gri3-wm/i3bar/src/xcb.c

/*
 * vim:ts=4:sw=4:expandtab
 *
 * i3bar - an xcb-based status- and ws-bar for i3
 * © 2010 Axel Wagner and contributors (see also: LICENSE)
 *
 * xcb.c: Communicating with X
 *
 */
#include <xcb/xcb.h>
#include <xcb/xkb.h>
#include <xcb/xproto.h>
#include <xcb/xcb_aux.h>
#include <xcb/xcb_cursor.h>

#ifdef XCB_COMPAT
#include "xcb_compat.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <i3/ipc.h>
#include <ev.h>
#include <errno.h>
#include <limits.h>
#include <err.h>

#include <X11/Xlib.h>
#include <X11/XKBlib.h>
#include <X11/extensions/XKB.h>

#include "common.h"
#include "libi3.h"

/** This is the equivalent of XC_left_ptr. I’m not sure why xcb doesn’t have a
 * constant for that. */
#define XCB_CURSOR_LEFT_PTR 68

/* We save the atoms in an easy to access array, indexed by an enum */
enum {
#define ATOM_DO(name) name,
#include "xcb_atoms.def"
    NUM_ATOMS
};

xcb_intern_atom_cookie_t atom_cookies[NUM_ATOMS];
xcb_atom_t atoms[NUM_ATOMS];

/* Variables, that are the same for all functions at all times */
xcb_connection_t *xcb_connection;
int screen;
xcb_screen_t *root_screen;
xcb_window_t xcb_root;
static xcb_cursor_t cursor;

/* selection window for tray support */
static xcb_window_t selwin = XCB_NONE;
static xcb_intern_atom_reply_t *tray_reply = NULL;

/* This is needed for integration with libi3 */
xcb_connection_t *conn;

/* The font we'll use */
static i3Font font;

/* Icon size (based on font size) */
int icon_size;

xcb_visualtype_t *visual_type;
uint8_t depth;
xcb_colormap_t colormap;

/* Overall height of the bar (based on font size) */
int bar_height;

/* These are only relevant for XKB, which we only need for grabbing modifiers */
int xkb_base;
int mod_pressed = 0;

/* Event watchers, to interact with the user */
ev_prepare *xcb_prep;
ev_check *xcb_chk;
ev_io *xcb_io;
ev_io *xkb_io;

/* The name of current binding mode */
static mode binding;

/* Indicates whether a new binding mode was recently activated */
bool activated_mode = false;

/* The parsed colors */
struct xcb_colors_t {
    color_t bar_fg;
    color_t bar_bg;
    color_t sep_fg;
    color_t focus_bar_fg;
    color_t focus_bar_bg;
    color_t focus_sep_fg;
    color_t active_ws_fg;
    color_t active_ws_bg;
    color_t active_ws_border;
    color_t inactive_ws_fg;
    color_t inactive_ws_bg;
    color_t inactive_ws_border;
    color_t urgent_ws_bg;
    color_t urgent_ws_fg;
    color_t urgent_ws_border;
    color_t focus_ws_bg;
    color_t focus_ws_fg;
    color_t focus_ws_border;
    color_t binding_mode_bg;
    color_t binding_mode_fg;
    color_t binding_mode_border;
};
struct xcb_colors_t colors;

/* Horizontal offset between a workspace label and button borders */
static const int ws_hoff_px = 4;

/* Vertical offset between a workspace label and button borders */
static const int ws_voff_px = 3;

/* Offset between two workspace buttons */
static const int ws_spacing_px = 1;

/* Offset between the statusline and 1) workspace buttons on the left
 *                                   2) the tray or screen edge on the right */
static const int sb_hoff_px = 4;

/* Additional offset between the tray and the statusline, if the tray is not empty */
static const int tray_loff_px = 2;

/* Vertical offset between the bar and a separator */
static const int sep_voff_px = 4;

int _xcb_request_failed(xcb_void_cookie_t cookie, char *err_msg, int line) {
    xcb_generic_error_t *err;
    if ((err = xcb_request_check(xcb_connection, cookie)) != NULL) {
        fprintf(stderr, "[%s:%d] ERROR: %s. X Error Code: %d\n", __FILE__, line, err_msg, err->error_code);
        return err->error_code;
    }
    return 0;
}

uint32_t get_sep_offset(struct status_block *block) {
    if (!block->no_separator && block->sep_block_width > 0)
        return block->sep_block_width / 2 + block->sep_block_width % 2;
    return 0;
}

int get_tray_width(struct tc_head *trayclients) {
    trayclient *trayclient;
    int tray_width = 0;
    TAILQ_FOREACH_REVERSE(trayclient, trayclients, tc_head, tailq) {
        if (!trayclient->mapped)
            continue;
        tray_width += icon_size + logical_px(config.tray_padding);
    }
    if (tray_width > 0)
        tray_width += logical_px(tray_loff_px);
    return tray_width;
}

