New files implementing a widget for entering ratios. Will be improved over

2006-12-30  Simon Budig  <simon@gimp.org>

	* libgimpwidgets/gimpratioentry.[ch]: New files implementing a widget
	for entering ratios. Will be improved over time...

	* libgimpwidgets/gimpwidgetstypes.h
	* libgimpwidgets/gimpwidgets.h
	* libgimpwidgets/Makefile.am: changed accordingly.

	* app/widgets/gimppropwidgets.c: use it for the crop/rectangle
	select tools.

svn path=/trunk/; revision=21613

ChangeLog

@@ -1,3 +1,15 @@
+2006-12-30  Simon Budig  <simon@gimp.org>
+
+	* libgimpwidgets/gimpratioentry.[ch]: New files implementing a widget
+	for entering ratios. Will be improved over time...
+
+	* libgimpwidgets/gimpwidgetstypes.h
+	* libgimpwidgets/gimpwidgets.h
+	* libgimpwidgets/Makefile.am: changed accordingly.
+
+	* app/widgets/gimppropwidgets.c: use it for the crop/rectangle
+	select tools.
+
 2006-12-30  Sven Neumann  <sven@gimp.org>
 
 	* plug-ins/print/print.c: use a GtkMessageDialog to display errors.

app/widgets/gimppropwidgets.c

@@ -558,20 +558,16 @@ typedef struct
   const gchar *height_property;
 } AspectData;
 
-static void gimp_prop_numeric_entry_notify        (GObject       *config,
+static void gimp_prop_ratio_entry_notify          (GObject       *config,
                                                    GParamSpec    *param_spec,
                                                    GtkEntry      *entry);
 
-static void gimp_prop_numeric_entry_callback      (GtkWidget     *widget,
-                                                   GObject       *config);
-
-static gboolean gimp_prop_numeric_entry_focus_out (GtkWidget     *widget,
-                                                   GdkEventFocus *event,
-                                                   GObject       *config);
 static void gimp_prop_aspect_ratio_flip           (GtkWidget     *widget,
                                                    gpointer       data);
 static void gimp_prop_aspect_ratio_square         (GtkWidget     *widget,
                                                    gpointer       data);
+static void gimp_prop_aspect_ratio_ratio          (GtkWidget     *widget,
+                                                   gpointer       data);
 static void gimp_prop_aspect_ratio_set            (GtkWidget     *widget,
                                                    gpointer       data);
 
@@ -614,14 +610,11 @@ gimp_prop_aspect_ratio_new (GObject     *config,
                             gint         col0)
 {
   AspectData *aspect_data;
-  GParamSpec *param_spec;
-  GtkWidget  *label;
   GtkWidget  *entry;
   GtkWidget  *hbox;
   GtkWidget  *button;
   gdouble     numerator;
   gdouble     denominator;
-  gchar       num_string[20];
 
   g_object_get (config,
                 numerator_property,   &numerator,
@@ -636,53 +629,23 @@ gimp_prop_aspect_ratio_new (GObject     *config,
   aspect_data->width_property        = width_property;
   aspect_data->height_property       = height_property;
 
