[gimp] libgimp: revive parameter range descriptions in the procedure browser

[Michael Natterer <mitch src gnome org>]

commit 15bedc9bf974a31064a066b10680cefae8271338
Author: Michael Natterer <mitch gimp org>
Date:   Tue Apr 28 19:06:44 2020 +0200

    libgimp: revive parameter range descriptions in the procedure browser
    
    Copy gimp_param_specs_get_desc() to libgimp and make it also mention
    default values. Don't install its header for now, because it's pretty
    much a utility function of GimpProcView. It also doesn't handle most
    GParamSpec types yet.
    
    As a side effect, this fixed issue #3947.

 libgimp/Makefile.am           |   2 +
 libgimp/gimpparamspecs-desc.c | 208 ++++++++++++++++++++++++++++++++++++++++++
 libgimp/gimpparamspecs-desc.h |  39 ++++++++
 libgimp/gimpprocview.c        |  19 +++-
 libgimp/meson.build           |   1 +
 5 files changed, 268 insertions(+), 1 deletion(-)
---
diff --git a/libgimp/Makefile.am b/libgimp/Makefile.am
index 9344d0990d..2c3bffd175 100644
--- a/libgimp/Makefile.am
+++ b/libgimp/Makefile.am
@@ -112,6 +112,8 @@ libgimp_private_sources = \
        gimp-shm.h                      \
        gimpgpparams.c                  \
        gimpgpparams.h                  \
+       gimpparamspecs-desc.c           \
+       gimpparamspecs-desc.h           \
        gimppdb-private.h               \
        gimppdbprocedure.c              \
        gimppdbprocedure.h              \
diff --git a/libgimp/gimpparamspecs-desc.c b/libgimp/gimpparamspecs-desc.c
new file mode 100644
index 0000000000..f085c9d2a2
--- /dev/null
+++ b/libgimp/gimpparamspecs-desc.c
@@ -0,0 +1,208 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
+ *
+ * gimpparamspecs-desc.c
+ *
+ * This library is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gio/gio.h>
+
+#include "libgimpbase/gimpbase.h"
+
+#include "gimp.h"
+#include "gimpparamspecs-desc.h"
+
+
+static gchar *
+gimp_param_spec_boolean_desc (GParamSpec *pspec)
+{
+  GParamSpecBoolean *bspec = G_PARAM_SPEC_BOOLEAN (pspec);
+
+  return g_strdup_printf ("(TRUE or FALSE, default %s)",
+                          bspec->default_value ? "TRUE" : "FALSE");
+}
+
+static gchar *
+gimp_param_spec_int_desc (GParamSpec *pspec)
+{
+  GParamSpecInt *ispec = G_PARAM_SPEC_INT (pspec);
+
+  if (ispec->minimum == G_MININT32 && ispec->maximum == G_MAXINT32)
+    return g_strdup_printf ("(default %d)",
+                            ispec->default_value);
+
+  if (ispec->minimum == G_MININT32)
+    return g_strdup_printf ("(%s <= %d, default %d)",
+                            g_param_spec_get_name (pspec),
+                            ispec->maximum,
+                            ispec->default_value);
+
+  if (ispec->maximum == G_MAXINT32)
+    return g_strdup_printf ("(%s >= %d, default %d)",
+                            g_param_spec_get_name (pspec),
+                            ispec->minimum,
+                            ispec->default_value);
+
+  return g_strdup_printf ("(%d <= %s <= %d, default %d)",
+                          ispec->minimum,
+                          g_param_spec_get_name (pspec),
+                          ispec->maximum,
+                          ispec->default_value);
+}
+
+static gchar *
+gimp_param_spec_double_desc (GParamSpec *pspec)
+{
+  GParamSpecDouble *dspec = G_PARAM_SPEC_DOUBLE (pspec);
+
+  if (dspec->minimum == - G_MAXDOUBLE && dspec->maximum == G_MAXDOUBLE)
+    return g_strdup_printf ("(default %g)",
+                            dspec->default_value);
+
+  if (dspec->minimum == - G_MAXDOUBLE)
+    return g_strdup_printf ("(%s <= %g, default %g)",
+                            g_param_spec_get_name (pspec),
+                            dspec->maximum,
+                            dspec->default_value);
+
+  if (dspec->maximum == G_MAXDOUBLE)
+    return g_strdup_printf ("(%s >= %g, default %g)",
+                            g_param_spec_get_name (pspec),
+                            dspec->minimum,
+                            dspec->default_value);
+
