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, 196 insertions, 0 deletions

diff --git a/xcb.c b/xcb.c
new file mode 100644
index 0000000..2fdb841
--- /dev/null
+++ b/xcb.c
@@ -0,0 +1,196 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * © 2010 Michael Stapelberg
+ *
+ * xcb.c: contains all functions which use XCB to talk to X11. Mostly wrappers
+ *        around the rather complicated/ugly parts of the XCB API.
+ *
+ */
+#include <xcb/xcb.h>
+#include <xcb/xcb_keysyms.h>
+#include <xcb/dpms.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <assert.h>
+#include <err.h>
+
+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];
+}       
+
+int x_event_type(xcb_generic_event_t *event) {
+    /* TODO: comment */
+    assert(event->response_type != 1);
+
+    if (event->response_type == 0) {
+        fprintf(stderr, "error\n");
+        exit(1);
+    }
+    int type = event->response_type;
+    assert(type < 256);
+    /* strip the highest bit (TODO: why?) */
+    type &= 0x7F;
+    assert(type >= 2);
+
+    return type;
+}
+
+xcb_visualtype_t *get_root_visual_type(xcb_screen_t *screen) {
+    xcb_visualtype_t *visual_type = NULL;
+    xcb_depth_iterator_t depth_iter;
+    xcb_visualtype_iterator_t visual_iter;
+
+    for (depth_iter = xcb_screen_allowed_depths_iterator(screen);
+         depth_iter.rem;
+         xcb_depth_next(&depth_iter)) {
+
+        for (visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
+             visual_iter.rem;
+             xcb_visualtype_next(&visual_iter)) {
+            if (screen->root_visual != visual_iter.data->visual_id)
+                continue;
+
+            visual_type = visual_iter.data;
+            return visual_type;
+        }
+    }
+
+    return NULL;
+}
+
+xcb_window_t open_fullscreen_window(xcb_connection_t *conn, xcb_screen_t *scr, char *color) {
+    uint32_t mask = 0;
+    uint32_t values[3];
+    xcb_window_t win = xcb_generate_id(conn);
+
+    mask |= XCB_CW_BACK_PIXEL;
+    values[0] = get_colorpixel(color);
+
+    mask |= XCB_CW_OVERRIDE_REDIRECT;
+    values[1] = 1;
+
+    mask |= XCB_CW_EVENT_MASK;
+    values[2] = XCB_EVENT_MASK_EXPOSURE | XCB_EVENT_MASK_KEY_PRESS | XCB_EVENT_MASK_KEY_RELEASE;
+
+    xcb_create_window(conn,
+                      24,
+                      win, /* the window id */
+                      scr->root, /* parent == root */
+                      0, 0,
+                      scr->width_in_pixels,
+                      scr->height_in_pixels, /* dimensions */
+                      0, /* border = 0, we draw our own */
+                      XCB_WINDOW_CLASS_INPUT_OUTPUT,
+                      XCB_WINDOW_CLASS_COPY_FROM_PARENT, /* copy visual from parent */
+                      mask,
+                      values);
+
+    /* Map the window (= make it visible) */
+    xcb_map_window(conn, win);
+
+    /* Raise window (put it on top) */
+    values[0] = XCB_STACK_MODE_ABOVE;
+    xcb_configure_window(conn, win, XCB_CONFIG_WINDOW_STACK_MODE, values);
+
+    return win;
+}
+
+/*
+ * Returns the mask for Mode_switch (to be used for looking up keysymbols by
+ * keycode).
+ *
+ */
+uint32_t get_mod_mask(xcb_connection_t *conn, xcb_key_symbols_t *symbols, uint32_t keycode) {
+    xcb_get_modifier_mapping_reply_t *modmap_r;
+    xcb_keycode_t *modmap, kc;
+    xcb_keycode_t *modeswitchcodes = xcb_key_symbols_get_keycode(symbols, keycode);
+    if (modeswitchcodes == NULL)
+        return 0;
+
+    modmap_r = xcb_get_modifier_mapping_reply(conn, xcb_get_modifier_mapping(conn), NULL);
+    modmap = xcb_get_modifier_mapping_keycodes(modmap_r);
+
+    for (int i = 0; i < 8; i++)
+        for (int j = 0; j < modmap_r->keycodes_per_modifier; j++) {
+            kc = modmap[i * modmap_r->keycodes_per_modifier + j];
+            for (xcb_keycode_t *ktest = modeswitchcodes; *ktest; ktest++) {
+                if (*ktest != kc)
+                    continue;
+
+                free(modeswitchcodes);
+                free(modmap_r);
+                return (1 << i);
+            }
+        }
+
+    return 0;
+}
+
+void dpms_turn_off_screen(xcb_connection_t *conn) {
+    xcb_dpms_enable(conn);
+    xcb_dpms_force_level(conn, XCB_DPMS_DPMS_MODE_OFF);
+    xcb_flush(conn);
+}
+
+/*
+ * Repeatedly tries to grab pointer and keyboard (up to 1000 times).
+ *
+ */
+void grab_pointer_and_keyboard(xcb_connection_t *conn, xcb_screen_t *screen) {
+    xcb_grab_pointer_cookie_t pcookie;
+    xcb_grab_pointer_reply_t *preply;
+
+    xcb_grab_keyboard_cookie_t kcookie;
+    xcb_grab_keyboard_reply_t *kreply;
+
+    int tries = 1000;
+
+    while (tries-- > 0) {
+        pcookie = xcb_grab_pointer(
+            conn,
+            false,               /* get all pointer events specified by the following mask */
+            screen->root,        /* grab the root window */
+            XCB_NONE,            /* which events to let through */
+            XCB_GRAB_MODE_ASYNC, /* pointer events should continue as normal */
+            XCB_GRAB_MODE_ASYNC, /* keyboard mode */
+            XCB_NONE,            /* confine_to = in which window should the cursor stay */
+            XCB_NONE,            /* don’t display a special cursor */
+            XCB_CURRENT_TIME
+        );
+
+        if ((preply = xcb_grab_pointer_reply(conn, pcookie, NULL)) &&
+            preply->status == XCB_GRAB_STATUS_SUCCESS) {
+            free(preply);
+            break;
+        }
+    }
+
+    while (tries-- > 0) {
+        kcookie = xcb_grab_keyboard(
+            conn,
+            true,                /* report events */
+            screen->root,        /* grab the root window */
+            XCB_CURRENT_TIME,
+            XCB_GRAB_MODE_ASYNC, /* process events as normal, do not require sync */
+            XCB_GRAB_MODE_ASYNC
+        );
+
+        if ((kreply = xcb_grab_keyboard_reply(conn, kcookie, NULL)) &&
+            kreply->status == XCB_GRAB_STATUS_SUCCESS) {
+            free(kreply);
+            break;
+        }
+    }
+
+    if (tries == 0)
+        errx(EXIT_FAILURE, "Cannot grab pointer/keyboard");
+}