-  /* numerator entry */
+  entry = gimp_ratio_entry_new ();
-  param_spec = find_param_spec (config, numerator_property, G_STRFUNC);
+  g_object_set_data (G_OBJECT (entry),
-  if (! param_spec)
+                     "gimp-ratio-entry-aspect-data",
-    return;
+                     aspect_data);
-  entry = gtk_entry_new ();
+  gtk_entry_set_width_chars (GTK_ENTRY (entry), 9);
-  gtk_entry_set_width_chars (GTK_ENTRY (entry), 5);
+  gimp_ratio_entry_set_fraction (GIMP_RATIO_ENTRY (entry),
-  sprintf (num_string, "%lg", numerator);
+                                 numerator, denominator);
-  gtk_entry_set_text (GTK_ENTRY (entry), num_string);
   gtk_table_attach_defaults (GTK_TABLE (table), entry,
-                             col0, col0 + 1, row0, row0 + 1);
+                             col0, col0 + 3, row0, row0 + 1);
-  set_param_spec (G_OBJECT (entry), entry, param_spec);
+  g_signal_connect (entry, "ratio-changed",
-  g_signal_connect (entry, "activate",
+                    G_CALLBACK (gimp_prop_aspect_ratio_ratio),
-                    G_CALLBACK (gimp_prop_numeric_entry_callback),
+                    aspect_data);
-                    config);
-  g_signal_connect (entry, "focus-out-event",
-                    G_CALLBACK (gimp_prop_numeric_entry_focus_out),
-                    config);
   connect_notify (config, numerator_property,
-                  G_CALLBACK (gimp_prop_numeric_entry_notify),
+                  G_CALLBACK (gimp_prop_ratio_entry_notify),
                   entry);
-  gtk_widget_show (entry);
-
-  /* ":" label */
-  label = gtk_label_new (":");
-  gtk_table_attach_defaults (GTK_TABLE (table), label,
-                             col0 + 1, col0 + 2, row0, row0 + 1);
-  gtk_widget_show (label);
-
-  /* denominator entry */
-  param_spec = find_param_spec (config, denominator_property, G_STRFUNC);
-  if (! param_spec)
-    return;
-  entry = gtk_entry_new ();
-  gtk_entry_set_width_chars (GTK_ENTRY (entry), 5);
-  sprintf (num_string, "%lg", denominator);
-  gtk_entry_set_text (GTK_ENTRY (entry), num_string);
-  gtk_table_attach_defaults (GTK_TABLE (table), entry,
-                             col0 + 2, col0 + 3, row0, row0 + 1);
-  set_param_spec (G_OBJECT (entry), entry, param_spec);
-  g_signal_connect (entry, "activate",
-                    G_CALLBACK (gimp_prop_numeric_entry_callback),
-                    config);
-  g_signal_connect (entry, "focus-out-event",
-                    G_CALLBACK (gimp_prop_numeric_entry_focus_out),
-                    config);
   connect_notify (config, denominator_property,
-                  G_CALLBACK (gimp_prop_numeric_entry_notify),
+                  G_CALLBACK (gimp_prop_ratio_entry_notify),
                   entry);
   gtk_widget_show (entry);
 
@@ -717,53 +680,23 @@ gimp_prop_aspect_ratio_new (GObject     *config,
 }
 
 static void
-gimp_prop_numeric_entry_notify (GObject       *config,
+gimp_prop_ratio_entry_notify (GObject    *config,
-                                GParamSpec    *param_spec,
+                              GParamSpec *param_spec,
-                                GtkEntry      *entry)
+                              GtkEntry   *entry)
 {
-  gdouble value;
+  AspectData *aspect_data = g_object_get_data (G_OBJECT (entry),
-  gchar   text[20];
+                                               "gimp-ratio-entry-aspect-data");
 
-  g_object_get (config, param_spec->name, &value, NULL);
+  gdouble num, denom;
 
-  sprintf (text, "%3lg", value);
+  g_return_if_fail (aspect_data != NULL);
 
-  gtk_entry_set_text (entry, text);
+  g_object_get (config,
-}
+                aspect_data->numerator_property, &num,
+                aspect_data->denominator_property, &denom,
+                NULL);
 
-static gboolean
+  gimp_ratio_entry_set_fraction (GTK_RATIO_ENTRY (entry), num, denom);
-gimp_prop_numeric_entry_focus_out (GtkWidget     *widget,
-                                   GdkEventFocus *event,
-                                   GObject       *config)
-{
-  gimp_prop_numeric_entry_callback (widget, config);
-
-  return FALSE;
-}
-
-static void
-gimp_prop_numeric_entry_callback (GtkWidget *widget,
-                                  GObject   *config)
-{
-  GParamSpec  *param_spec;
-  gdouble      value;
-
-  g_return_if_fail (GTK_IS_ENTRY (widget));
-
-  param_spec = get_param_spec (G_OBJECT (widget));
-  if (! param_spec)
-    return;
-
-  /* we use strtod instead of g_ascii_strtod because it uses the locale,
-     which is what we want here */
-  value = strtod (gtk_entry_get_text (GTK_ENTRY (widget)), NULL);
-
-  if (value != 0)
-    g_object_set (config,
-                  param_spec->name, value,
-                  NULL);
-  else
-    g_message ("Invalid value entered for aspect ratio.");
 }
 
 static void
@@ -830,6 +763,22 @@ gimp_prop_aspect_ratio_square (GtkWidget *widget,
                 NULL);
 }
 
