Adding upstream version 2.10.36.upstream/2.10.36

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 897 insertions, 0 deletions

diff --git a/app/pdb/gimpprocedure.c b/app/pdb/gimpprocedure.c
new file mode 100644
index 0000000..a12dab9
--- /dev/null
+++ b/app/pdb/gimpprocedure.c
@@ -0,0 +1,897 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdarg.h>
+#include <sys/types.h>
+
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <gegl.h>
+
+#include "libgimpbase/gimpbase.h"
+
+#include "pdb-types.h"
+
+#include "core/gimp.h"
+#include "core/gimp-memsize.h"
+#include "core/gimpchannel.h"
+#include "core/gimplayer.h"
+#include "core/gimpparamspecs.h"
+#include "core/gimpprogress.h"
+
+#include "vectors/gimpvectors.h"
+
+#include "gimppdbcontext.h"
+#include "gimppdberror.h"
+#include "gimpprocedure.h"
+
+#include "gimp-intl.h"
+
+
+static void          gimp_procedure_finalize            (GObject         *object);
+
+static gint64        gimp_procedure_get_memsize         (GimpObject      *object,
+                                                         gint64          *gui_size);
+
+static const gchar * gimp_procedure_real_get_label      (GimpProcedure   *procedure);
+static const gchar * gimp_procedure_real_get_menu_label (GimpProcedure   *procedure);
+static const gchar * gimp_procedure_real_get_blurb      (GimpProcedure   *procedure);
+static const gchar * gimp_procedure_real_get_help_id    (GimpProcedure   *procedure);
+static gboolean      gimp_procedure_real_get_sensitive  (GimpProcedure   *procedure,
+                                                         GimpObject      *object,
+                                                         const gchar    **tooltip);
+static GimpValueArray * gimp_procedure_real_execute     (GimpProcedure   *procedure,
+                                                         Gimp            *gimp,
+                                                         GimpContext     *context,
+                                                         GimpProgress    *progress,
+                                                         GimpValueArray  *args,
+                                                         GError         **error);
+static void        gimp_procedure_real_execute_async    (GimpProcedure   *procedure,
+                                                         Gimp            *gimp,
+                                                         GimpContext     *context,
+                                                         GimpProgress    *progress,
+                                                         GimpValueArray  *args,
+                                                         GimpObject      *display);
+
+static void          gimp_procedure_free_strings        (GimpProcedure   *procedure);
+static gboolean      gimp_procedure_validate_args       (GimpProcedure   *procedure,
+                                                         GParamSpec     **param_specs,
+                                                         gint             n_param_specs,
+                                                         GimpValueArray  *args,
+                                                         gboolean         return_vals,
+                                                         GError         **error);
+
+
+G_DEFINE_TYPE (GimpProcedure, gimp_procedure, GIMP_TYPE_VIEWABLE)
+
+#define parent_class gimp_procedure_parent_class
+
+
+static void
+gimp_procedure_class_init (GimpProcedureClass *klass)
+{
+  GObjectClass    *object_class      = G_OBJECT_CLASS (klass);
+  GimpObjectClass *gimp_object_class = GIMP_OBJECT_CLASS (klass);
+
+  object_class->finalize         = gimp_procedure_finalize;
+
+  gimp_object_class->get_memsize = gimp_procedure_get_memsize;
+
+  klass->get_label               = gimp_procedure_real_get_label;
+  klass->get_menu_label          = gimp_procedure_real_get_menu_label;
+  klass->get_blurb               = gimp_procedure_real_get_blurb;
+  klass->get_help_id             = gimp_procedure_real_get_help_id;
+  klass->get_sensitive           = gimp_procedure_real_get_sensitive;
+  klass->execute                 = gimp_procedure_real_execute;
+  klass->execute_async           = gimp_procedure_real_execute_async;
+}
+
+static void
+gimp_procedure_init (GimpProcedure *procedure)
+{
+  procedure->proc_type = GIMP_INTERNAL;
+}
+
+static void
+gimp_procedure_finalize (GObject *object)
+{
+  GimpProcedure *procedure = GIMP_PROCEDURE (object);
+  gint           i;
+
