surface: add wlr_surface_role.precommit

This allows to emit the unmap event before the surface becomes
actually unmapped for most shells.

include/types/wlr_xdg_shell.h

@@ -19,7 +19,8 @@ struct wlr_xdg_surface *create_xdg_surface(
 	uint32_t id);
 void unmap_xdg_surface(struct wlr_xdg_surface *surface);
 void destroy_xdg_surface(struct wlr_xdg_surface *surface);
-void handle_xdg_surface_committed(struct wlr_surface *wlr_surface);
+void handle_xdg_surface_commit(struct wlr_surface *wlr_surface);
+void handle_xdg_surface_precommit(struct wlr_surface *wlr_surface);
 
 void create_xdg_positioner(struct wlr_xdg_client *client, uint32_t id);
 struct wlr_xdg_positioner_resource *get_xdg_positioner_from_resource(

include/types/wlr_xdg_shell_v6.h

@@ -19,7 +19,8 @@ struct wlr_xdg_surface_v6 *create_xdg_surface_v6(
 	uint32_t id);
 void unmap_xdg_surface_v6(struct wlr_xdg_surface_v6 *surface);
 void destroy_xdg_surface_v6(struct wlr_xdg_surface_v6 *surface);
-void handle_xdg_surface_v6_committed(struct wlr_surface *wlr_surface);
+void handle_xdg_surface_v6_commit(struct wlr_surface *wlr_surface);
+void handle_xdg_surface_v6_precommit(struct wlr_surface *wlr_surface);
 
 void create_xdg_positioner_v6(struct wlr_xdg_client_v6 *client, uint32_t id);
 struct wlr_xdg_positioner_v6_resource *get_xdg_positioner_v6_from_resource(

include/wlr/types/wlr_surface.h

@@ -39,6 +39,7 @@ struct wlr_surface_state {
 struct wlr_surface_role {
 	const char *name;
 	void (*commit)(struct wlr_surface *surface);
+	void (*precommit)(struct wlr_surface *surface);
 };
 
 struct wlr_surface {

types/wlr_surface.c

@@ -360,10 +360,14 @@ static void surface_update_opaque_region(struct wlr_surface *surface) {
 }
 
 static void surface_commit_pending(struct wlr_surface *surface) {
-	bool invalid_buffer = surface->pending.committed & WLR_SURFACE_STATE_BUFFER;
-
 	surface_state_finalize(surface, &surface->pending);
 
+	if (surface->role && surface->role->precommit) {
+		surface->role->precommit(surface);
+	}
+
+	bool invalid_buffer = surface->pending.committed & WLR_SURFACE_STATE_BUFFER;
+
 	surface->sx += surface->pending.dx;
 	surface->sy += surface->pending.dy;
 	surface_update_damage(&surface->buffer_damage,

types/xdg_shell/wlr_xdg_popup.c

@@ -214,7 +214,8 @@ static void xdg_popup_handle_resource_destroy(struct wl_resource *resource) {
 
 const struct wlr_surface_role xdg_popup_surface_role = {
 	.name = "xdg_popup",
-	.commit = handle_xdg_surface_committed,
+	.commit = handle_xdg_surface_commit,
+	.precommit = handle_xdg_surface_precommit,
 };
 
 void create_xdg_popup(struct wlr_xdg_surface *xdg_surface,

types/xdg_shell/wlr_xdg_surface.c

@@ -313,7 +313,7 @@ static void xdg_surface_handle_surface_commit(struct wl_listener *listener,
 	}
 }
 
-void handle_xdg_surface_committed(struct wlr_surface *wlr_surface) {
+void handle_xdg_surface_commit(struct wlr_surface *wlr_surface) {
 	struct wlr_xdg_surface *surface =
 		wlr_xdg_surface_from_wlr_surface(wlr_surface);
 	if (surface == NULL) {
@@ -355,6 +355,22 @@ void handle_xdg_surface_committed(struct wlr_surface *wlr_surface) {
 	}
 }
 
