GimpImageBaseType  old_type;
+  GList             *all_layers;
   GList             *list;
   const gchar       *undo_desc = NULL;
   gint               nth_layer, n_layers;
@@ -797,7 +798,9 @@ gimp_image_convert (GimpImage               *image,
 
   gimp_set_busy (image->gimp);
 
-  n_layers = gimp_container_get_n_children (GIMP_CONTAINER (image->layers));
+  all_layers = gimp_image_get_layer_list (image);
+
+  n_layers = g_list_length (all_layers);
 
   switch (new_type)
     {
@@ -866,7 +869,7 @@ gimp_image_convert (GimpImage               *image,
           num_found_cols = 0;
 
           /*  Build the histogram  */
-          for (list = gimp_image_get_layer_iter (image), nth_layer = 0;
+          for (list = all_layers, nth_layer = 0;
                list;
                list = g_list_next (list), nth_layer++)
             {
@@ -951,7 +954,7 @@ gimp_image_convert (GimpImage               *image,
   if (quantobj)
     quantobj->n_layers = n_layers;
 
-  for (list = gimp_image_get_layer_iter (image), nth_layer = 0;
+  for (list = all_layers, nth_layer = 0;
        list;
        list = g_list_next (list), nth_layer++)
     {
@@ -1025,9 +1028,7 @@ gimp_image_convert (GimpImage               *image,
                             remap_table, &num_entries);
 
           /*  Convert all layers  */
-          for (list = gimp_image_get_layer_iter (image);
+          for (list = all_layers; list; list = g_list_next (list))
-               list;
-               list = g_list_next (list))
             {
               remap_indexed_layer (list->data, remap_table, num_entries);
             }
@@ -1086,6 +1087,8 @@ gimp_image_convert (GimpImage               *image,
   gimp_image_mode_changed (image);
   g_object_thaw_notify (G_OBJECT (image));
 
+  g_list_free (all_layers);
+
   gimp_unset_busy (image->gimp);
 
   return TRUE;

app/core/gimpimage-crop.c

@@ -118,9 +118,16 @@ gimp_image_crop (GimpImage   *image,
     }
   else
     {
+      GList    *all_layers;
+      GList    *all_channels;
+      GList    *all_vectors;
       GimpItem *item;
       GList    *list;
 
+      all_layers   = gimp_image_get_layer_list (image);
+      all_channels = gimp_image_get_channel_list (image);
+      all_vectors  = gimp_image_get_vectors_list (image);
+
       g_object_freeze_notify (G_OBJECT (image));
 
       if (crop_layers)
@@ -145,9 +152,7 @@ gimp_image_crop (GimpImage   *image,
                     NULL);
 
       /*  Resize all channels  */
-      for (list = gimp_image_get_channel_iter (image);
+      for (list = all_channels; list; list = g_list_next (list))
-           list;
-           list = g_list_next (list))
         {
           item = (GimpItem *) list->data;
 
@@ -155,9 +160,7 @@ gimp_image_crop (GimpImage   *image,
         }
 
       /*  Resize all vectors  */
-      for (list = gimp_image_get_vectors_iter (image);
+      for (list = all_vectors; list; list = g_list_next (list))
-           list;
-           list = g_list_next (list))
         {
           item = (GimpItem *) list->data;
 
@@ -169,14 +172,10 @@ gimp_image_crop (GimpImage   *image,
                         width, height, -x1, -y1);
 
       /*  crop all layers  */
-      list = gimp_image_get_layer_iter (image);
+      for (list = all_layers; list; list = g_list_next (list))
-
-      while (list)
         {
           item = (GimpItem *) list->data;
 
