Refactor destroy functions and save workspaces when there's no outputs

This changes the destroy functions to the following:

* output_begin_destroy
* output_destroy
* workspace_begin_destroy
* workspace_destroy
* container_begin_destroy
* container_destroy
* view_begin_destroy
* view_destroy

The terminology was `destroy` and `free`, and it has been changed to
`begin_destroy` and `destroy` respectively.

When the last output is disconnected, its workspaces will now be stashed
in the root. Upon connection of a new output they will be restored.

There is a new function `workspace_consider_destroy` which decides
whether the given workspace should be destroyed or not (ie. empty and
not visible).

Calling container_begin_destroy will no longer automatically reap the
parents. In some places we want to reap the parents and in some we
don't, so this is left to the caller.

container_reap_empty_recursive and container_reap_empty have been
combined into one function and it will recurse up the tree.

19 files changed, 267 insertions, 308 deletions

diff --git a/include/sway/output.h b/include/sway/output.h
index d0d034b3..098540fb 100644
--- a/include/sway/output.h
+++ b/include/sway/output.h
@@ -39,6 +39,12 @@ struct sway_output {
         } events;
 };
 
+struct sway_container *output_create(struct sway_output *sway_output);
+
+void output_destroy(struct sway_container *output);
+
+void output_begin_destroy(struct sway_container *output);
+
 typedef void (*sway_surface_iterator_func_t)(struct sway_output *output,
         struct wlr_surface *surface, struct wlr_box *box, float rotation,
         void *user_data);
diff --git a/include/sway/tree/container.h b/include/sway/tree/container.h
index cd886cd0..2cb23d3c 100644
--- a/include/sway/tree/container.h
+++ b/include/sway/tree/container.h
@@ -176,27 +176,6 @@ struct sway_container *container_create(enum sway_container_type type);
 
 const char *container_type_to_str(enum sway_container_type type);
 
-struct sway_container *output_create(struct sway_output *sway_output);
-
-/**
- * Create a new container container. A container container can be a a child of
- * a workspace container or another container container.
- */
-struct sway_container *container_container_create();
-
-/**
- * Create a new output. Outputs are children of the root container and have no
- * order in the tree structure.
- */
-struct sway_container *output_create(struct sway_output *sway_output);
-
-/**
- * Create a new workspace container. Workspaces are children of an output
- * container and are ordered alphabetically by name.
- */
-struct sway_container *workspace_create(struct sway_container *output,
-                const char *name);
-
 /*
  * Create a new view container. A view can be a child of a workspace container
  * or a container container and are rendered in the order and structure of
@@ -205,9 +184,9 @@ struct sway_container *workspace_create(struct sway_container *output,
 struct sway_container *container_view_create(
                 struct sway_container *sibling, struct sway_view *sway_view);
 
-void container_free(struct sway_container *cont);
+void container_destroy(struct sway_container *con);
 
-struct sway_container *container_destroy(struct sway_container *container);
+void container_begin_destroy(struct sway_container *con);
 
 struct sway_container *container_close(struct sway_container *container);
 
@@ -255,10 +234,7 @@ void container_update_textures_recursive(struct sway_container *con);
 
 void container_damage_whole(struct sway_container *container);
 
-bool container_reap_empty(struct sway_container *con);
-
-struct sway_container *container_reap_empty_recursive(
-                struct sway_container *con);
+struct sway_container *container_reap_empty(struct sway_container *con);
 
 struct sway_container *container_flatten(struct sway_container *container);
 
diff --git a/include/sway/tree/root.h b/include/sway/tree/root.h
index d1f04a96..ee4bd836 100644
--- a/include/sway/tree/root.h
+++ b/include/sway/tree/root.h
@@ -24,6 +24,7 @@ struct sway_root {
         struct wl_list outputs; // sway_output::link
 
         list_t *scratchpad; // struct sway_container
+        list_t *saved_workspaces; // For when there's no connected outputs
 
         struct {
                 struct wl_signal new_container;
diff --git a/include/sway/tree/view.h b/include/sway/tree/view.h
index 5fdecc2b..f73ce571 100644
--- a/include/sway/tree/view.h
+++ b/include/sway/tree/view.h
@@ -284,10 +284,10 @@ void view_for_each_popup(struct sway_view *view,
 void view_init(struct sway_view *view, enum sway_view_type type,
         const struct sway_view_impl *impl);
 
