Add CSD to border modes

This replaces view.using_csd with a new border mode: B_CSD. This also
removes sway_xdg_shell{_v6}_view.deco_mode and
view->has_client_side_decorations as we can now get these from the
border.

You can use `border toggle` to cycle through the modes including CSD, or
use `border csd` to set it directly. The client must support the
xdg-decoration protocol, and the only client I know of that does is the
example in wlroots.

If the client switches from SSD to CSD without us expecting it (via the
server-decoration protocol), we stash the previous border type into
view.saved_border so we can restore it if the client returns to SSD. I
haven't found a way to test this though.

1 files changed, 2 insertions, 0 deletions

diff --git a/sway/ipc-json.c b/sway/ipc-json.c
index f054ac9f..df24b812 100644
--- a/sway/ipc-json.c
+++ b/sway/ipc-json.c
@@ -216,6 +216,8 @@ static const char *describe_container_border(enum sway_container_border border)
                 return "pixel";
         case B_NORMAL:
                 return "normal";
+        case B_CSD:
+                return "csd";
         }
         return "unknown";
 }