Adding upstream version 2.10.22.upstream/2.10.22upstream

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

1 files changed, 1546 insertions, 0 deletions

diff --git a/app/widgets/gimpspinscale.c b/app/widgets/gimpspinscale.c
new file mode 100644
index 0000000..7fa4039
--- /dev/null
+++ b/app/widgets/gimpspinscale.c
@@ -0,0 +1,1546 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpspinscale.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *               2012 Øyvind Kolås    <pippin@gimp.org>
+ *
+ * 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 <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpwidgets/gimpwidgets.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "widgets-types.h"
+
+#include "gimpspinscale.h"
+
+#include "gimp-intl.h"
+
+
+#define RELATIVE_CHANGE_SPEED 0.1
+
+
+enum
+{
+  PROP_0,
+  PROP_LABEL
+};
+
+typedef enum
+{
+  TARGET_NONE,
+  TARGET_NUMBER,
+  TARGET_UPPER,
+  TARGET_LOWER
+} SpinScaleTarget;
+
+
+typedef struct _GimpSpinScalePrivate GimpSpinScalePrivate;
+
+struct _GimpSpinScalePrivate
+{
+  gboolean         compact;
+
+  gchar           *label;
+  gchar           *label_text;
+  gchar           *label_pattern;
+
+  GtkWindow       *mnemonic_window;
+  guint            mnemonic_keyval;
+  gboolean         mnemonics_visible;
+
+  gboolean         constrain_drag;
+
+  gboolean         scale_limits_set;
+  gdouble          scale_lower;
+  gdouble          scale_upper;
+  gdouble          gamma;
+
+  PangoLayout     *layout;
+  gboolean         changing_value;
+  gboolean         relative_change;
+  gdouble          start_x;
+  gdouble          start_value;
+  GdkScreen       *start_screen;
+  gint             start_pointer_x;
+  gint             start_pointer_y;
+  SpinScaleTarget  target;
+  gboolean         hover;
+  gboolean         pointer_warp;
+  gint             pointer_warp_x;
+  gint             pointer_warp_start_x;
+
+  gint             change_value_idle_id;
+  gdouble          change_value_idle_value;
+};
+
+#define GET_PRIVATE(obj) ((GimpSpinScalePrivate *) gimp_spin_scale_get_instance_private ((GimpSpinScale *) (obj)))
+
+
+static void       gimp_spin_scale_dispose           (GObject          *object);
+static void       gimp_spin_scale_finalize          (GObject          *object);
+static void       gimp_spin_scale_set_property      (GObject          *object,
+                                                     guint             property_id,
+                                                     const GValue     *value,
+                                                     GParamSpec       *pspec);
+static void       gimp_spin_scale_get_property      (GObject          *object,
+                                                     guint             property_id,
+                                                     GValue           *value,
+                                                     GParamSpec       *pspec);
+
+static void       gimp_spin_scale_map               (GtkWidget        *widget);
+static void       gimp_spin_scale_size_request      (GtkWidget        *widget,
+                                                     GtkRequisition   *requisition);
+static void       gimp_spin_scale_style_set         (GtkWidget        *widget,
+                                                     GtkStyle         *prev_style);
+static gboolean   gimp_spin_scale_expose            (GtkWidget        *widget,
+                                                     GdkEventExpose   *event);
+static gboolean   gimp_spin_scale_button_press      (GtkWidget        *widget,
+                                                     GdkEventButton   *event);
+static gboolean   gimp_spin_scale_button_release    (GtkWidget        *widget,
+                                                     GdkEventButton   *event);
+static gboolean   gimp_spin_scale_motion_notify     (GtkWidget        *widget,
+                                                     GdkEventMotion   *event);
+static gboolean   gimp_spin_scale_leave_notify      (GtkWidget        *widget,
+                                                     GdkEventCrossing *event);
+static void       gimp_spin_scale_hierarchy_changed (GtkWidget        *widget,
+                                                     GtkWidget        *old_toplevel);
+static void       gimp_spin_scale_screen_changed    (GtkWidget        *widget,
+                                                     GdkScreen        *old_screen);
+
+static void       gimp_spin_scale_value_changed     (GtkSpinButton    *spin_button);
+
+static void       gimp_spin_scale_settings_notify   (GtkSettings      *settings,
+                                                     const GParamSpec *pspec,
+                                                     GimpSpinScale    *scale);
+static void       gimp_spin_scale_mnemonics_notify  (GtkWindow        *window,
+                                                     const GParamSpec *pspec,
+                                                     GimpSpinScale    *scale);
+static void       gimp_spin_scale_setup_mnemonic    (GimpSpinScale    *scale,
+                                                     guint             previous_keyval);
+
+static gdouble    odd_pow                           (gdouble           x,
+                                                     gdouble           y);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpSpinScale, gimp_spin_scale,
+                            GIMP_TYPE_SPIN_BUTTON)
+
+#define parent_class gimp_spin_scale_parent_class
+
+
+static void
+gimp_spin_scale_class_init (GimpSpinScaleClass *klass)
+{
+  GObjectClass       *object_class      = G_OBJECT_CLASS (klass);
+  GtkWidgetClass     *widget_class      = GTK_WIDGET_CLASS (klass);
+  GtkSpinButtonClass *spin_button_class = GTK_SPIN_BUTTON_CLASS (klass);
+
+  object_class->dispose              = gimp_spin_scale_dispose;
+  object_class->finalize             = gimp_spin_scale_finalize;
+  object_class->set_property         = gimp_spin_scale_set_property;
+  object_class->get_property         = gimp_spin_scale_get_property;
+
+  widget_class->map                  = gimp_spin_scale_map;
+  widget_class->size_request         = gimp_spin_scale_size_request;
+  widget_class->style_set            = gimp_spin_scale_style_set;
+  widget_class->expose_event         = gimp_spin_scale_expose;