-void view_free(struct sway_view *view);
-
 void view_destroy(struct sway_view *view);
 
+void view_begin_destroy(struct sway_view *view);
+
 void view_map(struct sway_view *view, struct wlr_surface *wlr_surface);
 
 void view_unmap(struct sway_view *view);
diff --git a/include/sway/tree/workspace.h b/include/sway/tree/workspace.h
index 35c91017..efcb7c69 100644
--- a/include/sway/tree/workspace.h
+++ b/include/sway/tree/workspace.h
@@ -18,6 +18,15 @@ extern char *prev_workspace_name;
 
 struct sway_container *workspace_get_initial_output(const char *name);
 
+struct sway_container *workspace_create(struct sway_container *output,
+                const char *name);
+
+void workspace_destroy(struct sway_container *workspace);
+
+void workspace_begin_destroy(struct sway_container *workspace);
+
+void workspace_consider_destroy(struct sway_container *ws);
+
 char *workspace_next_name(const char *output_name);
 
 bool workspace_switch(struct sway_container *workspace,
diff --git a/sway/commands/move.c b/sway/commands/move.c
index c6dc0775..4c0189ec 100644
--- a/sway/commands/move.c
+++ b/sway/commands/move.c
@@ -247,7 +247,7 @@ static void workspace_move_to_output(struct sway_container *workspace,
         }
 
         // Try to remove an empty workspace from the destination output.
-        container_reap_empty_recursive(new_output_focus);
+        container_reap_empty(new_output_focus);
 
         output_sort_workspaces(output);
         seat_set_focus(seat, output);
diff --git a/sway/config/output.c b/sway/config/output.c
index 1d8cb3ef..7f9b1007 100644
--- a/sway/config/output.c
+++ b/sway/config/output.c
@@ -181,13 +181,11 @@ void apply_output_config(struct output_config *oc, struct sway_container *output
         struct wlr_output *wlr_output = output->sway_output->wlr_output;
 
         if (oc && oc->enabled == 0) {
-                struct sway_output *sway_output = output->sway_output;
                 if (output->sway_output->bg_pid != 0) {
                         terminate_swaybg(output->sway_output->bg_pid);
                         output->sway_output->bg_pid = 0;
                 }
-                container_destroy(output);
-                sway_output->swayc = NULL;
+                output_begin_destroy(output);
                 wlr_output_layout_remove(root_container.sway_root->output_layout,
                         wlr_output);
                 return;
diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 3d8bbff5..401d3c44 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -498,7 +498,7 @@ void output_damage_whole_container(struct sway_output *output,
 static void damage_handle_destroy(struct wl_listener *listener, void *data) {
         struct sway_output *output =
                 wl_container_of(listener, output, damage_destroy);
-        container_destroy(output->swayc);
+        output_begin_destroy(output->swayc);
 }
 
 static void handle_destroy(struct wl_listener *listener, void *data) {
@@ -506,7 +506,7 @@ static void handle_destroy(struct wl_listener *listener, void *data) {
         wl_signal_emit(&output->events.destroy, output);
 
         if (output->swayc) {
-                container_destroy(output->swayc);
+                output_begin_destroy(output->swayc);
         }
 
         wl_list_remove(&output->link);
diff --git a/sway/desktop/transaction.c b/sway/desktop/transaction.c
index f82e5ef2..c18529fb 100644
--- a/sway/desktop/transaction.c
+++ b/sway/desktop/transaction.c
@@ -54,7 +54,22 @@ static void transaction_destroy(struct sway_transaction *transaction) {
                         con->instruction = NULL;
                 }
                 if (con->destroying && con->ntxnrefs == 0) {
-                        container_free(con);
+                        switch (con->type) {
+                        case C_ROOT:
+                                break;
+                        case C_OUTPUT:
+                                output_destroy(con);
+                                break;
+                        case C_WORKSPACE:
+                                workspace_destroy(con);
+                                break;
+                        case C_CONTAINER:
+                        case C_VIEW:
+                                container_destroy(con);
+                                break;
+                        case C_TYPES:
+                                break;
+                        }
                 }
                 free(instruction);
         }
diff --git a/sway/desktop/xdg_shell.c b/sway/desktop/xdg_shell.c
index aae129bd..f5aaa575 100644
--- a/sway/desktop/xdg_shell.c
+++ b/sway/desktop/xdg_shell.c
@@ -448,7 +448,7 @@ static void handle_destroy(struct wl_listener *listener, void *data) {
         wl_list_remove(&xdg_shell_view->map.link);
         wl_list_remove(&xdg_shell_view->unmap.link);
         view->wlr_xdg_surface = NULL;
-        view_destroy(view);
+        view_begin_destroy(view);
 }
 
