[gimp] app: layers-crop-to-selection and layers-crop-to-content multi-layers…

[Jehan <jehanp src gnome org>]

commit 4b3348dffea2bb2d4027309866ac0f27241cc5f3
Author: Jehan <jehan girinstud io>
Date:   Thu Jul 30 18:35:34 2020 +0200

    app: layers-crop-to-selection and layers-crop-to-content multi-layers…
    
    … aware.

 app/actions/layers-actions.c  |   8 +--
 app/actions/layers-commands.c | 115 ++++++++++++++++++++++++++++--------------
 2 files changed, 81 insertions(+), 42 deletions(-)
---
diff --git a/app/actions/layers-actions.c b/app/actions/layers-actions.c
index 053d4b850f..3fff0a0fa4 100644
--- a/app/actions/layers-actions.c
+++ b/app/actions/layers-actions.c
@@ -248,13 +248,13 @@ static const GimpActionEntry layers_actions[] =
 
   { "layers-crop-to-selection", GIMP_ICON_TOOL_CROP,
     NC_("layers-action", "_Crop to Selection"), NULL,
-    NC_("layers-action", "Crop the layer to the extents of the selection"),
+    NC_("layers-action", "Crop the layers to the extents of the selection"),
     layers_crop_to_selection_cmd_callback,
     GIMP_HELP_LAYER_CROP },
 
   { "layers-crop-to-content", GIMP_ICON_TOOL_CROP,
     NC_("layers-action", "Crop to C_ontent"), NULL,
-    NC_("layers-action", "Crop the layer to the extents of its content (remove empty borders from the 
layer)"),
+    NC_("layers-action", "Crop the layers to the extents of their content (remove empty borders from the 
layer)"),
     layers_crop_to_content_cmd_callback,
     GIMP_HELP_LAYER_CROP },
 
@@ -1061,8 +1061,8 @@ layers_actions_update (GimpActionGroup *group,
   SET_SENSITIVE ("layers-resize-to-image", all_writable && all_movable && !ac);
   SET_SENSITIVE ("layers-scale",           writable && movable && !ac);
 
-  SET_SENSITIVE ("layers-crop-to-selection", writable && movable && sel);
-  SET_SENSITIVE ("layers-crop-to-content",   writable && movable);
+  SET_SENSITIVE ("layers-crop-to-selection", all_writable && all_movable && sel);
+  SET_SENSITIVE ("layers-crop-to-content",   all_writable && all_movable);
 
   SET_SENSITIVE ("layers-alpha-add",    writable && !children && !fs && !alpha);
   SET_SENSITIVE ("layers-alpha-remove", writable && !children && !fs &&  alpha);
diff --git a/app/actions/layers-commands.c b/app/actions/layers-commands.c
index f6b9a8985f..831c67d45b 100644
--- a/app/actions/layers-commands.c
+++ b/app/actions/layers-commands.c
@@ -1176,12 +1176,13 @@ layers_crop_to_selection_cmd_callback (GimpAction *action,
                                        gpointer    data)
 {
   GimpImage *image;
-  GimpLayer *layer;
+  GList     *layers;
+  GList     *iter;
   GtkWidget *widget;
+  gchar     *desc;
   gint       x, y;
   gint       width, height;
-  gint       off_x, off_y;
-  return_if_no_layer (image, layer, data);
+  return_if_no_layers (image, layers, data);
   return_if_no_widget (widget, data);
 
   if (! gimp_item_bounds (GIMP_ITEM (gimp_image_get_mask (image)),
@@ -1194,16 +1195,25 @@ layers_crop_to_selection_cmd_callback (GimpAction *action,
       return;
     }
 
-  gimp_item_get_offset (GIMP_ITEM (layer), &off_x, &off_y);
-  off_x -= x;
-  off_y -= y;
+  desc = g_strdup_printf (ngettext ("Crop Layer to Selection",
+                                    "Crop %d Layers to Selection",
+                                    g_list_length (layers)),
+                          g_list_length (layers));
+  gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_ITEM_RESIZE, desc);
+  g_free (desc);
 
-  gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_ITEM_RESIZE,
-                               _("Crop Layer to Selection"));
+  for (iter = layers; iter; iter = iter->next)
+    {
+      gint off_x, off_y;
 