+void handle_xdg_surface_precommit(struct wlr_surface *wlr_surface) {
+	struct wlr_xdg_surface *surface =
+		wlr_xdg_surface_from_wlr_surface(wlr_surface);
+	if (surface == NULL) {
+		return;
+	}
+
+	if (wlr_surface->pending.committed & WLR_SURFACE_STATE_BUFFER &&
+			wlr_surface->pending.buffer_resource == NULL) {
+		// This is a NULL commit
+		if (surface->configured && surface->mapped) {
+			unmap_xdg_surface(surface);
+		}
+	}
+}
+
 static void xdg_surface_handle_surface_destroy(struct wl_listener *listener,
 		void *data) {
 	struct wlr_xdg_surface *xdg_surface =

types/xdg_shell/wlr_xdg_toplevel.c

@@ -449,7 +449,8 @@ static void xdg_toplevel_handle_resource_destroy(struct wl_resource *resource) {
 
 const struct wlr_surface_role xdg_toplevel_surface_role = {
 	.name = "xdg_toplevel",
-	.commit = handle_xdg_surface_committed,
+	.commit = handle_xdg_surface_commit,
+	.precommit = handle_xdg_surface_precommit,
 };
 
 void create_xdg_toplevel(struct wlr_xdg_surface *xdg_surface,

types/xdg_shell_v6/wlr_xdg_popup_v6.c

@@ -251,7 +251,8 @@ void handle_xdg_surface_v6_popup_committed(struct wlr_xdg_surface_v6 *surface) {
 
 const struct wlr_surface_role xdg_popup_v6_surface_role = {
 	.name = "xdg_popup_v6",
-	.commit = handle_xdg_surface_v6_committed,
+	.commit = handle_xdg_surface_v6_commit,
+	.precommit = handle_xdg_surface_v6_precommit,
 };
 
 void create_xdg_popup_v6(struct wlr_xdg_surface_v6 *xdg_surface,

types/xdg_shell_v6/wlr_xdg_surface_v6.c

@@ -371,7 +371,7 @@ static void xdg_surface_handle_surface_commit(struct wl_listener *listener,
 	}
 }
 
-void handle_xdg_surface_v6_committed(struct wlr_surface *wlr_surface) {
+void handle_xdg_surface_v6_commit(struct wlr_surface *wlr_surface) {
 	struct wlr_xdg_surface_v6 *surface =
 		wlr_xdg_surface_v6_from_wlr_surface(wlr_surface);
 	if (surface == NULL) {
@@ -407,9 +407,21 @@ void handle_xdg_surface_v6_committed(struct wlr_surface *wlr_surface) {
 		surface->mapped = true;
 		wlr_signal_emit_safe(&surface->events.map, surface);
 	}
-	if (surface->configured && !wlr_surface_has_buffer(surface->surface) &&
-			surface->mapped) {
-		unmap_xdg_surface_v6(surface);
+}
+
+void handle_xdg_surface_v6_precommit(struct wlr_surface *wlr_surface) {
+	struct wlr_xdg_surface_v6 *surface =
+		wlr_xdg_surface_v6_from_wlr_surface(wlr_surface);
+	if (surface == NULL) {
+		return;
+	}
+
+	if (wlr_surface->pending.committed & WLR_SURFACE_STATE_BUFFER &&
+			wlr_surface->pending.buffer_resource == NULL) {
+		// This is a NULL commit
+		if (surface->configured && surface->mapped) {
+			unmap_xdg_surface_v6(surface);
+		}
 	}
 }
 

types/xdg_shell_v6/wlr_xdg_toplevel_v6.c

@@ -419,7 +419,8 @@ static void xdg_toplevel_handle_resource_destroy(struct wl_resource *resource) {
 
 const struct wlr_surface_role xdg_toplevel_v6_surface_role = {
 	.name = "xdg_toplevel_v6",
-	.commit = handle_xdg_surface_v6_committed,
+	.commit = handle_xdg_surface_v6_commit,
+	.precommit = handle_xdg_surface_v6_precommit,
 };
 
 void create_xdg_toplevel_v6(struct wlr_xdg_surface_v6 *xdg_surface,

xwayland/xwm.c

@@ -652,9 +652,27 @@ static void xwayland_surface_role_commit(struct wlr_surface *wlr_surface) {
 	}
 }
 
+static void xwayland_surface_role_precommit(struct wlr_surface *wlr_surface) {
+	assert(wlr_surface->role == &xwayland_surface_role);
+	struct wlr_xwayland_surface *surface = wlr_surface->role_data;
+	if (surface == NULL) {
+		return;
+	}
+
+	if (wlr_surface->pending.committed & WLR_SURFACE_STATE_BUFFER &&
+			wlr_surface->pending.buffer_resource == NULL) {
+		// This is a NULL commit
+		if (surface->mapped) {
+			wlr_signal_emit_safe(&surface->events.unmap, surface);
+			surface->mapped = false;
+		}
+	}
+}
+
 static const struct wlr_surface_role xwayland_surface_role = {
 	.name = "wlr_xwayland_surface",
 	.commit = xwayland_surface_role_commit,
+	.precommit = xwayland_surface_role_precommit,
 };
 
 static void handle_surface_destroy(struct wl_listener *listener, void *data) {