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/* See LICENSE file for copyright and license details. */
#define IN_LIBGAMMA_X_RANDR
#include "common.h"
/**
* Initialise an allocated site state
*
* @param this The site state to initialise
* @param site The site identifier, unless it is `NULL` it must a
* `free`:able. Once the state is destroyed the library
* will attempt to free it. There you should not free
* it yourself, and it must not be a string constant
* or allocate on the stack. Note however that it will
* not be free:d if this function fails.
* @return Zero on success, otherwise (negative) the value of an
* error identifier provided by this library
*/
int
libgamma_x_randr_site_initialise(libgamma_site_state_t *restrict this, char *restrict site)
{
xcb_generic_error_t *error = NULL;
xcb_connection_t *restrict connection;
xcb_randr_query_version_cookie_t cookie;
xcb_randr_query_version_reply_t *restrict reply;
const xcb_setup_t *restrict setup;
xcb_screen_iterator_t iter;
/* Connect to the display server */
this->data = connection = xcb_connect(site, NULL);
if (!connection || xcb_connection_has_error(connection))
return LIBGAMMA_OPEN_SITE_FAILED;
/* Query the version of the X RandR extension protocol */
cookie = xcb_randr_query_version(connection, RANDR_VERSION_MAJOR, RANDR_VERSION_MINOR);
reply = xcb_randr_query_version_reply(connection, cookie, &error);
/* Check for version query failure */
if (error || !reply) {
/* Release resources */
free(reply);
/* If `xcb_connect` failed, both `error` and `reply` will be `NULL`.
* TODO: Can both be `NULL` for any other reason? */
if (!error && !reply)
return LIBGAMMA_OPEN_SITE_FAILED;
xcb_disconnect(connection);
/* Translate and report error. */
if (error != NULL)
return libgamma_x_randr_internal_translate_error(error->error_code, LIBGAMMA_PROTOCOL_VERSION_QUERY_FAILED, 0);
return LIBGAMMA_PROTOCOL_VERSION_QUERY_FAILED;
}
/* Check protocol compatibility,
we require 1.3 but 2.x may not be backwards compatible */
if (reply->major_version != RANDR_VERSION_MAJOR || reply->minor_version < RANDR_VERSION_MINOR) {
#ifdef DEBUG
/* Print used protocol */
fprintf(stderr, "libgamma: RandR protocol version: %u.%u", reply->major_version, reply->minor_version);
#endif
/* Release resources */
free(reply);
xcb_disconnect(connection);
/* Report error */
return LIBGAMMA_PROTOCOL_VERSION_NOT_SUPPORTED;
}
/* We do not longer need to know the version of the protocol */
free(reply);
/* Get available screens */
setup = xcb_get_setup(connection);
if (!setup) {
xcb_disconnect(connection);
return LIBGAMMA_LIST_PARTITIONS_FAILED;
}
iter = xcb_setup_roots_iterator(setup);
/* Get the number of available screens */
this->partitions_available = (size_t)iter.rem;
/* Sanity check the number of available screens. */
return iter.rem >= 0 ? 0 : LIBGAMMA_NEGATIVE_PARTITION_COUNT;
}
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