[gimp] libgimp: make gimpgpparams-body.c identical for app/ and libgimp/ again

[Michael Natterer <mitch src gnome org>]

commit 773586f0c4d9f283e5e973de493c8f28b18b4e11
Author: Michael Natterer <mitch gimp org>
Date:   Fri Aug 23 23:31:19 2019 +0200

    libgimp: make gimpgpparams-body.c identical for app/ and libgimp/ again
    
    Use direct GType comparisons where possible, special case layer
    because it has core subclasses but only one PDB type, special case
    display because it's not visible from app/plug-in/, make code for
    GPParamDef and GPParam look the same.

 app/plug-in/gimpgpparams.c  |   6 ++
 libgimp/gimpgpparams-body.c | 169 ++++++++++++++++++++++++++++----------------
 libgimp/gimpgpparams.c      |   2 -
 3 files changed, 113 insertions(+), 64 deletions(-)
---
diff --git a/app/plug-in/gimpgpparams.c b/app/plug-in/gimpgpparams.c
index 59460bf6ef..f14c6bbbb1 100644
--- a/app/plug-in/gimpgpparams.c
+++ b/app/plug-in/gimpgpparams.c
@@ -31,8 +31,14 @@
 #include "plug-in-types.h"
 
 #include "core/gimp.h"
+#include "core/gimpimage.h"
+#include "core/gimplayer.h"
+#include "core/gimplayermask.h"
+#include "core/gimpselection.h"
 #include "core/gimpparamspecs.h"
 
+#include "vectors/gimpvectors.h"
+
 #include "libgimp/gimpgpparams.h"
 
 
diff --git a/libgimp/gimpgpparams-body.c b/libgimp/gimpgpparams-body.c
index 4ec7ab4bc9..c33b624be3 100644
--- a/libgimp/gimpgpparams-body.c
+++ b/libgimp/gimpgpparams-body.c
@@ -164,38 +164,60 @@ _gimp_param_spec_to_gp_param_def (GParamSpec *pspec,
     }
   else if (pspec_type == G_TYPE_PARAM_OBJECT)
     {
-      /* We can't pass objects over the wire, but we can support
-       * specific objects which are actually handled in the core through
-       * IDs by converting these types to their respective IDs.
-       */
+      GType        value_type = G_PARAM_SPEC_VALUE_TYPE (pspec);
+      const gchar *type_name  = NULL;
 
-      /* Don't compare with libgimp types directly as this file is also
-       * included from app/ which won't know of the types.
-       */
-      if (g_strcmp0 (g_type_name (pspec->value_type), "GimpImage") == 0)
-        param_def->type_name = "GimpParamImageID";
-      if (g_strcmp0 (g_type_name (pspec->value_type), "GimpDisplay") == 0)
-        param_def->type_name = "GimpParamDisplayID";
-      else if (g_strcmp0 (g_type_name (pspec->value_type), "GimpItem") == 0)
-        param_def->type_name = "GimpParamItemID";
-      else if (g_strcmp0 (g_type_name (pspec->value_type), "GimpDrawable") == 0)
-        param_def->type_name = "GimpParamDrawableID";
-      else if (g_strcmp0 (g_type_name (pspec->value_type), "GimpLayer") == 0)
-        param_def->type_name = "GimpParamLayerID";
-      else if (g_strcmp0 (g_type_name (pspec->value_type), "GimpChannel") == 0)
-        param_def->type_name = "GimpParamChannelID";
-      else if (g_strcmp0 (g_type_name (pspec->value_type), "GimpLayerMask") == 0)
-        param_def->type_name = "GimpParamLayerMaskID";
-      else if (g_strcmp0 (g_type_name (pspec->value_type), "GimpSelection") == 0)
-        param_def->type_name = "GimpParamSelectionID";
-      else if (g_strcmp0 (g_type_name (pspec->value_type), "GimpVectors") == 0)
-        param_def->type_name = "GimpParamVectorsID";
-
-      if (G_PARAM_SPEC_TYPE_NAME (pspec)  != param_def->type_name)
+      if (! strcmp (g_type_name (value_type), "GimpDisplay"))
+        {
+          /* strcmp() because GimpDisplay is not visible from app/plug-in */
+          type_name = "GimpParamDisplayID";
+        }
+      else if (value_type == GIMP_TYPE_IMAGE)
+        {
+          type_name = "GimpParamImageID";
+        }
+      else if (value_type == GIMP_TYPE_ITEM)
+        {
+          type_name = "GimpParamItemID";
+        }
+      else if (value_type == GIMP_TYPE_DRAWABLE)
         {
-          param_def->param_def_type = GP_PARAM_DEF_TYPE_ID;
+          type_name = "GimpParamDrawableID";
+        }
+      else if (g_type_is_a (value_type, GIMP_TYPE_LAYER))
+        {
+          /* g_type_is_a() because the core has layer subclasses */
+          type_name = "GimpParamLayerID";
+        }
+      else if (value_type == GIMP_TYPE_CHANNEL)
+        {
+          type_name = "GimpParamChannelID";
+        }
+      else if (value_type == GIMP_TYPE_LAYER_MASK)
+        {
+          type_name = "GimpParamLayerMaskID";
+        }
+      else if (value_type == GIMP_TYPE_SELECTION)
+        {
+          type_name = "GimpParamSelectionID";
+        }
+      else if (value_type == GIMP_TYPE_VECTORS)
+        {
+          type_name = "GimpParamVectorsID";
+        }
+
+      if (type_name)
+        {
+          param_def->param_def_type    = GP_PARAM_DEF_TYPE_ID;
+          param_def->type_name         = (gchar *) type_name;
           param_def->meta.m_id.none_ok = TRUE;
         }
+      else
+        {
+          g_printerr ("%s: GParamSpec is for object type "
+                      "which has no ID '%s'\n",
+                      G_STRFUNC, param_def->type_name);
+        }
     }
 }
 
