[gtk+] Ensure that GtkRange allocates enough space for the value

[Matthias Clasen <matthiasc src gnome org>]

commit 7f06f2818aaef1994cb7224d95522b956bfd4ab8
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jun 7 21:28:44 2016 -0400

    Ensure that GtkRange allocates enough space for the value
    
    This is a long-standing problem of GtkScale.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=766372
    https://bugzilla.gnome.org/show_bug.cgi?id=578626
    https://bugzilla.gnome.org/show_bug.cgi?id=79229

 gtk/gtkrange.c |   11 +++++++++++
 gtk/gtkrange.h |    6 +++++-
 gtk/gtkscale.c |   26 ++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkrange.c b/gtk/gtkrange.c
index 0b306e4..c124ca2 100644
--- a/gtk/gtkrange.c
+++ b/gtk/gtkrange.c
@@ -1894,6 +1894,17 @@ gtk_range_size_request (GtkWidget      *widget,
   gtk_css_gadget_get_preferred_size (priv->gadget, orientation, -1,
                                      minimum, natural,
                                      NULL, NULL);
+
+  if (GTK_RANGE_GET_CLASS (range)->get_range_size_request)
+    {
+      gint min, nat;
+
+      GTK_RANGE_GET_CLASS (range)->get_range_size_request (range, orientation,
+                                                           &min, &nat);
+
+      *minimum = MAX (*minimum, min);
+      *natural = MAX (*natural, nat);
+    }
 }
 
 static void
diff --git a/gtk/gtkrange.h b/gtk/gtkrange.h
index b21e844..e78b3b5 100644
--- a/gtk/gtkrange.h
+++ b/gtk/gtkrange.h
@@ -78,11 +78,15 @@ struct _GtkRangeClass
                              GtkScrollType scroll,
                              gdouble       new_value);
 
+   void (* get_range_size_request) (GtkRange       *range,
+                                    GtkOrientation  orientation,
+                                    gint           *minimum,
+                                    gint           *natural);
+
   /* Padding for future expansion */
   void (*_gtk_reserved1) (void);
   void (*_gtk_reserved2) (void);
   void (*_gtk_reserved3) (void);
-  void (*_gtk_reserved4) (void);
 };
 
 
diff --git a/gtk/gtkscale.c b/gtk/gtkscale.c
index 1a66d2c..43161a3 100644
--- a/gtk/gtkscale.c
+++ b/gtk/gtkscale.c
@@ -198,6 +198,10 @@ static void     gtk_scale_get_preferred_height    (GtkWidget      *widget,
                                                    gint           *natural);
 static void     gtk_scale_get_range_border        (GtkRange       *range,
                                                    GtkBorder      *border);
+static void     gtk_scale_get_range_size_request  (GtkRange       *range,
+                                                   GtkOrientation  orientation,
+                                                   gint           *minimum,
+                                                   gint           *natural);
 static void     gtk_scale_finalize                (GObject        *object);
 static void     gtk_scale_value_style_changed     (GtkCssNode        *node,
                                                    GtkCssStyleChange *change,
@@ -718,6 +722,7 @@ gtk_scale_class_init (GtkScaleClass *class)
   widget_class->get_preferred_height = gtk_scale_get_preferred_height;
 
   range_class->get_range_border = gtk_scale_get_range_border;
+  range_class->get_range_size_request = gtk_scale_get_range_size_request;
 
   class->get_layout_offsets = gtk_scale_real_get_layout_offsets;
 
@@ -1553,6 +1558,27 @@ gtk_scale_get_range_border (GtkRange  *range,
 }
 
 static void
+gtk_scale_get_range_size_request (GtkRange       *range,
+                                  GtkOrientation  orientation,
+                                  gint           *minimum,
+                                  gint           *natural)
+{
+  GtkScalePrivate *priv = GTK_SCALE (range)->priv;
+
+  /* Ensure the range requests enough size for our value */
+  if (priv->value_gadget)
+    gtk_css_gadget_get_preferred_size (priv->value_gadget,
+                                       orientation, -1,
+                                       minimum, natural,
+                                       NULL, NULL);
+  else
+    {
+      *minimum = 0;
+      *natural = 0;
+    }
+}
+
+static void
 gtk_scale_value_style_changed (GtkCssNode        *node,
                                GtkCssStyleChange *change,
                                GtkScale          *scale)