-          list = g_list_next (list);
-
           gimp_item_translate (item, -x1, -y1, TRUE);
 
           if (crop_layers)
@@ -281,6 +280,10 @@ gimp_image_crop (GimpImage   *image,
                                         previous_height);
 
       g_object_thaw_notify (G_OBJECT (image));
+
+      g_list_free (all_layers);
+      g_list_free (all_channels);
+      g_list_free (all_vectors);
     }
 
   gimp_unset_busy (image->gimp);

app/core/gimpimage-duplicate.c

@@ -202,6 +202,7 @@ gimp_image_duplicate_layers (GimpImage     *image,
 {
   GimpLayer *active_layer = NULL;
   GimpLayer *floating_selection;
+  GList     *all_layers;
   GList     *list;
   gint       count;
 
@@ -209,11 +210,11 @@ gimp_image_duplicate_layers (GimpImage     *image,
   floating_selection = gimp_image_get_floating_selection (image);
 
   if (floating_selection)
-    {
+    *floating_sel_drawable = gimp_layer_get_floating_sel_drawable (floating_selection);
-      *floating_sel_drawable = gimp_layer_get_floating_sel_drawable (floating_selection);
-    }
 
-  for (list = gimp_image_get_layer_iter (image), count = 0;
+  all_layers = gimp_image_get_layer_list (image);
+
+  for (list = all_layers, count = 0;
        list;
        list = g_list_next (list))
     {
@@ -248,6 +249,8 @@ gimp_image_duplicate_layers (GimpImage     *image,
         gimp_image_add_layer (new_image, new_layer, count++, FALSE);
     }
 
+  g_list_free (all_layers);
+
   return active_layer;
 }
 
@@ -258,10 +261,13 @@ gimp_image_duplicate_channels (GimpImage     *image,
                                GimpDrawable **new_floating_sel_drawable)
 {
   GimpChannel *active_channel = NULL;
+  GList       *all_channels;
   GList       *list;
   gint         count;
 
-  for (list = gimp_image_get_channel_iter (image), count = 0;
+  all_channels = gimp_image_get_channel_list (image);
+
+  for (list = all_channels, count = 0;
        list;
        list = g_list_next (list))
     {
@@ -277,7 +283,7 @@ gimp_image_duplicate_channels (GimpImage     *image,
                             gimp_object_get_name (GIMP_OBJECT (channel)));
 
       if (gimp_image_get_active_channel (image) == channel)
-        active_channel = (new_channel);
+        active_channel = new_channel;
 
       if (floating_sel_drawable == GIMP_DRAWABLE (channel))
         *new_floating_sel_drawable = GIMP_DRAWABLE (new_channel);
@@ -285,6 +291,8 @@ gimp_image_duplicate_channels (GimpImage     *image,
       gimp_image_add_channel (new_image, new_channel, count++, FALSE);
     }
 
+  g_list_free (all_channels);
+
   return active_channel;
 }
 
@@ -293,10 +301,13 @@ gimp_image_duplicate_vectors (GimpImage *image,
                               GimpImage *new_image)
 {
   GimpVectors *active_vectors = NULL;
+  GList       *all_vectors;
   GList       *list;
   gint         count;
 
-  for (list = gimp_image_get_vectors_iter (image), count = 0;
+  all_vectors = gimp_image_get_vectors_list (image);
+
+  for (list = all_vectors, count = 0;
        list;
        list = g_list_next (list))
     {
@@ -317,6 +328,8 @@ gimp_image_duplicate_vectors (GimpImage *image,
       gimp_image_add_vectors (new_image, new_vectors, count++, FALSE);
     }
 
+  g_list_free (all_vectors);
+
   return active_vectors;
 }
 
@@ -369,7 +382,9 @@ gimp_image_duplicate_guides (GimpImage *image,
 {
   GList *list;
 
-  for (list = gimp_image_get_guides (image); list; list = g_list_next (list))
+  for (list = gimp_image_get_guides (image);
+       list;
+       list = g_list_next (list))
     {
       GimpGuide *guide    = list->data;
       gint       position = gimp_guide_get_position (guide);

app/core/gimpimage-flip.c

@@ -42,6 +42,9 @@ gimp_image_flip (GimpImage           *image,
                  GimpOrientationType  flip_type,
                  GimpProgress        *progress)
 {
+  GList   *all_layers;
+  GList   *all_channels;
+  GList   *all_vectors;
   GList   *list;
   gdouble  axis;
   gdouble  progress_max;
@@ -68,17 +71,19 @@ gimp_image_flip (GimpImage           *image,
       return;
     }
 