+  widget_class->button_press_event   = gimp_spin_scale_button_press;
+  widget_class->button_release_event = gimp_spin_scale_button_release;
+  widget_class->motion_notify_event  = gimp_spin_scale_motion_notify;
+  widget_class->leave_notify_event   = gimp_spin_scale_leave_notify;
+  widget_class->hierarchy_changed    = gimp_spin_scale_hierarchy_changed;
+  widget_class->screen_changed       = gimp_spin_scale_screen_changed;
+
+  spin_button_class->value_changed   = gimp_spin_scale_value_changed;
+
+  g_object_class_install_property (object_class, PROP_LABEL,
+                                   g_param_spec_string ("label", NULL, NULL,
+                                                        NULL,
+                                                        GIMP_PARAM_READWRITE));
+
+  gtk_widget_class_install_style_property (widget_class,
+                                           g_param_spec_boolean ("compact",
+                                                                 NULL, NULL,
+                                                                 FALSE,
+                                                                 GIMP_PARAM_READABLE));
+}
+
+static void
+gimp_spin_scale_init (GimpSpinScale *scale)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (scale);
+
+  gtk_widget_add_events (GTK_WIDGET (scale),
+                         GDK_BUTTON_PRESS_MASK   |
+                         GDK_BUTTON_RELEASE_MASK |
+                         GDK_POINTER_MOTION_MASK |
+                         GDK_BUTTON1_MOTION_MASK |
+                         GDK_LEAVE_NOTIFY_MASK);
+
+  gtk_entry_set_alignment (GTK_ENTRY (scale), 1.0);
+  gtk_entry_set_has_frame (GTK_ENTRY (scale), FALSE);
+  gtk_spin_button_set_numeric (GTK_SPIN_BUTTON (scale), TRUE);
+
+  private->mnemonic_keyval = GDK_KEY_VoidSymbol;
+  private->gamma           = 1.0;
+}
+
+static void
+gimp_spin_scale_dispose (GObject *object)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (object);
+  guint                 keyval;
+
+  keyval = private->mnemonic_keyval;
+  private->mnemonic_keyval = GDK_KEY_VoidSymbol;
+
+  gimp_spin_scale_setup_mnemonic (GIMP_SPIN_SCALE (object), keyval);
+
+  g_clear_object (&private->layout);
+
+  if (private->change_value_idle_id)
+    {
+      GtkAdjustment *adjustment;
+
+      adjustment = gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (object));
+
+      g_source_remove (private->change_value_idle_id);
+
+      private->change_value_idle_id = 0;
+
+      gtk_adjustment_set_value (adjustment, private->change_value_idle_value);
+    }
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_spin_scale_finalize (GObject *object)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (object);
+
+  g_clear_pointer (&private->label,         g_free);
+  g_clear_pointer (&private->label_text,    g_free);
+  g_clear_pointer (&private->label_pattern, g_free);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_spin_scale_set_property (GObject      *object,
+                              guint         property_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
+{
+  GimpSpinScale *scale = GIMP_SPIN_SCALE (object);
+
+  switch (property_id)
+    {
+    case PROP_LABEL:
+      gimp_spin_scale_set_label (scale, g_value_get_string (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_spin_scale_get_property (GObject    *object,
+                              guint       property_id,
+                              GValue     *value,
+                              GParamSpec *pspec)
+{
+  GimpSpinScale *scale = GIMP_SPIN_SCALE (object);
+
+  switch (property_id)
+    {
+    case PROP_LABEL:
+      g_value_set_string (value, gimp_spin_scale_get_label (scale));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_spin_scale_map (GtkWidget *widget)
+{
+  GdkWindow *window;
+
+  GTK_WIDGET_CLASS (parent_class)->map (widget);
+
+  window = gtk_entry_get_text_window (GTK_ENTRY (widget));
+
+  if (window)
+    {
+      /* as per 2020, motion hints seem to be broken, at least on X: calling
+       * gdk_event_request_motions() doesn't seem to generate further motion
+       * events, causing motion events to be discarded, especially if the spin-
+       * scale is tied to some costly operation, such as projection
+       * invalidation, which blocks the main thread.
+       *
+       * to fix this, we simply avoid motion hints for the widget, and use an
+       * idle for setting the spin-scale value in response to motion events, as
+       * a form of ad-hoc motion compression.
+       *
+       * note that this isn't necessary with gtk3, which does its own motion
+       * compression.
+       */
+      gdk_window_set_events (window,
+                             gdk_window_get_events (window) &
+                             ~GDK_POINTER_MOTION_HINT_MASK);
+    }
+}
+
+static void
+gimp_spin_scale_size_request (GtkWidget      *widget,
+                              GtkRequisition *requisition)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+  GtkStyle             *style   = gtk_widget_get_style (widget);
+  PangoContext         *context = gtk_widget_get_pango_context (widget);
+  PangoFontMetrics     *metrics;
+
+  GTK_WIDGET_CLASS (parent_class)->size_request (widget, requisition);
+
+  metrics = pango_context_get_metrics (context, style->font_desc,
+                                       pango_context_get_language (context));
+
+  if (! private->compact)
+    {
+      gint height;
+
+      height = PANGO_PIXELS (pango_font_metrics_get_ascent (metrics) +
+                             pango_font_metrics_get_descent (metrics));
+
+      requisition->height += height;
+    }
+
+  if (private->label)
+    {
+      gint char_width;
+      gint digit_width;
+      gint char_pixels;
+
+      char_width = pango_font_metrics_get_approximate_char_width (metrics);
+      digit_width = pango_font_metrics_get_approximate_digit_width (metrics);
+      char_pixels = PANGO_PIXELS (MAX (char_width, digit_width));
+
+      /* ~3 chars for the ellipses */
+      requisition->width += char_pixels * 3;
+    }
+
+  pango_font_metrics_unref (metrics);
+}
+
+static void
+gimp_spin_scale_style_set (GtkWidget *widget,
+                           GtkStyle  *prev_style)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+
+  GTK_WIDGET_CLASS (parent_class)->style_set (widget, prev_style);
+
+  g_clear_object (&private->layout);
+
+  gtk_widget_style_get (widget,
