[nautilus] pathbar: fix underallocations

[Ernestas Kulik <ernestask src gnome org>]

commit d2f98e2fe0abe1a6ea39e08e1524157946a2f6b8
Author: Ernestas Kulik <ernestask src gnome org>
Date:   Mon Jul 18 11:58:41 2016 +0300

    pathbar: fix underallocations
    
    Starting with GTK+ 3.21, Nautilus is constantly reporting
    underallocations happening in the path bar. That is chiefly caused by
    some assumptions made in the code (i.e. both slider buttons are of the
    same width, which is untrue, due to the “linked” style class).
    
    This commit corrects those assumptions by using widths of both slider
    buttons in allocation calculations.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=768916

 src/nautilus-pathbar.c |   41 +++++++++++++++++++++++++----------------
 1 files changed, 25 insertions(+), 16 deletions(-)
---
diff --git a/src/nautilus-pathbar.c b/src/nautilus-pathbar.c
index d7c3d95..efd228e 100644
--- a/src/nautilus-pathbar.c
+++ b/src/nautilus-pathbar.c
@@ -85,7 +85,6 @@ struct _NautilusPathBarDetails {
        GtkWidget *up_slider_button;
        GtkWidget *down_slider_button;
        guint settings_signal_id;
-       gint slider_width;
        guint timer;
        guint slider_visible : 1;
        guint need_timer : 1;
@@ -454,6 +453,8 @@ nautilus_path_bar_get_preferred_width (GtkWidget *widget,
        gint child_height;
        gint height;
        gint child_min, child_nat;
+       gint up_slider_width;
+       gint down_slider_width;
 
        path_bar = NAUTILUS_PATH_BAR (widget);
 
@@ -483,12 +484,15 @@ nautilus_path_bar_get_preferred_width (GtkWidget *widget,
         * not going to worry about that now.
         */
         gtk_widget_get_preferred_width (path_bar->priv->down_slider_button,
-                                        &path_bar->priv->slider_width,
+                                        &down_slider_width,
+                                        NULL);
+       gtk_widget_get_preferred_width (path_bar->priv->up_slider_button,
+                                        &up_slider_width,
                                         NULL);
 
        if (path_bar->priv->button_list) {
-               *minimum += (path_bar->priv->slider_width) * 2;
-               *natural += (path_bar->priv->slider_width) * 2;
+               *minimum += (down_slider_width + up_slider_width);
+               *natural += (down_slider_width + up_slider_width);
        }
 }
 
@@ -594,6 +598,8 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
         GtkWidget *child;
         NautilusPathBar *path_bar;
         GtkTextDirection direction;
+        gint up_slider_width;
+        gint down_slider_width;
         GtkAllocation child_allocation;
         GList *list, *first_button;
         gint width;
@@ -623,7 +629,10 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
        }
         direction = gtk_widget_get_direction (widget);
        gtk_widget_get_preferred_width (path_bar->priv->up_slider_button,
-                                       &path_bar->priv->slider_width,
+                                       &up_slider_width,
+                                       NULL);
+       gtk_widget_get_preferred_width (path_bar->priv->down_slider_button,
+                                       &down_slider_width,
                                        NULL);
 
        /* First, we check to see if we need the scrollbars. */
@@ -645,7 +654,7 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
                 gboolean reached_end;
                 gint slider_space;
                reached_end = FALSE;
-               slider_space = 2 * (path_bar->priv->slider_width);
+               slider_space = down_slider_width + up_slider_width;
 
                 if (path_bar->priv->first_scrolled_button) {
                        first_button = path_bar->priv->first_scrolled_button;
@@ -698,21 +707,21 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
         if (direction == GTK_TEXT_DIR_RTL) {
                 child_allocation.x = allocation->x + allocation->width;
                 if (need_sliders) {
-                       child_allocation.x -= path_bar->priv->slider_width;
-                       up_slider_offset = allocation->width - path_bar->priv->slider_width;
+                       child_allocation.x -= up_slider_width;
+                       up_slider_offset = allocation->width - up_slider_width;
                }
         } else {
                 child_allocation.x = allocation->x;
                 if (need_sliders) {
                        up_slider_offset = 0;
-                       child_allocation.x += path_bar->priv->slider_width;
+                       child_allocation.x += up_slider_width;
                }
         }
 
         /* Determine the largest possible allocation size */
         largest_width = allocation->width;
         if (need_sliders) {
-               largest_width -= (path_bar->priv->slider_width) * 2;
+               largest_width -= (down_slider_width + up_slider_width);
         }
 
         for (list = first_button; list; list = list->prev) {
@@ -725,12 +734,12 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
                }
                 /* Check to see if we've don't have any more space to allocate buttons */
                 if (need_sliders && direction == GTK_TEXT_DIR_RTL) {
-                       if (child_allocation.x - path_bar->priv->slider_width < allocation->x) {
+                       if (child_allocation.x - down_slider_width < allocation->x) {
                            break;
                        }
                } else {
                        if (need_sliders && direction == GTK_TEXT_DIR_LTR) {
-                               if (child_allocation.x + child_allocation.width + 
path_bar->priv->slider_width > allocation->x + allocation->width) {
+                               if (child_allocation.x + child_allocation.width + down_slider_width > 
allocation->x + allocation->width) {
                                        break;  
                                }       
                        }
@@ -740,7 +749,7 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
                 gtk_widget_size_allocate (child, &child_allocation);
 
                 if (direction == GTK_TEXT_DIR_RTL) {
-                       down_slider_offset = child_allocation.x - allocation->x - 
path_bar->priv->slider_width;
+                       down_slider_offset = child_allocation.x - allocation->x - down_slider_width;
                } else {
                        down_slider_offset += child_allocation.width;
                        child_allocation.x += child_allocation.width;
@@ -758,7 +767,7 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
         }
 
         if (need_sliders) {
-                child_allocation.width = path_bar->priv->slider_width;
+                child_allocation.width = up_slider_width;
                 child_allocation.x = up_slider_offset + allocation->x;
                 gtk_widget_size_allocate (path_bar->priv->up_slider_button, &child_allocation);
 
@@ -766,14 +775,14 @@ nautilus_path_bar_size_allocate (GtkWidget     *widget,
                 gtk_widget_show_all (path_bar->priv->up_slider_button);
 
                if (direction == GTK_TEXT_DIR_LTR) {
-                       down_slider_offset += path_bar->priv->slider_width;
+                       down_slider_offset += up_slider_width;
                }
         } else {
                gtk_widget_set_child_visible (path_bar->priv->up_slider_button, FALSE);
         }
        
        if (need_sliders) {
-               child_allocation.width = path_bar->priv->slider_width;
+               child_allocation.width = down_slider_width;
                child_allocation.x = down_slider_offset + allocation->x;
                gtk_widget_size_allocate (path_bar->priv->down_slider_button, &child_allocation);