Implement moving workspaces as if they're regular containers

src/commands.c

@@ -388,7 +388,8 @@ void cmd_move_con_to_workspace(I3_CMD, char *which) {
      *  when criteria was specified but didn't match any window or
      *  when criteria wasn't specified and we don't have any window focused. */
     if ((!match_is_empty(current_match) && TAILQ_EMPTY(&owindows)) ||
-        (match_is_empty(current_match) && focused->type == CT_WORKSPACE)) {
+        (match_is_empty(current_match) && focused->type == CT_WORKSPACE &&
+        con_is_leaf(focused))) {
         ysuccess(false);
         return;
     }
@@ -476,9 +477,8 @@ void cmd_move_con_to_workspace_name(I3_CMD, char *name) {
         ysuccess(false);
         return;
     }
-
-    if (match_is_empty(current_match) && focused->type == CT_WORKSPACE) {
-        ELOG("No window to move, you have focused a workspace.\n");
+    else if (match_is_empty(current_match) && focused->type == CT_WORKSPACE &&
+        con_is_leaf(focused)) {
         ysuccess(false);
         return;
     }
@@ -512,7 +512,8 @@ void cmd_move_con_to_workspace_number(I3_CMD, char *which) {
      *  when criteria was specified but didn't match any window or
      *  when criteria wasn't specified and we don't have any window focused. */
     if ((!match_is_empty(current_match) && TAILQ_EMPTY(&owindows)) ||
-        (match_is_empty(current_match) && focused->type == CT_WORKSPACE)) {
+        (match_is_empty(current_match) && focused->type == CT_WORKSPACE &&
+        con_is_leaf(focused))) {
         ysuccess(false);
         return;
     }

src/con.c

@@ -607,11 +607,6 @@ void con_toggle_fullscreen(Con *con, int fullscreen_mode) {
  *
  */
 void con_move_to_workspace(Con *con, Con *workspace, bool fix_coordinates, bool dont_warp) {
-    if (con->type == CT_WORKSPACE) {
-        DLOG("Moving workspaces is not yet implemented.\n");
-        return;
-    }
-
     /* Prevent moving if this would violate the fullscreen focus restrictions. */
     if (!con_fullscreen_permits_focusing(workspace)) {
         LOG("Cannot move out of a fullscreen container");
@@ -629,6 +624,21 @@ void con_move_to_workspace(Con *con, Con *workspace, bool fix_coordinates, bool
         return;
     }
 
+    if (con->type == CT_WORKSPACE) {
+        con = workspace_encapsulate(con);
+        if (con == NULL) {
+            ELOG("Workspace failed to move its contents into a container!\n");
+            return;
+        }
+
+        /* Re-parent all of the old workspace's floating windows. */
+        Con *child;
+        while (!TAILQ_EMPTY(&(source_ws->floating_head))) {
+            child = TAILQ_FIRST(&(source_ws->floating_head));
+            con_move_to_workspace(child, workspace, true, true);
+        }
+    }
+
     /* Save the current workspace. So we can call workspace_show() by the end
      * of this function. */
     Con *current_ws = con_get_workspace(focused);

src/workspace.c

@@ -830,3 +830,34 @@ Con *workspace_attach_to(Con *ws) {
 
     return new;
 }
+
+/**
+ * Creates a new container and re-parents all of children from the given
+ * workspace into it.
+ *
+ * The container inherits the layout from the workspace.
+ */
+Con *workspace_encapsulate(Con *ws) {
+    if (TAILQ_EMPTY(&(ws->nodes_head))) {
+        ELOG("Workspace %p / %s has no children to encapsulate\n", ws, ws->name);
+        return NULL;
+    }
+
+    Con *new = con_new(NULL, NULL);
+    new->parent = ws;
+    new->layout = ws->layout;
+
+    DLOG("Moving children of workspace %p / %s into container %p\n",
+        ws, ws->name, new);
+
+    Con *child;
+    while (!TAILQ_EMPTY(&(ws->nodes_head))) {
+        child = TAILQ_FIRST(&(ws->nodes_head));
+        con_detach(child);
+        con_attach(child, new, true);
+    }
+
+    con_attach(new, ws, true);
+
+    return new;
+}