96 lines
3.1 KiB
C
96 lines
3.1 KiB
C
/*
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* vim:ts=4:sw=4:expandtab
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*
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* i3 - an improved dynamic tiling window manager
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* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
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*
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*/
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#include <stdio.h>
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#include <string.h>
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#include <stdbool.h>
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#include <limits.h>
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#include <stdlib.h>
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#include <math.h>
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#include <xcb/xcb.h>
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#include <xcb/xcb_aux.h>
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#include "libi3.h"
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/*
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* Try to get the contents of the given atom (for example I3_SOCKET_PATH) from
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* the X11 root window and return NULL if it doesn’t work.
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*
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* If the provided XCB connection is NULL, a new connection will be
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* established.
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*
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* The memory for the contents is dynamically allocated and has to be
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* free()d by the caller.
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*
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*/
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char *root_atom_contents(const char *atomname, xcb_connection_t *provided_conn, int screen) {
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xcb_intern_atom_cookie_t atom_cookie;
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xcb_intern_atom_reply_t *atom_reply;
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char *content = NULL;
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size_t content_max_words = 256;
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xcb_connection_t *conn = provided_conn;
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if (provided_conn == NULL &&
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((conn = xcb_connect(NULL, &screen)) == NULL ||
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xcb_connection_has_error(conn))) {
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return NULL;
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}
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atom_cookie = xcb_intern_atom(conn, 0, strlen(atomname), atomname);
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xcb_screen_t *root_screen = xcb_aux_get_screen(conn, screen);
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xcb_window_t root = root_screen->root;
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atom_reply = xcb_intern_atom_reply(conn, atom_cookie, NULL);
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if (atom_reply == NULL) {
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goto out_conn;
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}
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xcb_get_property_cookie_t prop_cookie;
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xcb_get_property_reply_t *prop_reply;
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prop_cookie = xcb_get_property_unchecked(conn, false, root, atom_reply->atom,
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XCB_GET_PROPERTY_TYPE_ANY, 0, content_max_words);
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prop_reply = xcb_get_property_reply(conn, prop_cookie, NULL);
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if (prop_reply == NULL) {
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goto out_atom;
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}
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if (xcb_get_property_value_length(prop_reply) > 0 && prop_reply->bytes_after > 0) {
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/* We received an incomplete value. Ask again but with a properly
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* adjusted size. */
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content_max_words += ceil(prop_reply->bytes_after / 4.0);
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/* Repeat the request, with adjusted size */
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free(prop_reply);
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prop_cookie = xcb_get_property_unchecked(conn, false, root, atom_reply->atom,
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XCB_GET_PROPERTY_TYPE_ANY, 0, content_max_words);
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prop_reply = xcb_get_property_reply(conn, prop_cookie, NULL);
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if (prop_reply == NULL) {
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goto out_atom;
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}
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}
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if (xcb_get_property_value_length(prop_reply) == 0) {
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goto out;
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}
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if (prop_reply->type == XCB_ATOM_CARDINAL) {
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/* We treat a CARDINAL as a >= 32-bit unsigned int. The only CARDINAL
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* we query is I3_PID, which is 32-bit. */
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sasprintf(&content, "%u", *((unsigned int *)xcb_get_property_value(prop_reply)));
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} else {
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sasprintf(&content, "%.*s", xcb_get_property_value_length(prop_reply),
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(char *)xcb_get_property_value(prop_reply));
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}
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out:
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free(prop_reply);
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out_atom:
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free(atom_reply);
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out_conn:
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if (provided_conn == NULL)
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xcb_disconnect(conn);
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return content;
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}
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