-  progress_max = (gimp_container_get_n_children (image->channels) +
+  all_layers   = gimp_image_get_layer_list (image);
-                  gimp_container_get_n_children (image->layers)   +
+  all_channels = gimp_image_get_channel_list (image);
-                  gimp_container_get_n_children (image->vectors)  +
+  all_vectors  = gimp_image_get_vectors_list (image);
+
+  progress_max = (g_list_length (all_layers)   +
+                  g_list_length (all_channels) +
+                  g_list_length (all_vectors)  +
                   1 /* selection */);
 
   gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_IMAGE_FLIP, NULL);
 
   /*  Flip all channels  */
-  for (list = gimp_image_get_channel_iter (image);
+  for (list = all_channels; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -89,9 +94,7 @@ gimp_image_flip (GimpImage           *image,
     }
 
   /*  Flip all vectors  */
-  for (list = gimp_image_get_vectors_iter (image);
+  for (list = all_vectors; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -109,9 +112,7 @@ gimp_image_flip (GimpImage           *image,
     gimp_progress_set_value (progress, progress_current++ / progress_max);
 
   /*  Flip all layers  */
-  for (list = gimp_image_get_layer_iter (image);
+  for (list = all_layers; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -122,7 +123,9 @@ gimp_image_flip (GimpImage           *image,
     }
 
   /*  Flip all Guides  */
-  for (list = gimp_image_get_guides (image); list; list = g_list_next (list))
+  for (list = gimp_image_get_guides (image);
+       list;
+       list = g_list_next (list))
     {
       GimpGuide *guide    = list->data;
       gint       position = gimp_guide_get_position (guide);
@@ -149,7 +152,9 @@ gimp_image_flip (GimpImage           *image,
     }
 
   /*  Flip all sample points  */
-  for (list = gimp_image_get_sample_points (image); list; list = g_list_next (list))
+  for (list = gimp_image_get_sample_points (image);
+       list;
+       list = g_list_next (list))
     {
       GimpSamplePoint *sample_point = list->data;
 
@@ -170,5 +175,9 @@ gimp_image_flip (GimpImage           *image,
 
   gimp_image_undo_group_end (image);
 
+  g_list_free (all_layers);
+  g_list_free (all_channels);
+  g_list_free (all_vectors);
+
   gimp_unset_busy (image->gimp);
 }

app/core/gimpimage-item-list.c

@@ -162,6 +162,7 @@ gimp_image_item_list_get_list (const GimpImage  *image,
                                GimpItemTypeMask  type,
                                GimpItemSet       set)
 {
+  GList *all_items;
   GList *list;
   GList *return_list = NULL;
 
@@ -170,41 +171,47 @@ gimp_image_item_list_get_list (const GimpImage  *image,
 
   if (type & GIMP_ITEM_TYPE_LAYERS)
     {
-      for (list = gimp_image_get_layer_iter (image);
+      all_items = gimp_image_get_layer_list (image);
-           list;
+
-           list = g_list_next (list))
+      for (list = all_items; list; list = g_list_next (list))
         {
           GimpItem *item = list->data;
 
           if (item != exclude && gimp_item_is_in_set (item, set))
             return_list = g_list_prepend (return_list, item);
         }
+
+      g_list_free (all_items);
     }
 
   if (type & GIMP_ITEM_TYPE_CHANNELS)
     {
-      for (list = gimp_image_get_channel_iter (image);
+      all_items = gimp_image_get_channel_list (image);
-           list;
+
-           list = g_list_next (list))
+      for (list = all_items; list; list = g_list_next (list))
         {
           GimpItem *item = list->data;
 
