[gtk+] gtkwindow: Allow edge resizing from corners if constraints forbid either side

[Carlos Garnacho <carlosg src gnome org>]

commit 8233cf36884cf07074f612300c1e014bf9057df2
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Dec 9 21:13:05 2017 +0100

    gtkwindow: Allow edge resizing from corners if constraints forbid either side
    
    The fix is twofold. First, when checking that a corner is resizable, we must
    check the constraints on both edges. Second, when checking either edge we
    must include both perpendicular sides in order to allow those to be
    resizable when the constraint does not allow resizing the edge being
    checked.

 gtk/gtkwindow.c |   66 +++++++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 54 insertions(+), 12 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 260e61b..d7e5613 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -1692,6 +1692,33 @@ device_removed_cb (GdkSeat   *seat,
     }
 }
 
+static guint
+constraints_for_edge (GdkWindowEdge edge)
+{
+  switch (edge)
+    {
+    case GDK_WINDOW_EDGE_NORTH_WEST:
+      return GDK_WINDOW_STATE_LEFT_RESIZABLE | GDK_WINDOW_STATE_TOP_RESIZABLE;
+    case GDK_WINDOW_EDGE_NORTH:
+      return GDK_WINDOW_STATE_TOP_RESIZABLE;
+    case GDK_WINDOW_EDGE_NORTH_EAST:
+      return GDK_WINDOW_STATE_RIGHT_RESIZABLE | GDK_WINDOW_STATE_TOP_RESIZABLE;
+    case GDK_WINDOW_EDGE_WEST:
+      return GDK_WINDOW_STATE_LEFT_RESIZABLE;
+    case GDK_WINDOW_EDGE_EAST:
+      return GDK_WINDOW_STATE_RIGHT_RESIZABLE;
+    case GDK_WINDOW_EDGE_SOUTH_WEST:
+      return GDK_WINDOW_STATE_LEFT_RESIZABLE | GDK_WINDOW_STATE_BOTTOM_RESIZABLE;
+    case GDK_WINDOW_EDGE_SOUTH:
+      return GDK_WINDOW_STATE_BOTTOM_RESIZABLE;
+    case GDK_WINDOW_EDGE_SOUTH_EAST:
+      return GDK_WINDOW_STATE_RIGHT_RESIZABLE | GDK_WINDOW_STATE_BOTTOM_RESIZABLE;
+    default:
+      g_warn_if_reached ();
+      return 0;
+    }
+}
+
 static gboolean
 edge_under_coordinates (GtkWindow     *window,
                         gint           x,
@@ -1704,6 +1731,7 @@ edge_under_coordinates (GtkWindow     *window,
   gint handle_v, handle_h;
   GtkBorder border;
   gboolean supports_edge_constraints;
+  guint constraints;
 
   if (priv->type != GTK_WINDOW_TOPLEVEL ||
       !priv->client_decorated ||
@@ -1713,15 +1741,13 @@ edge_under_coordinates (GtkWindow     *window,
     return FALSE;
 
   supports_edge_constraints = gdk_window_supports_edge_constraints (_gtk_widget_get_window (GTK_WIDGET 
(window)));
+  constraints = constraints_for_edge (edge);
 
   if (!supports_edge_constraints && priv->tiled)
     return FALSE;
 
   if (supports_edge_constraints &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_TOP_RESIZABLE) &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_RIGHT_RESIZABLE) &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_BOTTOM_RESIZABLE) &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_LEFT_RESIZABLE))
+      (priv->edge_constraints & constraints) != constraints)
     return FALSE;
 
   _gtk_widget_get_allocation (GTK_WIDGET (window), &allocation);
@@ -1755,22 +1781,30 @@ edge_under_coordinates (GtkWindow     *window,
     {
       if (edge != GDK_WINDOW_EDGE_NORTH_WEST &&
           edge != GDK_WINDOW_EDGE_WEST &&
-          edge != GDK_WINDOW_EDGE_SOUTH_WEST)
+          edge != GDK_WINDOW_EDGE_SOUTH_WEST &&
+          edge != GDK_WINDOW_EDGE_NORTH &&
+          edge != GDK_WINDOW_EDGE_SOUTH)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_LEFT_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_NORTH ||
+           edge == GDK_WINDOW_EDGE_SOUTH) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_WEST)))
         return FALSE;
     }
   else if (x >= allocation.x + allocation.width - border.right - handle_h)
     {
       if (edge != GDK_WINDOW_EDGE_NORTH_EAST &&
           edge != GDK_WINDOW_EDGE_EAST &&
-          edge != GDK_WINDOW_EDGE_SOUTH_EAST)
+          edge != GDK_WINDOW_EDGE_SOUTH_EAST &&
+          edge != GDK_WINDOW_EDGE_NORTH &&
+          edge != GDK_WINDOW_EDGE_SOUTH)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_RIGHT_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_NORTH ||
+           edge == GDK_WINDOW_EDGE_SOUTH) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_EAST)))
         return FALSE;
     }
   else if (edge != GDK_WINDOW_EDGE_NORTH &&
@@ -1782,22 +1816,30 @@ edge_under_coordinates (GtkWindow     *window,
     {
       if (edge != GDK_WINDOW_EDGE_NORTH_WEST &&
           edge != GDK_WINDOW_EDGE_NORTH &&
-          edge != GDK_WINDOW_EDGE_NORTH_EAST)
+          edge != GDK_WINDOW_EDGE_NORTH_EAST &&
+          edge != GDK_WINDOW_EDGE_EAST &&
+          edge != GDK_WINDOW_EDGE_WEST)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_TOP_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_EAST ||
+           edge == GDK_WINDOW_EDGE_WEST) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_NORTH)))
         return FALSE;
     }
   else if (y > allocation.y + allocation.height - border.bottom - handle_v)
     {
       if (edge != GDK_WINDOW_EDGE_SOUTH_WEST &&
           edge != GDK_WINDOW_EDGE_SOUTH &&
-          edge != GDK_WINDOW_EDGE_SOUTH_EAST)
+          edge != GDK_WINDOW_EDGE_SOUTH_EAST &&
+          edge != GDK_WINDOW_EDGE_EAST &&
+          edge != GDK_WINDOW_EDGE_WEST)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_BOTTOM_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_EAST ||
+           edge == GDK_WINDOW_EDGE_WEST) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_SOUTH)))
         return FALSE;
     }
   else if (edge != GDK_WINDOW_EDGE_WEST &&