[gtk+] GtkScrolledWindow: Take border into account

[Matthias Clasen <matthiasc src gnome org>]

commit a083809b937e6714ff9259e53ff28d659fb427e2
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Nov 28 17:20:23 2014 -0500

    GtkScrolledWindow: Take border into account
    
    Use the new scrollable API for getting non-scrollable borders
    and draw over/undershoot at the right place. In practice, this
    means that they now appear below treeview headers.

 gtk/gtkscrolledwindow.c |   25 +++++++++++++++++++++++--
 1 files changed, 23 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index c2b3ecb..1365eb6 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -1766,6 +1766,26 @@ gtk_scrolled_window_draw_scrollbars_junction (GtkScrolledWindow *scrolled_window
 }
 
 static void
+gtk_scrolled_window_inner_allocation (GtkWidget     *widget,
+                                      GtkAllocation *rect)
+{
+  GtkWidget *child;
+  GtkBorder border = { 0 };
+
+  gtk_scrolled_window_relative_allocation (widget, rect);
+
+  child = gtk_bin_get_child (GTK_BIN (widget));
+  if (GTK_IS_SCROLLABLE (child) &&
+      gtk_scrollable_get_border (GTK_SCROLLABLE (child), &border))
+    {
+      rect->x += border.left;
+      rect->y += border.top;
+      rect->width -= border.left + border.right;
+      rect->height -= border.top + border.bottom;
+    }
+}
+
+static void
 gtk_scrolled_window_draw_overshoot (GtkScrolledWindow *scrolled_window,
                                    cairo_t           *cr)
 {
@@ -1778,7 +1798,8 @@ gtk_scrolled_window_draw_overshoot (GtkScrolledWindow *scrolled_window,
     return;
 
   context = gtk_widget_get_style_context (widget);
-  gtk_scrolled_window_relative_allocation (widget, &rect);
+  gtk_scrolled_window_inner_allocation (widget, &rect);
+
   overshoot_x = CLAMP (overshoot_x, - MAX_OVERSHOOT_DISTANCE, MAX_OVERSHOOT_DISTANCE);
   overshoot_y = CLAMP (overshoot_y, - MAX_OVERSHOOT_DISTANCE, MAX_OVERSHOOT_DISTANCE);
 
@@ -1836,7 +1857,7 @@ gtk_scrolled_window_draw_undershoot (GtkScrolledWindow *scrolled_window,
   GtkAdjustment *adj;
 
   context = gtk_widget_get_style_context (widget);
-  gtk_scrolled_window_relative_allocation (widget, &rect);
+  gtk_scrolled_window_inner_allocation (widget, &rect);
 
   gtk_style_context_save (context);
   gtk_style_context_remove_class (context, GTK_STYLE_CLASS_FRAME);