-  gimp_item_resize (GIMP_ITEM (layer),
-                    action_data_get_context (data), GIMP_FILL_TRANSPARENT,
-                    width, height, off_x, off_y);
+      gimp_item_get_offset (GIMP_ITEM (iter->data), &off_x, &off_y);
+      off_x -= x;
+      off_y -= y;
+
+      gimp_item_resize (GIMP_ITEM (iter->data),
+                        action_data_get_context (data), GIMP_FILL_TRANSPARENT,
+                        width, height, off_x, off_y);
+    }
 
   gimp_image_undo_group_end (image);
   gimp_image_flush (image);
@@ -1215,45 +1225,74 @@ layers_crop_to_content_cmd_callback (GimpAction *action,
                                      gpointer    data)
 {
   GimpImage *image;
-  GimpLayer *layer;
+  GList     *layers;
+  GList     *iter;
   GtkWidget *widget;
+  gchar     *desc;
   gint       x, y;
   gint       width, height;
-  return_if_no_layer (image, layer, data);
+  gint       n_croppable = 0;
+  return_if_no_layers (image, layers, data);
   return_if_no_widget (widget, data);
 
-  switch (gimp_pickable_auto_shrink (GIMP_PICKABLE (layer),
-                                     0, 0,
-                                     gimp_item_get_width  (GIMP_ITEM (layer)),
-                                     gimp_item_get_height (GIMP_ITEM (layer)),
-                                     &x, &y, &width, &height))
+  for (iter = layers; iter; iter = iter->next)
     {
-    case GIMP_AUTO_SHRINK_SHRINK:
-      gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_ITEM_RESIZE,
-                                   _("Crop Layer to Content"));
-
-      gimp_item_resize (GIMP_ITEM (layer),
-                        action_data_get_context (data), GIMP_FILL_TRANSPARENT,
-                        width, height, -x, -y);
+      switch (gimp_pickable_auto_shrink (GIMP_PICKABLE (iter->data),
+                                         0, 0,
+                                         gimp_item_get_width  (iter->data),
+                                         gimp_item_get_height (iter->data),
+                                         &x, &y, &width, &height))
+        {
+        case GIMP_AUTO_SHRINK_SHRINK:
+          n_croppable++;
+          break;
 
-      gimp_image_undo_group_end (image);
-      gimp_image_flush (image);
-      break;
+        case GIMP_AUTO_SHRINK_EMPTY:
+          /* Cannot crop because the layer has no content. */
+        case GIMP_AUTO_SHRINK_UNSHRINKABLE:
+          /* Cannot crop because the active layer is already cropped to
+           * its content. */
+          break;
+        }
+    }
 
-    case GIMP_AUTO_SHRINK_EMPTY:
+  if (n_croppable == 0)
+    {
       gimp_message_literal (image->gimp,
                             G_OBJECT (widget), GIMP_MESSAGE_INFO,
-                            _("Cannot crop because the active layer "
-                              "has no content."));
-      break;
+                            _("Cannot crop because none of the selected"
+                              " layers have content or they are already"
+                              " cropped to their content."));
+      return;
+    }
 
-    case GIMP_AUTO_SHRINK_UNSHRINKABLE:
-      gimp_message_literal (image->gimp,
-                            G_OBJECT (widget), GIMP_MESSAGE_INFO,
-                            _("Cannot crop because the active layer "
-                              "is already cropped to its content."));
-      break;
+  desc = g_strdup_printf (ngettext ("Crop Layer to Content",
+                                    "Crop %d Layers to Content",
+                                    n_croppable),
+                          n_croppable);
+  gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_ITEM_RESIZE, desc);
+  g_free (desc);
+
+  for (iter = layers; iter; iter = iter->next)
+    {
+      switch (gimp_pickable_auto_shrink (GIMP_PICKABLE (iter->data),
+                                         0, 0,
+                                         gimp_item_get_width  (iter->data),
+                                         gimp_item_get_height (iter->data),
+                                         &x, &y, &width, &height))
+        {
+        case GIMP_AUTO_SHRINK_SHRINK:
+          gimp_item_resize (iter->data,
+                            action_data_get_context (data), GIMP_FILL_TRANSPARENT,
+                            width, height, -x, -y);
+
+          break;
+        default:
+          break;
+        }
     }
+  gimp_image_flush (image);
+  gimp_image_undo_group_end (image);
 }
 
 void