 struct sway_view *view_from_wlr_xdg_surface(
diff --git a/sway/desktop/xdg_shell_v6.c b/sway/desktop/xdg_shell_v6.c
index 277c53a3..f623b77b 100644
--- a/sway/desktop/xdg_shell_v6.c
+++ b/sway/desktop/xdg_shell_v6.c
@@ -441,7 +441,7 @@ static void handle_destroy(struct wl_listener *listener, void *data) {
         wl_list_remove(&xdg_shell_v6_view->map.link);
         wl_list_remove(&xdg_shell_v6_view->unmap.link);
         view->wlr_xdg_surface_v6 = NULL;
-        view_destroy(view);
+        view_begin_destroy(view);
 }
 
 struct sway_view *view_from_wlr_xdg_surface_v6(
diff --git a/sway/desktop/xwayland.c b/sway/desktop/xwayland.c
index ce7235e4..6fcc850d 100644
--- a/sway/desktop/xwayland.c
+++ b/sway/desktop/xwayland.c
@@ -341,7 +341,7 @@ static void handle_destroy(struct wl_listener *listener, void *data) {
         wl_list_remove(&xwayland_view->set_hints.link);
         wl_list_remove(&xwayland_view->map.link);
         wl_list_remove(&xwayland_view->unmap.link);
-        view_destroy(&xwayland_view->view);
+        view_begin_destroy(&xwayland_view->view);
 }
 
 static void handle_unmap(struct wl_listener *listener, void *data) {
diff --git a/sway/input/seat.c b/sway/input/seat.c
index 4077a8dd..997d7815 100644
--- a/sway/input/seat.c
+++ b/sway/input/seat.c
@@ -694,13 +694,11 @@ void seat_set_focus_warp(struct sway_seat *seat,
 
         // clean up unfocused empty workspace on new output
         if (new_output_last_ws) {
-                if (!workspace_is_visible(new_output_last_ws)
-                                && workspace_is_empty(new_output_last_ws)) {
-                        if (last_workspace == new_output_last_ws) {
-                                last_focus = NULL;
-                                last_workspace = NULL;
-                        }
-                        container_destroy(new_output_last_ws);
+                workspace_consider_destroy(new_output_last_ws);
+                if (new_output_last_ws->destroying &&
+                                last_workspace == new_output_last_ws) {
+                        last_focus = NULL;
+                        last_workspace = NULL;
                 }
         }
 
@@ -716,12 +714,9 @@ void seat_set_focus_warp(struct sway_seat *seat,
                         if (notify && last_workspace != new_workspace) {
                                  ipc_event_workspace(last_workspace, new_workspace, "focus");
                         }
-                        if (!workspace_is_visible(last_workspace)
-                                        && workspace_is_empty(last_workspace)) {
-                                if (last_workspace == last_focus) {
-                                        last_focus = NULL;
-                                }
-                                container_destroy(last_workspace);
+                        workspace_consider_destroy(last_workspace);
+                        if (last_workspace->destroying && last_workspace == last_focus) {
+                                last_focus = NULL;
                         }
                 }
 
diff --git a/sway/tree/container.c b/sway/tree/container.c
index a8c6e667..6da6212c 100644
--- a/sway/tree/container.c
+++ b/sway/tree/container.c
@@ -104,209 +104,52 @@ struct sway_container *container_create(enum sway_container_type type) {
         return c;
 }
 