+  gimp_procedure_free_strings (procedure);
+
+  if (procedure->args)
+    {
+      for (i = 0; i < procedure->num_args; i++)
+        g_param_spec_unref (procedure->args[i]);
+
+      g_clear_pointer (&procedure->args, g_free);
+    }
+
+  if (procedure->values)
+    {
+      for (i = 0; i < procedure->num_values; i++)
+        g_param_spec_unref (procedure->values[i]);
+
+      g_clear_pointer (&procedure->values, g_free);
+    }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static gint64
+gimp_procedure_get_memsize (GimpObject *object,
+                            gint64     *gui_size)
+{
+  GimpProcedure *procedure = GIMP_PROCEDURE (object);
+  gint64         memsize   = 0;
+  gint           i;
+
+  if (! procedure->static_strings)
+    {
+      memsize += gimp_string_get_memsize (procedure->original_name);
+      memsize += gimp_string_get_memsize (procedure->blurb);
+      memsize += gimp_string_get_memsize (procedure->help);
+      memsize += gimp_string_get_memsize (procedure->author);
+      memsize += gimp_string_get_memsize (procedure->copyright);
+      memsize += gimp_string_get_memsize (procedure->date);
+      memsize += gimp_string_get_memsize (procedure->deprecated);
+    }
+
+  memsize += procedure->num_args * sizeof (GParamSpec *);
+
+  for (i = 0; i < procedure->num_args; i++)
+    memsize += gimp_g_param_spec_get_memsize (procedure->args[i]);
+
+  memsize += procedure->num_values * sizeof (GParamSpec *);
+
+  for (i = 0; i < procedure->num_values; i++)
+    memsize += gimp_g_param_spec_get_memsize (procedure->values[i]);
+
+  return memsize + GIMP_OBJECT_CLASS (parent_class)->get_memsize (object,
+                                                                  gui_size);
+}
+
+static const gchar *
+gimp_procedure_real_get_label (GimpProcedure *procedure)
+{
+  return gimp_object_get_name (procedure); /* lame fallback */
+}
+
+static const gchar *
+gimp_procedure_real_get_menu_label (GimpProcedure *procedure)
+{
+  return gimp_procedure_get_label (procedure);
+}
+
+static const gchar *
+gimp_procedure_real_get_blurb (GimpProcedure *procedure)
+{
+  return procedure->blurb;
+}
+
+static const gchar *
+gimp_procedure_real_get_help_id (GimpProcedure *procedure)
+{
+  return NULL;
+}
+
+static gboolean
+gimp_procedure_real_get_sensitive (GimpProcedure  *procedure,
+                                   GimpObject     *object,
+                                   const gchar   **tooltip)
+{
+  return TRUE /* random fallback */;
+}
+
+static GimpValueArray *
+gimp_procedure_real_execute (GimpProcedure   *procedure,
+                             Gimp            *gimp,
+                             GimpContext     *context,
+                             GimpProgress    *progress,
+                             GimpValueArray  *args,
+                             GError         **error)
+{
+  g_return_val_if_fail (gimp_value_array_length (args) >=
+                        procedure->num_args, NULL);
+
+  return procedure->marshal_func (procedure, gimp,
+                                  context, progress,
+                                  args, error);
+}
+
+static void
+gimp_procedure_real_execute_async (GimpProcedure  *procedure,
+                                   Gimp           *gimp,
+                                   GimpContext    *context,
+                                   GimpProgress   *progress,
+                                   GimpValueArray *args,
+                                   GimpObject     *display)
+{
+  GimpValueArray *return_vals;
+  GError         *error = NULL;
+
+  g_return_if_fail (gimp_value_array_length (args) >= procedure->num_args);
+
+  return_vals = GIMP_PROCEDURE_GET_CLASS (procedure)->execute (procedure,
+                                                               gimp,
+                                                               context,
+                                                               progress,
+                                                               args,
+                                                               &error);
+
+  gimp_value_array_unref (return_vals);
+
+  if (error)
+    {
+      gimp_message_literal (gimp, G_OBJECT (progress), GIMP_MESSAGE_ERROR,
+                            error->message);
+      g_error_free (error);
+    }
+}
+
+
+/*  public functions  */
+
+GimpProcedure  *
+gimp_procedure_new (GimpMarshalFunc marshal_func)
+{
+  GimpProcedure *procedure;
+
+  g_return_val_if_fail (marshal_func != NULL, NULL);
+