+                        "compact", &private->compact,
+                        NULL);
+}
+
+static PangoAttrList *
+pattern_to_attrs (const gchar *text,
+                  const gchar *pattern)
+{
+  PangoAttrList *attrs = pango_attr_list_new ();
+  const char    *p     = text;
+  const char    *q     = pattern;
+  const char    *start;
+
+  while (TRUE)
+    {
+      while (*p && *q && *q != '_')
+        {
+          p = g_utf8_next_char (p);
+          q++;
+        }
+      start = p;
+      while (*p && *q && *q == '_')
+        {
+          p = g_utf8_next_char (p);
+          q++;
+        }
+
+      if (p > start)
+        {
+          PangoAttribute *attr = pango_attr_underline_new (PANGO_UNDERLINE_LOW);
+
+          attr->start_index = start - text;
+          attr->end_index   = p - text;
+
+          pango_attr_list_insert (attrs, attr);
+        }
+      else
+        break;
+    }
+
+  return attrs;
+}
+
+static gboolean
+gimp_spin_scale_expose (GtkWidget      *widget,
+                        GdkEventExpose *event)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+  GtkStyle             *style   = gtk_widget_get_style (widget);
+  cairo_t              *cr;
+  gboolean              rtl;
+  gint                  w, h;
+
+  GTK_WIDGET_CLASS (parent_class)->expose_event (widget, event);
+
+  cr = gdk_cairo_create (event->window);
+  gdk_cairo_region (cr, event->region);
+  cairo_clip (cr);
+
+  rtl = (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL);
+
+  w = gdk_window_get_width (event->window);
+  h = gdk_window_get_height (event->window);
+
+  /* upper/lower halves highlight */
+  if (! private->compact                                              &&
+      event->window == gtk_entry_get_text_window (GTK_ENTRY (widget)) &&
+      gtk_widget_get_sensitive (widget)                               &&
+      (private->target == TARGET_UPPER || private->target == TARGET_LOWER))
+    {
+      gint            window_width;
+      gint            window_height;
+      const GdkColor *color;
+      gdouble         r, g, b, a;
+
+      window_width  = gdk_window_get_width  (event->window);
+      window_height = gdk_window_get_height (event->window);
+
+      color = &style->text[gtk_widget_get_state (widget)];
+
+      switch (private->target)
+        {
+        case TARGET_UPPER:
+          cairo_rectangle (cr, 0, 0, window_width, window_height / 2);
+          break;
+
+        case TARGET_LOWER:
+          cairo_rectangle (cr, 0, window_height / 2, window_width, (window_height + 1) / 2);
+          break;
+
+        default:
+          break;
+        }
+
+      r = (gdouble) color->red   / 0xffff;
+      g = (gdouble) color->green / 0xffff;
+      b = (gdouble) color->blue  / 0xffff;
+      a = 0.12 + 0.04 * MAX (r, MAX (g, b));
+
+      if (private->changing_value)
+        a *= 1.6;
+
+      cairo_set_source_rgba (cr, r, g, b, a);
+
+      cairo_fill (cr);
+    }
+
+  cairo_set_line_width (cr, 1.0);
+
+  if (event->window == gtk_entry_get_text_window (GTK_ENTRY (widget)))
+    {
+      /* let spinbutton-side line of rectangle disappear */
+      if (rtl)
+        cairo_rectangle (cr, -0.5, 0.5, w, h - 1.0);
+      else
+        cairo_rectangle (cr, 0.5, 0.5, w, h - 1.0);
+
+      gdk_cairo_set_source_color (cr,
+                                  &style->text_aa[gtk_widget_get_state (widget)]);
+      cairo_stroke (cr);
+    }
+  else
+    {
+      /* let text-box-side line of rectangle disappear */
+      if (rtl)
+        cairo_rectangle (cr, 0.5, 0.5, w, h - 1.0);
+      else
+        cairo_rectangle (cr, -0.5, 0.5, w, h - 1.0);
+
+      gdk_cairo_set_source_color (cr,
+                                  &style->text_aa[gtk_widget_get_state (widget)]);
+      cairo_stroke (cr);
+
+      if (rtl)
+        cairo_rectangle (cr, 1.5, 1.5, w - 2.0, h - 3.0);
+      else
+        cairo_rectangle (cr, 0.5, 1.5, w - 2.0, h - 3.0);
+
+      gdk_cairo_set_source_color (cr,
+                                  &style->base[gtk_widget_get_state (widget)]);
+      cairo_stroke (cr);
+    }
+
+  if (private->label &&
+      gtk_widget_is_drawable (widget) &&
+      event->window == gtk_entry_get_text_window (GTK_ENTRY (widget)))
+    {
+      GtkRequisition requisition;
+      GtkAllocation  allocation;
+      PangoRectangle logical;
+      gint           layout_offset_x;
+      gint           layout_offset_y;
+      GtkStateType   state;
+      GdkColor       text_color;
+      GdkColor       bar_text_color;
+      gint           window_width;
+      gint           window_height;
+      gdouble        progress_fraction;
+      gint           progress_x;
+      gint           progress_y;
+      gint           progress_width;
+      gint           progress_height;
+
+      GTK_WIDGET_CLASS (parent_class)->size_request (widget, &requisition);
+      gtk_widget_get_allocation (widget, &allocation);
+
+      if (! private->layout)
+        {
+          private->layout = gtk_widget_create_pango_layout (widget,
+                                                            private->label_text);
+          pango_layout_set_ellipsize (private->layout, PANGO_ELLIPSIZE_END);
+
+          if (private->mnemonics_visible)
+            {
+              PangoAttrList *attrs;
+
+              attrs = pattern_to_attrs (private->label_text,
+                                        private->label_pattern);
+              if (attrs)
+                {
+                  pango_layout_set_attributes (private->layout, attrs);
+                  pango_attr_list_unref (attrs);
+                }
+            }
+        }
+
+      pango_layout_set_width (private->layout,
+                              PANGO_SCALE *
+                              (allocation.width - requisition.width));
+      pango_layout_get_pixel_extents (private->layout, NULL, &logical);
+
+      gtk_entry_get_layout_offsets (GTK_ENTRY (widget), NULL, &layout_offset_y);
+
+      if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
+        layout_offset_x = w - logical.width - 2;
+      else
+        layout_offset_x = 2;
+
+      layout_offset_x -= logical.x;
+
+      state = GTK_STATE_SELECTED;
+      if (! gtk_widget_get_sensitive (widget))
+        state = GTK_STATE_INSENSITIVE;
+      text_color     = style->text[gtk_widget_get_state (widget)];
+      bar_text_color = style->fg[state];
+
+      window_width  = gdk_window_get_width  (event->window);