           if (item != exclude && gimp_item_is_in_set (item, set))
             return_list = g_list_prepend (return_list, item);
         }
+
+      g_list_free (all_items);
     }
 
   if (type & GIMP_ITEM_TYPE_VECTORS)
     {
-      for (list = gimp_image_get_vectors_iter (image);
+      all_items = gimp_image_get_vectors_list (image);
-           list;
+
-           list = g_list_next (list))
+      for (list = all_items; list; list = g_list_next (list))
         {
           GimpItem *item = list->data;
 
           if (item != exclude && gimp_item_is_in_set (item, set))
             return_list = g_list_prepend (return_list, item);
         }
+
+      g_list_free (all_items);
     }
 
   return g_list_reverse (return_list);

app/core/gimpimage-resize.c

@@ -65,6 +65,9 @@ gimp_image_resize_with_layers (GimpImage    *image,
                                GimpItemSet   layer_set,
                                GimpProgress *progress)
 {
+  GList   *all_layers;
+  GList   *all_channels;
+  GList   *all_vectors;
   GList   *list;
   GList   *resize_layers;
   gdouble  progress_max;
@@ -78,9 +81,13 @@ gimp_image_resize_with_layers (GimpImage    *image,
 
   gimp_set_busy (image->gimp);
 
-  progress_max = (gimp_container_get_n_children (image->channels) +
+  all_layers   = gimp_image_get_layer_list (image);
-                  gimp_container_get_n_children (image->layers)   +
+  all_channels = gimp_image_get_channel_list (image);
-                  gimp_container_get_n_children (image->vectors)  +
+  all_vectors  = gimp_image_get_vectors_list (image);
+
+  progress_max = (g_list_length (all_layers)   +
+                  g_list_length (all_channels) +
+                  g_list_length (all_vectors)  +
                   1 /* selection */);
 
   g_object_freeze_notify (G_OBJECT (image));
@@ -110,9 +117,7 @@ gimp_image_resize_with_layers (GimpImage    *image,
                 NULL);
 
   /*  Resize all channels  */
-  for (list = gimp_image_get_channel_iter (image);
+  for (list = all_channels; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -124,9 +129,7 @@ gimp_image_resize_with_layers (GimpImage    *image,
     }
 
   /*  Resize all vectors  */
-  for (list = gimp_image_get_vectors_iter (image);
+  for (list = all_vectors; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -145,9 +148,7 @@ gimp_image_resize_with_layers (GimpImage    *image,
     gimp_progress_set_value (progress, progress_current++ / progress_max);
 
   /*  Reposition all layers  */
-  for (list = gimp_image_get_layer_iter (image);
+  for (list = all_layers; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
       gint      old_offset_x;
@@ -169,7 +170,9 @@ gimp_image_resize_with_layers (GimpImage    *image,
   g_list_free (resize_layers);
 
   /*  Reposition or remove all guides  */
-  for (list = gimp_image_get_guides (image); list; list = g_list_next (list))
+  for (list = gimp_image_get_guides (image);
+       list;
+       list = g_list_next (list))
     {
       GimpGuide *guide        = list->data;
       gboolean   remove_guide = FALSE;
@@ -200,7 +203,9 @@ gimp_image_resize_with_layers (GimpImage    *image,
     }
 
   /*  Reposition or remove sample points  */
-  for (list = gimp_image_get_sample_points (image); list; list = g_list_next (list))
+  for (list = gimp_image_get_sample_points (image);
+       list;
+       list = g_list_next (list))
     {
       GimpSamplePoint *sample_point        = list->data;
       gboolean         remove_sample_point = FALSE;
@@ -232,6 +237,10 @@ gimp_image_resize_with_layers (GimpImage    *image,
 
   g_object_thaw_notify (G_OBJECT (image));
 
+  g_list_free (all_layers);
+  g_list_free (all_channels);
+  g_list_free (all_vectors);
+
   gimp_unset_busy (image->gimp);
 }
 