/*
 * Draws a separator for the given block if necessary.
 *
 */
static void draw_separator(i3_output *output, uint32_t x, struct status_block *block, bool use_focus_colors) {
    color_t sep_fg = (use_focus_colors ? colors.focus_sep_fg : colors.sep_fg);
    color_t bar_bg = (use_focus_colors ? colors.focus_bar_bg : colors.bar_bg);

    uint32_t sep_offset = get_sep_offset(block);
    if (TAILQ_NEXT(block, blocks) == NULL || sep_offset == 0)
        return;

    uint32_t center_x = x - sep_offset;
    if (config.separator_symbol == NULL) {
        /* Draw a classic one pixel, vertical separator. */
        draw_util_rectangle(xcb_connection, &output->statusline_buffer, sep_fg,
                            center_x,
                            logical_px(sep_voff_px),
                            logical_px(1),
                            bar_height - 2 * logical_px(sep_voff_px));
    } else {
        /* Draw a custom separator. */
        uint32_t separator_x = MAX(x - block->sep_block_width, center_x - separator_symbol_width / 2);
        draw_util_text(config.separator_symbol, &output->statusline_buffer, sep_fg, bar_bg,
                       separator_x, logical_px(ws_voff_px), x - separator_x);
    }
}

uint32_t predict_statusline_length(bool use_short_text) {
    uint32_t width = 0;
    struct status_block *block;

    TAILQ_FOREACH(block, &statusline_head, blocks) {
        i3String *text = block->full_text;
        struct status_block_render_desc *render = &block->full_render;
        if (use_short_text && block->short_text != NULL) {
            text = block->short_text;
            render = &block->short_render;
        }

        if (i3string_get_num_bytes(text) == 0)
            continue;

        render->width = predict_text_width(text);
        if (block->border)
            render->width += logical_px(2);

        /* Compute offset and append for text aligment in min_width. */
        if (block->min_width <= render->width) {
            render->x_offset = 0;
            render->x_append = 0;
        } else {
            uint32_t padding_width = block->min_width - render->width;
            switch (block->align) {
                case ALIGN_LEFT:
                    render->x_append = padding_width;
                    break;
                case ALIGN_RIGHT:
                    render->x_offset = padding_width;
                    break;
                case ALIGN_CENTER:
                    render->x_offset = padding_width / 2;
                    render->x_append = padding_width / 2 + padding_width % 2;
                    break;
            }
        }

        width += render->width + render->x_offset + render->x_append;

        /* If this is not the last block, add some pixels for a separator. */
        if (TAILQ_NEXT(block, blocks) != NULL)
            width += block->sep_block_width;
    }

    return width;
}

/*
 * Redraws the statusline to the output's statusline_buffer
 */
void draw_statusline(i3_output *output, uint32_t clip_left, bool use_focus_colors, bool use_short_text) {
    struct status_block *block;

    color_t bar_color = (use_focus_colors ? colors.focus_bar_bg : colors.bar_bg);
    draw_util_clear_surface(xcb_connection, &output->statusline_buffer, bar_color);

    /* Use unsigned integer wraparound to clip off the left side.
     * For example, if clip_left is 75, then x will start at the very large
     * number INT_MAX-75, which is way outside the surface dimensions. Drawing
     * to that x position is a no-op which XCB and Cairo safely ignore. Once x moves
     * up by 75 and goes past INT_MAX, it will wrap around again to 0, and we start
     * actually rendering content to the surface. */
    uint32_t x = 0 - clip_left;

    /* Draw the text of each block */
    TAILQ_FOREACH(block, &statusline_head, blocks) {
        i3String *text = block->full_text;
        struct status_block_render_desc *render = &block->full_render;
        if (use_short_text && block->short_text != NULL) {
            text = block->short_text;
            render = &block->short_render;
        }

        if (i3string_get_num_bytes(text) == 0)
            continue;

        color_t fg_color;
        if (block->urgent) {
            fg_color = colors.urgent_ws_fg;
        } else if (block->color) {
            fg_color = draw_util_hex_to_color(block->color);
        } else if (use_focus_colors) {
            fg_color = colors.focus_bar_fg;
        } else {
            fg_color = colors.bar_fg;
        }

        color_t bg_color = bar_color;

        int border_width = (block->border) ? logical_px(1) : 0;
        int full_render_width = render->width + render->x_offset + render->x_append;
        if (block->border || block->background || block->urgent) {
            /* Let's determine the colors first. */
            color_t border_color = bar_color;
            if (block->urgent) {
                border_color = colors.urgent_ws_border;
                bg_color = colors.urgent_ws_bg;
            } else {
                if (block->border)
                    border_color = draw_util_hex_to_color(block->border);
                if (block->background)
                    bg_color = draw_util_hex_to_color(block->background);
            }

            /* Draw the border. */
            draw_util_rectangle(xcb_connection, &output->statusline_buffer, border_color,
                                x, logical_px(1),
                                full_render_width,
                                bar_height - logical_px(2));

            /* Draw the background. */
            draw_util_rectangle(xcb_connection, &output->statusline_buffer, bg_color,
                                x + border_width,
                                logical_px(1) + border_width,
                                full_render_width - 2 * border_width,
                                bar_height - 2 * border_width - logical_px(2));
        }

        draw_util_text(text, &output->statusline_buffer, fg_color, bg_color,
                       x + render->x_offset + border_width, logical_px(ws_voff_px),
                       render->width - 2 * border_width);
        x += full_render_width;

        /* If this is not the last block, draw a separator. */
        if (TAILQ_NEXT(block, blocks) != NULL) {
            x += block->sep_block_width;
            draw_separator(output, x, block, use_focus_colors);
        }
    }
}

/*
 * Hides all bars (unmaps them)
 *
 */
void hide_bars(void) {
    if ((config.hide_on_modifier == M_DOCK) || (config.hidden_state == S_SHOW && config.hide_on_modifier == M_HIDE)) {
        return;
    }

    i3_output *walk;
    SLIST_FOREACH(walk, outputs, slist) {
        if (!walk->active) {
            continue;
        }
        xcb_unmap_window(xcb_connection, walk->bar.id);
    }
    stop_child();
}

