workspaces.c

/*
 * vim:ts=4:sw=4:expandtab
 *
 * i3bar - an xcb-based status- and ws-bar for i3
 * © 2010 Axel Wagner and contributors (see also: LICENSE)
 *
 * workspaces.c: Maintaining the workspace lists
 *
 */
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <yajl/yajl_parse.h>
#include <yajl/yajl_version.h>

#include "common.h"

/* A datatype to pass through the callbacks to save the state */
struct workspaces_json_params {
    struct ws_head *workspaces;
    i3_ws *workspaces_walk;
    char *cur_key;
    char *json;
};

/*
 * Parse a boolean value (visible, focused, urgent)
 *
 */
static int workspaces_boolean_cb(void *params_, int val) {
    struct workspaces_json_params *params = (struct workspaces_json_params *)params_;

    if (!strcmp(params->cur_key, "visible")) {
        params->workspaces_walk->visible = val;
        FREE(params->cur_key);
        return 1;
    }

    if (!strcmp(params->cur_key, "focused")) {
        params->workspaces_walk->focused = val;
        FREE(params->cur_key);
        return 1;
    }

    if (!strcmp(params->cur_key, "urgent")) {
        params->workspaces_walk->urgent = val;
        FREE(params->cur_key);
        return 1;
    }

    FREE(params->cur_key);

    return 0;
}

/*
 * Parse an integer (num or the rect)
 *
 */
static int workspaces_integer_cb(void *params_, long long val) {
    struct workspaces_json_params *params = (struct workspaces_json_params *)params_;

    if (!strcmp(params->cur_key, "num")) {
        params->workspaces_walk->num = (int)val;
        FREE(params->cur_key);
        return 1;
    }

    if (!strcmp(params->cur_key, "x")) {
        params->workspaces_walk->rect.x = (int)val;
        FREE(params->cur_key);
        return 1;
    }

    if (!strcmp(params->cur_key, "y")) {
        params->workspaces_walk->rect.y = (int)val;
        FREE(params->cur_key);
        return 1;
    }

    if (!strcmp(params->cur_key, "width")) {
        params->workspaces_walk->rect.w = (int)val;
        FREE(params->cur_key);
        return 1;
    }

    if (!strcmp(params->cur_key, "height")) {
        params->workspaces_walk->rect.h = (int)val;
        FREE(params->cur_key);
        return 1;
    }

    FREE(params->cur_key);
    return 0;
}

/*
 * Parse a string (name, output)
 *
 */
static int workspaces_string_cb(void *params_, const unsigned char *val, size_t len) {
    struct workspaces_json_params *params = (struct workspaces_json_params *)params_;

    if (!strcmp(params->cur_key, "name")) {
        const char *ws_name = (const char *)val;
        params->workspaces_walk->canonical_name = sstrndup(ws_name, len);

        if (config.strip_ws_numbers && params->workspaces_walk->num >= 0) {
            /* Special case: strip off the workspace number */
            static char ws_num[10];

            snprintf(ws_num, sizeof(ws_num), "%d", params->workspaces_walk->num);

            /* Calculate the length of the number str in the name */
            size_t offset = strspn(ws_name, ws_num);

            /* Also strip off the conventional ws name delimiter */
            if (offset && ws_name[offset] == ':')
                offset += 1;

            /* Offset may be equal to length, in which case display the number */
            params->workspaces_walk->name = (offset < len
                                                 ? i3string_from_markup_with_length(ws_name + offset, len - offset)
                                                 : i3string_from_markup(ws_num));

        } else {
            /* Default case: just save the name */
            params->workspaces_walk->name = i3string_from_markup_with_length(ws_name, len);
        }

        /* Save its rendered width */
        params->workspaces_walk->name_width =
            predict_text_width(params->workspaces_walk->name);