+      window_height = gdk_window_get_height (event->window);
+
+      progress_fraction = gtk_entry_get_progress_fraction (GTK_ENTRY (widget));
+
+      if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
+        {
+          progress_fraction = 1.0 - progress_fraction;
+
+          progress_x      = window_width * progress_fraction;
+          progress_y      = 0;
+          progress_width  = window_width - progress_x;
+          progress_height = window_height;
+        }
+      else
+        {
+          progress_x      = 0;
+          progress_y      = 0;
+          progress_width  = window_width * progress_fraction;
+          progress_height = window_height;
+        }
+
+      cairo_save (cr);
+
+      cairo_set_fill_rule (cr, CAIRO_FILL_RULE_EVEN_ODD);
+      cairo_rectangle (cr, 0, 0, window_width, window_height);
+      cairo_rectangle (cr, progress_x, progress_y,
+                       progress_width, progress_height);
+      cairo_clip (cr);
+      cairo_set_fill_rule (cr, CAIRO_FILL_RULE_WINDING);
+
+      cairo_move_to (cr, layout_offset_x, layout_offset_y);
+      gdk_cairo_set_source_color (cr, &text_color);
+      pango_cairo_show_layout (cr, private->layout);
+
+      cairo_restore (cr);
+
+      cairo_rectangle (cr, progress_x, progress_y,
+                       progress_width, progress_height);
+      cairo_clip (cr);
+
+      cairo_move_to (cr, layout_offset_x, layout_offset_y);
+      gdk_cairo_set_source_color (cr, &bar_text_color);
+      pango_cairo_show_layout (cr, private->layout);
+    }
+
+  cairo_destroy (cr);
+
+  return FALSE;
+}
+
+static SpinScaleTarget
+gimp_spin_scale_get_target (GtkWidget      *widget,
+                            gdouble         x,
+                            gdouble         y,
+                            GdkEventButton *event)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+  GtkAllocation         allocation;
+  PangoRectangle        logical;
+  gint                  layout_x;
+  gint                  layout_y;
+
+  if (private->compact && ! event)
+    return TARGET_UPPER;
+
+  gtk_widget_get_allocation (widget, &allocation);
+  gtk_entry_get_layout_offsets (GTK_ENTRY (widget), &layout_x, &layout_y);
+  pango_layout_get_pixel_extents (gtk_entry_get_layout (GTK_ENTRY (widget)),
+                                  NULL, &logical);
+
+  if (x >= layout_x && x < layout_x + logical.width  &&
+      y >= layout_y && y < layout_y + logical.height &&
+      (! private->compact                            ||
+       (gtk_widget_has_focus (widget)                &&
+        gdk_event_triggers_context_menu ((GdkEvent *) event))))
+    {
+      return TARGET_NUMBER;
+    }
+
+  if (private->compact)
+    {
+      switch (event->button)
+        {
+        case 1:
+          if (event->state & GDK_SHIFT_MASK)
+            return TARGET_LOWER;
+          else
+            return TARGET_UPPER;
+
+        case 3:
+          return TARGET_LOWER;
+
+        default:
+          return TARGET_NUMBER;
+        }
+    }
+   else
+    {
+      if (y >= allocation.height / 2)
+        return TARGET_LOWER;
+      else
+        return TARGET_UPPER;
+    }
+}
+
+static void
+gimp_spin_scale_update_target (GtkWidget      *widget,
+                               GdkWindow      *window,
+                               gdouble         x,
+                               gdouble         y,
+                               GdkEventButton *event)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+  SpinScaleTarget       target;
+
+  target = gimp_spin_scale_get_target (widget, x, y, event);
+
+  if (target != private->target)
+    {
+      GdkDisplay *display = gtk_widget_get_display (widget);
+      GdkCursor  *cursor  = NULL;
+
+      private->target = target;
+
+      switch (target)
+        {
+        case TARGET_NUMBER:
+          cursor = gdk_cursor_new_for_display (display, GDK_XTERM);
+          break;
+
+        case TARGET_UPPER:
+          cursor = gdk_cursor_new_for_display (display, GDK_SB_UP_ARROW);
+          break;
+
+        case TARGET_LOWER:
+          cursor = gdk_cursor_new_for_display (display, GDK_SB_H_DOUBLE_ARROW);
+          break;
+
+        default:
+          break;
+        }
+
+      gdk_window_set_cursor (window, cursor);
+
+      gtk_widget_queue_draw (widget);
+
+      if (cursor)
+        gdk_cursor_unref (cursor);
+    }
+}
+
+static void
+gimp_spin_scale_clear_target (GtkWidget *widget,
+                              GdkWindow *window)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+
+  if (private->target != TARGET_NONE)
+    {
+      private->target = TARGET_NONE;
+
+      gdk_window_set_cursor (window, NULL);
+
+      gtk_widget_queue_draw (widget);
+    }
+}
+
+static void
+gimp_spin_scale_get_limits (GimpSpinScale *scale,
+                            gdouble       *lower,
+                            gdouble       *upper)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (scale);
+
+  if (private->scale_limits_set)
+    {
+      *lower = private->scale_lower;
+      *upper = private->scale_upper;
+    }
+  else
+    {
+      GtkSpinButton *spin_button = GTK_SPIN_BUTTON (scale);
+      GtkAdjustment *adjustment  = gtk_spin_button_get_adjustment (spin_button);
+
+      *lower = gtk_adjustment_get_lower (adjustment);
+      *upper = gtk_adjustment_get_upper (adjustment);
+    }
+}
+
+static gboolean
+gimp_spin_scale_change_value_idle (GimpSpinScale *scale)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (scale);
+  GtkAdjustment        *adjustment;
+
+  private->change_value_idle_id = 0;
+
+  adjustment = gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (scale));
+
+  gtk_adjustment_set_value (adjustment, private->change_value_idle_value);
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+gimp_spin_scale_change_value (GtkWidget *widget,
+                              gdouble    x,
+                              guint      state,
+                              gboolean   now)
+{
+  GimpSpinScalePrivate *private     = GET_PRIVATE (widget);
+  GtkSpinButton        *spin_button = GTK_SPIN_BUTTON (widget);
+  GtkAdjustment        *adjustment  = gtk_spin_button_get_adjustment (spin_button);
+  GdkWindow            *text_window = gtk_entry_get_text_window (GTK_ENTRY (widget));
+  gdouble               lower;
+  gdouble               upper;
+  gint                  width;
+  gdouble               value;