+static void
+gimp_prop_aspect_ratio_ratio (GtkWidget *widget,
+                              gpointer   data)
+{
+  AspectData *aspect_data  = data;
+  gdouble num, denom;
+
+  gimp_ratio_entry_get_fraction (GIMP_RATIO_ENTRY (widget), &num, &denom);
+
+  g_object_set (aspect_data->config,
+                aspect_data->numerator_property,    num,
+                aspect_data->denominator_property,  denom,
+                aspect_data->fixed_aspect_property, TRUE,
+                NULL);
+}
+
 static void
 gimp_prop_aspect_ratio_set (GtkWidget *widget,
                             gpointer   data)

libgimpwidgets/Makefile.am

@@ -142,6 +142,8 @@ libgimpwidgets_2_0_la_sources = \
 	gimppropwidgets.h	\
 	gimpquerybox.c		\
 	gimpquerybox.h		\
+	gimpratioentry.c	\
+	gimpratioentry.h	\
 	gimpresolutionentry.c   \
 	gimpresolutionentry.h   \
 	gimpscrolledpreview.c	\

libgimpwidgets/gimpratioentry.c

@@ -0,0 +1,424 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
+ *
+ * gimpratioentry.c
+ * Copyright (C) 2006  Simon Budig  <simon@gimp.org>
+ *
+ * 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 2 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
+ * Library 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include <math.h>
+#include <string.h>
+
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "gimpwidgetstypes.h"
+
+#include "gimpratioentry.h"
+
+#define EPSILON 0.000001
+
+enum
+{
+  RATIO_CHANGED,
+  LAST_SIGNAL
+};
+
+enum
+{
+  PROP_0,
+  PROP_RATIO,
+  PROP_NUMERATOR,
+  PROP_DENOMINATOR,
+};
+
+
+static void      gimp_ratio_entry_set_property (GObject         *object,
+                                                guint            property_id,
+                                                const GValue    *value,
+                                                GParamSpec      *pspec);
+static void      gimp_ratio_entry_get_property (GObject         *object,
+                                                guint            property_id,
+                                                GValue          *value,
+                                                GParamSpec      *pspec);
+static gboolean  gimp_ratio_entry_events       (GtkWidget       *widget,
+                                                GdkEvent        *event);
+static void      gimp_ratio_entry_format_text  (GimpRatioEntry  *entry);
+static void      gimp_ratio_entry_parse_text   (GimpRatioEntry  *entry,
+                                                const gchar     *text);
+
+G_DEFINE_TYPE (GimpRatioEntry, gimp_ratio_entry, GTK_TYPE_ENTRY)
+
+#define parent_class gimp_ratio_entry_parent_class
+
+static guint entry_signals[LAST_SIGNAL] = { 0 };
+
+
+static void
+gimp_ratio_entry_class_init (GimpRatioEntryClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  entry_signals[RATIO_CHANGED] =
+    g_signal_new ("ratio-changed",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpRatioEntryClass, ratio_changed),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
+  klass->ratio_changed = NULL;
+
+  object_class->set_property = gimp_ratio_entry_set_property;
+  object_class->get_property = gimp_ratio_entry_get_property;
+
+  g_object_class_install_property (object_class, PROP_RATIO,
+                                   g_param_spec_double ("ratio",
+                                                        "Ratio", NULL,
+                                                        G_MINDOUBLE, G_MAXDOUBLE,
+                                                        1.0,
+                                                        GIMP_PARAM_READWRITE));
+  g_object_class_install_property (object_class, PROP_NUMERATOR,
+                                   g_param_spec_double ("numerator",
+                                                        "Numerator of the ratio", NULL,
+                                                        G_MINDOUBLE, G_MAXDOUBLE,
+                                                        1.0,
+                                                        GIMP_PARAM_READWRITE));
+  g_object_class_install_property (object_class, PROP_DENOMINATOR,
+                                   g_param_spec_double ("denominator",
