#define _XOPEN_SOURCE 700 // for realpath #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "sway/input/input-manager.h" #include "sway/input/seat.h" #include "sway/commands.h" #include "sway/config.h" #include "sway/criteria.h" #include "sway/desktop/transaction.h" #include "sway/swaynag.h" #include "sway/tree/arrange.h" #include "sway/tree/root.h" #include "sway/tree/workspace.h" #include "cairo.h" #include "pango.h" #include "stringop.h" #include "list.h" #include "log.h" struct sway_config *config = NULL; static void free_mode(struct sway_mode *mode) { if (!mode) { return; } free(mode->name); if (mode->keysym_bindings) { for (int i = 0; i < mode->keysym_bindings->length; i++) { free_sway_binding(mode->keysym_bindings->items[i]); } list_free(mode->keysym_bindings); } if (mode->keycode_bindings) { for (int i = 0; i < mode->keycode_bindings->length; i++) { free_sway_binding(mode->keycode_bindings->items[i]); } list_free(mode->keycode_bindings); } if (mode->mouse_bindings) { for (int i = 0; i < mode->mouse_bindings->length; i++) { free_sway_binding(mode->mouse_bindings->items[i]); } list_free(mode->mouse_bindings); } free(mode); } void free_config(struct sway_config *config) { if (!config) { return; } memset(&config->handler_context, 0, sizeof(config->handler_context)); // TODO: handle all currently unhandled lists as we add implementations if (config->symbols) { for (int i = 0; i < config->symbols->length; ++i) { free_sway_variable(config->symbols->items[i]); } list_free(config->symbols); } if (config->modes) { for (int i = 0; i < config->modes->length; ++i) { free_mode(config->modes->items[i]); } list_free(config->modes); } if (config->bars) { for (int i = 0; i < config->bars->length; ++i) { free_bar_config(config->bars->items[i]); } list_free(config->bars); } list_free(config->cmd_queue); if (config->workspace_configs) { for (int i = 0; i < config->workspace_configs->length; i++) { free_workspace_config(config->workspace_configs->items[i]); } list_free(config->workspace_configs); } if (config->output_configs) { for (int i = 0; i < config->output_configs->length; i++) { free_output_config(config->output_configs->items[i]); } list_free(config->output_configs); } if (config->input_configs) { for (int i = 0; i < config->input_configs->length; i++) { free_input_config(config->input_configs->items[i]); } list_free(config->input_configs); } if (config->seat_configs) { for (int i = 0; i < config->seat_configs->length; i++) { free_seat_config(config->seat_configs->items[i]); } list_free(config->seat_configs); } if (config->criteria) { for (int i = 0; i < config->criteria->length; ++i) { criteria_destroy(config->criteria->items[i]); } list_free(config->criteria); } list_free(config->no_focus); list_free(config->active_bar_modifiers); list_free(config->config_chain); list_free(config->command_policies); list_free(config->feature_policies); list_free(config->ipc_policies); free(config->floating_scroll_up_cmd); free(config->floating_scroll_down_cmd); free(config->floating_scroll_left_cmd); free(config->floating_scroll_right_cmd); free(config->font); free(config->swaybg_command); free(config->swaynag_command); free((char *)config->current_config_path); free((char *)config->current_config); free(config); } static void destroy_removed_seats(struct sway_config *old_config, struct sway_config *new_config) { struct seat_config *seat_config; struct sway_seat *seat; int i; for (i = 0; i < old_config->seat_configs->length; i++) { seat_config = old_config->seat_configs->items[i]; // Skip the wildcard seat config, it won't have a matching real seat. if (strcmp(seat_config->name, "*") == 0) { continue; } /* Also destroy seats that aren't present in new config */ if (new_config && list_seq_find(new_config->seat_configs, seat_name_cmp, seat_config->name) < 0) { seat = input_manager_get_seat(seat_config->name, false); if (seat) { seat_destroy(seat); } } } } static void set_color(float dest[static 4], uint32_t color) { dest[0] = ((color >> 16) & 0xff) / 255.0; dest[1] = ((color >> 8) & 0xff) / 255.0; dest[2] = (color & 0xff) / 255.0; dest[3] = 1.0; } static void config_defaults(struct sway_config *config) { if (!