+  gint                  digits;
+  gint                  power = 1;
+
+  gimp_spin_scale_get_limits (GIMP_SPIN_SCALE (widget), &lower, &upper);
+
+  width = gdk_window_get_width (text_window);
+
+  if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
+    x = width - x;
+
+  if (private->relative_change)
+    {
+      gdouble step;
+
+      step = (upper - lower) / width * RELATIVE_CHANGE_SPEED;
+
+      if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
+        step *= x - (width - private->start_x);
+      else
+        step *= x - private->start_x;
+
+      if (state & GDK_CONTROL_MASK)
+        {
+          gdouble page_inc = gtk_adjustment_get_page_increment (adjustment);
+
+          step = RINT (step / page_inc) * page_inc;
+        }
+
+      value = private->start_value + step;
+    }
+  else
+    {
+      gdouble x0, x1;
+      gdouble fraction;
+
+      x0 = odd_pow (lower, 1.0 / private->gamma);
+      x1 = odd_pow (upper, 1.0 / private->gamma);
+
+      fraction = x / (gdouble) width;
+
+      value = fraction * (x1 - x0) + x0;
+      value = odd_pow (value, private->gamma);
+
+      if (state & GDK_CONTROL_MASK)
+        {
+          gdouble page_inc = gtk_adjustment_get_page_increment (adjustment);
+
+          value = RINT (value / page_inc) * page_inc;
+        }
+    }
+
+  digits = gtk_spin_button_get_digits (spin_button);
+  while (digits--)
+    power *= 10;
+
+  /*  round the value to the possible precision of the spinbutton, so
+   *  a focus-out will not change the value again, causing inadvertend
+   *  adjustment signals.
+   */
+  value *= power;
+  value = RINT (value);
+  value /= power;
+
+  if (private->constrain_drag)
+    value = rint (value);
+
+  if (now)
+    {
+      if (private->change_value_idle_id)
+        {
+          g_source_remove (private->change_value_idle_id);
+
+          private->change_value_idle_id = 0;
+        }
+
+      gtk_adjustment_set_value (adjustment, value);
+    }
+  else if (! private->change_value_idle_id)
+    {
+      private->change_value_idle_value = value;
+
+      private->change_value_idle_id = g_idle_add_full (
+        G_PRIORITY_DEFAULT + 1,
+        (GSourceFunc) gimp_spin_scale_change_value_idle,
+        widget, NULL);
+    }
+}
+
+static gboolean
+gimp_spin_scale_button_press (GtkWidget      *widget,
+                              GdkEventButton *event)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+
+  private->changing_value  = FALSE;
+  private->relative_change = FALSE;
+  private->pointer_warp    = FALSE;
+
+  if (event->window == gtk_entry_get_text_window (GTK_ENTRY (widget)))
+    {
+      gimp_spin_scale_update_target (widget, event->window,
+                                     event->x, event->y, event);
+
+      gtk_widget_queue_draw (widget);
+
+      switch (private->target)
+        {
+        case TARGET_UPPER:
+          private->changing_value = TRUE;
+
+          gtk_widget_grab_focus (widget);
+
+          gimp_spin_scale_change_value (widget, event->x, event->state, TRUE);
+
+          return TRUE;
+
+        case TARGET_LOWER:
+          private->changing_value = TRUE;
+
+          gtk_widget_grab_focus (widget);
+
+          private->relative_change = TRUE;
+          private->start_x = event->x;
+          private->start_value = gtk_adjustment_get_value (gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (widget)));
+
+          private->start_screen    = gdk_event_get_screen ((GdkEvent *) event);
+          private->start_pointer_x = floor (event->x_root);
+          private->start_pointer_y = floor (event->y_root);
+
+          return TRUE;
+
+        default:
+          break;
+        }
+    }
+
+  return GTK_WIDGET_CLASS (parent_class)->button_press_event (widget, event);
+}
+
+static gboolean
+gimp_spin_scale_button_release (GtkWidget      *widget,
+                                GdkEventButton *event)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+
+  if (private->changing_value)
+    {
+      private->changing_value = FALSE;
+
+      /* don't change the value if we're in the middle of a pointer warp, since
+       * we didn't adjust start_x yet.  see the comment in
+       * gimp_spin_scale_motion_notify().
+       */
+      if (! private->pointer_warp)
+        gimp_spin_scale_change_value (widget, event->x, event->state, TRUE);
+
+      if (private->relative_change)
+        {
+          gdk_display_warp_pointer (gdk_screen_get_display (private->start_screen),
+                                    private->start_screen,
+                                    private->start_pointer_x,
+                                    private->start_pointer_y);
+        }
+
+      if (private->hover)
+        gimp_spin_scale_update_target (widget, event->window,
+                                       event->x, event->y, NULL);
+      else
+        gimp_spin_scale_clear_target (widget, event->window);
+
+      gtk_widget_queue_draw (widget);
+
+      return TRUE;
+    }
+
+  return GTK_WIDGET_CLASS (parent_class)->button_release_event (widget, event);
+}
+
+static gboolean
+gimp_spin_scale_motion_notify (GtkWidget      *widget,
+                               GdkEventMotion *event)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+
+  gdk_event_request_motions (event);
+
+  if (event->window == gtk_entry_get_text_window (GTK_ENTRY (widget)))
+    private->hover = TRUE;
+
+  if (private->changing_value)
+    {
+      GdkScreen    *screen;
+      GdkDisplay   *display;
+      gint          pointer_x;
+      gint          pointer_y;
+      gint          monitor;
+      GdkRectangle  monitor_geometry;
+
+      screen  = gdk_event_get_screen ((GdkEvent *) event);
+      display = gdk_screen_get_display (screen);
+
+      pointer_x = floor (event->x_root);
+      pointer_y = floor (event->y_root);
+
+      monitor = gdk_screen_get_monitor_at_point (screen, pointer_x, pointer_y);
+      gdk_screen_get_monitor_geometry (screen, monitor, &monitor_geometry);
+
+      /* when applying a relative change, we wrap the pointer around the left
+       * and right edges of the current monitor, so that the adjustment is not
+       * limited by the monitor geometry.  when the pointer reaches one of the
+       * monitor edges, we move it one pixel away from the opposite edge, so
+       * that it can be subsequently moved in the other direction, and adjust
+       * start_x accordingly.
