[gtk+] range: read and use CSS margin values for the trough component

[Cosimo Cecchi <cosimoc src gnome org>]

commit e32da246a84492f02b4dac5a448bb46cb23d68b8
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Wed May 16 17:01:33 2012 -0400

    range: read and use CSS margin values for the trough component
    
    Many themes want to render the trough background/stroke thinner than the
    full height/width (which is constructed around the value of the
    'slider-width' style property).
    Read and apply the CSS margin from the theme on the trough component, so
    that themes can make it smaller at their will without the need to
    override the render_background, render_frame and render_activity methods
    of GtkThemingEngine.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=676196

 gtk/gtkrange.c |   43 +++++++++++++++++++++++++++++--------------
 1 files changed, 29 insertions(+), 14 deletions(-)
---
diff --git a/gtk/gtkrange.c b/gtk/gtkrange.c
index 981d700..529a8d7 100644
--- a/gtk/gtkrange.c
+++ b/gtk/gtkrange.c
@@ -2010,6 +2010,7 @@ gtk_range_draw (GtkWidget *widget,
   gboolean draw_trough = TRUE;
   gboolean draw_slider = TRUE;
   GtkStyleContext *context;
+  GtkBorder margin;
 
   context = gtk_widget_get_style_context (widget);
 
@@ -2107,6 +2108,12 @@ gtk_range_draw (GtkWidget *widget,
 
       gtk_style_context_save (context);
       gtk_style_context_add_class (context, GTK_STYLE_CLASS_TROUGH);
+      gtk_style_context_get_margin (context, widget_state, &margin);
+
+      x += margin.left;
+      y += margin.top;
+      width -= margin.left + margin.right;
+      height -= margin.top + margin.bottom;
 
       if (draw_trough)
         {
@@ -3576,13 +3583,15 @@ gtk_range_calc_layout (GtkRange *range,
   GtkRangePrivate *priv = range->priv;
   gint slider_width, stepper_size, focus_width, trough_border, stepper_spacing;
   gint slider_length;
-  GtkBorder border;
+  GtkBorder border, trough_margin;
   gint n_steppers;
   gboolean has_steppers_ab;
   gboolean has_steppers_cd;
   gboolean trough_under_steppers;
   GdkRectangle range_rect;
   GtkWidget *widget;
+  GtkStyleContext *context;
+  GtkStateFlags state;
 
   if (!priv->need_recalc)
     return;
@@ -3598,6 +3607,13 @@ gtk_range_calc_layout (GtkRange *range,
    */
 
   widget = GTK_WIDGET (range);
+  context = gtk_widget_get_style_context (widget);
+
+  state = gtk_widget_get_state_flags (widget);
+  gtk_style_context_save (context);
+  gtk_style_context_add_class (context, GTK_STYLE_CLASS_TROUGH);
+  gtk_style_context_get_margin (context, state, &trough_margin);
+  gtk_style_context_restore (context);
 
   gtk_range_get_props (range,
                        &slider_width, &stepper_size,
@@ -3716,16 +3732,16 @@ gtk_range_calc_layout (GtkRange *range,
       /* Now the trough is the remaining space between steppers B and C,
        * if any, minus spacing
        */
-      priv->trough.x = range_rect.x;
-      priv->trough.y = priv->stepper_b.y + priv->stepper_b.height + stepper_spacing * has_steppers_ab;
-      priv->trough.width = range_rect.width;
-      priv->trough.height = priv->stepper_c.y - priv->trough.y - stepper_spacing * has_steppers_cd;
+      priv->trough.x = range_rect.x + trough_margin.left;
+      priv->trough.y = priv->stepper_b.y + priv->stepper_b.height + stepper_spacing * has_steppers_ab + trough_margin.top;
+      priv->trough.width = range_rect.width - trough_margin.left - trough_margin.right;
+      priv->trough.height = priv->stepper_c.y - priv->trough.y - stepper_spacing * has_steppers_cd - trough_margin.bottom;
 
       /* Slider fits into the trough, with stepper_spacing on either side,
        * and the size/position based on the adjustment or fixed, depending.
        */
-      priv->slider.x = priv->trough.x + focus_width + trough_border;
-      priv->slider.width = priv->trough.width - (focus_width + trough_border) * 2;
+      priv->slider.x = range_rect.x + focus_width + trough_border;
+      priv->slider.width = range_rect.width - (focus_width + trough_border) * 2;
 
       /* Compute slider position/length */
       {
@@ -3864,17 +3880,16 @@ gtk_range_calc_layout (GtkRange *range,
       /* Now the trough is the remaining space between steppers B and C,
        * if any
        */
-      priv->trough.x = priv->stepper_b.x + priv->stepper_b.width + stepper_spacing * has_steppers_ab;
-      priv->trough.y = range_rect.y;
-
-      priv->trough.width = priv->stepper_c.x - priv->trough.x - stepper_spacing * has_steppers_cd;
-      priv->trough.height = range_rect.height;
+      priv->trough.x = priv->stepper_b.x + priv->stepper_b.width + stepper_spacing * has_steppers_ab + trough_margin.left;
+      priv->trough.y = range_rect.y + trough_margin.top;
+      priv->trough.width = priv->stepper_c.x - priv->trough.x - stepper_spacing * has_steppers_cd - trough_margin.right;
+      priv->trough.height = range_rect.height - trough_margin.top - trough_margin.bottom;
 
       /* Slider fits into the trough, with stepper_spacing on either side,
        * and the size/position based on the adjustment or fixed, depending.
        */
-      priv->slider.y = priv->trough.y + focus_width + trough_border;
-      priv->slider.height = priv->trough.height - (focus_width + trough_border) * 2;
+      priv->slider.y = range_rect.y + focus_width + trough_border;
+      priv->slider.height = range_rect.height - (focus_width + trough_border) * 2;
 
       /* Compute slider position/length */
       {