(config->swaynag_command = strdup("swaynag"))) goto cleanup; config->swaynag_config_errors = (struct swaynag_instance){ .args = "--type error " "--message 'There are errors in your config file' " "--detailed-message " "--button 'Exit sway' 'swaymsg exit' " "--button 'Reload sway' 'swaymsg reload'", .pid = -1, .detailed = true, }; if (!(config->symbols = create_list())) goto cleanup; if (!(config->modes = create_list())) goto cleanup; if (!(config->bars = create_list())) goto cleanup; if (!(config->workspace_configs = create_list())) goto cleanup; if (!(config->criteria = create_list())) goto cleanup; if (!(config->no_focus = create_list())) goto cleanup; if (!(config->input_configs = create_list())) goto cleanup; if (!(config->seat_configs = create_list())) goto cleanup; if (!(config->output_configs = create_list())) goto cleanup; if (!(config->cmd_queue = create_list())) goto cleanup; if (!(config->current_mode = malloc(sizeof(struct sway_mode)))) goto cleanup; if (!(config->current_mode->name = malloc(sizeof("default")))) goto cleanup; strcpy(config->current_mode->name, "default"); if (!(config->current_mode->keysym_bindings = create_list())) goto cleanup; if (!(config->current_mode->keycode_bindings = create_list())) goto cleanup; if (!(config->current_mode->mouse_bindings = create_list())) goto cleanup; list_add(config->modes, config->current_mode); config->floating_mod = 0; config->floating_mod_inverse = false; config->dragging_key = BTN_LEFT; config->resizing_key = BTN_RIGHT; if (!(config->floating_scroll_up_cmd = strdup(""))) goto cleanup; if (!(config->floating_scroll_down_cmd = strdup(""))) goto cleanup; if (!(config->floating_scroll_left_cmd = strdup(""))) goto cleanup; if (!(config->floating_scroll_right_cmd = strdup(""))) goto cleanup; config->default_layout = L_NONE; config->default_orientation = L_NONE; if (!(config->font = strdup("monospace 10"))) goto cleanup; config->font_height = 17; // height of monospace 10 config->urgent_timeout = 500; config->popup_during_fullscreen = POPUP_SMART; config->xwayland = true; config->titlebar_border_thickness = 1; config->titlebar_h_padding = 5; config->titlebar_v_padding = 4; // floating view config->floating_maximum_width = 0; config->floating_maximum_height = 0; config->floating_minimum_width = 75; config->floating_minimum_height = 50; // Flags config->focus_follows_mouse = FOLLOWS_YES; config->mouse_warping = WARP_OUTPUT; config->focus_wrapping = WRAP_YES; config->validating = false; config->reloading = false; config->active = false; config->failed = false; config->auto_back_and_forth = false; config->reading = false; config->show_marks = true; config->title_align = ALIGN_LEFT; config->tiling_drag = true; config->tiling_drag_threshold = 9; config->smart_gaps = false; config->gaps_inner = 0; config->gaps_outer.top = 0; config->gaps_outer.right = 0; config->gaps_outer.bottom = 0; config->gaps_outer.left = 0; if (!(config->active_bar_modifiers = create_list())) goto cleanup; if (!(config->swaybg_command = strdup("swaybg"))) goto cleanup; if (!(config->config_chain = create_list())) goto cleanup; config->current_config_path = NULL; config->current_config = NULL; // borders config->border = B_NORMAL; config->floating_border = B_NORMAL; config->border_thickness = 2; config->floating_border_thickness = 2; config->hide_edge_borders = E_NONE; config->saved_edge_borders = E_NONE; // border colors set_color(config->border_colors.focused.border, 0x4C7899); set_color(config->border_colors.focused.background, 0x285577); set_color(config->border_colors.focused.text, 0xFFFFFFFF); set_color(config->border_colors.focused.indicator, 0x2E9EF4); set_color(config->border_colors.focused.child_border, 0x285577); set_color(config->border_colors.focused_inactive.border, 0x333333); set_color(config->border_colors.focused_inactive.background, 0x5F676A); set_color(config->border_colors.focused_inactive.text, 0xFFFFFFFF); set_color(config->border_colors.focused_inactive.indicator, 