+       *
+       * unfortunately, we can't rely on gdk_display_warp_pointer() to actually
+       * move the pointer (for example, it doesn't work on wayland), and
+       * there's no easy way to tell whether the pointer moved or not.  in
+       * particular, even when the pointer doesn't move, gdk still simulates a
+       * motion event, and reports the "new" pointer position until a real
+       * motion event occurs.
+       *
+       * in order not to erroneously adjust start_x when
+       * gdk_display_warp_pointer() fails, we remember that we *tried* to warp
+       * the pointer, and defer the actual adjustment of start_x until a future
+       * motion event, where the pointer's x coordinate is different from the
+       * one passed to gdk_display_warp_pointer().  when that happens, we
+       * "guess" whether the pointer got warped or not by comparing its x
+       * coordinate to the one passed to gdk_display_warp_pointer(): if their
+       * difference is less than half the monitor width, then we assume the
+       * pointer got warped (otherwise, the user must have very quickly moved
+       * the mouse across half the screen.)  yes, this is an ugly ugly hack :)
+       */
+
+      if (private->pointer_warp)
+        {
+          if (pointer_x == private->pointer_warp_x)
+            return TRUE;
+
+          private->pointer_warp = FALSE;
+
+          if (ABS (pointer_x - private->pointer_warp_x) < monitor_geometry.width / 2)
+            private->start_x = private->pointer_warp_start_x;
+        }
+
+      /* change the value in an idle, as a form of motion compression, since we
+       * don't use motion hints.  see the comment in gimp_spin_scale_map().
+       */
+      gimp_spin_scale_change_value (widget, event->x, event->state, FALSE);
+
+      if (private->relative_change)
+        {
+          GtkAdjustment *adjustment;
+          gdouble        value;
+          gdouble        lower;
+          gdouble        upper;
+
+          adjustment = gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (widget));
+
+          value = gtk_adjustment_get_value (adjustment);
+          lower = gtk_adjustment_get_lower (adjustment);
+          upper = gtk_adjustment_get_upper (adjustment);
+
+          if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
+            {
+              gdouble temp;
+
+              value = -value;
+
+              temp  = lower;
+              lower = -upper;
+              upper = -temp;
+            }
+
+          if (pointer_x <= monitor_geometry.x &&
+              value > lower)
+            {
+              private->pointer_warp         = TRUE;
+              private->pointer_warp_x       = (monitor_geometry.width - 1) + pointer_x - 1;
+              private->pointer_warp_start_x = private->start_x + (monitor_geometry.width - 2);
+            }
+          else if (pointer_x >= monitor_geometry.x + (monitor_geometry.width - 1) &&
+                   value < upper)
+            {
+              private->pointer_warp         = TRUE;
+              private->pointer_warp_x       = pointer_x - (monitor_geometry.width - 1) + 1;
+              private->pointer_warp_start_x = private->start_x - (monitor_geometry.width - 2);
+            }
+
+          if (private->pointer_warp)
+            {
+              gdk_display_warp_pointer (display,
+                                        screen,
+                                        private->pointer_warp_x,
+                                        pointer_y);
+            }
+        }
+
+      return TRUE;
+    }
+
+  GTK_WIDGET_CLASS (parent_class)->motion_notify_event (widget, event);
+
+  if (! (event->state &
+         (GDK_BUTTON1_MASK | GDK_BUTTON2_MASK | GDK_BUTTON3_MASK)) &&
+      private->hover)
+    {
+      gimp_spin_scale_update_target (widget, event->window,
+                                     event->x, event->y, NULL);
+    }
+
+  return FALSE;
+}
+
+static gboolean
+gimp_spin_scale_leave_notify (GtkWidget        *widget,
+                              GdkEventCrossing *event)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+
+  if (event->window == gtk_entry_get_text_window (GTK_ENTRY (widget)))
+    {
+      private->hover = FALSE;
+
+      if (! (event->state &
+             (GDK_BUTTON1_MASK | GDK_BUTTON2_MASK | GDK_BUTTON3_MASK)))
+        {
+          gimp_spin_scale_clear_target (widget, event->window);
+        }
+    }
+
+  return GTK_WIDGET_CLASS (parent_class)->leave_notify_event (widget, event);
+}
+
+static void
+gimp_spin_scale_hierarchy_changed (GtkWidget *widget,
+                                   GtkWidget *old_toplevel)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (widget);
+
+  gimp_spin_scale_setup_mnemonic (GIMP_SPIN_SCALE (widget),
+                                  private->mnemonic_keyval);
+}
+
+static void
+gimp_spin_scale_screen_changed (GtkWidget *widget,
+                                GdkScreen *old_screen)
+{
+  GimpSpinScale        *scale   = GIMP_SPIN_SCALE (widget);
+  GimpSpinScalePrivate *private = GET_PRIVATE (scale);
+  GtkSettings          *settings;
+
+  g_clear_object (&private->layout);
+
+  if (old_screen)
+    {
+      settings = gtk_settings_get_for_screen (old_screen);
+
+      g_signal_handlers_disconnect_by_func (settings,
+                                            gimp_spin_scale_settings_notify,