/*
 * Unhides all bars (maps them)
 *
 */
void unhide_bars(void) {
    if (config.hide_on_modifier != M_HIDE) {
        return;
    }

    i3_output *walk;
    xcb_void_cookie_t cookie;
    uint32_t mask;
    uint32_t values[5];

    cont_child();

    SLIST_FOREACH(walk, outputs, slist) {
        if (walk->bar.id == XCB_NONE) {
            continue;
        }
        mask = XCB_CONFIG_WINDOW_X |
               XCB_CONFIG_WINDOW_Y |
               XCB_CONFIG_WINDOW_WIDTH |
               XCB_CONFIG_WINDOW_HEIGHT |
               XCB_CONFIG_WINDOW_STACK_MODE;
        values[0] = walk->rect.x;
        if (config.position == POS_TOP)
            values[1] = walk->rect.y;
        else
            values[1] = walk->rect.y + walk->rect.h - bar_height;
        values[2] = walk->rect.w;
        values[3] = bar_height;
        values[4] = XCB_STACK_MODE_ABOVE;
        DLOG("Reconfiguring window for output %s to %d,%d\n", walk->name, values[0], values[1]);
        cookie = xcb_configure_window_checked(xcb_connection,
                                              walk->bar.id,
                                              mask,
                                              values);

        if (xcb_request_failed(cookie, "Could not reconfigure window")) {
            exit(EXIT_FAILURE);
        }
        xcb_map_window(xcb_connection, walk->bar.id);
    }
}

/*
 * Parse the colors into a format that we can use
 *
 */
void init_colors(const struct xcb_color_strings_t *new_colors) {
#define PARSE_COLOR(name, def)                                                           \
    do {                                                                                 \
        colors.name = draw_util_hex_to_color(new_colors->name ? new_colors->name : def); \
    } while (0)
    PARSE_COLOR(bar_fg, "#FFFFFF");
    PARSE_COLOR(bar_bg, "#000000");
    PARSE_COLOR(sep_fg, "#666666");
    PARSE_COLOR(active_ws_fg, "#FFFFFF");
    PARSE_COLOR(active_ws_bg, "#333333");
    PARSE_COLOR(active_ws_border, "#333333");
    PARSE_COLOR(inactive_ws_fg, "#888888");
    PARSE_COLOR(inactive_ws_bg, "#222222");
    PARSE_COLOR(inactive_ws_border, "#333333");
    PARSE_COLOR(urgent_ws_fg, "#FFFFFF");
    PARSE_COLOR(urgent_ws_bg, "#900000");
    PARSE_COLOR(urgent_ws_border, "#2f343a");
    PARSE_COLOR(focus_ws_fg, "#FFFFFF");
    PARSE_COLOR(focus_ws_bg, "#285577");
    PARSE_COLOR(focus_ws_border, "#4c7899");
#undef PARSE_COLOR

#define PARSE_COLOR_FALLBACK(name, fallback)                                                         \
    do {                                                                                             \
        colors.name = new_colors->name ? draw_util_hex_to_color(new_colors->name) : colors.fallback; \
    } while (0)

    /* For the binding mode indicator colors, we don't hardcode a default.
     * Instead, we fall back to urgent_ws_* colors. */
    PARSE_COLOR_FALLBACK(binding_mode_fg, urgent_ws_fg);
    PARSE_COLOR_FALLBACK(binding_mode_bg, urgent_ws_bg);
    PARSE_COLOR_FALLBACK(binding_mode_border, urgent_ws_border);

    /* Similarly, for unspecified focused bar colors, we fall back to the
     * regular bar colors. */
    PARSE_COLOR_FALLBACK(focus_bar_fg, bar_fg);
    PARSE_COLOR_FALLBACK(focus_bar_bg, bar_bg);
    PARSE_COLOR_FALLBACK(focus_sep_fg, sep_fg);
#undef PARSE_COLOR_FALLBACK

    init_tray_colors();
    xcb_flush(xcb_connection);
}

/*
 * Handle a button press event (i.e. a mouse click on one of our bars).
 * We determine, whether the click occured on a workspace button or if the scroll-
 * wheel was used and change the workspace appropriately
 *
 */
void handle_button(xcb_button_press_event_t *event) {
    /* Determine, which bar was clicked */
    i3_output *walk;
    xcb_window_t bar = event->event;
    SLIST_FOREACH(walk, outputs, slist) {
        if (walk->bar.id == bar) {
            break;
        }
    }

    if (walk == NULL) {
        DLOG("Unknown bar clicked!\n");
        return;
    }

    int32_t x = event->event_x >= 0 ? event->event_x : 0;

    DLOG("Got button %d\n", event->detail);

    int workspace_width = 0;
    i3_ws *cur_ws = NULL, *clicked_ws = NULL, *ws_walk;

    TAILQ_FOREACH(ws_walk, walk->workspaces, tailq) {
        int w = 2 * logical_px(ws_hoff_px) + 2 * logical_px(1) + ws_walk->name_width;
        if (x >= workspace_width && x <= workspace_width + w)
            clicked_ws = ws_walk;
        if (ws_walk->visible)
            cur_ws = ws_walk;
        workspace_width += w;
        if (TAILQ_NEXT(ws_walk, tailq) != NULL)
            workspace_width += logical_px(ws_spacing_px);
    }

    if (x > workspace_width && child_want_click_events()) {
        /* If the child asked for click events,
         * check if a status block has been clicked. */
        int tray_width = get_tray_width(walk->trayclients);
        int block_x = 0, last_block_x;
        int offset = walk->rect.w - walk->statusline_width - tray_width - logical_px(sb_hoff_px);
        int32_t statusline_x = x - offset;

        if (statusline_x >= 0 && statusline_x < walk->statusline_width) {
            struct status_block *block;
            int sep_offset_remainder = 0;