0x484E50); set_color(config->border_colors.focused_inactive.child_border, 0x5F676A); set_color(config->border_colors.unfocused.border, 0x333333); set_color(config->border_colors.unfocused.background, 0x222222); set_color(config->border_colors.unfocused.text, 0x88888888); set_color(config->border_colors.unfocused.indicator, 0x292D2E); set_color(config->border_colors.unfocused.child_border, 0x222222); set_color(config->border_colors.urgent.border, 0x2F343A); set_color(config->border_colors.urgent.background, 0x900000); set_color(config->border_colors.urgent.text, 0xFFFFFFFF); set_color(config->border_colors.urgent.indicator, 0x900000); set_color(config->border_colors.urgent.child_border, 0x900000); set_color(config->border_colors.placeholder.border, 0x000000); set_color(config->border_colors.placeholder.background, 0x0C0C0C); set_color(config->border_colors.placeholder.text, 0xFFFFFFFF); set_color(config->border_colors.placeholder.indicator, 0x000000); set_color(config->border_colors.placeholder.child_border, 0x0C0C0C); set_color(config->border_colors.background, 0xFFFFFF); // Security if (!(config->command_policies = create_list())) goto cleanup; if (!(config->feature_policies = create_list())) goto cleanup; if (!(config->ipc_policies = create_list())) goto cleanup; return; cleanup: sway_abort("Unable to allocate config structures"); } static bool file_exists(const char *path) { return path && access(path, R_OK) != -1; } static char *get_config_path(void) { static const char *config_paths[] = { "$HOME/.sway/config", "$XDG_CONFIG_HOME/sway/config", "$HOME/.i3/config", "$XDG_CONFIG_HOME/i3/config", SYSCONFDIR "/sway/config", SYSCONFDIR "/i3/config", }; char *config_home = getenv("XDG_CONFIG_HOME"); if (!config_home || !*config_home) { config_paths[1] = "$HOME/.config/sway/config"; config_paths[3] = "$HOME/.config/i3/config"; } for (size_t i = 0; i < sizeof(config_paths) / sizeof(char *); ++i) { wordexp_t p; if (wordexp(config_paths[i], &p, WRDE_UNDEF) == 0) { char *path = strdup(p.we_wordv[0]); wordfree(&p); if (file_exists(path)) { return path; } free(path); } } return NULL; } static bool load_config(const char *path, struct sway_config *config, struct swaynag_instance *swaynag) { if (path == NULL) { sway_log(SWAY_ERROR, "Unable to find a config file!"); return false; } sway_log(SWAY_INFO, "Loading config from %s", path); struct stat sb; if (stat(path, &sb) == 0 && S_ISDIR(sb.st_mode)) { sway_log(SWAY_ERROR, "%s is a directory not a config file", path); return false; } FILE *f = fopen(path, "r"); if (!f) { sway_log(SWAY_ERROR, "Unable to open %s for reading", path); return false; } bool config_load_success = read_config(f, config, swaynag); fclose(f); if (!config_load_success) { sway_log(SWAY_ERROR, "Error(s) loading config!"); } return true; } bool load_main_config(const char *file, bool is_active, bool validating) { char *path; if (file != NULL) { path = strdup(file); } else { path = get_config_path(); } char *real_path = realpath(path, NULL); if (real_path == NULL) { sway_log(SWAY_DEBUG, "%s not found.", path); free(path); return false; } struct sway_config *old_config = config; config = calloc(1, sizeof(struct sway_config)); if (!config) { sway_abort("Unable to allocate config"); } config_defaults(config); config->validating = validating; if (is_active) { sway_log(SWAY_DEBUG, "Performing configuration file %s", validating ? "validation" : "reload"); config->reloading = true; config->active = true; swaynag_kill(&old_config->swaynag_config_errors); memcpy(&config->swaynag_config_errors, &old_config->swaynag_config_errors, sizeof(struct swaynag_instance)); input_manager_reset_all_inputs(); } config->current_config_path = path; list_add(config->config_chain, real_path); config->reading = true; // Read security configs // TODO: Security bool success = true; /* DIR *dir = opendir(SYSCONFDIR "/sway/security.d"); if (!dir) { sway_log(SWAY_ERROR, "%s does not exist, sway will have no security configuration" " and will probably be broken", SYSCONFDIR "/sway/security.d"); } else { list_t *secconfigs = create_list(); char *base = SYSCONFDIR "/sway/security.d/"; struct dirent *ent = readdir(dir); struct stat s; while (ent != NULL) { char *_path = malloc(strlen(ent->d_name) + strlen(base) + 1); strcpy(_path, base); strcat(_path, ent->d_name); lstat(_path, &s); if (S_ISREG(s.st_mode) && ent->d_name[0] != '.') { list_add(secconfigs, _path); } else { free(_path); } ent = readdir(dir); } closedir(dir); list_qsort(secconfigs, qstrcmp); for (int i = 0; i < secconfigs->length; ++i) { char *_path = secconfigs->items[i]; if (stat(_path, &s) || s.st_uid != 0 || s.st_gid != 0 || (((s.st_mode & 0777) != 0644) && (s.st_mode & 0777) != 0444)) { sway_log(SWAY_ERROR, "Refusing to load %s - it must be owned by root " "and mode 644 or 444", _path); success = false; } else { success = success && load_config(_path, config); } } list_free_items_and_destroy(secconfigs); } */ success = success && load_config(path, config, &config->swaynag_config_errors); if (validating) { free_config(config); config = old_config; return success; } if (is_active) { for (int i = 0; i < config->output_configs->length; i++) { apply_output_config_to_outputs(config->output_configs->items[i]); } config->reloading = false; if (config->swaynag_config_errors.pid > 0) { swaynag_show(&config->swaynag_config_errors); } input_manager_verify_fallback_seat(); for (int i = 0; i < config->seat_configs->length; i++) { input_manager_apply_seat_config(config->seat_configs->items[i]); } } if (old_config) { destroy_removed_seats(old_config, config); free_config(old_config); } config->reading = false; return success; } static bool load_include_config(const char *path, const char *parent_dir, struct sway_config *config, struct swaynag_instance *swaynag) { // save parent config const char *parent_config = config->current_config_path; char *full_path; int len = strlen(path); if (len >= 1 && path[0] != '/') { len = len + strlen(parent_dir) + 2; full_path = malloc(len * sizeof(char)); if (!full_path) { sway_log(SWAY_ERROR, "Unable to allocate full path to included config"); return false; } snprintf(full_path, len, "%s/%s", parent_dir, path); } else { full_path = strdup(path); } char *real_path = realpath(full_path, NULL); free(full_path); if (real_path == NULL) { sway_log(SWAY_DEBUG, "%s not found.", path); return false; } // check if config has already been included int j; for (j = 0; j < config->config_chain->length; ++j) { char *old_path = config->config_chain->items[j]; if (strcmp(real_path, old_path) == 0) { sway_log(SWAY_DEBUG, "%s already included once, won't be included again.", real_path); free(real_path); return false; } } config->current_config_path = real_path; list_add(config->config_chain, real_path); int index = config->config_chain->length - 1; if (!load_config(real_path, config, swaynag)) { free(real_path); config->current_config_path = parent_config; list_del(config->config_chain, index); return false; } // restore current_config_path config->current_config_path = parent_config; return true; } bool load_include_configs(const char *path, struct sway_config *config, struct swaynag_instance *swaynag) { char *wd = getcwd(NULL, 0); char *parent_path = strdup(config->current_config_path); const char *parent_dir = dirname(parent_path); if (chdir(parent_dir) < 0) { goto error_chdir; } wordexp_t p; if (wordexp(path, &p, 0) != 0) { goto error_wordexp; } char **w = p.we_wordv; size_t i; for (i = 0; i < p.we_wordc; ++i) { bool found = load_include_config(w[i], parent_dir, config, swaynag); if (!found) { goto error_not_found; } } free(parent_path); wordfree(&p); // restore wd if (chdir(wd) < 0) { free(wd); sway_log(SWAY_ERROR, "failed to restore working directory"); return false; } free(wd); return true; error_not_found: wordfree(&p); error_wordexp: if (chdir(wd) < 0) { sway_log(SWAY_ERROR, "failed to restore working directory"); } error_chdir: free(parent_path); free(wd); return false; } void run_deferred_commands(void) { if (!config->cmd_queue->length) { return; } sway_log(SWAY_DEBUG, "Running deferred commands"); while (config->cmd_queue->length) { char *line = config->cmd_queue->items[0]; list_t *res_list = execute_command(line, NULL, NULL); for (int i = 0; i < res_list->length; ++i) { struct cmd_results *res = res_list->items[i]; if (res->status != CMD_SUCCESS) { sway_log(SWAY_ERROR, "Error on line '%s': %s", line, res->error); } free_cmd_results(res); } list_del(config->cmd_queue, 0); list_free(res_list); free(line); } transaction_commit_dirty(); } // get line, with backslash continuation static ssize_t getline_with_cont(char **lineptr, size_t *line_size, FILE *file, int *nlines) { char *next_line = NULL; size_t next_line_size = 0; ssize_t nread = getline(lineptr, line_size, file); *nlines = nread == -1 ? 0 : 1; while (nread >= 2 && strcmp(&(*lineptr)[nread - 2], "\\\n") == 0) { ssize_t next_nread = getline(&next_line, &next_line_size, file); if (next_nread == -1) { break; } (*nlines)++; nread += next_nread - 2; if ((ssize_t) *line_size < nread + 1) { *line_size = nread + 1; *lineptr = realloc(*lineptr, *line_size); if (!*lineptr) { nread = -1; break; } } strcpy(&(*lineptr)[nread - next_nread], next_line); } free(next_line); return nread; } static int detect_brace(FILE *file) { int ret = 0; int lines = 0; long pos = ftell(file); char *line = NULL; size_t line_size = 0; while ((getline(&line, &line_size, file)) != -1) { lines++; strip_whitespace(line); if (*line) { if (strcmp(line, "{") == 0) { ret = lines; } break; } } free(line); if (ret == 0) { fseek(file, pos, SEEK_SET); } return ret; } static char *expand_line(const char *block, const char *line, bool add_brace) { int size = (block ? strlen(block) + 1 : 0) + strlen(line) + (add_brace ? 2 : 0) + 1; char *expanded = calloc(1, size); if (!expanded) { sway_log(SWAY_ERROR, "Cannot allocate expanded line buffer"); return NULL; } snprintf(expanded, size, "%s%s%s%s", block ? block : "", block ? " " : "", line, add_brace ? " {" : ""); return expanded; } bool read_config(FILE *file, struct sway_config *config, struct swaynag_instance *swaynag) { bool reading_main_config = false; char *this_config = NULL; size_t config_size = 0; if (config->current_config == NULL) { reading_main_config = true; int ret_seek = fseek(file, 0, SEEK_END); long ret_tell = ftell(file); if (ret_seek == -1 || ret_tell == -1) { sway_log(SWAY_ERROR, "Unable to get size of config file"); return false; } config_size = ret_tell; rewind(file); config->current_config = this_config = calloc(1, config_size + 1); if (this_config == NULL) { sway_log(SWAY_ERROR, "Unable to allocate buffer for config contents"); return false; } } bool success = true; int line_number = 0; char *line = NULL; size_t line_size = 0; ssize_t nread; list_t *stack = create_list(); size_t read = 0; int nlines = 0; while ((nread = getline_with_cont(&line, &line_size, file, &nlines)) != -1) { if (reading_main_config) { if (read + nread > config_size) { sway_log(SWAY_ERROR, "Config file changed during reading"); success = false; break; } strcpy(&this_config[read], line); read += nread; } if (line[nread - 1] == '\n') { line[nread - 1] = '\0'; } line_number += nlines; sway_log(SWAY_DEBUG, "Read line %d: %s", line_number, line); strip_whitespace(line); if (!*line || line[0] == '#') { continue; } int brace_detected = 0; if (line[strlen(line) - 1] != '{' && line[strlen(line) - 1] != '}') { brace_detected = detect_brace(file); if (brace_detected > 0) { line_number += brace_detected; sway_log(SWAY_DEBUG, "Detected open brace on line %d", line_number); } } char *block = stack->length ? stack->items[0] : NULL; char *expanded = expand_line(block, line, brace_detected > 0); if (!expanded) { success = false; break; } config->current_config_line_number = line_number; config->current_config_line = line; struct cmd_results *res; char *new_block = NULL; if (block && strcmp(block, "") == 0) { // Special case res = config_commands_command(expanded); } else { res = config_command(expanded, &new_block); } switch(res->status) { case CMD_FAILURE: case CMD_INVALID: sway_log(SWAY_ERROR, "Error on line %i '%s': %s (%s)", line_number, line, res->error, config->current_config_path); if (!config->validating) { swaynag_log(config->swaynag_command, swaynag, "Error