i3bar: Add current binding mode indicator

i3bar/src/mode.c

@@ -0,0 +1,141 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * i3bar - an xcb-based status- and ws-bar for i3
+ * © 2010-2012 Axel Wagner and contributors (see also: LICENSE)
+ *
+ * mode.c: Handle mode-event and show current binding mode in the bar
+ *
+ */
+#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 mode_json_params {
+    char  *json;
+    char  *cur_key;
+    mode  *mode;
+};
+
+/*
+ * Parse a string (change)
+ *
+ */
+#if YAJL_MAJOR >= 2
+static int mode_string_cb(void *params_, const unsigned char *val, size_t len) {
+#else
+static int mode_string_cb(void *params_, const unsigned char *val, unsigned int len) {
+#endif
+        struct mode_json_params *params = (struct mode_json_params*) params_;
+
+        if (!strcmp(params->cur_key, "change")) {
+
+            /* Save the name */
+            params->mode->name = i3string_from_utf8_with_length((const char *)val, len);
+            /* Save its rendered width */
+            params->mode->width = predict_text_width(params->mode->name);
+
+            DLOG("Got mode change: %s\n", i3string_as_utf8(params->mode->name));
+            FREE(params->cur_key);
+
+            return 1;
+        }
+
+        return 0;
+}
+
+/*
+ * Parse a key.
+ *
+ * Essentially we just save it in the parsing-state
+ *
+ */
+#if YAJL_MAJOR >= 2
+static int mode_map_key_cb(void *params_, const unsigned char *keyVal, size_t keyLen) {
+#else
+static int mode_map_key_cb(void *params_, const unsigned char *keyVal, unsigned int keyLen) {
+#endif
+    struct mode_json_params *params = (struct mode_json_params*) params_;
+    FREE(params->cur_key);
+
+    params->cur_key = smalloc(sizeof(unsigned char) * (keyLen + 1));
+    strncpy(params->cur_key, (const char*) keyVal, keyLen);
+    params->cur_key[keyLen] = '\0';
+
+    return 1;
+}
+
+/* A datastructure to pass all these callbacks to yajl */
+yajl_callbacks mode_callbacks = {
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    &mode_string_cb,
+    NULL,
+    &mode_map_key_cb,
+    NULL,
+    NULL,
+    NULL
+};
+
+/*
+ * Start parsing the received json-string
+ *
+ */
+void parse_mode_json(char *json) {
+    /* FIXME: Fasciliate stream-processing, i.e. allow starting to interpret
+     * JSON in chunks */
+    struct mode_json_params params;
+
+    mode binding;
+
+    params.cur_key = NULL;
+    params.json = json;
+    params.mode = &binding;
+
+    yajl_handle handle;
+    yajl_status state;
+
+#if YAJL_MAJOR < 2
+    yajl_parser_config parse_conf = { 0, 0 };
+
+    handle = yajl_alloc(&mode_callbacks, &parse_conf, NULL, (void*) &params);
+#else
+    handle = yajl_alloc(&mode_callbacks, NULL, (void*) &params);
+#endif
+
+    state = yajl_parse(handle, (const unsigned char*) json, strlen(json));
+
+    /* FIXME: Propper errorhandling for JSON-parsing */
+    switch (state) {
+        case yajl_status_ok:
+            break;
+        case yajl_status_client_canceled:
+#if YAJL_MAJOR < 2
+        case yajl_status_insufficient_data:
+#endif
+        case yajl_status_error:
+            ELOG("Could not parse mode-event!\n");
+            exit(EXIT_FAILURE);
+            break;
+    }
+
+    /* We don't want to indicate default binding mode */
+    if (strcmp("default", i3string_as_utf8(params.mode->name)) == 0)
+        I3STRING_FREE(params.mode->name);
+
+    /* Set the new binding mode */
+    set_current_mode(&binding);
+
+    yajl_free(handle);
+
+    FREE(params.cur_key);
+}