+                                            scale);
+    }
+
+  if (! gtk_widget_has_screen (widget))
+    return;
+
+  settings = gtk_widget_get_settings (widget);
+
+  g_signal_connect (settings, "notify::gtk-enable-mnemonics",
+                    G_CALLBACK (gimp_spin_scale_settings_notify),
+                    scale);
+  g_signal_connect (settings, "notify::gtk-enable-accels",
+                    G_CALLBACK (gimp_spin_scale_settings_notify),
+                    scale);
+
+  gimp_spin_scale_settings_notify (settings, NULL, scale);
+}
+
+static void
+gimp_spin_scale_value_changed (GtkSpinButton *spin_button)
+{
+  GimpSpinScalePrivate *private    = GET_PRIVATE (spin_button);
+  GtkAdjustment        *adjustment = gtk_spin_button_get_adjustment (spin_button);
+  gdouble               lower;
+  gdouble               upper;
+  gdouble               value;
+  gdouble               x0, x1;
+  gdouble               x;
+
+  gimp_spin_scale_get_limits (GIMP_SPIN_SCALE (spin_button), &lower, &upper);
+
+  value = CLAMP (gtk_adjustment_get_value (adjustment), lower, upper);
+
+  x0 = odd_pow (lower, 1.0 / private->gamma);
+  x1 = odd_pow (upper, 1.0 / private->gamma);
+  x  = odd_pow (value, 1.0 / private->gamma);
+
+  gtk_entry_set_progress_fraction (GTK_ENTRY (spin_button),
+                                   (x - x0) / (x1 - x0));
+}
+
+static void
+gimp_spin_scale_settings_notify (GtkSettings      *settings,
+                                 const GParamSpec *pspec,
+                                 GimpSpinScale    *scale)
+{
+  GtkWidget *toplevel = gtk_widget_get_toplevel (GTK_WIDGET (scale));
+
+  if (GTK_IS_WINDOW (toplevel))
+    gimp_spin_scale_mnemonics_notify (GTK_WINDOW (toplevel), NULL, scale);
+}
+
+static void
+gimp_spin_scale_mnemonics_notify (GtkWindow        *window,
+                                  const GParamSpec *pspec,
+                                  GimpSpinScale    *scale)
+{
+  GimpSpinScalePrivate *private           = GET_PRIVATE (scale);
+  gboolean              mnemonics_visible = FALSE;
+  gboolean              enable_mnemonics;
+  gboolean              auto_mnemonics;
+
+  g_object_get (gtk_widget_get_settings (GTK_WIDGET (scale)),
+                "gtk-enable-mnemonics", &enable_mnemonics,
+                "gtk-auto-mnemonics",   &auto_mnemonics,
+                NULL);
+
+  if (enable_mnemonics &&
+      (! auto_mnemonics ||
+       gtk_widget_is_sensitive (GTK_WIDGET (scale))))
+    {
+      g_object_get (window,
+                    "mnemonics-visible", &mnemonics_visible,
+                    NULL);
+    }
+
+  if (private->mnemonics_visible != mnemonics_visible)
+    {
+      private->mnemonics_visible = mnemonics_visible;
+
+      g_clear_object (&private->layout);
+
+      gtk_widget_queue_draw (GTK_WIDGET (scale));
+    }
+}
+
+static void
+gimp_spin_scale_setup_mnemonic (GimpSpinScale *scale,
+                                guint          previous_keyval)
+{
+  GimpSpinScalePrivate *private = GET_PRIVATE (scale);
+  GtkWidget            *widget  = GTK_WIDGET (scale);
+  GtkWidget            *toplevel;
+
+  if (private->mnemonic_window)
+    {
+      g_signal_handlers_disconnect_by_func (private->mnemonic_window,
+                                            gimp_spin_scale_mnemonics_notify,
+                                            scale);
+
+      gtk_window_remove_mnemonic (private->mnemonic_window,
+                                  previous_keyval,
+                                  widget);
+      private->mnemonic_window = NULL;
+    }
+
+  toplevel = gtk_widget_get_toplevel (widget);
+
+  if (gtk_widget_is_toplevel (toplevel) &&
+      private->mnemonic_keyval != GDK_KEY_VoidSymbol)
+    {
+      gtk_window_add_mnemonic (GTK_WINDOW (toplevel),
+                               private->mnemonic_keyval,
+                               widget);
+      private->mnemonic_window = GTK_WINDOW (toplevel);
+
+      g_signal_connect (toplevel, "notify::mnemonics-visible",
+                        G_CALLBACK (gimp_spin_scale_mnemonics_notify),
+                        scale);
+     }
+}
+
+static gdouble
+odd_pow (gdouble x,
+         gdouble y)
+{
+  if (x >= 0.0)
+    return pow (x, y);
+  else
+    return -pow (-x, y);
+}
+
+
+/*  public functions  */
+
+GtkWidget *
+gimp_spin_scale_new (GtkAdjustment *adjustment,
+                     const gchar   *label,
+                     gint           digits)
+{
+  g_return_val_if_fail (GTK_IS_ADJUSTMENT (adjustment), NULL);
+
+  return g_object_new (GIMP_TYPE_SPIN_SCALE,
+                       "adjustment", adjustment,
+                       "label",      label,
+                       "digits",     digits,
+                       NULL);
+}
+
+static gboolean
+separate_uline_pattern (const gchar  *str,
+                        guint        *accel_key,
+                        gchar       **new_str,
+                        gchar       **pattern)
+{
+  gboolean underscore;
+  const gchar *src;
+  gchar *dest;
+  gchar *pattern_dest;
+
+  *accel_key = GDK_KEY_VoidSymbol;
+  *new_str = g_new (gchar, strlen (str) + 1);
+  *pattern = g_new (gchar, g_utf8_strlen (str, -1) + 1);
+
+  underscore = FALSE;
+
+  src = str;
+  dest = *new_str;
+  pattern_dest = *pattern;
+
+  while (*src)
+    {
+      gunichar c;
+      const gchar *next_src;
+
+      c = g_utf8_get_char (src);
+      if (c == (gunichar)-1)