on line %i (%s) '%s': %s", line_number, config->current_config_path, line, res->error); } success = false; break; case CMD_DEFER: sway_log(SWAY_DEBUG, "Deferring command `%s'", line); list_add(config->cmd_queue, strdup(expanded)); break; case CMD_BLOCK_COMMANDS: sway_log(SWAY_DEBUG, "Entering commands block"); list_insert(stack, 0, ""); break; case CMD_BLOCK: sway_log(SWAY_DEBUG, "Entering block '%s'", new_block); list_insert(stack, 0, strdup(new_block)); if (strcmp(new_block, "bar") == 0) { config->current_bar = NULL; } break; case CMD_BLOCK_END: if (!block) { sway_log(SWAY_DEBUG, "Unmatched '}' on line %i", line_number); success = false; break; } if (strcmp(block, "bar") == 0) { config->current_bar = NULL; } sway_log(SWAY_DEBUG, "Exiting block '%s'", block); list_del(stack, 0); free(block); memset(&config->handler_context, 0, sizeof(config->handler_context)); default:; } free(new_block); free(expanded); free_cmd_results(res); } free(line); list_free_items_and_destroy(stack); config->current_config_line_number = 0; config->current_config_line = NULL; return success; } void config_add_swaynag_warning(char *fmt, ...) { if (config->reading && !config->validating) { va_list args; va_start(args, fmt); size_t length = vsnprintf(NULL, 0, fmt, args) + 1; va_end(args); char *temp = malloc(length + 1); if (!temp) { sway_log(SWAY_ERROR, "Failed to allocate buffer for warning."); return; } va_start(args, fmt); vsnprintf(temp, length, fmt, args); va_end(args); swaynag_log(config->swaynag_command, &config->swaynag_config_errors, "Warning on line %i (%s) '%s': %s", config->current_config_line_number, config->current_config_path, config->current_config_line, temp); } } char *do_var_replacement(char *str) { int i; char *find = str; while ((find = strchr(find, '$'))) { // Skip if escaped. if (find > str && find[-1] == '\\') { if (find == str + 1 || !(find > str + 1 && find[-2] == '\\')) { ++find; continue; } } // Unescape double $ and move on if (find[1] == '$') { size_t length = strlen(find + 1); memmove(find, find + 1, length); find[length] = '\0'; ++find; continue; } // Find matching variable for (i = 0; i < config->symbols->length; ++i) { struct sway_variable *var = config->symbols->items[i]; int vnlen = strlen(var->name); if (strncmp(find, var->name, vnlen) == 0) { int vvlen = strlen(var->value); char *newstr = malloc(strlen(str) - vnlen + vvlen + 1); if (!newstr) { sway_log(SWAY_ERROR, "Unable to allocate replacement " "during variable expansion"); break; } char *newptr = newstr; int offset = find - str; strncpy(newptr, str, offset); newptr += offset; strncpy(newptr, var->value, vvlen); newptr += vvlen; strcpy(newptr, find + vnlen); free(str); str = newstr; find = str + offset + vvlen; break; } } if (i == config->symbols->length) { ++find; } } return str; } // the naming is intentional (albeit long): a workspace_output_cmp function // would compare two structs in full, while this method only compares the // workspace. int workspace_output_cmp_workspace(const void *a, const void *b) { const struct workspace_config *wsa = a, *wsb = b; return lenient_strcmp(wsa->workspace, wsb->workspace); } static void find_font_height_iterator(struct sway_container *con, void *data) { size_t amount_below_baseline = con->title_height - con->title_baseline; size_t extended_height = config->font_baseline + amount_below_baseline; if (extended_height > config->font_height) { config->font_height = extended_height; } } static void find_baseline_iterator(struct sway_container *con, void *data) { bool *recalculate = data; if (*recalculate) { container_calculate_title_height(con); } if (con->title_baseline > config->font_baseline) { config->font_baseline = con->title_baseline; } } void config_update_font_height(bool recalculate) { size_t prev_max_height = config->font_height; config->font_height = 0; config->font_baseline = 0; root_for_each_container(find_baseline_iterator, &recalculate); root_for_each_container(find_font_height_iterator, NULL); if (config->font_height != prev_max_height) { arrange_root(); } }