+  procedure = g_object_new (GIMP_TYPE_PROCEDURE, NULL);
+
+  procedure->marshal_func = marshal_func;
+
+  return procedure;
+}
+
+void
+gimp_procedure_set_strings (GimpProcedure *procedure,
+                            const gchar   *original_name,
+                            const gchar   *blurb,
+                            const gchar   *help,
+                            const gchar   *author,
+                            const gchar   *copyright,
+                            const gchar   *date,
+                            const gchar   *deprecated)
+{
+  g_return_if_fail (GIMP_IS_PROCEDURE (procedure));
+
+  gimp_procedure_free_strings (procedure);
+
+  procedure->original_name = g_strdup (original_name);
+  procedure->blurb         = g_strdup (blurb);
+  procedure->help          = g_strdup (help);
+  procedure->author        = g_strdup (author);
+  procedure->copyright     = g_strdup (copyright);
+  procedure->date          = g_strdup (date);
+  procedure->deprecated    = g_strdup (deprecated);
+
+  procedure->static_strings = FALSE;
+}
+
+void
+gimp_procedure_set_static_strings (GimpProcedure *procedure,
+                                   const gchar   *original_name,
+                                   const gchar   *blurb,
+                                   const gchar   *help,
+                                   const gchar   *author,
+                                   const gchar   *copyright,
+                                   const gchar   *date,
+                                   const gchar   *deprecated)
+{
+  g_return_if_fail (GIMP_IS_PROCEDURE (procedure));
+
+  gimp_procedure_free_strings (procedure);
+
+  procedure->original_name = (gchar *) original_name;
+  procedure->blurb         = (gchar *) blurb;
+  procedure->help          = (gchar *) help;
+  procedure->author        = (gchar *) author;
+  procedure->copyright     = (gchar *) copyright;
+  procedure->date          = (gchar *) date;
+  procedure->deprecated    = (gchar *) deprecated;
+
+  procedure->static_strings = TRUE;
+}
+
+void
+gimp_procedure_take_strings (GimpProcedure *procedure,
+                             gchar         *original_name,
+                             gchar         *blurb,
+                             gchar         *help,
+                             gchar         *author,
+                             gchar         *copyright,
+                             gchar         *date,
+                             gchar         *deprecated)
+{
+  g_return_if_fail (GIMP_IS_PROCEDURE (procedure));
+
+  gimp_procedure_free_strings (procedure);
+
+  procedure->original_name = original_name;
+  procedure->blurb         = blurb;
+  procedure->help          = help;
+  procedure->author        = author;
+  procedure->copyright     = copyright;
+  procedure->date          = date;
+  procedure->deprecated    = deprecated;
+
+  procedure->static_strings = FALSE;
+}
+
+const gchar *
+gimp_procedure_get_label (GimpProcedure *procedure)
+{
+  g_return_val_if_fail (GIMP_IS_PROCEDURE (procedure), NULL);
+
+  return GIMP_PROCEDURE_GET_CLASS (procedure)->get_label (procedure);
+}
+
+const gchar *
+gimp_procedure_get_menu_label (GimpProcedure *procedure)
+{
+  g_return_val_if_fail (GIMP_IS_PROCEDURE (procedure), NULL);
+
+  return GIMP_PROCEDURE_GET_CLASS (procedure)->get_menu_label (procedure);
+}
+
+const gchar *
+gimp_procedure_get_blurb (GimpProcedure *procedure)
+{
+  g_return_val_if_fail (GIMP_IS_PROCEDURE (procedure), NULL);
+
+  return GIMP_PROCEDURE_GET_CLASS (procedure)->get_blurb (procedure);
+}
+
+const gchar *
+gimp_procedure_get_help_id (GimpProcedure *procedure)
+{
+  g_return_val_if_fail (GIMP_IS_PROCEDURE (procedure), NULL);
+
+  return GIMP_PROCEDURE_GET_CLASS (procedure)->get_help_id (procedure);
+}
+
+gboolean
+gimp_procedure_get_sensitive (GimpProcedure  *procedure,
+                              GimpObject     *object,
+                              const gchar   **tooltip)
+{
+  const gchar *my_tooltip = NULL;
+  gboolean     sensitive;
+
+  g_return_val_if_fail (GIMP_IS_PROCEDURE (procedure), FALSE);
+  g_return_val_if_fail (object == NULL || GIMP_IS_OBJECT (object), FALSE);
+
+  sensitive = GIMP_PROCEDURE_GET_CLASS (procedure)->get_sensitive (procedure,
+                                                                   object,
+                                                                   &my_tooltip);
+
+  if (tooltip)
+    *tooltip = my_tooltip;
+
+  return sensitive;
+}
+
+GimpValueArray *