+  return g_strdup_printf ("(%g <= %s <= %g, default %g)",
+                          dspec->minimum,
+                          g_param_spec_get_name (pspec),
+                          dspec->maximum,
+                          dspec->default_value);
+}
+
+static gchar *
+gimp_param_spec_enum_desc (GParamSpec *pspec)
+{
+  GParamSpecEnum *espec      = G_PARAM_SPEC_ENUM (pspec);
+  GEnumClass     *enum_class = g_type_class_peek (pspec->value_type);
+  GEnumValue     *enum_value;
+  GSList         *excluded;
+  GString        *str          = g_string_new (NULL);
+  gchar          *default_name = NULL;
+  gint            i, n;
+
+#if 0
+  if (GIMP_IS_PARAM_SPEC_ENUM (pspec))
+    excluded = GIMP_PARAM_SPEC_ENUM (pspec)->excluded_values;
+  else
+#endif
+    excluded = NULL;
+
+  g_string_append (str, "{ ");
+
+  for (i = 0, n = 0, enum_value = enum_class->values;
+       i < enum_class->n_values;
+       i++, enum_value++)
+    {
+      GSList *list;
+      gchar  *name;
+
+      for (list = excluded; list; list = list->next)
+        {
+          gint value = GPOINTER_TO_INT (list->data);
+
+          if (value == enum_value->value)
+            break;
+        }
+
+      if (list)
+        continue;
+
+      if (n > 0)
+        g_string_append (str, ", ");
+
+      if (G_LIKELY (g_str_has_prefix (enum_value->value_name, "GIMP_")))
+        name = gimp_canonicalize_identifier (enum_value->value_name + 5);
+      else
+        name = gimp_canonicalize_identifier (enum_value->value_name);
+
+      if (enum_value->value == espec->default_value)
+        default_name = g_strdup (name);
+
+      g_string_append (str, name);
+      g_free (name);
+
+      g_string_append_printf (str, " (%d)", enum_value->value);
+
+      n++;
+    }
+
+  g_string_append (str, " }");
+
+  if (default_name)
+    {
+      g_string_append_printf (str, ", default %s (%d)",
+                              default_name, espec->default_value);
+      g_free (default_name);
+    }
+
+  return g_string_free (str, FALSE);
+}
+
+/**
+ * gimp_param_spec_get_desc:
+ * @pspec: a #GParamSpec
+ *
+ * This function creates a description of the passed @pspec, which is
+ * suitable for use in the PDB.  Actually, it currently only deals with
+ * parameter types used in the PDB and should not be used for anything
+ * else.
+ *
+ * Returns: A newly allocated string describing the parameter.
+ *
+ * Since: 3.0
+ */
+gchar *
+gimp_param_spec_get_desc (GParamSpec *pspec)
+{
+  g_return_val_if_fail (G_IS_PARAM_SPEC (pspec), NULL);
+
+  if (GIMP_IS_PARAM_SPEC_UNIT (pspec))
+    {
+    }
+  else if (G_IS_PARAM_SPEC_INT (pspec))
+    {
+      return gimp_param_spec_int_desc (pspec);
+    }
+  else
+    {
+      switch (G_TYPE_FUNDAMENTAL (pspec->value_type))
+        {
+        case G_TYPE_BOOLEAN:
+          return gimp_param_spec_boolean_desc (pspec);
+
+        case G_TYPE_DOUBLE:
+          return gimp_param_spec_double_desc (pspec);
+
+        case G_TYPE_ENUM:
+          return gimp_param_spec_enum_desc (pspec);
+        }
+    }
+
+  return NULL;
+}
diff --git a/libgimp/gimpparamspecs-desc.h b/libgimp/gimpparamspecs-desc.h
new file mode 100644
index 0000000000..95ee31c77d
--- /dev/null
+++ b/libgimp/gimpparamspecs-desc.h
@@ -0,0 +1,39 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
+ *
+ * gimpparamspecs-desc.h
+ *
+ * This library is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+#if !defined (__GIMP_H_INSIDE__) && !defined (GIMP_COMPILATION)
+#error "Only <libgimp/gimp.h> can be included directly."
+#endif
+
+#ifndef __GIMP_PARAM_SPECS_DESC_H__
+#define __GIMP_PARAM_SPECS_DESC_H__
+
+G_BEGIN_DECLS
+
+
+/* For information look into the C source or the html documentation */
+
+
+gchar * gimp_param_spec_get_desc (GParamSpec *pspec);
+
+
+G_END_DECLS
+
+#endif  /*  __GIMP_PARAM_SPECS_DESC_H__  */
diff --git a/libgimp/gimpprocview.c b/libgimp/gimpprocview.c
index 7668300b9a..fec30ecabe 100644
--- a/libgimp/gimpprocview.c
+++ b/libgimp/gimpprocview.c
@@ -36,6 +36,7 @@
 #include "libgimpwidgets/gimpwidgets.h"
 