-static void container_workspace_free(struct sway_workspace *ws) {
-        list_foreach(ws->output_priority, free);
-        list_free(ws->output_priority);
-        list_free(ws->floating);
-        free(ws);
-}
-
-void container_free(struct sway_container *cont) {
-        if (!sway_assert(cont->destroying,
+void container_destroy(struct sway_container *con) {
+        if (!sway_assert(con->type == C_CONTAINER || con->type == C_VIEW,
+                                "Expected a container or view")) {
+                return;
+        }
+        if (!sway_assert(con->destroying,
                                 "Tried to free container which wasn't marked as destroying")) {
                 return;
         }
-        if (!sway_assert(cont->ntxnrefs == 0, "Tried to free container "
+        if (!sway_assert(con->ntxnrefs == 0, "Tried to free container "
                                 "which is still referenced by transactions")) {
                 return;
         }
-        free(cont->name);
-        free(cont->formatted_title);
-        wlr_texture_destroy(cont->title_focused);
-        wlr_texture_destroy(cont->title_focused_inactive);
-        wlr_texture_destroy(cont->title_unfocused);
-        wlr_texture_destroy(cont->title_urgent);
-        list_free(cont->children);
-        list_free(cont->current.children);
-        list_free(cont->outputs);
-
-        switch (cont->type) {
-        case C_ROOT:
-                break;
-        case C_OUTPUT:
-                break;
-        case C_WORKSPACE:
-                container_workspace_free(cont->sway_workspace);
-                break;
-        case C_CONTAINER:
-                break;
-        case C_VIEW:
-                {
-                        struct sway_view *view = cont->sway_view;
-                        view->swayc = NULL;
-                        free(view->title_format);
-                        view->title_format = NULL;
-
-                        if (view->destroying) {
-                                view_free(view);
-                        }
-                }
-                break;
-        case C_TYPES:
-                sway_assert(false, "Didn't expect to see C_TYPES here");
-                break;
-        }
-
-        free(cont);
-}
-
-static struct sway_container *container_destroy_noreaping(
-                struct sway_container *con);
-
-static struct sway_container *container_workspace_destroy(
-                struct sway_container *workspace) {
-        if (!sway_assert(workspace, "cannot destroy null workspace")) {
-                return NULL;
-        }
-
-        struct sway_container *output = container_parent(workspace, C_OUTPUT);
-
-        // If we're destroying the output, it will be NULL here. Return the root so
-        // that it doesn't appear that the workspace has refused to be destoyed,
-        // which would leave it in a broken state with no parent.
-        if (output == NULL) {
-                return &root_container;
-        }
-
-        // Do not destroy this if it's the last workspace on this output
-        if (output->children->length == 1) {
-                return NULL;
-        }
-
-        wlr_log(WLR_DEBUG, "destroying workspace '%s'", workspace->name);
-
-        if (!workspace_is_empty(workspace)) {
-                // Move children to a different workspace on this output
-                struct sway_container *new_workspace = NULL;
-                for (int i = 0; i < output->children->length; i++) {
-                        if (output->children->items[i] != workspace) {
-                                new_workspace = output->children->items[i];
-                                break;
-                        }
-                }
-
-                wlr_log(WLR_DEBUG, "moving children to different workspace '%s' -> '%s'",
-                        workspace->name, new_workspace->name);
-                for (int i = 0; i < workspace->children->length; i++) {
-                        container_move_to(workspace->children->items[i], new_workspace);
-                }
-                list_t *floating = workspace->sway_workspace->floating;
-                for (int i = 0; i < floating->length; i++) {
-                        struct sway_container *floater = floating->items[i];
-                        container_remove_child(floater);
-                        workspace_add_floating(new_workspace, floater);
-                }
-        }
-
-        return output;
-}
-
-static void untrack_output(struct sway_container *con, void *data) {
-        struct sway_output *output = data;
-        int index = list_find(con->outputs, output);
-        if (index != -1) {
-                list_del(con->outputs, index);
-        }
-}
-
-static struct sway_container *container_output_destroy(
-                struct sway_container *output) {
-        if (!sway_assert(output, "cannot destroy null output")) {
-                return NULL;
-        }
-
-        if (output->children->length > 0) {
-                // TODO save workspaces when there are no outputs.
-                // TODO also check if there will ever be no outputs except for exiting
-                // program
-                if (root_container.children->length > 1) {
-                        // Move workspace from this output to another output
-                        struct sway_container *fallback_output =
-                                root_container.children->items[0];
-                        if (fallback_output == output) {
-                                fallback_output = root_container.children->items[1];
-                        }
-
-                        while (output->children->length) {
-                                struct sway_container *workspace = output->children->items[0];
-
-                                struct sway_container *new_output =
-                                        workspace_output_get_highest_available(workspace, output);
-                                if (!new_output) {
-                                        new_output = fallback_output;
-                                        workspace_output_add_priority(workspace, new_output);
-                                }
+        free(con->name);
+        free(con->formatted_title);
+        wlr_texture_destroy(con->title_focused);
+        wlr_texture_destroy(con->title_focused_inactive);
+        wlr_texture_destroy(con->title_unfocused);
+        wlr_texture_destroy(con->title_urgent);
+        list_free(con->children);
+        list_free(con->current.children);
+        list_free(con->outputs);
 