+gimp_procedure_execute (GimpProcedure   *procedure,
+                        Gimp            *gimp,
+                        GimpContext     *context,
+                        GimpProgress    *progress,
+                        GimpValueArray  *args,
+                        GError         **error)
+{
+  GimpValueArray *return_vals;
+  GError         *pdb_error = NULL;
+
+  g_return_val_if_fail (GIMP_IS_PROCEDURE (procedure), NULL);
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), NULL);
+  g_return_val_if_fail (GIMP_IS_CONTEXT (context), NULL);
+  g_return_val_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress), NULL);
+  g_return_val_if_fail (args != NULL, NULL);
+  g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+
+  if (! gimp_procedure_validate_args (procedure,
+                                      procedure->args, procedure->num_args,
+                                      args, FALSE, &pdb_error))
+    {
+      return_vals = gimp_procedure_get_return_values (procedure, FALSE,
+                                                      pdb_error);
+      g_propagate_error (error, pdb_error);
+
+      return return_vals;
+    }
+
+  if (GIMP_IS_PDB_CONTEXT (context))
+    context = g_object_ref (context);
+  else
+    context = gimp_pdb_context_new (gimp, context, TRUE);
+
+  if (progress)
+    g_object_ref (progress);
+
+  /*  call the procedure  */
+  return_vals = GIMP_PROCEDURE_GET_CLASS (procedure)->execute (procedure,
+                                                               gimp,
+                                                               context,
+                                                               progress,
+                                                               args,
+                                                               error);
+
+  if (progress)
+    g_object_unref (progress);
+
+  g_object_unref (context);
+
+  if (return_vals)
+    {
+      switch (g_value_get_enum (gimp_value_array_index (return_vals, 0)))
+        {
+        case GIMP_PDB_CALLING_ERROR:
+        case GIMP_PDB_EXECUTION_ERROR:
+          /*  If the error has not already been set, construct one
+           *  from the error message that is optionally passed with
+           *  the return values.
+           */
+          if (error && *error == NULL &&
+              gimp_value_array_length (return_vals) > 1 &&
+              G_VALUE_HOLDS_STRING (gimp_value_array_index (return_vals, 1)))
+            {
+              GValue      *value   = gimp_value_array_index (return_vals, 1);
+              const gchar *message = g_value_get_string (value);
+
+              if (message)
+                g_set_error_literal (error, GIMP_PDB_ERROR,
+                                     GIMP_PDB_ERROR_FAILED,
+                                     message);
+            }
+          break;
+
+        default:
+          break;
+        }
+    }
+  else
+    {
+      g_warning ("%s: no return values, shouldn't happen", G_STRFUNC);
+
+      pdb_error = g_error_new (GIMP_PDB_ERROR,
+                               GIMP_PDB_ERROR_INVALID_RETURN_VALUE,
+                               _("Procedure '%s' returned no return values"),
+                               gimp_object_get_name (procedure));
+
+      return_vals = gimp_procedure_get_return_values (procedure, FALSE,
+                                                      pdb_error);
+      if (error && *error == NULL)
+        g_propagate_error (error, pdb_error);
+      else
+        g_error_free (pdb_error);
+
+    }
+
+  return return_vals;
+}
+
+void
+gimp_procedure_execute_async (GimpProcedure  *procedure,
+                              Gimp           *gimp,
+                              GimpContext    *context,
+                              GimpProgress   *progress,
+                              GimpValueArray *args,
+                              GimpObject     *display,
+                              GError        **error)
+{
+  g_return_if_fail (GIMP_IS_PROCEDURE (procedure));
+  g_return_if_fail (GIMP_IS_GIMP (gimp));
+  g_return_if_fail (GIMP_IS_CONTEXT (context));
+  g_return_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress));
+  g_return_if_fail (args != NULL);
+  g_return_if_fail (display == NULL || GIMP_IS_OBJECT (display));
+  g_return_if_fail (error == NULL || *error == NULL);
+
+  if (gimp_procedure_validate_args (procedure,
+                                    procedure->args, procedure->num_args,
+                                    args, FALSE, error))