        DLOG("Got workspace canonical: %s, name: '%s', name_width: %d, glyphs: %zu\n",
             params->workspaces_walk->canonical_name,
             i3string_as_utf8(params->workspaces_walk->name),
             params->workspaces_walk->name_width,
             i3string_get_num_glyphs(params->workspaces_walk->name));
        FREE(params->cur_key);

        return 1;
    }

    if (!strcmp(params->cur_key, "output")) {
        /* We add the ws to the TAILQ of the output, it belongs to */
        char *output_name = NULL;
        sasprintf(&output_name, "%.*s", len, val);

        i3_output *target = get_output_by_name(output_name);
        if (target != NULL) {
            params->workspaces_walk->output = target;

            TAILQ_INSERT_TAIL(params->workspaces_walk->output->workspaces,
                              params->workspaces_walk,
                              tailq);
        }

        FREE(output_name);
        return 1;
    }

    return 0;
}

/*
 * We hit the start of a JSON map (rect or a new output)
 *
 */
static int workspaces_start_map_cb(void *params_) {
    struct workspaces_json_params *params = (struct workspaces_json_params *)params_;

    i3_ws *new_workspace = NULL;

    if (params->cur_key == NULL) {
        new_workspace = smalloc(sizeof(i3_ws));
        new_workspace->num = -1;
        new_workspace->name = NULL;
        new_workspace->visible = 0;
        new_workspace->focused = 0;
        new_workspace->urgent = 0;
        memset(&new_workspace->rect, 0, sizeof(rect));
        new_workspace->output = NULL;

        params->workspaces_walk = new_workspace;
        return 1;
    }

    return 1;
}

/*
 * Parse a key.
 *
 * Essentially we just save it in the parsing state
 *
 */
static int workspaces_map_key_cb(void *params_, const unsigned char *keyVal, size_t keyLen) {
    struct workspaces_json_params *params = (struct workspaces_json_params *)params_;
    FREE(params->cur_key);
    sasprintf(&(params->cur_key), "%.*s", keyLen, keyVal);
    return 1;
}

/* A datastructure to pass all these callbacks to yajl */
static yajl_callbacks workspaces_callbacks = {
    .yajl_boolean = workspaces_boolean_cb,
    .yajl_integer = workspaces_integer_cb,
    .yajl_string = workspaces_string_cb,
    .yajl_start_map = workspaces_start_map_cb,
    .yajl_map_key = workspaces_map_key_cb,
};

/*
 * Start parsing the received JSON string
 *
 */
void parse_workspaces_json(char *json) {
    /* FIXME: Fasciliate stream processing, i.e. allow starting to interpret
     * JSON in chunks */
    struct workspaces_json_params params;

    free_workspaces();

    params.workspaces_walk = NULL;
    params.cur_key = NULL;
    params.json = json;

    yajl_handle handle;
    yajl_status state;
    handle = yajl_alloc(&workspaces_callbacks, NULL, (void *)&params);

    state = yajl_parse(handle, (const unsigned char *)json, strlen(json));

    /* FIXME: Proper error handling for JSON parsing */
    switch (state) {
        case yajl_status_ok:
            break;
        case yajl_status_client_canceled:
        case yajl_status_error:
            ELOG("Could not parse workspaces reply!\n");
            exit(EXIT_FAILURE);
            break;
    }

    yajl_free(handle);

    FREE(params.cur_key);
}

/*
 * free() all workspace data structures. Does not free() the heads of the tailqueues.
 *
 */
void free_workspaces(void) {
    i3_output *outputs_walk;
    if (outputs == NULL) {
        return;
    }
    i3_ws *ws_walk;

    SLIST_FOREACH(outputs_walk, outputs, slist) {
        if (outputs_walk->workspaces != NULL && !TAILQ_EMPTY(outputs_walk->workspaces)) {
            TAILQ_FOREACH(ws_walk, outputs_walk->workspaces, tailq) {
                I3STRING_FREE(ws_walk->name);
                FREE(ws_walk->canonical_name);
            }
            FREE_TAILQ(outputs_walk->workspaces, i3_ws);
        }
    }
}