1 files changed, 297 insertions, 0 deletions

diff --git a/randr.c b/randr.c
new file mode 100644
index 0000000..4b1ea97
--- /dev/null
+++ b/randr.c
@@ -0,0 +1,297 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * © 2010 Michael Stapelberg
+ *
+ * See LICENSE for licensing information
+ *
+ */
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <xcb/xcb.h>
+#include <xcb/xinerama.h>
+#include <xcb/randr.h>
+
+#include "i3lock.h"
+#include "xcb.h"
+#include "randr.h"
+
+/* Number of Xinerama screens which are currently present. */
+int xr_screens = 0;
+
+/* The resolutions of the currently present Xinerama screens. */
+Rect *xr_resolutions = NULL;
+
+static bool xinerama_active;
+static bool has_randr = false;
+static bool has_randr_1_5 = false;
+extern bool debug_mode;
+
+void _xinerama_init(void);
+
+void randr_init(int *event_base, xcb_window_t root) {
+    const xcb_query_extension_reply_t *extreply;
+
+    extreply = xcb_get_extension_data(conn, &xcb_randr_id);
+    if (!extreply->present) {
+        DEBUG("RandR is not present, falling back to Xinerama.\n");
+        _xinerama_init();
+        return;
+    }
+
+    xcb_generic_error_t *err;
+    xcb_randr_query_version_reply_t *randr_version =
+        xcb_randr_query_version_reply(
+            conn, xcb_randr_query_version(conn, XCB_RANDR_MAJOR_VERSION, XCB_RANDR_MINOR_VERSION), &err);
+    if (err != NULL) {
+        DEBUG("Could not query RandR version: X11 error code %d\n", err->error_code);
+        _xinerama_init();
+        return;
+    }
+
+    has_randr = true;
+
+    has_randr_1_5 = (randr_version->major_version >= 1) &&
+                    (randr_version->minor_version >= 5);
+
+    free(randr_version);
+
+    if (event_base != NULL)
+        *event_base = extreply->first_event;
+
+    xcb_randr_select_input(conn, root,
+                           XCB_RANDR_NOTIFY_MASK_SCREEN_CHANGE |
+                               XCB_RANDR_NOTIFY_MASK_OUTPUT_CHANGE |
+                               XCB_RANDR_NOTIFY_MASK_CRTC_CHANGE |
+                               XCB_RANDR_NOTIFY_MASK_OUTPUT_PROPERTY);
+
+    xcb_flush(conn);
+}
+
+void _xinerama_init(void) {
+    if (!xcb_get_extension_data(conn, &xcb_xinerama_id)->present) {
+        DEBUG("Xinerama extension not found, disabling.\n");
+        return;
+    }
+
+    xcb_xinerama_is_active_cookie_t cookie;
+    xcb_xinerama_is_active_reply_t *reply;
+
+    cookie = xcb_xinerama_is_active(conn);
+    reply = xcb_xinerama_is_active_reply(conn, cookie, NULL);
+    if (!reply)
+        return;
+
+    if (!reply->state) {
+        free(reply);
+        return;
+    }
+
+    xinerama_active = true;
+    free(reply);
+}
+
+/*
+ * randr_query_outputs_15 uses RandR ≥ 1.5 to update outputs.
+ *
+ */
+static bool _randr_query_monitors_15(xcb_window_t root) {
+#if XCB_RANDR_MINOR_VERSION < 5
+    return false;
+#else
+    /* RandR 1.5 available at compile-time, i.e. libxcb is new enough */
+    if (!has_randr_1_5) {
+        return false;
+    }
+    /* RandR 1.5 available at run-time (supported by the server) */
+    DEBUG("Querying monitors using RandR 1.5\n");
+    xcb_generic_error_t *err;
+    xcb_randr_get_monitors_reply_t *monitors =
+        xcb_randr_get_monitors_reply(
+            conn, xcb_randr_get_monitors(conn, root, true), &err);
+    if (err != NULL) {
+        DEBUG("Could not get RandR monitors: X11 error code %d\n", err->error_code);
+        free(err);
+        /* Fall back to RandR ≤ 1.4 */
+        return false;
+    }
+
+    int screens = xcb_randr_get_monitors_monitors_length(monitors);
+    DEBUG("%d RandR monitors found (timestamp %d)\n",
+          screens, monitors->timestamp);
+
+    Rect *resolutions = malloc(screens * sizeof(Rect));
+    /* No memory? Just keep on using the old information. */
+    if (!resolutions) {
+        free(monitors);
+        return true;
+    }
+
+    xcb_randr_monitor_info_iterator_t iter;
+    int screen;
+    for (iter = xcb_randr_get_monitors_monitors_iterator(monitors), screen = 0;
+         iter.rem;
+         xcb_randr_monitor_info_next(&iter), screen++) {
+        const xcb_randr_monitor_info_t *monitor_info = iter.data;
+
+        resolutions[screen].x = monitor_info->x;
+        resolutions[screen].y = monitor_info->y;
+        resolutions[screen].width = monitor_info->width;
+        resolutions[screen].height = monitor_info->height;
+        DEBUG("found RandR monitor: %d x %d at %d x %d\n",
+              monitor_info->width, monitor_info->height,
+              monitor_info->x, monitor_info->y);
+    }
+    free(xr_resolutions);
+    xr_resolutions = resolutions;
+    xr_screens = screens;
+
+    free(monitors);
+    return true;
+#endif
+}
+
+/*
+ * randr_query_outputs_14 uses RandR ≤ 1.4 to update outputs.
+ *
+ */
+static bool _randr_query_outputs_14(xcb_window_t root) {
+    if (!has_randr) {
+        return false;
+    }
+    DEBUG("Querying outputs using RandR ≤ 1.4\n");
+
+    /* Get screen resources (primary output, crtcs, outputs, modes) */
+    xcb_randr_get_screen_resources_current_cookie_t rcookie;
+    rcookie = xcb_randr_get_screen_resources_current(conn, root);
+
+    xcb_randr_get_screen_resources_current_reply_t *res =
+        xcb_randr_get_screen_resources_current_reply(conn, rcookie, NULL);
+    if (res == NULL) {
+        DEBUG("Could not query screen resources.\n");
+        return false;
+    }
+
+    /* timestamp of the configuration so that we get consistent replies to all
+     * requests (if the configuration changes between our different calls) */
+    const xcb_timestamp_t cts = res->config_timestamp;
+
+    const int len = xcb_randr_get_screen_resources_current_outputs_length(res);
+
+    /* an output is VGA-1, LVDS-1, etc. (usually physical video outputs) */
+    xcb_randr_output_t *randr_outputs = xcb_randr_get_screen_resources_current_outputs(res);
+
+    /* Request information for each output */
+    xcb_randr_get_output_info_cookie_t ocookie[len];
+    for (int i = 0; i < len; i++) {
+        ocookie[i] = xcb_randr_get_output_info(conn, randr_outputs[i], cts);
+    }
+    Rect *resolutions = malloc(len * sizeof(Rect));
+    /* No memory? Just keep on using the old information. */
+    if (!resolutions) {
+        free(res);
+        return true;
+    }
+
+    /* Loop through all outputs available for this X11 screen */
+    int screen = 0;
+
+    for (int i = 0; i < len; i++) {
+        xcb_randr_get_output_info_reply_t *output;
+
+        if ((output = xcb_randr_get_output_info_reply(conn, ocookie[i], NULL)) == NULL) {
+            continue;
+        }
+
+        if (output->crtc == XCB_NONE) {
+            free(output);
+            continue;
+        }
+
+        xcb_randr_get_crtc_info_cookie_t icookie;
+        xcb_randr_get_crtc_info_reply_t *crtc;
+        icookie = xcb_randr_get_crtc_info(conn, output->crtc, cts);
+        if ((crtc = xcb_randr_get_crtc_info_reply(conn, icookie, NULL)) == NULL) {
+            DEBUG("Skipping output: could not get CRTC (0x%08x)\n", output->crtc);
+            free(output);
+            continue;
+        }
+
+        resolutions[screen].x = crtc->x;
+        resolutions[screen].y = crtc->y;
+        resolutions[screen].width = crtc->width;
+        resolutions[screen].height = crtc->height;
+
+        DEBUG("found RandR output: %d x %d at %d x %d\n",
+              crtc->width, crtc->height,
+              crtc->x, crtc->y);
+
+        screen++;
+
+        free(crtc);
+
+        free(output);
+    }
+    free(xr_resolutions);
+    xr_resolutions = resolutions;
+    xr_screens = screen;
+    free(res);
+    return true;
+}
+
+void _xinerama_query_screens(void) {
+    if (!xinerama_active) {
+        return;
+    }
+
+    xcb_xinerama_query_screens_cookie_t cookie;
+    xcb_xinerama_query_screens_reply_t *reply;
+    xcb_xinerama_screen_info_t *screen_info;
+    xcb_generic_error_t *err;
+    cookie = xcb_xinerama_query_screens_unchecked(conn);
+    reply = xcb_xinerama_query_screens_reply(conn, cookie, &err);
+    if (!reply) {
+        DEBUG("Couldn't get Xinerama screens: X11 error code %d\n", err->error_code);
+        free(err);
+        return;
+    }
+    screen_info = xcb_xinerama_query_screens_screen_info(reply);
+    int screens = xcb_xinerama_query_screens_screen_info_length(reply);
+
+    Rect *resolutions = malloc(screens * sizeof(Rect));
+    /* No memory? Just keep on using the old information. */
+    if (!resolutions) {
+        free(reply);
+        return;
+    }
+
+    for (int screen = 0; screen < xr_screens; screen++) {
+        resolutions[screen].x = screen_info[screen].x_org;
+        resolutions[screen].y = screen_info[screen].y_org;
+        resolutions[screen].width = screen_info[screen].width;
+        resolutions[screen].height = screen_info[screen].height;
+        DEBUG("found Xinerama screen: %d x %d at %d x %d\n",
+              screen_info[screen].width, screen_info[screen].height,
+              screen_info[screen].x_org, screen_info[screen].y_org);
+    }
+
+    free(xr_resolutions);
+    xr_resolutions = resolutions;
+    xr_screens = screens;
+
+    free(reply);
+}
+
+void randr_query(xcb_window_t root) {
+    if (_randr_query_monitors_15(root)) {
+        return;
+    }
+
+    if (_randr_query_outputs_14(root)) {
+        return;
+    }
+
+    _xinerama_query_screens();
+}