            TAILQ_FOREACH(block, &statusline_head, blocks) {
                i3String *text = block->full_text;
                struct status_block_render_desc *render = &block->full_render;
                if (walk->statusline_short_text && block->short_text != NULL) {
                    text = block->short_text;
                    render = &block->short_render;
                }

                if (i3string_get_num_bytes(text) == 0)
                    continue;

                last_block_x = block_x;
                block_x += render->width + render->x_offset + render->x_append + get_sep_offset(block) + sep_offset_remainder;

                if (statusline_x <= block_x && statusline_x >= last_block_x) {
                    send_block_clicked(event->detail, block->name, block->instance, event->root_x, event->root_y);
                    return;
                }

                sep_offset_remainder = block->sep_block_width - get_sep_offset(block);
            }
        }
    }

    /* If a custom command was specified for this mouse button, it overrides
     * the default behavior. */
    binding_t *binding;
    TAILQ_FOREACH(binding, &(config.bindings), bindings) {
        if (binding->input_code != event->detail)
            continue;

        i3_send_msg(I3_IPC_MESSAGE_TYPE_COMMAND, binding->command);
        return;
    }

    if (cur_ws == NULL) {
        DLOG("No workspace active?\n");
        return;
    }
    switch (event->detail) {
        case 4:
            /* Mouse wheel up. We select the previous ws, if any.
             * If there is no more workspace, don’t even send the workspace
             * command, otherwise (with workspace auto_back_and_forth) we’d end
             * up on the wrong workspace. */
            if (cur_ws == TAILQ_FIRST(walk->workspaces))
                return;

            cur_ws = TAILQ_PREV(cur_ws, ws_head, tailq);
            break;
        case 5:
            /* Mouse wheel down. We select the next ws, if any.
             * If there is no more workspace, don’t even send the workspace
             * command, otherwise (with workspace auto_back_and_forth) we’d end
             * up on the wrong workspace. */
            if (cur_ws == TAILQ_LAST(walk->workspaces, ws_head))
                return;

            cur_ws = TAILQ_NEXT(cur_ws, tailq);
            break;
        case 1:
            cur_ws = clicked_ws;

            /* if no workspace was clicked, focus our currently visible
             * workspace if it is not already focused */
            if (cur_ws == NULL) {
                TAILQ_FOREACH(cur_ws, walk->workspaces, tailq) {
                    if (cur_ws->visible && !cur_ws->focused)
                        break;
                }
            }

            /* if there is nothing to focus, we are done */
            if (cur_ws == NULL)
                return;

            break;
        default:
            return;
    }

    /* To properly handle workspace names with double quotes in them, we need
     * to escape the double quotes. Unfortunately, that’s rather ugly in C: We
     * first count the number of double quotes, then we allocate a large enough
     * buffer, then we copy character by character. */
    int num_quotes = 0;
    size_t namelen = 0;
    const char *utf8_name = cur_ws->canonical_name;
    for (const char *walk = utf8_name; *walk != '\0'; walk++) {
        if (*walk == '"' || *walk == '\\')
            num_quotes++;
        /* While we’re looping through the name anyway, we can save one
         * strlen(). */
        namelen++;
    }

    const size_t len = namelen + strlen("workspace \"\"") + 1;
    char *buffer = scalloc(len + num_quotes, 1);
    strncpy(buffer, "workspace \"", strlen("workspace \""));
    size_t inpos, outpos;
    for (inpos = 0, outpos = strlen("workspace \"");
         inpos < namelen;
         inpos++, outpos++) {
        if (utf8_name[inpos] == '"' || utf8_name[inpos] == '\\') {
            buffer[outpos] = '\\';
            outpos++;
        }
        buffer[outpos] = utf8_name[inpos];
    }
    buffer[outpos] = '"';
    i3_send_msg(I3_IPC_MESSAGE_TYPE_COMMAND, buffer);
    free(buffer);
}

/*
 * Handle visibility notifications: when none of the bars are visible, e.g.
 * if windows are in fullscreen on each output, suspend the child process.
 *
 */
static void handle_visibility_notify(xcb_visibility_notify_event_t *event) {
    bool visible = (event->state != XCB_VISIBILITY_FULLY_OBSCURED);
    int num_visible = 0;
    i3_output *output;

    SLIST_FOREACH(output, outputs, slist) {
        if (!output->active) {
            continue;
        }
        if (output->bar.id == event->window) {
            if (output->visible == visible) {
                return;
            }
            output->visible = visible;
        }
        num_visible += output->visible;
    }

    if (num_visible == 0) {
        stop_child();
    } else if (num_visible == visible) {
        /* Wake the child only when transitioning from 0 to 1 visible bar.
         * We cannot transition from 0 to 2 or more visible bars at once since
         * visibility events are delivered to each window separately */
        cont_child();
    }
}

/*
 * Adjusts the size of the tray window and alignment of the tray clients by
 * configuring their respective x coordinates. To be called when mapping or
 * unmapping a tray client window.
 *
 */
static void configure_trayclients(void) {
    trayclient *trayclient;
    i3_output *output;
    SLIST_FOREACH(output, outputs, slist) {
        if (!output->active)
            continue;

        int clients = 0;
        TAILQ_FOREACH_REVERSE(trayclient, output->trayclients, tc_head, tailq) {
            if (!trayclient->mapped)
                continue;
            clients++;