-                                container_remove_child(workspace);
-                                if (!workspace_is_empty(workspace)) {
-                                        container_add_child(new_output, workspace);
-                                        ipc_event_workspace(NULL, workspace, "move");
-                                } else {
-                                        container_destroy(workspace);
-                                }
+        if (con->type == C_VIEW) {
+                struct sway_view *view = con->sway_view;
+                view->swayc = NULL;
+                free(view->title_format);
+                view->title_format = NULL;
 
-                                output_sort_workspaces(new_output);
-                        }
+                if (view->destroying) {
+                        view_destroy(view);
                 }
         }
 
-        root_for_each_container(untrack_output, output->sway_output);
-
-        wl_list_remove(&output->sway_output->mode.link);
-        wl_list_remove(&output->sway_output->transform.link);
-        wl_list_remove(&output->sway_output->scale.link);
-
-        wl_list_remove(&output->sway_output->damage_destroy.link);
-        wl_list_remove(&output->sway_output->damage_frame.link);
-
-        output->sway_output->swayc = NULL;
-        output->sway_output = NULL;
-
-        wlr_log(WLR_DEBUG, "OUTPUT: Destroying output '%s'", output->name);
-
-        return &root_container;
+        free(con);
 }
 
-/**
- * Implement the actual destroy logic, without reaping.
- */
-static struct sway_container *container_destroy_noreaping(
-                struct sway_container *con) {
-        if (con == NULL) {
-                return NULL;
-        }
-        if (con->destroying) {
-                return NULL;
+void container_begin_destroy(struct sway_container *con) {
+        if (!sway_assert(con->type == C_CONTAINER || con->type == C_VIEW,
+                                "Expected a container or view")) {
+                return;
         }
 
         wl_signal_emit(&con->events.destroy, con);
-
-        // emit IPC event
         if (con->type == C_VIEW) {
                 ipc_event_window(con, "close");
-        } else if (con->type == C_WORKSPACE) {
-                ipc_event_workspace(NULL, con, "empty");
-        }
-
-        // The below functions move their children to somewhere else.
-        if (con->type == C_OUTPUT) {
-                container_output_destroy(con);
-        } else if (con->type == C_WORKSPACE) {
-                // Workspaces will refuse to be destroyed if they're the last workspace
-                // on their output.
-                if (!container_workspace_destroy(con)) {
-                        return NULL;
-                }
         }
 
         container_end_mouse_operation(con);
@@ -318,51 +161,22 @@ static struct sway_container *container_destroy_noreaping(
                 root_scratchpad_remove_container(con);
         }
 
-        if (!con->parent) {
-                return NULL;
-        }
-
-        return container_remove_child(con);
-}
-
-bool container_reap_empty(struct sway_container *con) {
-        switch (con->type) {
-        case C_ROOT:
-        case C_OUTPUT:
-                // dont reap these
-                break;
-        case C_WORKSPACE:
-                if (!workspace_is_visible(con) && workspace_is_empty(con)) {
-                        wlr_log(WLR_DEBUG, "Destroying workspace via reaper");
-                        container_destroy_noreaping(con);
-                        return true;
-                }
-                break;
-        case C_CONTAINER:
-                if (con->children->length == 0) {
-                        container_destroy_noreaping(con);
-                        return true;
-                }
-        case C_VIEW:
-                break;
-        case C_TYPES:
-                sway_assert(false, "container_reap_empty called on an invalid "
-                        "container");
-                break;
+        if (con->parent) {
+                container_remove_child(con);
         }
-
-        return false;
 }
 
-struct sway_container *container_reap_empty_recursive(
-                struct sway_container *con) {
-        while (con) {
+struct sway_container *container_reap_empty(struct sway_container *con) {
+        while (con && con->type == C_CONTAINER) {
                 struct sway_container *next = con->parent;
-                if (!container_reap_empty(con)) {
-                        break;
+                if (con->children->length == 0) {
+                        container_begin_destroy(con);
                 }
                 con = next;
         }
+        if (con && con->type == C_WORKSPACE) {
+                workspace_consider_destroy(con);
+        }
         return con;
 }
 