+    {
+      if (GIMP_IS_PDB_CONTEXT (context))
+        context = g_object_ref (context);
+      else
+        context = gimp_pdb_context_new (gimp, context, TRUE);
+
+      if (progress)
+        g_object_ref (progress);
+
+      GIMP_PROCEDURE_GET_CLASS (procedure)->execute_async (procedure, gimp,
+                                                           context, progress,
+                                                           args, display);
+
+      if (progress)
+        g_object_unref (progress);
+
+      g_object_unref (context);
+    }
+}
+
+GimpValueArray *
+gimp_procedure_get_arguments (GimpProcedure *procedure)
+{
+  GimpValueArray *args;
+  GValue          value = G_VALUE_INIT;
+  gint            i;
+
+  g_return_val_if_fail (GIMP_IS_PROCEDURE (procedure), NULL);
+
+  args = gimp_value_array_new (procedure->num_args);
+
+  for (i = 0; i < procedure->num_args; i++)
+    {
+      g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (procedure->args[i]));
+      gimp_value_array_append (args, &value);
+      g_value_unset (&value);
+    }
+
+  return args;
+}
+
+GimpValueArray *
+gimp_procedure_get_return_values (GimpProcedure *procedure,
+                                  gboolean       success,
+                                  const GError  *error)
+{
+  GimpValueArray *args;
+  GValue          value = G_VALUE_INIT;
+  gint            i;
+
+  g_return_val_if_fail (success == FALSE || GIMP_IS_PROCEDURE (procedure),
+                        NULL);
+
+  if (success)
+    {
+      args = gimp_value_array_new (procedure->num_values + 1);
+
+      g_value_init (&value, GIMP_TYPE_PDB_STATUS_TYPE);
+      g_value_set_enum (&value, GIMP_PDB_SUCCESS);
+      gimp_value_array_append (args, &value);
+      g_value_unset (&value);
+
+      for (i = 0; i < procedure->num_values; i++)
+        {
+          g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (procedure->values[i]));
+          gimp_value_array_append (args, &value);
+          g_value_unset (&value);
+        }
+    }
+  else
+    {
+      args = gimp_value_array_new ((error && error->message) ? 2 : 1);
+
+      g_value_init (&value, GIMP_TYPE_PDB_STATUS_TYPE);
+
+      /*  errors in the GIMP_PDB_ERROR domain are calling errors  */
+      if (error && error->domain == GIMP_PDB_ERROR)
+        {
+          switch ((GimpPdbErrorCode) error->code)
+            {
+            case GIMP_PDB_ERROR_FAILED:
+            case GIMP_PDB_ERROR_PROCEDURE_NOT_FOUND:
+            case GIMP_PDB_ERROR_INVALID_ARGUMENT:
+            case GIMP_PDB_ERROR_INVALID_RETURN_VALUE:
+            case GIMP_PDB_ERROR_INTERNAL_ERROR:
+              g_value_set_enum (&value, GIMP_PDB_CALLING_ERROR);
+              break;
+
+            case GIMP_PDB_ERROR_CANCELLED:
+              g_value_set_enum (&value, GIMP_PDB_CANCEL);
+              break;
+
+            default:
+              gimp_assert_not_reached ();
+            }
+        }
+      else
+        {
+          g_value_set_enum (&value, GIMP_PDB_EXECUTION_ERROR);
+        }
+
+      gimp_value_array_append (args, &value);
+      g_value_unset (&value);
+
+      if (error && error->message)
+        {
+          g_value_init (&value, G_TYPE_STRING);
+          g_value_set_string (&value, error->message);
+          gimp_value_array_append (args, &value);
+          g_value_unset (&value);
+        }
+    }
+
+  return args;
+}
+
+void
+gimp_procedure_add_argument (GimpProcedure *procedure,
+                             GParamSpec    *pspec)
+{
+  g_return_if_fail (GIMP_IS_PROCEDURE (procedure));
+  g_return_if_fail (G_IS_PARAM_SPEC (pspec));
+
+  procedure->args = g_renew (GParamSpec *, procedure->args,
+                             procedure->num_args + 1);
+
+  procedure->args[procedure->num_args] = pspec;
+
+  g_param_spec_ref_sink (pspec);
+
+  procedure->num_args++;
+}
+
+void
+gimp_procedure_add_return_value (GimpProcedure *procedure,
+                                 GParamSpec    *pspec)
+{
+  g_return_if_fail (GIMP_IS_PROCEDURE (procedure));
+  g_return_if_fail (G_IS_PARAM_SPEC (pspec));
+
+  procedure->values = g_renew (GParamSpec *, procedure->values,
+                               procedure->num_values + 1);
+
+  procedure->values[procedure->num_values] = pspec;
+
+  g_param_spec_ref_sink (pspec);
+
+  procedure->num_values++;
+}
+
+/**
+ * gimp_procedure_create_override:
+ * @procedure:
+ * @new_marshal_func:
+ *
+ * Creates a new GimpProcedure that can be used to override the
+ * existing @procedure.