            DLOG("Configuring tray window %08x to x=%d\n",
                 trayclient->win, output->rect.w - (clients * (icon_size + logical_px(config.tray_padding))));
            uint32_t x = output->rect.w - (clients * (icon_size + logical_px(config.tray_padding)));
            xcb_configure_window(xcb_connection,
                                 trayclient->win,
                                 XCB_CONFIG_WINDOW_X,
                                 &x);
        }
    }
}

/*
 * Handles ClientMessages (messages sent from another client directly to us).
 *
 * At the moment, only the tray window will receive client messages. All
 * supported client messages currently are _NET_SYSTEM_TRAY_OPCODE.
 *
 */
static void handle_client_message(xcb_client_message_event_t *event) {
    if (event->type == atoms[_NET_SYSTEM_TRAY_OPCODE] &&
        event->format == 32) {
        DLOG("_NET_SYSTEM_TRAY_OPCODE received\n");
        /* event->data.data32[0] is the timestamp */
        uint32_t op = event->data.data32[1];
        uint32_t mask;
        uint32_t values[2];
        if (op == SYSTEM_TRAY_REQUEST_DOCK) {
            xcb_window_t client = event->data.data32[2];

            /* Listen for PropertyNotify events to get the most recent value of
             * the XEMBED_MAPPED atom, also listen for UnmapNotify events */
            mask = XCB_CW_EVENT_MASK;
            values[0] = XCB_EVENT_MASK_PROPERTY_CHANGE |
                        XCB_EVENT_MASK_STRUCTURE_NOTIFY;
            xcb_change_window_attributes(xcb_connection,
                                         client,
                                         mask,
                                         values);

            /* Request the _XEMBED_INFO property. The XEMBED specification
             * (which is referred by the tray specification) says this *has* to
             * be set, but VLC does not set it… */
            bool map_it = true;
            int xe_version = 1;
            xcb_get_property_cookie_t xembedc;
            xcb_generic_error_t *error;
            xembedc = xcb_get_property(xcb_connection,
                                       0,
                                       client,
                                       atoms[_XEMBED_INFO],
                                       XCB_GET_PROPERTY_TYPE_ANY,
                                       0,
                                       2 * 32);

            xcb_get_property_reply_t *xembedr = xcb_get_property_reply(xcb_connection,
                                                                       xembedc,
                                                                       &error);
            if (error != NULL) {
                ELOG("Error getting _XEMBED_INFO property: error_code %d\n",
                     error->error_code);
                free(error);
                return;
            }
            if (xembedr != NULL && xembedr->length != 0) {
                DLOG("xembed format = %d, len = %d\n", xembedr->format, xembedr->length);
                uint32_t *xembed = xcb_get_property_value(xembedr);
                DLOG("xembed version = %d\n", xembed[0]);
                DLOG("xembed flags = %d\n", xembed[1]);
                map_it = ((xembed[1] & XEMBED_MAPPED) == XEMBED_MAPPED);
                xe_version = xembed[0];
                if (xe_version > 1)
                    xe_version = 1;
                free(xembedr);
            } else {
                ELOG("Window %08x violates the XEMBED protocol, _XEMBED_INFO not set\n", client);
            }

            DLOG("X window %08x requested docking\n", client);
            i3_output *output = NULL;
            i3_output *walk = NULL;
            tray_output_t *tray_output = NULL;
            /* We need to iterate through the tray_output assignments first in
             * order to prioritize them. Otherwise, if this bar manages two
             * outputs and both are assigned as tray_output as well, the first
             * output in our list would receive the tray rather than the first
             * one defined via tray_output. */
            TAILQ_FOREACH(tray_output, &(config.tray_outputs), tray_outputs) {
                SLIST_FOREACH(walk, outputs, slist) {
                    if (!walk->active)
                        continue;

                    if (strcasecmp(walk->name, tray_output->output) == 0) {
                        DLOG("Found tray_output assignment for output %s.\n", walk->name);
                        output = walk;
                        break;
                    }

                    if (walk->primary && strcasecmp("primary", tray_output->output) == 0) {
                        DLOG("Found tray_output assignment on primary output %s.\n", walk->name);
                        output = walk;
                        break;
                    }
                }

                /* If we found an output, we're done. */
                if (output != NULL)
                    break;
            }

            /* Check whether any "tray_output primary" was defined for this bar. */
            bool contains_primary = false;
            TAILQ_FOREACH(tray_output, &(config.tray_outputs), tray_outputs) {
                if (strcasecmp("primary", tray_output->output) == 0) {
                    contains_primary = true;
                    break;
                }
            }

            /* In case of tray_output == primary and there is no primary output
             * configured, we fall back to the first available output. We do the
             * same if no tray_output was specified. */
            if (output == NULL && (contains_primary || TAILQ_EMPTY(&(config.tray_outputs)))) {
                SLIST_FOREACH(walk, outputs, slist) {
                    if (!walk->active)
                        continue;
                    DLOG("Falling back to output %s because no primary output is configured\n", walk->name);
                    output = walk;
                    break;
                }
            }
            if (output == NULL) {
                ELOG("No output found\n");
                return;
            }

            xcb_void_cookie_t rcookie = xcb_reparent_window(xcb_connection,
                                                            client,
                                                            output->bar.id,
                                                            output->rect.w - icon_size - logical_px(config.tray_padding),
                                                            logical_px(config.tray_padding));
            if (xcb_request_failed(rcookie, "Could not reparent window. Maybe it is using an incorrect depth/visual?"))
                return;

