Improve CSD logic

This does the following:

* Removes the xdg-decoration surface_commit listener. I was under the
impression the client could ignore the server's preference and set
whatever decoration they like using this protocol, but I don't think
that's right.
* Adds a listener for the xdg-decoration request_mode signal. The
protocol states that the server should respond to this with its
preference. We'll always respond with SSD here.
* Makes it so tiled views which use CSD will still have sway decorations
rendered. To do this, using_csd had to be added back to the view struct,
and the border is changed when floating or unfloating a view.

4 files changed, 60 insertions, 29 deletions

diff --git a/sway/commands/border.c b/sway/commands/border.c
index 5e101564..bfd3b9ed 100644
--- a/sway/commands/border.c
+++ b/sway/commands/border.c
@@ -7,15 +7,49 @@
 #include "sway/tree/container.h"
 #include "sway/tree/view.h"
 
+// A couple of things here:
+// - view->border should never be B_CSD when the view is tiled, even when CSD is
+//   in use (we set using_csd instead and render a sway border).
+// - view->saved_border should be the last applied border when switching to CSD.
+// - view->using_csd should always reflect whether CSD is applied or not.
 static void set_border(struct sway_view *view,
                 enum sway_container_border new_border) {
-        if (view->border == B_CSD && new_border != B_CSD) {
+        if (view->using_csd && new_border != B_CSD) {
                 view_set_csd_from_server(view, false);
-        } else if (view->border != B_CSD && new_border == B_CSD) {
+        } else if (!view->using_csd && new_border == B_CSD) {
                 view_set_csd_from_server(view, true);
+                view->saved_border = view->border;
+        }
+        if (new_border != B_CSD || container_is_floating(view->container)) {
+                view->border = new_border;
+        }
+        view->using_csd = new_border == B_CSD;
+}
+
+static void border_toggle(struct sway_view *view) {
+        if (view->using_csd) {
+                set_border(view, B_NONE);
+                return;
+        }
+        switch (view->border) {
+        case B_NONE:
+                set_border(view, B_PIXEL);
+                break;
+        case B_PIXEL:
+                set_border(view, B_NORMAL);
+                break;
+        case B_NORMAL:
+                if (view->xdg_decoration) {
+                        set_border(view, B_CSD);
+                } else {
+                        set_border(view, B_NONE);
+                }
+                break;
+        case B_CSD:
+                // view->using_csd should be true so it would have returned above
+                sway_assert(false, "Unreachable");
+                break;
         }
-        view->saved_border = view->border;
-        view->border = new_border;
 }
 
 struct cmd_results *cmd_border(int argc, char **argv) {
@@ -44,8 +78,7 @@ struct cmd_results *cmd_border(int argc, char **argv) {
                 }
                 set_border(view, B_CSD);
         } else if (strcmp(argv[0], "toggle") == 0) {
-                int num_available = view->xdg_decoration ? 4 : 3;
-                set_border(view, (view->border + 1) % num_available);
+                border_toggle(view);
         } else {
                 return cmd_results_new(CMD_INVALID, "border",
                                 "Expected 'border <none|normal|pixel|toggle>' "
diff --git a/sway/tree/container.c b/sway/tree/container.c
index d75e34a5..9b671c1d 100644
--- a/sway/tree/container.c
+++ b/sway/tree/container.c
@@ -669,6 +669,9 @@ void container_set_floating(struct sway_container *container, bool enable) {
                 container_init_floating(container);
                 if (container->view) {
                         view_set_tiled(container->view, false);
+                        if (container->view->using_csd) {
+                                container->view->border = B_CSD;
+                        }
                 }
                 if (old_parent) {
                         container_reap_empty(old_parent);
@@ -695,6 +698,9 @@ void container_set_floating(struct sway_container *container, bool enable) {
                 }
                 if (container->view) {
                         view_set_tiled(container->view, true);
+                        if (container->view->using_csd) {
+                                container->view->border = container->view->saved_border;
+                        }
                 }
                 container->is_sticky = false;
         }
diff --git a/sway/tree/view.c b/sway/tree/view.c
index 1c94de4c..9ffcf206 100644
--- a/sway/tree/view.c
+++ b/sway/tree/view.c
@@ -309,6 +309,7 @@ void view_request_activate(struct sway_view *view) {
 }
 
