Destroy empty workspaces when moving away

3 files changed, 93 insertions, 3 deletions

diff --git a/sway/input/seat.c b/sway/input/seat.c
index 7cf0dd08..ae536264 100644
--- a/sway/input/seat.c
+++ b/sway/input/seat.c
@@ -8,6 +8,7 @@
 #include "sway/input/keyboard.h"
 #include "sway/ipc-server.h"
 #include "sway/output.h"
+#include "sway/tree/container.h"
 #include "sway/tree/view.h"
 #include "log.h"
 
@@ -331,6 +332,9 @@ void sway_seat_set_focus(struct sway_seat *seat, struct sway_container *containe
                 if (last_ws) {
                         wlr_log(L_DEBUG, "sending workspace event");
                         ipc_event_workspace(last_ws, container, "focus");
+                        if (last_ws->children->length == 0) {
+                                container_workspace_destroy(last_ws);
+                        }
                 }
         }
 
diff --git a/sway/tree/container.c b/sway/tree/container.c
index 2eac812e..ed39a154 100644
--- a/sway/tree/container.c
+++ b/sway/tree/container.c
@@ -58,7 +58,7 @@ static struct sway_container *container_create(enum sway_container_type type) {
         return c;
 }
 
-static void container_destroy(struct sway_container *cont) {
+void container_destroy(struct sway_container *cont) {
         if (cont == NULL) {
                 return;
         }
@@ -203,8 +203,7 @@ struct sway_container *container_view_create(struct sway_container *sibling,
 }
 
 struct sway_container *container_output_destroy(struct sway_container *output) {
-        if (!sway_assert(output,
-                                "null output passed to container_output_destroy")) {
+        if (!sway_assert(output, "cannot destroy null output")) {
                 return NULL;
         }
 
@@ -236,6 +235,45 @@ struct sway_container *container_output_destroy(struct sway_container *output) {
         return &root_container;
 }
 
+struct sway_container *container_workspace_destroy(
+                struct sway_container *workspace) {
+        if (!sway_assert(workspace, "cannot destroy null workspace")) {
+                return NULL;
+        }
+
+        // Do not destroy this if it's the last workspace on this output
+        struct sway_container *output = container_parent(workspace, C_OUTPUT);
+        if (output && output->children->length == 1) {
+                return NULL;
+        }
+
+        struct sway_container *parent = workspace->parent;
+        if (workspace->children->length == 0) {
+                // destroy the WS if there are no children (TODO check for floating)
+                wlr_log(L_DEBUG, "destroying workspace '%s'", workspace->name);
+                ipc_event_workspace(workspace, NULL, "empty");
+        } else {
+                // Move children to a different workspace on this output
+                struct sway_container *new_workspace = NULL;
+                // TODO move floating
+                for (int i = 0; i < output->children->length; i++) {
+                        if (output->children->items[i] != workspace) {
+                                new_workspace = output->children->items[i];
+                                break;
+                        }
+                }
+
+                wlr_log(L_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);
+                }
+        }
+
+        container_destroy(workspace);
+        return parent;
+}
+
 struct sway_container *container_view_destroy(struct sway_container *view) {
         if (!view) {
                 return NULL;
@@ -438,3 +476,14 @@ void container_for_each_descendant_bfs(struct sway_container *con,
                 list_cat(queue, current->children);
         }
 }
+
+bool container_has_anscestor(struct sway_container *descendant,
+                struct sway_container *anscestor) {
+        while (descendant->type != C_ROOT) {
+                descendant = descendant->parent;
+                if (descendant == anscestor) {
+                        return true;
+                }
+        }
+        return false;
+}
diff --git a/sway/tree/layout.c b/sway/tree/layout.c
index dc0ee5b4..97007888 100644
--- a/sway/tree/layout.c
+++ b/sway/tree/layout.c
@@ -11,6 +11,7 @@
 #include "sway/output.h"
 #include "sway/tree/view.h"
 #include "sway/input/seat.h"
+#include "sway/ipc-server.h"
 #include "list.h"
 #include "log.h"
 
@@ -121,6 +122,42 @@ struct sway_container *container_remove_child(struct sway_container *child) {
         return parent;
 }
 
+struct sway_container *container_reap_empty(struct sway_container *container) {
+        if (!sway_assert(container, "reaping null container")) {
+                return NULL;
+        }
+        while (container->children->length == 0 && container->type == C_CONTAINER) {
+                wlr_log(L_DEBUG, "Container: Destroying container '%p'", container);
+                struct sway_container *parent = container->parent;
+                container_destroy(container);
+                container = parent;
+        }
+        return container;
+}
+
+void container_move_to(struct sway_container* container,
+                struct sway_container* destination) {
+        if (container == destination
+                        || container_has_anscestor(container, destination)) {
+                return;
+        }
+        struct sway_container *old_parent = container_remove_child(container);
+        container->width = container->height = 0;
+        struct sway_container *new_parent =
+                container_add_sibling(destination, container);
+        if (destination->type == C_WORKSPACE) {
+                // If the workspace only has one child after adding one, it
+                // means that the workspace was just initialized.
+                // TODO: Consider floating views in this test
+                if (destination->children->length == 1) {
+                        ipc_event_workspace(NULL, destination, "init");
+                }
+        }
+        old_parent = container_reap_empty(old_parent);
+        arrange_windows(old_parent, -1, -1);
+        arrange_windows(new_parent, -1, -1);
+}
+
 enum sway_container_layout container_get_default_layout(
                 struct sway_container *output) {
         /* TODO WLR