+                                                        "Denominator of the ratio", NULL,
+                                                        G_MINDOUBLE, G_MAXDOUBLE,
+                                                        1.0,
+                                                        GIMP_PARAM_READWRITE));
+}
+
+static void
+gimp_ratio_entry_set_property (GObject      *object,
+                               guint         property_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GimpRatioEntry *entry = GIMP_RATIO_ENTRY (object);
+
+  switch (property_id)
+    {
+    case PROP_RATIO:
+      gimp_ratio_entry_set_ratio (entry, g_value_get_double (value));
+      break;
+    case PROP_NUMERATOR:
+      gimp_ratio_entry_set_fraction (entry,
+                                     g_value_get_double (value),
+                                     entry->denominator);
+      break;
+    case PROP_DENOMINATOR:
+      gimp_ratio_entry_set_fraction (entry,
+                                     entry->numerator,
+                                     g_value_get_double (value));
+      break;
+    }
+}
+
+static void
+gimp_ratio_entry_get_property (GObject    *object,
+                               guint       property_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GimpRatioEntry *entry = GIMP_RATIO_ENTRY (object);
+
+  switch (property_id)
+    {
+    case PROP_RATIO:
+      g_value_set_double (value, gimp_ratio_entry_get_ratio (entry));
+      break;
+    case PROP_NUMERATOR:
+      g_value_set_double (value, entry->numerator);
+      break;
+    case PROP_DENOMINATOR:
+      g_value_set_double (value, entry->denominator);
+      break;
+    }
+}
+
+
+static void
+gimp_ratio_entry_init (GimpRatioEntry *entry)
+{
+  entry->numerator   = 1;
+  entry->denominator = 1;
+
+  gtk_entry_set_text (GTK_ENTRY (entry), "1:1");
+
+  g_signal_connect (entry, "focus-out-event",
+                    G_CALLBACK (gimp_ratio_entry_events),
+                    NULL);
+  g_signal_connect (entry, "key-press-event",
+                    G_CALLBACK (gimp_ratio_entry_events),
+                    NULL);
+}
+
+/**
+ * gimp_ratio_entry_new:
+ *
+ * Return value: a new #GimpRatioEntry widget
+ *
+ * Since: GIMP 2.4
+ **/
+GtkWidget *
+gimp_ratio_entry_new (void)
+{
+  return g_object_new (GIMP_TYPE_RATIO_ENTRY, NULL);
+}
+
+/**
+ * gimp_ratio_entry_set_ratio:
+ * @entry: a #GimpRatioEntry widget
+ * @ratio: ratio to set in the widget
+ * @calc_fraction: convert into a fraction?
+ *
+ * Sets the ratio displayed by a #GimpRatioEntry. If the new ratio is
+ * different than the previous ratio, the "ratio-changed" signal is
+ * emitted.
+ *
+ * An attempt is made to convert the decimal number into a fraction with
+ * numerator and denominator < 1000.
+ *
+ * Since: GIMP 2.4
+ **/
+void
+gimp_ratio_entry_set_ratio (GimpRatioEntry *entry,
+                            gdouble         ratio)
+{
+  gdouble  remainder, next_cf;
+  gint     p0, p1, p2;
+  gint     q0, q1, q2;
+
+  /* calculate the continued fraction to approximate the desired ratio */
+
+  p0 = 1;
+  q0 = 0;
+  p1 = floor (ratio);
+  q1 = 1;
+
+  remainder = ratio - p1;
+
+  while (fabs (remainder) >= 0.0001 &&
+         fabs (((gdouble) p1 / q1) - ratio) > 0.0001)
+    {
+      remainder = 1.0 / remainder;
+
+      next_cf = floor (remainder);
+
+      p2 = next_cf * p1 + p0;
+      q2 = next_cf * q1 + q0;
+
+      /* remember the last two fractions */
+      p0 = p1;
+      q0 = q1;
+      p1 = p2;
+      q1 = q2;
+
+      remainder = remainder - next_cf;
+    }
+
+  /* only use the calculated fraction if it is "reasonable" */
+  if (p1 < 1000 && q1 < 1000)
+    gimp_ratio_entry_set_fraction (entry, p1, q1);
+  else
+    gimp_ratio_entry_set_fraction (entry, ratio, 1.0);
+}
+
+/**
+ * gimp_ratio_entry_get_ratio:
+ * @entry: a #GimpRatioEntry widget
+ *
+ * Retrieves the ratio value displayed by a #GimpRatioEntry.
+ *
+ * Since: GIMP 2.4
+ **/
+gdouble
+gimp_ratio_entry_get_ratio (GimpRatioEntry *entry)
+{
+  return entry->denominator == 0.0 ? entry->numerator :
+                                     entry->numerator / entry->denominator;
+}
+
+/**
+ * gimp_ratio_entry_set_fraction:
+ * @entry: a #GimpRatioEntry widget