@@ -371,34 +185,12 @@ struct sway_container *container_flatten(struct sway_container *container) {
                 struct sway_container *child = container->children->items[0];
                 struct sway_container *parent = container->parent;
                 container_replace_child(container, child);
-                container_destroy_noreaping(container);
+                container_begin_destroy(container);
                 container = parent;
         }
         return container;
 }
 
-/**
- * container_destroy() is the first step in destroying a container. We'll emit
- * events, detach it from the tree and mark it as destroying. The container will
- * remain in memory until it's no longer used by a transaction, then it will be
- * freed via container_free().
- *
- * This function just wraps container_destroy_noreaping(), then does reaping.
- */
-struct sway_container *container_destroy(struct sway_container *con) {
-        if (con->is_fullscreen) {
-                struct sway_container *ws = container_parent(con, C_WORKSPACE);
-                ws->sway_workspace->fullscreen = NULL;
-        }
-        struct sway_container *parent = container_destroy_noreaping(con);
-
-        if (!parent) {
-                return NULL;
-        }
-
-        return container_reap_empty_recursive(parent);
-}
-
 static void container_close_func(struct sway_container *container, void *data) {
         if (container->type == C_VIEW) {
                 view_close(container->sway_view);
diff --git a/sway/tree/layout.c b/sway/tree/layout.c
index a3de44ce..12e7342b 100644
--- a/sway/tree/layout.c
+++ b/sway/tree/layout.c
@@ -302,7 +302,7 @@ static void workspace_rejigger(struct sway_container *ws,
                 move_dir == MOVE_LEFT || move_dir == MOVE_RIGHT ? L_HORIZ : L_VERT;
 
         container_flatten(ws);
-        container_reap_empty_recursive(original_parent);
+        container_reap_empty(original_parent);
         container_create_notify(new_parent);
 }
 
@@ -325,7 +325,7 @@ static void move_out_of_tabs_stacks(struct sway_container *container,
                 container_insert_child(new_parent->parent, container, offs < 0 ? 0 : 1);
         } else {
                 container_insert_child(new_parent, container, offs < 0 ? 0 : 1);
-                container_reap_empty_recursive(new_parent->parent);
+                container_reap_empty(new_parent->parent);
                 container_flatten(new_parent->parent);
         }
         container_create_notify(new_parent);
diff --git a/sway/tree/output.c b/sway/tree/output.c
index 6da63064..80636c11 100644
--- a/sway/tree/output.c
+++ b/sway/tree/output.c
@@ -10,6 +10,7 @@
 #include "log.h"
 
 static void restore_workspaces(struct sway_container *output) {
+        // Workspace output priority
         for (int i = 0; i < root_container.children->length; i++) {
                 struct sway_container *other = root_container.children->items[i];
                 if (other == output) {
@@ -29,6 +30,15 @@ static void restore_workspaces(struct sway_container *output) {
                 }
         }
 
+        // Saved workspaces
+        list_t *saved = root_container.sway_root->saved_workspaces;
+        for (int i = 0; i < saved->length; ++i) {
+                struct sway_container *ws = saved->items[i];
+                container_add_child(output, ws);
+                ipc_event_workspace(NULL, ws, "move");
+        }
+        saved->length = 0;
+
         output_sort_workspaces(output);
 }
 
@@ -68,7 +78,7 @@ struct sway_container *output_create(
         output->sway_output = sway_output;
         output->name = strdup(name);
         if (output->name == NULL) {
-                container_destroy(output);
+                output_begin_destroy(output);
                 return NULL;
         }
 
@@ -103,6 +113,102 @@ struct sway_container *output_create(
         return output;
 }
 