            /* We reconfigure the window to use a reasonable size. The systray
             * specification explicitly says:
             *   Tray icons may be assigned any size by the system tray, and
             *   should do their best to cope with any size effectively
             */
            mask = XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT;
            values[0] = icon_size;
            values[1] = icon_size;
            xcb_configure_window(xcb_connection,
                                 client,
                                 mask,
                                 values);

            /* send the XEMBED_EMBEDDED_NOTIFY message */
            void *event = scalloc(32, 1);
            xcb_client_message_event_t *ev = event;
            ev->response_type = XCB_CLIENT_MESSAGE;
            ev->window = client;
            ev->type = atoms[_XEMBED];
            ev->format = 32;
            ev->data.data32[0] = XCB_CURRENT_TIME;
            ev->data.data32[1] = atoms[XEMBED_EMBEDDED_NOTIFY];
            ev->data.data32[2] = output->bar.id;
            ev->data.data32[3] = xe_version;
            xcb_send_event(xcb_connection,
                           0,
                           client,
                           XCB_EVENT_MASK_NO_EVENT,
                           (char *)ev);
            free(event);

            /* Put the client inside the save set. Upon termination (whether
             * killed or normal exit does not matter) of i3bar, these clients
             * will be correctly reparented to their most closest living
             * ancestor. Without this, tray icons might die when i3bar
             * exits/crashes. */
            xcb_change_save_set(xcb_connection, XCB_SET_MODE_INSERT, client);

            trayclient *tc = smalloc(sizeof(trayclient));
            tc->win = client;
            tc->xe_version = xe_version;
            tc->mapped = false;
            TAILQ_INSERT_TAIL(output->trayclients, tc, tailq);

            if (map_it) {
                DLOG("Mapping dock client\n");
                xcb_map_window(xcb_connection, client);
            } else {
                DLOG("Not mapping dock client yet\n");
            }
            /* Trigger an update to copy the statusline text to the appropriate
             * position */
            configure_trayclients();
            draw_bars(false);
        }
    }
}

/*
 * Handles DestroyNotify events by removing the tray client from the data
 * structure. According to the XEmbed protocol, this is one way for a tray
 * client to finish the protocol. After this event is received, there is no
 * further interaction with the tray client.
 *
 * See: http://standards.freedesktop.org/xembed-spec/xembed-spec-latest.html
 *
 */
static void handle_destroy_notify(xcb_destroy_notify_event_t *event) {
    DLOG("DestroyNotify for window = %08x, event = %08x\n", event->window, event->event);

    i3_output *walk;
    SLIST_FOREACH(walk, outputs, slist) {
        if (!walk->active)
            continue;
        DLOG("checking output %s\n", walk->name);
        trayclient *trayclient;
        TAILQ_FOREACH(trayclient, walk->trayclients, tailq) {
            if (trayclient->win != event->window)
                continue;

            DLOG("Removing tray client with window ID %08x\n", event->window);
            TAILQ_REMOVE(walk->trayclients, trayclient, tailq);

            /* Trigger an update, we now have more space for the statusline */
            configure_trayclients();
            draw_bars(false);
            return;
        }
    }
}

/*
 * Handles MapNotify events. These events happen when a tray client shows its
 * window. We respond by realigning the tray clients.
 *
 */
static void handle_map_notify(xcb_map_notify_event_t *event) {
    DLOG("MapNotify for window = %08x, event = %08x\n", event->window, event->event);

    i3_output *walk;
    SLIST_FOREACH(walk, outputs, slist) {
        if (!walk->active)
            continue;
        DLOG("checking output %s\n", walk->name);
        trayclient *trayclient;
        TAILQ_FOREACH(trayclient, walk->trayclients, tailq) {
            if (trayclient->win != event->window)
                continue;

            DLOG("Tray client mapped (window ID %08x). Adjusting tray.\n", event->window);
            trayclient->mapped = true;

            /* Trigger an update, we now have more space for the statusline */
            configure_trayclients();
            draw_bars(false);
            return;
        }
    }
}
/*
 * Handles UnmapNotify events. These events happen when a tray client hides its
 * window. We respond by realigning the tray clients.
 *
 */
static void handle_unmap_notify(xcb_unmap_notify_event_t *event) {
    DLOG("UnmapNotify for window = %08x, event = %08x\n", event->window, event->event);

    i3_output *walk;
    SLIST_FOREACH(walk, outputs, slist) {
        if (!walk->active)
            continue;
        DLOG("checking output %s\n", walk->name);
        trayclient *trayclient;
        TAILQ_FOREACH(trayclient, walk->trayclients, tailq) {
            if (trayclient->win != event->window)
                continue;

            DLOG("Tray client unmapped (window ID %08x). Adjusting tray.\n", event->window);
            trayclient->mapped = false;

            /* Trigger an update, we now have more space for the statusline */
            configure_trayclients();
            draw_bars(false);
            return;
        }
    }
}

/*
 * Handle PropertyNotify messages. Currently only the _XEMBED_INFO property is
 * handled, which tells us whether a dock client should be mapped or unmapped.
 *
 */
static void handle_property_notify(xcb_property_notify_event_t *event) {
    DLOG("PropertyNotify\n");
    if (event->atom == atoms[_XEMBED_INFO] &&
        event->state == XCB_PROPERTY_NEW_VALUE) {
        DLOG("xembed_info updated\n");
        trayclient *trayclient = NULL, *walk;
        i3_output *o_walk;
        SLIST_FOREACH(o_walk, outputs, slist) {
            if (!o_walk->active)
                continue;