+ *
+ * Returns: The new #GimpProcedure.
+ **/
+GimpProcedure *
+gimp_procedure_create_override (GimpProcedure   *procedure,
+                                GimpMarshalFunc  new_marshal_func)
+{
+  GimpProcedure *new_procedure = NULL;
+  const gchar   *name          = NULL;
+  int            i             = 0;
+
+  new_procedure = gimp_procedure_new (new_marshal_func);
+  name          = gimp_object_get_name (procedure);
+
+  gimp_object_set_static_name (GIMP_OBJECT (new_procedure), name);
+
+  for (i = 0; i < procedure->num_args; i++)
+    gimp_procedure_add_argument (new_procedure, procedure->args[i]);
+
+  for (i = 0; i < procedure->num_values; i++)
+    gimp_procedure_add_return_value (new_procedure, procedure->values[i]);
+
+  return new_procedure;
+}
+
+gint
+gimp_procedure_name_compare (GimpProcedure *proc1,
+                             GimpProcedure *proc2)
+{
+  /* Assume there always is a name, don't bother with NULL checks */
+  return strcmp (proc1->original_name,
+                 proc2->original_name);
+}
+
+/*  private functions  */
+
+static void
+gimp_procedure_free_strings (GimpProcedure *procedure)
+{
+  if (! procedure->static_strings)
+    {
+      g_free (procedure->original_name);
+      g_free (procedure->blurb);
+      g_free (procedure->help);
+      g_free (procedure->author);
+      g_free (procedure->copyright);
+      g_free (procedure->date);
+      g_free (procedure->deprecated);
+    }
+
+  procedure->original_name = NULL;
+  procedure->blurb         = NULL;
+  procedure->help          = NULL;
+  procedure->author        = NULL;
+  procedure->copyright     = NULL;
+  procedure->date          = NULL;
+  procedure->deprecated    = NULL;
+
+  procedure->static_strings = FALSE;
+}
+
+static gboolean
+gimp_procedure_validate_args (GimpProcedure  *procedure,
+                              GParamSpec    **param_specs,
+                              gint            n_param_specs,
+                              GimpValueArray *args,
+                              gboolean        return_vals,
+                              GError        **error)
+{
+  gint i;
+
+  for (i = 0; i < MIN (gimp_value_array_length (args), n_param_specs); i++)
+    {
+      GValue     *arg       = gimp_value_array_index (args, i);
+      GParamSpec *pspec     = param_specs[i];
+      GType       arg_type  = G_VALUE_TYPE (arg);
+      GType       spec_type = G_PARAM_SPEC_VALUE_TYPE (pspec);
+
+      if (arg_type != spec_type)
+        {
+          if (return_vals)
+            {
+              g_set_error (error,
+                           GIMP_PDB_ERROR, GIMP_PDB_ERROR_INVALID_RETURN_VALUE,
+                           _("Procedure '%s' returned a wrong value type "
+                             "for return value '%s' (#%d). "
+                             "Expected %s, got %s."),
+                           gimp_object_get_name (procedure),
+                           g_param_spec_get_name (pspec),
+                           i + 1, g_type_name (spec_type),
+                           g_type_name (arg_type));
+            }
+          else
+            {
+              g_set_error (error,
+                           GIMP_PDB_ERROR, GIMP_PDB_ERROR_INVALID_ARGUMENT,
+                           _("Procedure '%s' has been called with a "
+                             "wrong value type for argument '%s' (#%d). "
+                             "Expected %s, got %s."),
+                           gimp_object_get_name (procedure),
+                           g_param_spec_get_name (pspec),
+                           i + 1, g_type_name (spec_type),
+                           g_type_name (arg_type));
+            }
+
+          return FALSE;
+        }
+      else if (! (pspec->flags & GIMP_PARAM_NO_VALIDATE))
+        {
+          GValue string_value = G_VALUE_INIT;
+
+          g_value_init (&string_value, G_TYPE_STRING);
+
+          if (g_value_type_transformable (arg_type, G_TYPE_STRING))
+            g_value_transform (arg, &string_value);
+          else
+            g_value_set_static_string (&string_value,
+                                       "<not transformable to string>");
+
+          if (g_param_value_validate (pspec, arg))
+            {
+              if (GIMP_IS_PARAM_SPEC_DRAWABLE_ID (pspec) &&
+                  g_value_get_int (arg) == -1)
+                {
+                  if (return_vals)
+                    {
+                      g_set_error (error,
+                                   GIMP_PDB_ERROR,
+                                   GIMP_PDB_ERROR_INVALID_RETURN_VALUE,
+                                   _("Procedure '%s' returned an "