+ * @numerator: numerator of the fraction to set in the widget
+ * @denominator: denominator of the fraction to set in the widget
+ *
+ * Sets the fraction displayed by a #GimpRatioEntry. If the resulting
+ * ratio is different to the previously set ratio, the "ratio-changed"
+ * signal is emitted.
+ *
+ * If the denominator is zero, the #GimpRatioEntry will silently
+ * convert it to 1.0.
+ *
+ * Since: GIMP 2.4
+ **/
+void
+gimp_ratio_entry_set_fraction (GimpRatioEntry *entry,
+                               const gdouble   numerator,
+                               const gdouble   denominator)
+{
+  gdouble old_ratio;
+  g_return_if_fail (GIMP_IS_RATIO_ENTRY (entry));
+
+  old_ratio = entry->numerator / entry->denominator;
+
+  entry->numerator = numerator;
+  entry->denominator = denominator;
+
+  if (entry->denominator < 0)
+    {
+      entry->numerator *= -1;
+      entry->denominator *= -1;
+    }
+
+  if (entry->denominator < EPSILON)
+    entry->denominator = 1.0;
+
+  gimp_ratio_entry_format_text (entry);
+
+  if (fabs (old_ratio - entry->numerator / entry->denominator) > EPSILON)
+    g_signal_emit (entry, entry_signals[RATIO_CHANGED], 0);
+}
+
+/**
+ * gimp_ratio_entry_get_fraction:
+ * @entry: a #GimpRatioEntry widget
+ * @numerator: pointer to store the numerator of the fraction
+ * @denominator: pointer to store the denominator of the fraction
+ *
+ * Gets the fraction displayed by a #GimpRatioEntry.
+ *
+ * The denominator may be zero if the #GimpRatioEntry shows just a single
+ * value. You can use #gimp_ratio_entry_get_ratio to retrieve the ratio
+ * as a single decimal value.
+ *
+ * Since: GIMP 2.4
+ **/
+void
+gimp_ratio_entry_get_fraction (GimpRatioEntry *entry,
+                               gdouble        *numerator,
+                               gdouble        *denominator)
+{
+  g_return_if_fail (GIMP_IS_RATIO_ENTRY (entry));
+  g_return_if_fail (numerator != NULL);
+  g_return_if_fail (denominator != NULL);
+
+  *numerator = entry->numerator;
+  *denominator = entry->denominator;
+}
+
+static gboolean
+gimp_ratio_entry_events (GtkWidget *widget,
+                         GdkEvent  *event)
+{
+  GimpRatioEntry *entry = GIMP_RATIO_ENTRY (widget);
+  const gchar    *text;
+
+  switch (event->type)
+    {
+    case GDK_KEY_PRESS:
+      if (((GdkEventKey *) event)->keyval != GDK_Return)
+        break;
+      /*  else fall through  */
+
+    case GDK_FOCUS_CHANGE:
+      text = gtk_entry_get_text (GTK_ENTRY (entry));
+      gimp_ratio_entry_parse_text (entry, text);
+      break;
+
+    default:
+      /*  do nothing  */
+      break;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_ratio_entry_format_text (GimpRatioEntry *entry)
+{
+  gchar   *buffer;
+
+  buffer = g_strdup_printf ("%g:%g", entry->numerator, entry->denominator);
+
+  gtk_entry_set_text (GTK_ENTRY (entry), buffer);
+  g_free (buffer);
+}
+
+static void
+gimp_ratio_entry_parse_text (GimpRatioEntry *entry,
+                             const gchar    *text)
+{
+  gint    count;
+  gchar   op1, op2, dummy;
+  gdouble num = 1.0, denom = 0.0;
+
+  count = sscanf (text, " %lf %c %lf %c %c ", &num, &op1, &denom, &op2, &dummy);
+
+  switch (count)
+    {
+    case EOF:
+    case 0:
+      gimp_ratio_entry_set_fraction (entry, 1.0, 1.0);
+      break;
+
+    case 1:
+      gimp_ratio_entry_set_fraction (entry, num, 1.0);
+      break;
+
+    case 2:
+      if (op1 == '=')
+        gimp_ratio_entry_set_ratio (entry, num);
+      break;
+
+    case 3:
+      if (op1 == ':' || op1 == '/')
+        gimp_ratio_entry_set_fraction (entry, num, denom);
+      break;
+
+    case 4:
+      if ((op1 == ':' || op1 == '/') && denom != 0 && op2 == '=')
+        {
+          if (fabs (denom - 1.0) < EPSILON)
+            gimp_ratio_entry_set_ratio (entry, num / denom);
+          else
+            gimp_ratio_entry_set_fraction (entry, num / denom, 1.0);
+        }
+      break;
+
+    case 5:
+      /* we have additional stuff at the end - malformed input. */
+      break;
+
+    default:
+      break;
+    }
+
+  /* sanitize text */
+  gimp_ratio_entry_format_text (entry);
+
+  gtk_editable_set_position (GTK_EDITABLE (entry), -1);
+}