            TAILQ_FOREACH(walk, o_walk->trayclients, tailq) {
                if (walk->win != event->window)
                    continue;
                trayclient = walk;
                break;
            }

            if (trayclient)
                break;
        }
        if (!trayclient) {
            ELOG("PropertyNotify received for unknown window %08x\n",
                 event->window);
            return;
        }
        xcb_get_property_cookie_t xembedc;
        xembedc = xcb_get_property_unchecked(xcb_connection,
                                             0,
                                             trayclient->win,
                                             atoms[_XEMBED_INFO],
                                             XCB_GET_PROPERTY_TYPE_ANY,
                                             0,
                                             2 * 32);

        xcb_get_property_reply_t *xembedr = xcb_get_property_reply(xcb_connection,
                                                                   xembedc,
                                                                   NULL);
        if (xembedr == NULL || xembedr->length == 0) {
            DLOG("xembed_info unset\n");
            return;
        }

        DLOG("xembed format = %d, len = %d\n", xembedr->format, xembedr->length);
        uint32_t *xembed = xcb_get_property_value(xembedr);
        DLOG("xembed version = %d\n", xembed[0]);
        DLOG("xembed flags = %d\n", xembed[1]);
        bool map_it = ((xembed[1] & XEMBED_MAPPED) == XEMBED_MAPPED);
        DLOG("map state now %d\n", map_it);
        if (trayclient->mapped && !map_it) {
            /* need to unmap the window */
            xcb_unmap_window(xcb_connection, trayclient->win);
        } else if (!trayclient->mapped && map_it) {
            /* need to map the window */
            xcb_map_window(xcb_connection, trayclient->win);
        }
        free(xembedr);
    }
}

/*
 * Handle ConfigureRequests by denying them and sending the client a
 * ConfigureNotify with its actual size.
 *
 */
static void handle_configure_request(xcb_configure_request_event_t *event) {
    DLOG("ConfigureRequest for window = %08x\n", event->window);

    trayclient *trayclient;
    i3_output *output;
    SLIST_FOREACH(output, outputs, slist) {
        if (!output->active)
            continue;

        int clients = 0;
        TAILQ_FOREACH_REVERSE(trayclient, output->trayclients, tc_head, tailq) {
            if (!trayclient->mapped)
                continue;
            clients++;

            if (trayclient->win != event->window)
                continue;

            xcb_rectangle_t rect;
            rect.x = output->rect.w - (clients * (icon_size + logical_px(config.tray_padding)));
            rect.y = logical_px(config.tray_padding);
            rect.width = icon_size;
            rect.height = icon_size;

            DLOG("This is a tray window. x = %d\n", rect.x);
            fake_configure_notify(xcb_connection, rect, event->window, 0);
            return;
        }
    }

    DLOG("WARNING: Could not find corresponding tray window.\n");
}

/*
 * This function is called immediately before the main loop locks. We flush xcb
 * then (and only then)
 *
 */
void xcb_prep_cb(struct ev_loop *loop, ev_prepare *watcher, int revents) {
    xcb_flush(xcb_connection);
}

/*
 * This function is called immediately after the main loop locks, so when one
 * of the watchers registered an event.
 * We check whether an X-Event arrived and handle it.
 *
 */
void xcb_chk_cb(struct ev_loop *loop, ev_check *watcher, int revents) {
    xcb_generic_event_t *event;

    if (xcb_connection_has_error(xcb_connection)) {
        ELOG("X11 connection was closed unexpectedly - maybe your X server terminated / crashed?\n");
        exit(1);
    }

    while ((event = xcb_poll_for_event(xcb_connection)) != NULL) {
        if (event->response_type == 0) {
            xcb_generic_error_t *error = (xcb_generic_error_t *)event;
            DLOG("Received X11 error, sequence 0x%x, error_code = %d\n", error->sequence, error->error_code);
            free(event);
            continue;
        }

        int type = (event->response_type & ~0x80);

        if (type == xkb_base && xkb_base > -1) {
            DLOG("received an xkb event\n");

            xcb_xkb_state_notify_event_t *state = (xcb_xkb_state_notify_event_t *)event;
            if (state->xkbType == XCB_XKB_STATE_NOTIFY) {
                int modstate = state->mods & config.modifier;

#define DLOGMOD(modmask, status)                        \
    do {                                                \
        switch (modmask) {                              \
            case ShiftMask:                             \
                DLOG("ShiftMask got " #status "!\n");   \
                break;                                  \
            case ControlMask:                           \
                DLOG("ControlMask got " #status "!\n"); \
                break;                                  \
            case Mod1Mask:                              \
                DLOG("Mod1Mask got " #status "!\n");    \
                break;                                  \
            case Mod2Mask:                              \
                DLOG("Mod2Mask got " #status "!\n");    \
                break;                                  \
            case Mod3Mask:                              \
                DLOG("Mod3Mask got " #status "!\n");    \
                break;                                  \
            case Mod4Mask:                              \
                DLOG("Mod4Mask got " #status "!\n");    \
                break;                                  \
            case Mod5Mask:                              \
                DLOG("Mod5Mask got " #status "!\n");    \
                break;                                  \
        }                                               \
    } while (0)

                if (modstate != mod_pressed) {
                    if (modstate == 0) {
                        DLOGMOD(config.modifier, released);
                        if (!activated_mode)
                            hide_bars();
                    } else {
                        DLOGMOD(config.modifier, pressed);
                        activated_mode = false;
                        unhide_bars();
                    }
                    mod_pressed = modstate;
                }
#undef DLOGMOD
            }