@@ -240,25 +249,33 @@ gimp_image_resize_to_layers (GimpImage    *image,
                              GimpContext  *context,
                              GimpProgress *progress)
 {
-  GList    *list = gimp_image_get_layer_iter (image);
+  GList    *all_layers;
+  GList    *list;
   GimpItem *item;
   gint      min_x, max_x;
   gint      min_y, max_y;
 
-  if (!list)
+  g_return_if_fail (GIMP_IS_IMAGE (image));
+  g_return_if_fail (GIMP_IS_CONTEXT (context));
+  g_return_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress));
+
+  all_layers = gimp_image_get_layer_list (image);
+
+  if (! all_layers)
     return;
 
+  list = all_layers;
+
   /* figure out starting values */
   item = list->data;
+
   min_x = gimp_item_get_offset_x (item);
   min_y = gimp_item_get_offset_y (item);
   max_x = gimp_item_get_offset_x (item) + gimp_item_get_width  (item);
   max_y = gimp_item_get_offset_y (item) + gimp_item_get_height (item);
 
   /*  Respect all layers  */
-  for (list = g_list_next (list);
+  for (list = g_list_next (list); list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       item = list->data;
 

app/core/gimpimage-rotate.c

@@ -53,6 +53,9 @@ gimp_image_rotate (GimpImage        *image,
                    GimpRotationType  rotate_type,
                    GimpProgress     *progress)
 {
+  GList    *all_layers;
+  GList    *all_channels;
+  GList    *all_vectors;
   GList    *list;
   gdouble   center_x;
   gdouble   center_y;
@@ -78,9 +81,13 @@ gimp_image_rotate (GimpImage        *image,
   center_x              = previous_image_width  / 2.0;
   center_y              = previous_image_height / 2.0;
 
-  progress_max = (gimp_container_get_n_children (image->channels) +
+  all_layers   = gimp_image_get_layer_list (image);
-                  gimp_container_get_n_children (image->layers)   +
+  all_channels = gimp_image_get_channel_list (image);
-                  gimp_container_get_n_children (image->vectors)  +
+  all_vectors  = gimp_image_get_vectors_list (image);
+
+  progress_max = (g_list_length (all_layers)   +
+                  g_list_length (all_channels) +
+                  g_list_length (all_vectors)  +
                   1 /* selection */);
 
   g_object_freeze_notify (G_OBJECT (image));
@@ -113,9 +120,7 @@ gimp_image_rotate (GimpImage        *image,
     }
 
   /*  Rotate all channels  */
-  for (list = gimp_image_get_channel_iter (image);
+  for (list = all_channels; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -128,9 +133,7 @@ gimp_image_rotate (GimpImage        *image,
     }
 
   /*  Rotate all vectors  */
-  for (list = gimp_image_get_vectors_iter (image);
+  for (list = all_vectors; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -167,9 +170,7 @@ gimp_image_rotate (GimpImage        *image,
   }
 
   /*  Rotate all layers  */
-  for (list = gimp_image_get_layer_iter (image);
+  for (list = all_layers; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
       gint      off_x;
@@ -226,6 +227,10 @@ gimp_image_rotate (GimpImage        *image,
 
   g_object_thaw_notify (G_OBJECT (image));
 
+  g_list_free (all_layers);
+  g_list_free (all_channels);
+  g_list_free (all_vectors);
+
   gimp_unset_busy (image->gimp);
 }
 

app/core/gimpimage-scale.c

@@ -51,8 +51,10 @@ gimp_image_scale (GimpImage             *image,
                   GimpProgress          *progress)
 {
   GimpProgress *sub_progress;
+  GList        *all_layers;
+  GList        *all_channels;
+  GList        *all_vectors;
   GList        *list;
-  GList        *remove           = NULL;
   gint          old_width;
   gint          old_height;
   gint          offset_x;
@@ -70,9 +72,13 @@ gimp_image_scale (GimpImage             *image,
 
   sub_progress = gimp_sub_progress_new (progress);
 