 #include "gimp.h"
+#include "gimpparamspecs-desc.h"
 
 #include "gimpuitypes.h"
 #include "gimpprocview.h"
@@ -327,6 +328,20 @@ gimp_proc_view_create_args (GimpProcedure *procedure,
     {
       GParamSpec *pspec = pspecs[i];
       GtkWidget  *label;
+      gchar      *desc;
+      gchar      *blurb;
+
+      desc = gimp_param_spec_get_desc (pspec);
+
+      if (desc)
+        {
+          blurb = g_strconcat (g_param_spec_get_blurb (pspec), " ", desc, NULL);
+          g_free (desc);
+        }
+      else
+        {
+          blurb = g_strdup (g_param_spec_get_blurb (pspec));
+        }
 
       /* name */
       label = gtk_label_new (g_param_spec_get_name (pspec));
@@ -349,7 +364,7 @@ gimp_proc_view_create_args (GimpProcedure *procedure,
       gtk_widget_show (label);
 
       /* description */
-      label = gtk_label_new (g_param_spec_get_blurb (pspec));
+      label = gtk_label_new (blurb);
       gtk_label_set_selectable (GTK_LABEL (label), TRUE);
       gtk_label_set_xalign (GTK_LABEL (label), 0.0);
       gtk_label_set_yalign (GTK_LABEL (label), 0.0);
@@ -357,6 +372,8 @@ gimp_proc_view_create_args (GimpProcedure *procedure,
       gtk_size_group_add_widget (desc_group, label);
       gtk_grid_attach (GTK_GRID (grid), label, 2, i, 1, 1);
       gtk_widget_show (label);
+
+      g_free (blurb);
     }
 
   return grid;
diff --git a/libgimp/meson.build b/libgimp/meson.build
index c616ac69d6..7a24d7e088 100644
--- a/libgimp/meson.build
+++ b/libgimp/meson.build
@@ -173,6 +173,7 @@ libgimp_sources = [
   'gimp-debug.c',
   'gimp-shm.c',
   'gimpgpparams.c',
+  'gimpparamspecs-desc.c',
   'gimppdb_pdb.c',
   'gimppdbprocedure.c',
   'gimppixbuf.c',