[gtk+/gtk-3-14] GtkRange: Fix drawing of fill-level

[Matthias Clasen <matthiasc src gnome org>]

commit 5a61fcd1b31605a222711f6916c10eb1357fd624
Author: Marcus Karlsson <mk acc umu se>
Date:   Tue Mar 24 22:31:52 2015 +0100

    GtkRange: Fix drawing of fill-level
    
    Compute the proportion of the range that should be filled to match the
    fill level, and use it to compute the starting point and length of the
    area between the slider and the fill level.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=734741

 gtk/gtkrange.c |   56 ++++++++++++++++++++++++++++++--------------------------
 1 files changed, 30 insertions(+), 26 deletions(-)
---
diff --git a/gtk/gtkrange.c b/gtk/gtkrange.c
index 036802e..51726c8 100644
--- a/gtk/gtkrange.c
+++ b/gtk/gtkrange.c
@@ -2130,11 +2130,12 @@ gtk_range_draw (GtkWidget *widget,
           gtk_adjustment_get_upper (priv->adjustment) - gtk_adjustment_get_page_size (priv->adjustment) -
           gtk_adjustment_get_lower (priv->adjustment) != 0)
         {
-          gdouble  fill_level  = priv->fill_level;
-          gint     fill_x      = x;
-          gint     fill_y      = y;
-          gint     fill_width  = width;
-          gint     fill_height = height;
+          gdouble  fill_level      = priv->fill_level;
+          gint     fill_x          = x;
+          gint     fill_y          = y;
+          gint     fill_width      = width;
+          gint     fill_height     = height;
+          gdouble  fill_proportion = 0.0;
 
           gtk_style_context_save (context);
           gtk_style_context_add_class (context, GTK_STYLE_CLASS_PROGRESSBAR);
@@ -2143,33 +2144,36 @@ gtk_range_draw (GtkWidget *widget,
                               gtk_adjustment_get_upper (priv->adjustment) -
                               gtk_adjustment_get_page_size (priv->adjustment));
 
-          if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
-            {
-              fill_x     = priv->trough.x;
-              fill_width = (priv->slider.width +
-                            (fill_level - gtk_adjustment_get_lower (priv->adjustment)) /
+          fill_proportion = (fill_level - gtk_adjustment_get_lower (priv->adjustment)) /
                             (gtk_adjustment_get_upper (priv->adjustment) -
                              gtk_adjustment_get_lower (priv->adjustment) -
-                             gtk_adjustment_get_page_size (priv->adjustment)) *
-                            (priv->trough.width -
-                             priv->slider.width));
+                             gtk_adjustment_get_page_size (priv->adjustment));
 
-              if (should_invert (range))
-                fill_x += priv->trough.width - fill_width;
+          if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
+            {
+              if (!should_invert (range))
+                {
+                  fill_x     = priv->slider.x + (priv->slider.width / 2);
+                  fill_width = (width * fill_proportion) - fill_x + x;
+                }
+              else
+                {
+                  fill_x     = x + width * (1.0 - fill_proportion);
+                  fill_width = priv->slider.x + (priv->slider.width / 2) - fill_x;
+                }
             }
           else
             {
-              fill_y      = priv->trough.y;
-              fill_height = (priv->slider.height +
-                             (fill_level - gtk_adjustment_get_lower (priv->adjustment)) /
-                             (gtk_adjustment_get_upper (priv->adjustment) -
-                              gtk_adjustment_get_lower (priv->adjustment) -
-                              gtk_adjustment_get_page_size (priv->adjustment)) *
-                             (priv->trough.height -
-                              priv->slider.height));
-
-              if (should_invert (range))
-                fill_y += priv->trough.height - fill_height;
+              if (!should_invert (range))
+                {
+                  fill_y      = priv->slider.y + (priv->slider.height / 2);
+                  fill_height = (height * fill_proportion) - fill_y + y;
+                }
+              else
+                {
+                  fill_y      = y + height * (1.0 - fill_proportion);
+                  fill_height = priv->slider.y + (priv->slider.height / 2) - fill_y;
+                }
             }
 
           gtk_render_background (context, cr, fill_x, fill_y, fill_width, fill_height);