+                                     "invalid ID for argument '%s'. "
+                                     "Most likely a plug-in is trying "
+                                     "to work on a layer that doesn't "
+                                     "exist any longer."),
+                                   gimp_object_get_name (procedure),
+                                   g_param_spec_get_name (pspec));
+                    }
+                  else
+                    {
+                      g_set_error (error,
+                                   GIMP_PDB_ERROR,
+                                   GIMP_PDB_ERROR_INVALID_ARGUMENT,
+                                   _("Procedure '%s' has been called with an "
+                                     "invalid ID for argument '%s'. "
+                                     "Most likely a plug-in is trying "
+                                     "to work on a layer that doesn't "
+                                     "exist any longer."),
+                                   gimp_object_get_name (procedure),
+                                   g_param_spec_get_name (pspec));
+                    }
+                }
+              else if (GIMP_IS_PARAM_SPEC_IMAGE_ID (pspec) &&
+                       g_value_get_int (arg) == -1)
+                {
+                  if (return_vals)
+                    {
+                      g_set_error (error,
+                                   GIMP_PDB_ERROR,
+                                   GIMP_PDB_ERROR_INVALID_RETURN_VALUE,
+                                   _("Procedure '%s' returned an "
+                                     "invalid ID for argument '%s'. "
+                                     "Most likely a plug-in is trying "
+                                     "to work on an image that doesn't "
+                                     "exist any longer."),
+                                   gimp_object_get_name (procedure),
+                                   g_param_spec_get_name (pspec));
+                    }
+                  else
+                    {
+                      g_set_error (error,
+                                   GIMP_PDB_ERROR,
+                                   GIMP_PDB_ERROR_INVALID_ARGUMENT,
+                                   _("Procedure '%s' has been called with an "
+                                     "invalid ID for argument '%s'. "
+                                     "Most likely a plug-in is trying "
+                                     "to work on an image that doesn't "
+                                     "exist any longer."),
+                                   gimp_object_get_name (procedure),
+                                   g_param_spec_get_name (pspec));
+                    }
+                }
+              else
+                {
+                  const gchar *value = g_value_get_string (&string_value);
+
+                  if (value == NULL)
+                    value = "(null)";
+
+                  if (return_vals)
+                    {
+                      g_set_error (error,
+                                   GIMP_PDB_ERROR,
+                                   GIMP_PDB_ERROR_INVALID_RETURN_VALUE,
+                                   _("Procedure '%s' returned "
+                                     "'%s' as return value '%s' "
+                                     "(#%d, type %s). "
+                                     "This value is out of range."),
+                                   gimp_object_get_name (procedure),
+                                   value,
+                                   g_param_spec_get_name (pspec),
+                                   i + 1, g_type_name (spec_type));
+                    }
+                  else
+                    {
+                      g_set_error (error,
+                                   GIMP_PDB_ERROR,
+                                   GIMP_PDB_ERROR_INVALID_ARGUMENT,
+                                   _("Procedure '%s' has been called with "
+                                     "value '%s' for argument '%s' "
+                                     "(#%d, type %s). "
+                                     "This value is out of range."),
+                                   gimp_object_get_name (procedure),
+                                   value,
+                                   g_param_spec_get_name (pspec),
+                                   i + 1, g_type_name (spec_type));
+                    }
+                }
+
+              g_value_unset (&string_value);
+
+              return FALSE;
+            }
+
+          g_value_unset (&string_value);
+        }
+    }
+
+  return TRUE;
+}