 void view_set_csd_from_server(struct sway_view *view, bool enabled) {
+        wlr_log(WLR_DEBUG, "Telling view %p to set CSD to %i", view, enabled);
         if (view->xdg_decoration) {
                 uint32_t mode = enabled ?
                         WLR_XDG_TOPLEVEL_DECORATION_V1_MODE_CLIENT_SIDE :
@@ -316,15 +317,20 @@ void view_set_csd_from_server(struct sway_view *view, bool enabled) {
                 wlr_xdg_toplevel_decoration_v1_set_mode(
                                 view->xdg_decoration->wlr_xdg_decoration, mode);
         }
+        view->using_csd = enabled;
 }
 
 void view_update_csd_from_client(struct sway_view *view, bool enabled) {
+        wlr_log(WLR_DEBUG, "View %p updated CSD to %i", view, enabled);
         if (enabled && view->border != B_CSD) {
                 view->saved_border = view->border;
-                view->border = B_CSD;
+                if (container_is_floating(view->container)) {
+                        view->border = B_CSD;
+                }
         } else if (!enabled && view->border == B_CSD) {
                 view->border = view->saved_border;
         }
+        view->using_csd = enabled;
 }
 
 void view_set_tiled(struct sway_view *view, bool tiled) {
diff --git a/sway/xdg_decoration.c b/sway/xdg_decoration.c
index 80b2f57e..39e0df56 100644
--- a/sway/xdg_decoration.c
+++ b/sway/xdg_decoration.c
@@ -12,31 +12,22 @@ static void xdg_decoration_handle_destroy(struct wl_listener *listener,
                 wl_container_of(listener, deco, destroy);
         deco->view->xdg_decoration = NULL;
         wl_list_remove(&deco->destroy.link);
-        wl_list_remove(&deco->surface_commit.link);
+        wl_list_remove(&deco->request_mode.link);
         wl_list_remove(&deco->link);
         free(deco);
 }
 
-static void xdg_decoration_handle_surface_commit(struct wl_listener *listener,
+static void xdg_decoration_handle_request_mode(struct wl_listener *listener,
                 void *data) {
-        struct sway_xdg_decoration *decoration =
-                wl_container_of(listener, decoration, surface_commit);
-
-        bool csd = decoration->wlr_xdg_decoration->current_mode ==
-                WLR_XDG_TOPLEVEL_DECORATION_V1_MODE_CLIENT_SIDE;
-        struct sway_view *view = decoration->view;
-
-        view_update_csd_from_client(view, csd);
-
-        arrange_container(view->container);
-        transaction_commit_dirty();
+        struct sway_xdg_decoration *deco =
+                wl_container_of(listener, deco, request_mode);
+        wlr_xdg_toplevel_decoration_v1_set_mode(deco->wlr_xdg_decoration,
+                        WLR_XDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
 }
 
 void handle_xdg_decoration(struct wl_listener *listener, void *data) {
         struct wlr_xdg_toplevel_decoration_v1 *wlr_deco = data;
         struct sway_xdg_shell_view *xdg_shell_view = wlr_deco->surface->data;
-        struct wlr_xdg_surface *wlr_xdg_surface =
-                xdg_shell_view->view.wlr_xdg_surface;
 
         struct sway_xdg_decoration *deco = calloc(1, sizeof(*deco));
         if (deco == NULL) {
@@ -50,13 +41,8 @@ void handle_xdg_decoration(struct wl_listener *listener, void *data) {
         wl_signal_add(&wlr_deco->events.destroy, &deco->destroy);
         deco->destroy.notify = xdg_decoration_handle_destroy;
 
-        // Note: We don't listen to the request_mode signal here, effectively
-        // ignoring any modes the client asks to set. The client can still force a
-        // mode upon us, in which case we get upset but live with it.
-
-        deco->surface_commit.notify = xdg_decoration_handle_surface_commit;
-        wl_signal_add(&wlr_xdg_surface->surface->events.commit,
-                &deco->surface_commit);
+        wl_signal_add(&wlr_deco->events.request_mode, &deco->request_mode);
+        deco->request_mode.notify = xdg_decoration_handle_request_mode;
 
         wl_list_insert(&server.xdg_decorations, &deco->link);
 }