+static void output_evacuate(struct sway_container *output) {
+        if (!output->children->length) {
+                return;
+        }
+        struct sway_container *fallback_output = NULL;
+        if (root_container.children->length > 1) {
+                fallback_output = root_container.children->items[0];
+                if (fallback_output == output) {
+                        fallback_output = root_container.children->items[1];
+                }
+        }
+
+        while (output->children->length) {
+                struct sway_container *workspace = output->children->items[0];
+
+                struct sway_container *new_output =
+                        workspace_output_get_highest_available(workspace, output);
+                if (!new_output) {
+                        new_output = fallback_output;
+                }
+
+                container_remove_child(workspace);
+
+                if (new_output) {
+                        workspace_output_add_priority(workspace, new_output);
+                        container_add_child(new_output, workspace);
+                        output_sort_workspaces(new_output);
+                        ipc_event_workspace(NULL, workspace, "move");
+                } else {
+                        list_add(root_container.sway_root->saved_workspaces, workspace);
+                }
+        }
+}
+
+void output_destroy(struct sway_container *output) {
+        if (!sway_assert(output->type == C_OUTPUT, "Expected an output")) {
+                return;
+        }
+        if (!sway_assert(output->destroying,
+                                "Tried to free output which wasn't marked as destroying")) {
+                return;
+        }
+        if (!sway_assert(output->ntxnrefs == 0, "Tried to free output "
+                                "which is still referenced by transactions")) {
+                return;
+        }
+        free(output->name);
+        free(output->formatted_title);
+        wlr_texture_destroy(output->title_focused);
+        wlr_texture_destroy(output->title_focused_inactive);
+        wlr_texture_destroy(output->title_unfocused);
+        wlr_texture_destroy(output->title_urgent);
+        list_free(output->children);
+        list_free(output->current.children);
+        list_free(output->outputs);
+        free(output);
+
+        // NOTE: We don't actually destroy the sway_output here
+}
+
+static void untrack_output(struct sway_container *con, void *data) {
+        struct sway_output *output = data;
+        int index = list_find(con->outputs, output);
+        if (index != -1) {
+                list_del(con->outputs, index);
+        }
+}
+
+void output_begin_destroy(struct sway_container *output) {
+        if (!sway_assert(output->type == C_OUTPUT, "Expected an output")) {
+                return;
+        }
+        wlr_log(WLR_DEBUG, "OUTPUT: Destroying output '%s'", output->name);
+        wl_signal_emit(&output->events.destroy, output);
+
+        output_evacuate(output);
+
+        output->destroying = true;
+        container_set_dirty(output);
+
+        root_for_each_container(untrack_output, output->sway_output);
+
+        wl_list_remove(&output->sway_output->mode.link);
+        wl_list_remove(&output->sway_output->transform.link);
+        wl_list_remove(&output->sway_output->scale.link);
+        wl_list_remove(&output->sway_output->damage_destroy.link);
+        wl_list_remove(&output->sway_output->damage_frame.link);
+
+        output->sway_output->swayc = NULL;
+        output->sway_output = NULL;
+
+        if (output->parent) {
+                container_remove_child(output);
+        }
+}
+
 void output_for_each_workspace(struct sway_container *output,
                 void (*f)(struct sway_container *con, void *data), void *data) {
         if (!sway_assert(output->type == C_OUTPUT, "Expected an output")) {
diff --git a/sway/tree/root.c b/sway/tree/root.c
index c27ff2c3..5602f0a0 100644
--- a/sway/tree/root.c
+++ b/sway/tree/root.c
@@ -39,6 +39,7 @@ void root_create(void) {
         wl_list_init(&root_container.sway_root->drag_icons);
         wl_signal_init(&root_container.sway_root->events.new_container);
         root_container.sway_root->scratchpad = create_list();
+        root_container.sway_root->saved_workspaces = create_list();
 
         root_container.sway_root->output_layout_change.notify =
                 output_layout_handle_change;
@@ -50,6 +51,7 @@ void root_destroy(void) {
         // sway_root
         wl_list_remove(&root_container.sway_root->output_layout_change.link);
         list_free(root_container.sway_root->scratchpad);
+        list_free(root_container.sway_root->saved_workspaces);
         wlr_output_layout_destroy(root_container.sway_root->output_layout);
         free(root_container.sway_root);
 
diff --git a/sway/tree/view.c b/sway/tree/view.c
index 7bf7325a..ba4a880f 100644
--- a/sway/tree/view.c
+++ b/sway/tree/view.c
@@ -35,7 +35,7 @@ void view_init(struct sway_view *view, enum sway_view_type type,
         wl_signal_init(&view->events.unmap);
 }
 