libgimpwidgets/gimpratioentry.h

@@ -0,0 +1,79 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
+ *
+ * gimpratioentry.h
+ * Copyright (C) 2006  Simon Budig  <simon@gimp.org>
+ *
+ * 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 2 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
+ * Library 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GIMP_RATIO_ENTRY_H__
+#define __GIMP_RATIO_ENTRY_H__
+
+G_BEGIN_DECLS
+
+
+#define GIMP_TYPE_RATIO_ENTRY            (gimp_ratio_entry_get_type ())
+#define GIMP_RATIO_ENTRY(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_RATIO_ENTRY, GimpRatioEntry))
+#define GIMP_RATIO_ENTRY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_RATIO_ENTRY, GimpRatioEntryClass))
+#define GIMP_IS_RATIO_ENTRY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_RATIO_ENTRY))
+#define GIMP_IS_RATIO_ENTRY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_RATIO_ENTRY))
+#define GIMP_RATIO_ENTRY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_RATIO_AREA, GimpRatioEntryClass))
+
+
+typedef struct _GimpRatioEntryClass  GimpRatioEntryClass;
+
+struct _GimpRatioEntry
+{
+  GtkEntry        parent_instance;
+
+  gdouble         numerator;
+  gdouble         denominator;
+};
+
+struct _GimpRatioEntryClass
+{
+  GtkEntryClass   parent_class;
+
+  void (* ratio_changed) (GimpRatioEntry *entry);
+
+  /* Padding for future expansion */
+  void (* _gimp_reserved1) (void);
+  void (* _gimp_reserved2) (void);
+  void (* _gimp_reserved3) (void);
+  void (* _gimp_reserved4) (void);
+};
+
+
+GType       gimp_ratio_entry_get_type     (void) G_GNUC_CONST;
+
+GtkWidget * gimp_ratio_entry_new          (void);
+
+void        gimp_ratio_entry_set_fraction (GimpRatioEntry *entry,
+                                           gdouble         numerator,
+                                           gdouble         denominator);
+void        gimp_ratio_entry_get_fraction (GimpRatioEntry *entry,
+                                           gdouble        *numerator,
+                                           gdouble        *denominator);
+
+void        gimp_ratio_entry_set_ratio    (GimpRatioEntry *entry,
+                                           gdouble         ratio);
+gdouble     gimp_ratio_entry_get_ratio    (GimpRatioEntry *entry);
+
+
+G_END_DECLS
+
+#endif /* __GIMP_RATIO_ENTRY_H__ */

libgimpwidgets/gimpwidgets.h

@@ -63,6 +63,7 @@
 #include <libgimpwidgets/gimppreviewarea.h>
 #include <libgimpwidgets/gimppropwidgets.h>
 #include <libgimpwidgets/gimpquerybox.h>
+#include <libgimpwidgets/gimpratioentry.h>
 #include <libgimpwidgets/gimpresolutionentry.h>
 #include <libgimpwidgets/gimpscrolledpreview.h>
 #include <libgimpwidgets/gimpsizeentry.h>

libgimpwidgets/gimpwidgetstypes.h

@@ -64,6 +64,7 @@ typedef struct _GimpPickButton         GimpPickButton;
 typedef struct _GimpPreview            GimpPreview;
 typedef struct _GimpPreviewArea        GimpPreviewArea;
 typedef struct _GimpPixmap             GimpPixmap;
+typedef struct _GimpRatioEntry         GimpRatioEntry;
 typedef struct _GimpResolutionEntry    GimpResolutionEntry;
 typedef struct _GimpScrolledPreview    GimpScrolledPreview;
 typedef struct _GimpSizeEntry          GimpSizeEntry;