+        {
+          g_warning ("Invalid input string");
+          g_free (*new_str);
+          g_free (*pattern);
+
+          return FALSE;
+        }
+      next_src = g_utf8_next_char (src);
+
+      if (underscore)
+        {
+          if (c == '_')
+            *pattern_dest++ = ' ';
+          else
+            {
+              *pattern_dest++ = '_';
+              if (*accel_key == GDK_KEY_VoidSymbol)
+                *accel_key = gdk_keyval_to_lower (gdk_unicode_to_keyval (c));
+            }
+
+          while (src < next_src)
+            *dest++ = *src++;
+
+          underscore = FALSE;
+        }
+      else
+        {
+          if (c == '_')
+            {
+              underscore = TRUE;
+              src = next_src;
+            }
+          else
+            {
+              while (src < next_src)
+                *dest++ = *src++;
+
+              *pattern_dest++ = ' ';
+            }
+        }
+    }
+
+  *dest = 0;
+  *pattern_dest = 0;
+
+  return TRUE;
+}
+
+void
+gimp_spin_scale_set_label (GimpSpinScale *scale,
+                           const gchar   *label)
+{
+  GimpSpinScalePrivate *private;
+  guint                 accel_key = GDK_KEY_VoidSymbol;
+  gchar                *text      = NULL;
+  gchar                *pattern   = NULL;
+
+  g_return_if_fail (GIMP_IS_SPIN_SCALE (scale));
+
+  private = GET_PRIVATE (scale);
+
+  if (label == private->label)
+    return;
+
+  if (label && ! separate_uline_pattern (label, &accel_key, &text, &pattern))
+    return;
+
+  g_free (private->label);
+  private->label = g_strdup (label);
+
+  g_free (private->label_text);
+  private->label_text = text; /* don't dup */
+
+  g_free (private->label_pattern);
+  private->label_pattern = pattern; /* don't dup */
+
+  if (private->mnemonic_keyval != accel_key)
+    {
+      guint previous = private->mnemonic_keyval;
+
+      private->mnemonic_keyval = accel_key;
+
+      gimp_spin_scale_setup_mnemonic (scale, previous);
+    }
+
+  g_clear_object (&private->layout);
+
+  gtk_widget_queue_resize (GTK_WIDGET (scale));
+
+  g_object_notify (G_OBJECT (scale), "label");
+}
+
+const gchar *
+gimp_spin_scale_get_label (GimpSpinScale *scale)
+{
+  g_return_val_if_fail (GIMP_IS_SPIN_SCALE (scale), NULL);
+
+  return GET_PRIVATE (scale)->label;
+}
+
+void
+gimp_spin_scale_set_scale_limits (GimpSpinScale *scale,
+                                  gdouble        lower,
+                                  gdouble        upper)
+{
+  GimpSpinScalePrivate *private;
+  GtkSpinButton        *spin_button;
+  GtkAdjustment        *adjustment;
+
+  g_return_if_fail (GIMP_IS_SPIN_SCALE (scale));
+
+  private     = GET_PRIVATE (scale);
+  spin_button = GTK_SPIN_BUTTON (scale);
+  adjustment  = gtk_spin_button_get_adjustment (spin_button);
+
+  g_return_if_fail (lower >= gtk_adjustment_get_lower (adjustment));
+  g_return_if_fail (upper <= gtk_adjustment_get_upper (adjustment));
+
+  private->scale_limits_set = TRUE;
+  private->scale_lower      = lower;
+  private->scale_upper      = upper;
+  private->gamma            = 1.0;
+
+  gimp_spin_scale_value_changed (spin_button);
+}
+
+void
+gimp_spin_scale_unset_scale_limits (GimpSpinScale *scale)
+{
+  GimpSpinScalePrivate *private;
+
+  g_return_if_fail (GIMP_IS_SPIN_SCALE (scale));
+
+  private = GET_PRIVATE (scale);
+
+  private->scale_limits_set = FALSE;
+  private->scale_lower      = 0.0;
+  private->scale_upper      = 0.0;
+
+  gimp_spin_scale_value_changed (GTK_SPIN_BUTTON (scale));
+}
+
+gboolean
+gimp_spin_scale_get_scale_limits (GimpSpinScale *scale,
+                                  gdouble       *lower,
+                                  gdouble       *upper)
+{
+  GimpSpinScalePrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_SPIN_SCALE (scale), FALSE);
+
+  private = GET_PRIVATE (scale);
+
+  if (lower)
+    *lower = private->scale_lower;
+
+  if (upper)
+    *upper = private->scale_upper;
+
+  return private->scale_limits_set;
+}
+
+void
+gimp_spin_scale_set_gamma (GimpSpinScale *scale,
+                           gdouble        gamma)
+{
+  GimpSpinScalePrivate *private;
+
+  g_return_if_fail (GIMP_IS_SPIN_SCALE (scale));
+
+  private = GET_PRIVATE (scale);
+
+  private->gamma = gamma;
+
+  gimp_spin_scale_value_changed (GTK_SPIN_BUTTON (scale));
+}
+
+gdouble
+gimp_spin_scale_get_gamma (GimpSpinScale *scale)
+{
+  g_return_val_if_fail (GIMP_IS_SPIN_SCALE (scale), 1.0);
+
+  return GET_PRIVATE (scale)->gamma;
+}
+
+/**
+ * gimp_spin_scale_set_constrain_drag:
+ * @scale: the #GimpSpinScale.
+ * @constrain: whether constraining to integer values when dragging with
+ *             pointer.
+ *
+ * If @constrain_drag is TRUE, dragging the scale with the pointer will
+ * only result into integer values. It will still possible to set the
+ * scale to fractional values (if the spin scale "digits" is above 0)
+ * for instance with keyboard edit.
+ */
+void
+gimp_spin_scale_set_constrain_drag (GimpSpinScale *scale,
+                                    gboolean       constrain)
+{
+  GimpSpinScalePrivate *private;
+
+  g_return_if_fail (GIMP_IS_SPIN_SCALE (scale));
+
+  private = GET_PRIVATE (scale);
+
+  private->constrain_drag = constrain;
+}
+
+gboolean
+gimp_spin_scale_get_constrain_drag (GimpSpinScale *scale)
+{
+  g_return_val_if_fail (GIMP_IS_SPIN_SCALE (scale), 1.0);
+
+  return GET_PRIVATE (scale)->constrain_drag;
+}