[gimp] libgimp: read and write channel should be boxed properties.

[Jehan <jehanp src gnome org>]

commit fc620ee67e96660c887fd0e334494d38a636e159
Author: Jehan <jehan girinstud io>
Date:   Wed Aug 7 11:54:54 2019 +0200

    libgimp: read and write channel should be boxed properties.
    
    gpointer is not introspectable, and we should always prefer boxed types
    over generic pointer types (thanks nielsdg!).
    This also fixes gjs (JavaScript) binding of our API which was dropping
    our properties even though they didn't need to be handled in JS.
    
    See https://gitlab.gnome.org/GNOME/gjs/issues/266

 libgimp/gimpplugin.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)
---
diff --git a/libgimp/gimpplugin.c b/libgimp/gimpplugin.c
index 6ce01caa62..008128f708 100644
--- a/libgimp/gimpplugin.c
+++ b/libgimp/gimpplugin.c
@@ -91,18 +91,20 @@ gimp_plug_in_class_init (GimpPlugInClass *klass)
   object_class->get_property = gimp_plug_in_get_property;
 
   props[PROP_READ_CHANNEL] =
-    g_param_spec_pointer ("read-channel",
-                          "Read channel",
-                          "The GIOChanel to read from GIMP",
-                          GIMP_PARAM_READWRITE |
-                          G_PARAM_CONSTRUCT_ONLY);
+    g_param_spec_boxed ("read-channel",
+                        "Read channel",
+                        "The GIOChanel to read from GIMP",
+                        G_TYPE_IO_CHANNEL,
+                        GIMP_PARAM_READWRITE |
+                        G_PARAM_CONSTRUCT_ONLY);
 
   props[PROP_WRITE_CHANNEL] =
-    g_param_spec_pointer ("write-channel",
-                          "Write channel",
-                          "The GIOChanel to write to GIMP",
-                          GIMP_PARAM_READWRITE |
-                          G_PARAM_CONSTRUCT_ONLY);
+    g_param_spec_boxed ("write-channel",
+                        "Write channel",
+                        "The GIOChanel to write to GIMP",
+                        G_TYPE_IO_CHANNEL,
+                        GIMP_PARAM_READWRITE |
+                        G_PARAM_CONSTRUCT_ONLY);
 
   g_object_class_install_properties (object_class, N_PROPS, props);
 }
@@ -178,11 +180,11 @@ gimp_plug_in_set_property (GObject      *object,
   switch (property_id)
     {
     case PROP_READ_CHANNEL:
-      plug_in->priv->read_channel = g_value_get_pointer (value);
+      plug_in->priv->read_channel = g_value_get_boxed (value);
       break;
 
     case PROP_WRITE_CHANNEL:
-      plug_in->priv->write_channel = g_value_get_pointer (value);
+      plug_in->priv->write_channel = g_value_get_boxed (value);
       break;
 
     default:
@@ -202,11 +204,11 @@ gimp_plug_in_get_property (GObject    *object,
   switch (property_id)
     {
     case PROP_READ_CHANNEL:
-      g_value_set_pointer (value, plug_in->priv->read_channel);
+      g_value_set_boxed (value, plug_in->priv->read_channel);
       break;
 
     case PROP_WRITE_CHANNEL:
-      g_value_set_pointer (value, plug_in->priv->write_channel);
+      g_value_set_boxed (value, plug_in->priv->write_channel);
       break;
 
     default: