Initial commit of the XCB rewrite of i3lock

Changes:
- Uses XCB instead of Xlib (like i3), thus cleaner/faster code
- Uses cairo to load PNG images (*much* faster than XPM)

1 files changed, 303 insertions, 355 deletions

diff --git a/i3lock.c b/i3lock.c
index 7daf9ba..8064595 100644
--- a/i3lock.c
+++ b/i3lock.c
@@ -1,128 +1,169 @@
 /*
- * vim:ts=8:expandtab
+ * vim:ts=4:sw=4:expandtab
  *
- * i3lock - an improved version of slock
+ * © 2010 Michael Stapelberg
  *
- * i3lock © 2009 Michael Stapelberg and contributors
- * i3lock © 2009 Jan-Erik Rediger
- * slock  © 2006-2008 Anselm R Garbe
- *
- * See file LICENSE for license information.
- *
- * Note that on any error (calloc is out of memory for example)
- * we do not do anything so that the user can fix the error by
- * himself (kill X to get more free memory or stop some other
- * program using SSH/console).
+ * See LICENSE for licensing information
  *
  */
-#define _XOPEN_SOURCE 500
-
-#include <ctype.h>
-#include <stdarg.h>
-#include <stdlib.h>
 #include <stdio.h>
-#include <stdint.h>
+#include <stdlib.h>
 #include <string.h>
-#include <math.h>
 #include <unistd.h>
-#include <sys/types.h>
-#include <X11/keysym.h>
-#include <X11/Xlib.h>
-#include <X11/Xutil.h>
-#include <X11/xpm.h>
-#include <X11/extensions/dpms.h>
 #include <stdbool.h>
-#include <getopt.h>
+#include <stdint.h>
+#include <xcb/xcb.h>
+#include <xcb/dpms.h>
+#include <xcb/xcb_image.h>
+#include <xcb/xcb_keysyms.h>
 #include <err.h>
-
+#include <cairo.h>
+#include <assert.h>
 #include <security/pam_appl.h>
+/* FIXME: can we get rid of this header? */
+#include <X11/keysym.h>
+#include <getopt.h>
+#include <string.h>
 
-#include "cursors.h"
-
-static char passwd[256];
-
-/*
- * displays an xpm image tiled over the whole screen
- * (the image will be visible on all screens
- * when using a multi monitor setup)
- *
- */
-static void tile_image(XpmImage *image, int disp_height, int disp_width,
-                       Display *dpy, Pixmap pix, Window w, GC gc)
-{
-        int rows = (int)ceil(disp_height / (float)image->height),
-            cols = (int)ceil(disp_width / (float)image->width);
-
-        for (int y = 0; y < rows; y++) {
-                for (int x = 0; x < cols; x++) {
-                        XCopyArea(dpy, pix, w, gc, 0, 0,
-                                  image->width, image->height,
-                                  image->width * x, image->height * y);
-                }
-        }
+#include "keysym2ucs.h"
+#include "ucs2_to_utf8.h"
+#include "xcb.h"
+
+static xcb_connection_t *conn;
+static xcb_key_symbols_t *symbols;
+static cairo_t *ctx = NULL;
+static pam_handle_t *pam_handle;
+static int input_position = 0;
+/* holds the password you enter (in UTF-8) */
+static char password[512];
+static bool modeswitch_active = false;
+static int modeswitchmask;
+static int numlockmask;
+static bool beep = false;
+
+static void input_done() {
+    if (input_position == 0)
+        return;
+
+    /* TODO: change cursor during authentication? */
+    if (pam_authenticate(pam_handle, 0) == PAM_SUCCESS) {
+        printf("successfully authenticated\n");
+        exit(0);
+    }
+
+    /* beep on authentication failure, if enabled */
+    if (beep) {
+        xcb_bell(conn, 100);
+        xcb_flush(conn);
+    }
 }
 
 /*
- * Returns the colorpixel to use for the given hex color (think of HTML).
- *
- * The hex_color may not start with #, for example FF00FF works.
- *
- * NOTE that get_colorpixel() does _NOT_ check the given color code for validity.
- * This has to be done by the caller.
+ * Called when we should draw the image (if any).
  *
  */
-static uint32_t get_colorpixel(char *hex) {
-        char strgroups[3][3] = {{hex[0], hex[1], '\0'},
-                                {hex[2], hex[3], '\0'},
-                                {hex[4], hex[5], '\0'}};
-        uint32_t rgb16[3] = {(strtol(strgroups[0], NULL, 16)),
-                             (strtol(strgroups[1], NULL, 16)),
-                             (strtol(strgroups[2], NULL, 16))};
-
-        return (rgb16[0] << 16) + (rgb16[1] << 8) + rgb16[2];
+static void handle_expose_event() {
+    if (!ctx)
+        return;
+
+    cairo_paint(ctx);
+    xcb_flush(conn);
 }
 
 /*
- * Check if given file can be opened => exists
+ * Called when the user releases a key. We need to leave the Mode_switch
+ * state when the user releases the Mode_switch key.
  *
  */
-static bool file_exists(const char *filename)
-{
-        FILE * file = fopen(filename, "r");
-        if(file)
-        {
-                fclose(file);
-                return true;
-        }
-        return false;
+static void handle_key_release(xcb_key_release_event_t *event) {
+    printf("releasing %d, state raw = %d\n", event->detail, event->state);
+
+    /* fix state */
+    event->state &= ~numlockmask;
+
+    xcb_keysym_t sym = xcb_key_press_lookup_keysym(symbols, event, event->state);
+    if (sym == XK_Mode_switch) {
+        printf("Mode switch disabled\n");
+        modeswitch_active = false;
+    }
 }
 
 /*
- * Puts the given XPM error code to stderr
+ * Handle key presses. Fixes state, then looks up the key symbol for the
+ * given keycode, then looks up the key symbol (as UCS-2), converts it to
+ * UTF-8 and stores it in the password array.
  *
  */
-static void print_xpm_error(int err)
-{
-        switch (err) {
-                case XpmColorError:
-                        fprintf(stderr, "XPM: Could not parse or alloc requested color\n");
-                        break;
-                case XpmOpenFailed:
-                        fprintf(stderr, "XPM: Cannot open file\n");
-                        break;
-                case XpmFileInvalid:
-                        fprintf(stderr, "XPM: invalid XPM file\n");
-                        break;
-                case XpmNoMemory:
-                        fprintf(stderr, "XPM: Not enough memory\n");
-                        break;
-                case XpmColorFailed:
-                        fprintf(stderr, "XPM: Color not found\n");
-                        break;
-        }
+static void handle_key_press(xcb_key_press_event_t *event) {
+    printf("keypress %d, state raw = %d\n", event->detail, event->state);
+
+    /* fix state */
+    if (modeswitch_active)
+            event->state |= modeswitchmask;
+
+    /* Apparantly, after activating numlock once, the numlock modifier
+     * stays turned on (use xev(1) to verify). So, to resolve useful
+     * keysyms, we remove the numlock flag from the event state */
+    event->state &= ~numlockmask;
+
+    if ((input_position + 8) >= sizeof(password))
+        return;
+
+    xcb_keysym_t sym = xcb_key_press_lookup_keysym(symbols, event, event->state);
+    switch (sym) {
+    case XK_Mode_switch:
+        printf("Mode switch enabled\n");
+        modeswitch_active = true;
+        return;
+
+    case XK_Return:
+        input_done();
+    case XK_Escape:
+        input_position = 0;
+        password[input_position] = '\0';
+        return;
+
+    case XK_BackSpace:
+        if (input_position == 0)
+            return;
+
+        /* decrement input_position to point to the previous glyph */
+        u8_dec(password, &input_position);
+        password[input_position] = '\0';
+        printf("new input position = %d, new password = %s\n", input_position, password);
+        return;
+    }
+
+    /* FIXME: handle all of these? */
+    printf("is_keypad_key = %d\n", xcb_is_keypad_key(sym));
+    printf("is_private_keypad_key = %d\n", xcb_is_private_keypad_key(sym));
+    printf("xcb_is_cursor_key = %d\n", xcb_is_cursor_key(sym));
+    printf("xcb_is_pf_key = %d\n", xcb_is_pf_key(sym));
+    printf("xcb_is_function_key = %d\n", xcb_is_function_key(sym));
+    printf("xcb_is_misc_function_key = %d\n", xcb_is_misc_function_key(sym));
+    printf("xcb_is_modifier_key = %d\n", xcb_is_modifier_key(sym));
+
+    if (xcb_is_modifier_key(sym) || xcb_is_cursor_key(sym))
+            return;
+
+    printf("sym = %c (%d)\n", sym, sym);
+
+    /* convert the keysym to UCS */
+    uint16_t ucs = keysym2ucs(sym);
+    if ((int16_t)ucs == -1) {
+            fprintf(stderr, "Keysym could not be converted to UCS, skipping\n");
+            return;
+    }
+
+    /* store the UCS in a string to convert it */
+    uint8_t inp[3] = {(ucs & 0xFF00) >> 8, (ucs & 0xFF), 0};
+
+    /* store it in the password array as UTF-8 */
+    input_position += convert_ucs_to_utf8((char*)inp, password + input_position);
+    password[input_position] = '\0';
+    printf("current password = %s\n", password);
 }
 
-
 /*
  * Callback function for PAM. We only react on password request callbacks.
  *
@@ -130,278 +171,185 @@ static void print_xpm_error(int err)
 static int conv_callback(int num_msg, const struct pam_message **msg,
                          struct pam_response **resp, void *appdata_ptr)
 {
-        if (num_msg == 0)
-                return 1;
-
-        /* PAM expects an arry of responses, one for each message */
-        if ((*resp = calloc(num_msg, sizeof(struct pam_message))) == NULL) {
-                perror("calloc");
-                return 1;
+    if (num_msg == 0)
+        return 1;
+
+    /* PAM expects an arry of responses, one for each message */
+    if ((*resp = calloc(num_msg, sizeof(struct pam_message))) == NULL) {
+        perror("calloc");
+        return 1;
+    }
+
+    for (int c = 0; c < num_msg; c++) {
+        if (msg[c]->msg_style != PAM_PROMPT_ECHO_OFF &&
+            msg[c]->msg_style != PAM_PROMPT_ECHO_ON)
+            continue;
+
+        /* return code is currently not used but should be set to zero */
+        resp[c]->resp_retcode = 0;
+        if ((resp[c]->resp = strdup(password)) == NULL) {
+            perror("strdup");
+            return 1;
         }
+    }
 
-        for (int c = 0; c < num_msg; c++) {
-                if (msg[c]->msg_style != PAM_PROMPT_ECHO_OFF &&
-                    msg[c]->msg_style != PAM_PROMPT_ECHO_ON)
-                        continue;
-
-                /* return code is currently not used but should be set to zero */
-                resp[c]->resp_retcode = 0;
-                if ((resp[c]->resp = strdup(passwd)) == NULL) {
-                        perror("strdup");
-                        return 1;
-                }
-        }
-
-        return 0;
+    return 0;
 }
 
-int main(int argc, char *argv[])
-{
-        char buf[32];
-        char *username;
-        int num, screen;
-
-        unsigned int len;
-        bool running = true;
-
-        /* By default, fork, don’t beep and don’t turn off monitor */
-        bool dont_fork = false;
-        bool beep = false;
-        bool dpms = false;
-        bool xpm_image = false;
-        bool tiling = false;
-        char xpm_image_path[256];
-        char color[7] = "ffffff"; // white
-
-        unsigned char *curs = NULL;
-        unsigned char *mask = NULL;
-        unsigned int curs_w, curs_h;
-
-        Cursor cursor;
-        Display *dpy;
-        KeySym ksym;
-        Pixmap px_curs;
-        Pixmap px_mask;
-        Window root, w;
-        XColor black, white, dummy;
-        XEvent ev;
-        XSetWindowAttributes wa;
-
-        pam_handle_t *handle;
-        struct pam_conv conv = {conv_callback, NULL};
-
-        char opt;
-        int optind = 0;
-        static struct option long_options[] = {
-                {"version", no_argument, NULL, 'v'},
-                {"nofork", no_argument, NULL, 'n'},
-                {"beep", no_argument, NULL, 'b'},
-                {"dpms", no_argument, NULL, 'd'},
-                {"image", required_argument, NULL, 'i'},
-                {"color", required_argument, NULL, 'c'},
-                {"tiling", no_argument, NULL, 't'},
-                {"pointer", required_argument, NULL , 'p'},
-                {NULL, no_argument, NULL, 0}
-        };
-        curs = curs_invisible_bits;
-        mask = curs_invisible_bits;
-        curs_w = curs_invisible_width;
-        curs_h = curs_invisible_height;
-
-        while ((opt = getopt_long(argc, argv, "vnbdi:c:tp:", long_options, &optind)) != -1) {
-                switch (opt) {
-                        case 'v':
-                                errx(0, "i3lock-"VERSION", © 2009 Michael Stapelberg\n"
-                                    "based on slock, which is © 2006-2008 Anselm R Garbe\n");
-                        case 'n':
-                                dont_fork = true;
-                                break;
-                        case 'b':
-                                beep = true;
-                                break;
-                        case 'd':
-                                dpms = true;
-                                break;
-                        case 'i':
-                                strncpy(xpm_image_path, optarg, 255);
-                                xpm_image = true;
-                                break;
-                        case 'c':
-                        {
-                                char *arg = optarg;
-                                /* Skip # if present */
-                                if (arg[0] == '#')
-                                        arg++;
-
-                                if (strlen(arg) != 6 || sscanf(arg, "%06[0-9a-fA-F]", color) != 1)
-                                        errx(1, "color is invalid, color must be given in 6-byte format: rrggbb\n");
-
-                                break;
-                        }
-                        case 't':
-                                tiling = true;
-                                break;
-                        case 'p':
-                                if (!strcmp(optarg, "default")) {
-                                        curs = NULL;
-                                        break;
-                                }
-                                if (!strcmp(optarg, "win")) {
-                                        curs = curs_windows_bits;
-                                        mask = mask_windows_bits;
-                                        curs_w = curs_windows_width;
-                                        curs_h = curs_windows_height;
-                                        break;
-                                }
-                                break;
-                        default:
-                                errx(1, "i3lock: Unknown option. Syntax: i3lock [-v] [-n] [-b] [-d] [-i image.xpm] [-c color] [-t] [-p win|default]\n");
-                }
+int main(int argc, char *argv[]) {
+    bool dont_fork = false;
+    bool dpms = false;
+    char color[7] = "ffffff";
+    char *username;
+    char *image_path = NULL;
+    int ret;
+    struct pam_conv conv = {conv_callback, NULL};
+    int screen;
+    cairo_surface_t *img = NULL;
+    xcb_visualtype_t *vistype;
+    xcb_generic_event_t *event;
+    xcb_screen_t *scr;
+    xcb_window_t win;
+    char o;
+    int optind = 0;
+    struct option longopts[] = {
+        {"version", no_argument, NULL, 'v'},
+        {"nofork", no_argument, NULL, 'n'},
+        {"beep", no_argument, NULL, 'b'},
+        {"dpms", no_argument, NULL, 'd'},
+        {"image", required_argument, NULL, 'i'},
+        {"color", required_argument, NULL, 'c'},
+        {"tiling", no_argument, NULL, 't'},
+        {"pointer", required_argument, NULL , 'p'},
+        {NULL, no_argument, NULL, 0}
+    };
+
+    if ((username = getenv("USER")) == NULL)
+        errx(1, "USER environment variable not set, please set it.\n");
+
+    while ((o = getopt_long(argc, argv, "vnbdi:c:tp:", longopts, &optind)) != -1) {
+        switch (o) {
+        case 'v':
+            errx(EXIT_SUCCESS, "i3lock © 2010 Michael Stapelberg\n");
+        case 'n':
+            dont_fork = true;
+            break;
+        case 'b':
+            beep = true;
+            break;
+        case 'd':
+            dpms = true;
+            break;
+        case 'i':
+            image_path = strdup(optarg);
+            break;
+        case 'c': {
+            char *arg = optarg;
+
+            /* Skip # if present */
+            if (arg[0] == '#')
+                arg++;
+
+            if (strlen(arg) != 6 || sscanf(arg, "%06[0-9a-fA-F]", color) != 1)
+                errx(1, "color is invalid, color must be given in 6-byte format: rrggbb\n");
+
+            break;
+        }
+        case 't':
+            /* TODO: tile image */
+            break;
+        case 'p':
+            /* TODO: cursor */
+            break;
+        default:
+            errx(1, "i3lock: Unknown option. Syntax: i3lock [-v] [-n] [-b] [-d] [-i image.png] [-c color] [-t] [-p win|default]\n");
         }
+    }
+
+    /* Initialize PAM */
+    ret = pam_start("i3lock", username, &conv, &pam_handle);
+    if (ret != PAM_SUCCESS)
+        errx(EXIT_FAILURE, "PAM: %s\n", pam_strerror(pam_handle, ret));
+
+    /* Initialize connection to X11 */
+    if ((conn = xcb_connect(NULL, &screen)) == NULL)
+        err(EXIT_FAILURE, "xcb_connect()");
+
+    if (!dont_fork) {
+        /* In the parent process, we exit */
+        if (fork() != 0)
+            return 0;
+    }
+
+    /* if DPMS is enabled, check if the X server really supports it */
+    if (dpms) {
+        xcb_dpms_capable_cookie_t dpmsc = xcb_dpms_capable(conn);
+        xcb_dpms_capable_reply_t *dpmsr;
+        if ((dpmsr = xcb_dpms_capable_reply(conn, dpmsc, NULL)) && !dpmsr->capable) {
+            fprintf(stderr, "Disabling DPMS, X server not DPMS capable\n");
+            dpms = false;
+        }
+    }
 
-        if ((username = getenv("USER")) == NULL)
-                errx(1, "USER environment variable not set, please set it.\n");
+    scr = xcb_setup_roots_iterator(xcb_get_setup(conn)).data;
+    vistype = get_root_visual_type(scr);
 
-        int ret = pam_start("i3lock", username, &conv, &handle);
-        if (ret != PAM_SUCCESS)
-                errx(1, "PAM: %s\n", pam_strerror(handle, ret));
+    /* open the fullscreen window and flush immediately afterwards so that X11
+     * can generate an expose event while we load the PNG file (so that we are
+     * ready to handle the expose event immediately afterwards) */
+    win = open_fullscreen_window(conn, scr, color);
 
-        if(!(dpy = XOpenDisplay(0)))
-                errx(1, "i3lock: cannot open display\n");
-        screen = DefaultScreen(dpy);
-        root = RootWindow(dpy, screen);
+    grab_pointer_and_keyboard(conn, scr);
 
-        if (!dont_fork) {
-                if (fork() != 0)
-                        return 0;
-        }
+    if (image_path)
+        img = cairo_image_surface_create_from_png(image_path);
 
-        /* init */
-        wa.override_redirect = 1;
-        wa.background_pixel = get_colorpixel(color);
-        w = XCreateWindow(dpy, root, 0, 0, DisplayWidth(dpy, screen), DisplayHeight(dpy, screen),
-                        0, DefaultDepth(dpy, screen), CopyFromParent,
-                        DefaultVisual(dpy, screen), CWOverrideRedirect | CWBackPixel, &wa);
-        XAllocNamedColor(dpy, DefaultColormap(dpy, screen), "black", &black, &dummy);
-        XAllocNamedColor(dpy, DefaultColormap(dpy, screen), "white", &white, &dummy);
-        if (curs != NULL) {
-                px_curs = XCreateBitmapFromData(dpy, w, (char*) curs, curs_w, curs_h);
-                px_mask = XCreateBitmapFromData(dpy, w, (char*) mask, curs_w, curs_h);
-                cursor = XCreatePixmapCursor(dpy, px_curs, px_mask, &white, &black, 0, 0);
-                XDefineCursor(dpy, w, cursor);
-        } else {
-                px_curs = 0;
-                px_mask = 0;
-                cursor = 0;
-        }
-        XMapRaised(dpy, w);
-
-        if (xpm_image && file_exists(xpm_image_path)) {
-                GC gc = XDefaultGC(dpy, 0);
-                int depth = DefaultDepth(dpy, screen);
-                int disp_width = DisplayWidth(dpy, screen);
-                int disp_height = DisplayHeight(dpy, screen);
-                Pixmap pix = XCreatePixmap(dpy, w, disp_width, disp_height, depth);
-                XpmImage xpm_image;
-                XpmInfo xpm_info;
-
-                int err = XpmReadFileToXpmImage(xpm_image_path, &xpm_image, &xpm_info);
-                if (err != 0) {
-                        print_xpm_error(err);
-                        return 1;
-                }
-
-                err = XpmCreatePixmapFromXpmImage(dpy, w, &xpm_image, &pix, 0, 0);
-                if (err != 0) {
-                        print_xpm_error(err);
-                        return 1;
-                }
-
-                if (tiling)
-                        tile_image(&xpm_image, disp_height, disp_width, dpy, pix, w, gc);
-                else
-                        XCopyArea(dpy, pix, w, gc, 0, 0, disp_width, disp_height, 0, 0);
-        }
+    symbols = xcb_key_symbols_alloc(conn);
+    modeswitchmask = get_mod_mask(conn, symbols, XK_Mode_switch);
+    numlockmask = get_mod_mask(conn, symbols, XK_Num_Lock);
 
-        for(len = 1000; len; len--) {
-                if(XGrabPointer(dpy, root, False, ButtonPressMask | ButtonReleaseMask,
-                        GrabModeAsync, GrabModeAsync, None, cursor, CurrentTime) == GrabSuccess)
-                        break;
-                usleep(1000);
-        }
-        if((running = running && (len > 0))) {
-                for(len = 1000; len; len--) {
-                        if(XGrabKeyboard(dpy, root, True, GrabModeAsync, GrabModeAsync, CurrentTime)
-                                == GrabSuccess)
-                                break;
-                        usleep(1000);
-                }
-                running = (len > 0);
+
+    if (img) {
+        /* Initialize cairo */
+        cairo_surface_t *output;
+        output = cairo_xcb_surface_create(conn, win, vistype,
+                 scr->width_in_pixels, scr->height_in_pixels);
+        /* TODO: tiling of the image */
+        ctx = cairo_create(output);
+        cairo_set_source_surface(ctx, img, 0, 0);
+
+        handle_expose_event();
+    }
+
+    if (dpms)
+        dpms_turn_off_screen(conn);
+
+    while ((event = xcb_wait_for_event(conn))) {
+        int type = x_event_type(event);
+
+        if (type == XCB_EXPOSE) {
+            handle_expose_event();
+            continue;
         }
-        len = 0;
-        XSync(dpy, False);
-
-        /* main event loop */
-        while(running && !XNextEvent(dpy, &ev)) {
-                if (len == 0 && dpms && DPMSCapable(dpy)) {
-                        DPMSEnable(dpy);
-                        DPMSForceLevel(dpy, DPMSModeOff);
-                }
-
-                if(ev.type != KeyPress)
-                        continue;
-
-                buf[0] = 0;
-                num = XLookupString(&ev.xkey, buf, sizeof buf, &ksym, 0);
-                if(IsKeypadKey(ksym)) {
-                        if(ksym == XK_KP_Enter)
-                                ksym = XK_Return;
-                        else if(ksym >= XK_KP_0 && ksym <= XK_KP_9)
-                                ksym = (ksym - XK_KP_0) + XK_0;
-                }
-                if(IsFunctionKey(ksym) ||
-                   IsKeypadKey(ksym) ||
-                   IsMiscFunctionKey(ksym) ||
-                   IsPFKey(ksym) ||
-                   IsPrivateKeypadKey(ksym))
-                        continue;
-                switch(ksym) {
-                case XK_Return:
-                        passwd[len] = 0;
-                        /* Skip empty passwords */
-                        if (len == 0)
-                                continue;
-                        if ((ret = pam_authenticate(handle, 0)) == PAM_SUCCESS)
-                                running = false;
-                        else {
-                                fprintf(stderr, "PAM: %s\n", pam_strerror(handle, ret));
-                                if (beep)
-                                        XBell(dpy, 100);
-                        }
-                        len = 0;
-                        break;
-                case XK_Escape:
-                        len = 0;
-                        break;
-                case XK_BackSpace:
-                        if (len > 0)
-                                len--;
-                        break;
-                default:
-                        if(num && !iscntrl((int) buf[0]) && (len + num < sizeof passwd)) {
-                                memcpy(passwd + len, buf, num);
-                                len += num;
-                        }
-                        break;
-                }
+
+        if (type == XCB_KEY_PRESS) {
+            handle_key_press((xcb_key_press_event_t*)event);
+            continue;
         }
 
-        XUngrabPointer(dpy, CurrentTime);
-        if (px_curs != 0) {
-                XFreePixmap(dpy, px_curs);
-                XFreePixmap(dpy, px_mask);
+        if (type == XCB_KEY_RELEASE) {
+            handle_key_release((xcb_key_release_event_t*)event);
+
+            /* If this was the backspace or escape key we are back at an
+             * empty input, so turn off the screen if DPMS is enabled */
+            if (dpms && input_position == 0)
+                dpms_turn_off_screen(conn);
+
+            continue;
         }
-        XDestroyWindow(dpy, w);
-        XCloseDisplay(dpy);
-        return 0;
+
+        printf("WARNING: unhandled event of type %d\n", type);
+    }
+
+    return 0;
 }