-void view_free(struct sway_view *view) {
+void view_destroy(struct sway_view *view) {
         if (!sway_assert(view->surface == NULL, "Tried to free mapped view")) {
                 return;
         }
@@ -75,14 +75,14 @@ void view_free(struct sway_view *view) {
  * destroying flag will make the view get freed when the transaction is
  * finished.
  */
-void view_destroy(struct sway_view *view) {
+void view_begin_destroy(struct sway_view *view) {
         if (!sway_assert(view->surface == NULL, "Tried to destroy a mapped view")) {
                 return;
         }
         view->destroying = true;
 
         if (!view->swayc) {
-                view_free(view);
+                view_destroy(view);
         }
 }
 
@@ -560,7 +560,9 @@ void view_unmap(struct sway_view *view) {
         }
 
         bool was_fullscreen = view->swayc->is_fullscreen;
-        struct sway_container *surviving_ancestor = container_destroy(view->swayc);
+        struct sway_container *parent = view->swayc->parent;
+        container_begin_destroy(view->swayc);
+        struct sway_container *surviving_ancestor = container_reap_empty(parent);
 
         // If the workspace wasn't reaped
         if (surviving_ancestor && surviving_ancestor->type >= C_WORKSPACE) {
diff --git a/sway/tree/workspace.c b/sway/tree/workspace.c
index cf50ee09..93c4b3d3 100644
--- a/sway/tree/workspace.c
+++ b/sway/tree/workspace.c
@@ -79,6 +79,65 @@ struct sway_container *workspace_create(struct sway_container *output,
         return workspace;
 }
 
+void workspace_destroy(struct sway_container *workspace) {
+        if (!sway_assert(workspace->type == C_WORKSPACE, "Expected a workspace")) {
+                return;
+        }
+        if (!sway_assert(workspace->destroying,
+                                "Tried to free workspace which wasn't marked as destroying")) {
+                return;
+        }
+        if (!sway_assert(workspace->ntxnrefs == 0, "Tried to free workspace "
+                                "which is still referenced by transactions")) {
+                return;
+        }
+        // sway_workspace
+        struct sway_workspace *ws = workspace->sway_workspace;
+        list_foreach(ws->output_priority, free);
+        list_free(ws->output_priority);
+        list_free(ws->floating);
+        free(ws);
+
+        // swayc
+        free(workspace->name);
+        free(workspace->formatted_title);
+        wlr_texture_destroy(workspace->title_focused);
+        wlr_texture_destroy(workspace->title_focused_inactive);
+        wlr_texture_destroy(workspace->title_unfocused);
+        wlr_texture_destroy(workspace->title_urgent);
+        list_free(workspace->children);
+        list_free(workspace->current.children);
+        list_free(workspace->outputs);
+        free(workspace);
+}
+
+void workspace_begin_destroy(struct sway_container *workspace) {
+        if (!sway_assert(workspace->type == C_WORKSPACE, "Expected a workspace")) {
+                return;
+        }
+        wlr_log(WLR_DEBUG, "Destroying workspace '%s'", workspace->name);
+        wl_signal_emit(&workspace->events.destroy, workspace);
+        ipc_event_workspace(NULL, workspace, "empty"); // intentional
+
+        workspace->destroying = true;
+        container_set_dirty(workspace);
+
+        if (workspace->parent) {
+                container_remove_child(workspace);
+        }
+}
+
+void workspace_consider_destroy(struct sway_container *ws) {
+        if (!sway_assert(ws->type == C_WORKSPACE, "Expected a workspace")) {
+                return;
+        }
+        struct sway_seat *seat = input_manager_current_seat(input_manager);
+        if (ws->children->length == 0 && ws->sway_workspace->floating->length == 0
+                        && seat_get_active_child(seat, ws->parent) != ws) {
+                workspace_begin_destroy(ws);
+        }
+}
+
 char *prev_workspace_name = NULL;
 
 void next_name_map(struct sway_container *ws, void *data) {
@@ -421,9 +480,7 @@ bool workspace_switch(struct sway_container *workspace,
                 // no op. We therefore need to send the IPC event and clean up the old
                 // workspace here.
                 ipc_event_workspace(active_ws, workspace, "focus");
-                if (!workspace_is_visible(active_ws) && workspace_is_empty(active_ws)) {
-                        container_destroy(active_ws);
-                }
+                workspace_consider_destroy(active_ws);
         }
         seat_set_focus(seat, next);
         struct sway_container *output = container_parent(workspace, C_OUTPUT);