@@ -448,7 +470,7 @@ _gimp_value_to_gp_param (const GValue *value,
   g_return_if_fail (value != NULL);
   g_return_if_fail (param != NULL);
 
-  type  = G_VALUE_TYPE (value);
+  type = G_VALUE_TYPE (value);
 
   param->param_type = -1;
 
@@ -612,53 +634,76 @@ _gimp_value_to_gp_param (const GValue *value,
     }
   else if (G_VALUE_HOLDS_OBJECT (value))
     {
-#ifdef  __LIBGIMP_GPPARAMS__
-      GObject     *object    = g_value_get_object (value);
       const gchar *type_name = NULL;
 
-      if (full_copy)
-        g_clear_pointer (&param->type_name, g_free);
-
-      if (GIMP_IS_IMAGE (object))
+      if (! strcmp (g_type_name (type), "GimpDisplay"))
+        {
+          /* strcmp() because GimpDisplay is not visible from app/plug-in */
+          type_name = "GimpDisplayID";
+        }
+      else if (type == GIMP_TYPE_IMAGE)
         {
           type_name = "GimpImageID";
-          param->param_type = GP_PARAM_TYPE_INT;
-          param->data.d_int = gimp_image_get_id (GIMP_IMAGE (object));
         }
-      if (GIMP_IS_DISPLAY (object))
+      else if (type == GIMP_TYPE_ITEM)
         {
-          type_name = "GimpDisplayID";
-          param->param_type = GP_PARAM_TYPE_INT;
-          param->data.d_int = gimp_display_get_id (GIMP_DISPLAY (object));
+          type_name = "GimpItemID";
         }
-      else if (GIMP_IS_ITEM (object))
+      else if (type == GIMP_TYPE_DRAWABLE)
         {
-          param->param_type = GP_PARAM_TYPE_INT;
-          param->data.d_int = gimp_item_get_id (GIMP_ITEM (object));
-
-          if (GIMP_IS_LAYER (object))
-            type_name = "GimpLayerID";
-          else if (GIMP_IS_LAYER_MASK (object))
-            type_name = "GimpLayerMaskID";
-          else if (GIMP_IS_SELECTION (object))
-            type_name = "GimpSelectionID";
-          else if (GIMP_IS_VECTORS (object))
-            type_name = "GimpVectorsID";
-          else if (GIMP_IS_CHANNEL (object))
-            type_name = "GimpChannelID";
-          else if (GIMP_IS_DRAWABLE (object))
-            type_name = "GimpDrawableID";
-          else
-            type_name = "GimpItemID";
+          type_name = "GimpDrawableID";
+        }
+      else if (g_type_is_a (type, GIMP_TYPE_LAYER))
+        {
+          /* g_type_is_a() because the core has layer subclasses */
+          type_name = "GimpLayerID";
         }
+      else if (type == GIMP_TYPE_CHANNEL)
+        {
+          type_name = "GimpChannelID";
+        }
+      else if (type == GIMP_TYPE_LAYER_MASK)
+        {
+          type_name = "GimpLayerMaskID";
+        }
+      else if (type == GIMP_TYPE_SELECTION)
+        {
+          type_name = "GimpSelectionID";
+        }
+      else if (type == GIMP_TYPE_VECTORS)
+        {
+          type_name = "GimpVectorsID";
+        }
+
       if (type_name)
         {
+          GObject *object = g_value_get_object (value);
+          gint     id     = -1;
+
+          if (object)
+            g_object_get (object, "id", id, NULL);
+
+          param->param_type = GP_PARAM_TYPE_INT;
+
           if (full_copy)
-            param->type_name = g_strdup (type_name);
+            {
+              g_free (param->type_name);
+              param->type_name = g_strdup (type_name);
+            }
           else
-            param->type_name = (gchar *) type_name;
+            {
+              param->type_name = (gchar *) type_name;
+            }
+
+          param->data.d_int = id;
+        }
+      else
+        {
+          g_printerr ("%s: GValue contains unsupported object type "
+                      "which has no ID '%s'\n",
+                      G_STRFUNC, param->type_name);
+          return;
         }
-#endif  /* __LIBGIMP_GPPARAMS__ */
     }
 
   if (param->param_type == -1)
diff --git a/libgimp/gimpgpparams.c b/libgimp/gimpgpparams.c
index b78a060482..a7bfd1daaf 100644
--- a/libgimp/gimpgpparams.c
+++ b/libgimp/gimpgpparams.c
@@ -37,9 +37,7 @@
 /*  include the implementation, they are shared between app/ and
  *  libgimp/ but need different headers.
  */
-#define  __LIBGIMP_GPPARAMS__
 #include "gimpgpparams-body.c"
-#undef  __LIBGIMP_GPPARAMS__
 
 GParamSpec *
 _gimp_gp_param_def_to_param_spec (gpointer          gimp,