[gtk/resizing-fixes] toplevelsize: Add shadow size

[Matthias Clasen <matthiasc src gnome org>]

commit ece755ff623805429f8abf8d5063e32c765d5cf7
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Aug 12 07:59:16 2020 -0400

    toplevelsize: Add shadow size
    
    Setting the shadow together with the size makes
    sense, since the shadow is needed to make sense
    of the size.

 gdk/gdktoplevelsize.c        | 28 ++++++++++++++++++++++++++++
 gdk/gdktoplevelsize.h        |  6 ++++++
 gdk/gdktoplevelsizeprivate.h |  5 +++++
 3 files changed, 39 insertions(+)
---
diff --git a/gdk/gdktoplevelsize.c b/gdk/gdktoplevelsize.c
index 276e63f951..1b100223af 100644
--- a/gdk/gdktoplevelsize.c
+++ b/gdk/gdktoplevelsize.c
@@ -118,6 +118,31 @@ gdk_toplevel_size_set_min_size (GdkToplevelSize *size,
   size->min_height = min_height;
 }
 
+/**
+ * gdk_toplevel_size_set_shadow_size:
+ * @size: a #GdkToplevelSize
+ * @left: The left extent
+ * @right: The right extent
+ * @top: The top extent
+ * @bottom: The bottom extent
+ *
+ * Determine the size of the shadow and border area that should be
+ * considered “outside” for the purposes of window placement and
+ * edge snapping.
+ */
+void
+gdk_toplevel_size_set_shadow_size (GdkToplevelSize *size,
+                                   int              left,
+                                   int              right,
+                                   int              top,
+                                   int              bottom)
+{
+  size->shadow_left = left;
+  size->shadow_right = right;
+  size->shadow_top = top;
+  size->shadow_bottom = bottom;
+}
+
 void
 gdk_toplevel_size_validate (GdkToplevelSize *size)
 {
@@ -132,4 +157,7 @@ gdk_toplevel_size_validate (GdkToplevelSize *size)
   if (size->min_width > size->width ||
       size->min_height > size->height)
     g_warning ("GdkToplevelSize: min_size exceeds size");
+
+  if (size->width <= 0 || size->height <= 0)
+    g_warning ("GdkToplevelSize: size can't be zero");
 }
diff --git a/gdk/gdktoplevelsize.h b/gdk/gdktoplevelsize.h
index 013a061ee9..22ec86ef5a 100644
--- a/gdk/gdktoplevelsize.h
+++ b/gdk/gdktoplevelsize.h
@@ -54,6 +54,12 @@ void                    gdk_toplevel_size_set_min_size  (GdkToplevelSize       *
                                                          int                    min_width,
                                                          int                    min_height);
 
+GDK_AVAILABLE_IN_ALL
+void                    gdk_toplevel_size_set_shadow_size  (GdkToplevelSize       *size,
+                                                            int                    left,
+                                                            int                    right,
+                                                            int                    top,
+                                                            int                    bottom);
 G_END_DECLS
 
 #endif /* __GDK_TOPLEVEL_SIZE_H__ */
diff --git a/gdk/gdktoplevelsizeprivate.h b/gdk/gdktoplevelsizeprivate.h
index 3576513888..2f773a3783 100644
--- a/gdk/gdktoplevelsizeprivate.h
+++ b/gdk/gdktoplevelsizeprivate.h
@@ -30,6 +30,11 @@ struct _GdkToplevelSize
   int height;
   int min_width;
   int min_height;
+
+  int shadow_left;
+  int shadow_right;
+  int shadow_top;
+  int shadow_bottom;
 };
 
 void gdk_toplevel_size_init (GdkToplevelSize *size,