-  progress_steps = (gimp_container_get_n_children (image->channels) +
+  all_layers   = gimp_image_get_layer_list (image);
-                    gimp_container_get_n_children (image->layers)   +
+  all_channels = gimp_image_get_channel_list (image);
-                    gimp_container_get_n_children (image->vectors)  +
+  all_vectors  = gimp_image_get_vectors_list (image);
+
+  progress_steps = (g_list_length (all_layers)   +
+                    g_list_length (all_channels) +
+                    g_list_length (all_vectors)  +
                     1 /* selection */);
 
   g_object_freeze_notify (G_OBJECT (image));
@@ -103,9 +109,7 @@ gimp_image_scale (GimpImage             *image,
                 NULL);
 
   /*  Scale all channels  */
-  for (list = gimp_image_get_channel_iter (image);
+  for (list = all_channels; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -118,9 +122,7 @@ gimp_image_scale (GimpImage             *image,
     }
 
   /*  Scale all vectors  */
-  for (list = gimp_image_get_vectors_iter (image);
+  for (list = all_vectors; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -141,9 +143,7 @@ gimp_image_scale (GimpImage             *image,
                    interpolation_type, sub_progress);
 
   /*  Scale all layers  */
-  for (list = gimp_image_get_layer_iter (image);
+  for (list = all_layers; list; list = g_list_next (list))
-       list;
-       list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
@@ -159,24 +159,10 @@ gimp_image_scale (GimpImage             *image,
            * here. Upstream warning implemented in resize_check_layer_scaling(),
            * which offers the user the chance to bail out.
            */
-          remove = g_list_prepend (remove, item);
+          gimp_image_remove_layer (image, GIMP_LAYER (item), TRUE, NULL);
         }
     }
 
-  /* We defer removing layers lost to scaling until now so as not to mix
-   * the operations of iterating over and removal from image->layers.
-   */
-  remove = g_list_reverse (remove);
-
-  for (list = remove; list; list = g_list_next (list))
-    {
-      GimpLayer *layer = list->data;
-
-      gimp_image_remove_layer (image, layer, TRUE, NULL);
-    }
-
-  g_list_free (remove);
-
   /*  Scale all Guides  */
   for (list = gimp_image_get_guides (image); list; list = g_list_next (list))
     {
@@ -214,6 +200,10 @@ gimp_image_scale (GimpImage             *image,
 
   gimp_image_undo_group_end (image);
 
+  g_list_free (all_layers);
+  g_list_free (all_channels);
+  g_list_free (all_vectors);
+
   g_object_unref (sub_progress);
 
   gimp_image_size_changed_detailed (image,
@@ -254,6 +244,7 @@ gimp_image_scale_check (const GimpImage *image,
                         gint64          *new_memsize)
 {
   GList  *drawables;
+  GList  *all_layers;
   GList  *list;
   gint64  current_size;
   gint64  scalable_size;
@@ -330,15 +321,21 @@ gimp_image_scale_check (const GimpImage *image,
   if (new_size > current_size && new_size > max_memsize)
     return GIMP_IMAGE_SCALE_TOO_BIG;
 
-  for (list = gimp_image_get_layer_iter (image);
+  all_layers = gimp_image_get_layer_list (image);
-       list;
+
-       list = g_list_next (list))
+  for (list = all_layers; list; list = g_list_next (list))
     {
       GimpItem *item = list->data;
 
       if (! gimp_item_check_scaling (item, new_width, new_height))
-        return GIMP_IMAGE_SCALE_TOO_SMALL;
+        {
+          g_list_free (all_layers);
+
+          return GIMP_IMAGE_SCALE_TOO_SMALL;
+        }
     }
 
+  g_list_free (all_layers);
+
   return GIMP_IMAGE_SCALE_OK;
 }