            free(event);
            continue;
        }

        switch (type) {
            case XCB_VISIBILITY_NOTIFY:
                /* Visibility change: a bar is [un]obscured by other window */
                handle_visibility_notify((xcb_visibility_notify_event_t *)event);
                break;
            case XCB_EXPOSE:
                /* Expose-events happen, when the window needs to be redrawn */
                redraw_bars();
                break;
            case XCB_BUTTON_PRESS:
                /* Button press events are mouse buttons clicked on one of our bars */
                handle_button((xcb_button_press_event_t *)event);
                break;
            case XCB_CLIENT_MESSAGE:
                /* Client messages are used for client-to-client communication, for
                 * example system tray widgets talk to us directly via client messages. */
                handle_client_message((xcb_client_message_event_t *)event);
                break;
            case XCB_DESTROY_NOTIFY:
                /* DestroyNotify signifies the end of the XEmbed protocol */
                handle_destroy_notify((xcb_destroy_notify_event_t *)event);
                break;
            case XCB_UNMAP_NOTIFY:
                /* UnmapNotify is received when a tray client hides its window. */
                handle_unmap_notify((xcb_unmap_notify_event_t *)event);
                break;
            case XCB_MAP_NOTIFY:
                handle_map_notify((xcb_map_notify_event_t *)event);
                break;
            case XCB_PROPERTY_NOTIFY:
                /* PropertyNotify */
                handle_property_notify((xcb_property_notify_event_t *)event);
                break;
            case XCB_CONFIGURE_REQUEST:
                /* ConfigureRequest, sent by a tray child */
                handle_configure_request((xcb_configure_request_event_t *)event);
                break;
        }
        free(event);
    }
}

/*
 * Dummy callback. We only need this, so that the prepare and check watchers
 * are triggered
 *
 */
void xcb_io_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
}

/*
 * Early initialization of the connection to X11: Everything which does not
 * depend on 'config'.
 *
 */
char *init_xcb_early() {
    /* FIXME: xcb_connect leaks memory */
    xcb_connection = xcb_connect(NULL, &screen);
    if (xcb_connection_has_error(xcb_connection)) {
        ELOG("Cannot open display\n");
        exit(EXIT_FAILURE);
    }
    conn = xcb_connection;
    DLOG("Connected to xcb\n");

/* We have to request the atoms we need */
#define ATOM_DO(name) atom_cookies[name] = xcb_intern_atom(xcb_connection, 0, strlen(#name), #name);
#include "xcb_atoms.def"

    root_screen = xcb_aux_get_screen(xcb_connection, screen);
    xcb_root = root_screen->root;

    depth = root_screen->root_depth;
    colormap = root_screen->default_colormap;
    visual_type = get_visualtype(root_screen);

    xcb_cursor_context_t *cursor_ctx;
    if (xcb_cursor_context_new(conn, root_screen, &cursor_ctx) == 0) {
        cursor = xcb_cursor_load_cursor(cursor_ctx, "left_ptr");
        xcb_cursor_context_free(cursor_ctx);
    } else {
        cursor = xcb_generate_id(xcb_connection);
        i3Font cursor_font = load_font("cursor", false);
        xcb_create_glyph_cursor(
            xcb_connection,
            cursor,
            cursor_font.specific.xcb.id,
            cursor_font.specific.xcb.id,
            XCB_CURSOR_LEFT_PTR,
            XCB_CURSOR_LEFT_PTR + 1,
            0, 0, 0,
            65535, 65535, 65535);
    }

    /* The various watchers to communicate with xcb */
    xcb_io = smalloc(sizeof(ev_io));
    xcb_prep = smalloc(sizeof(ev_prepare));
    xcb_chk = smalloc(sizeof(ev_check));

    ev_io_init(xcb_io, &xcb_io_cb, xcb_get_file_descriptor(xcb_connection), EV_READ);
    ev_prepare_init(xcb_prep, &xcb_prep_cb);
    ev_check_init(xcb_chk, &xcb_chk_cb);

    ev_io_start(main_loop, xcb_io);
    ev_prepare_start(main_loop, xcb_prep);
    ev_check_start(main_loop, xcb_chk);

    /* Now we get the atoms and save them in a nice data structure */
    get_atoms();

    char *path = root_atom_contents("I3_SOCKET_PATH", xcb_connection, screen);

    return path;
}

/*
 * Register for xkb keyevents. To grab modifiers without blocking other applications from receiving key events
 * involving that modifier, we sadly have to use xkb which is not yet fully supported
 * in xcb.
 *
 */
void register_xkb_keyevents() {
    const xcb_query_extension_reply_t *extreply;
    extreply = xcb_get_extension_data(conn, &xcb_xkb_id);
    if (!extreply->present) {
        ELOG("xkb is not present on this server\n");
        exit(EXIT_FAILURE);
    }
    DLOG("initializing xcb-xkb\n");
    xcb_xkb_use_extension(conn, XCB_XKB_MAJOR_VERSION, XCB_XKB_MINOR_VERSION);
    xcb_xkb_select_events(conn,
                          XCB_XKB_ID_USE_CORE_KBD,
                          XCB_XKB_EVENT_TYPE_STATE_NOTIFY,
                          0,
                          XCB_XKB_EVENT_TYPE_STATE_NOTIFY,
                          0xff,
                          0xff,
                          NULL);
    xkb_base = extreply->first_event;
}

/*
 * Deregister from xkb keyevents.
 *
 */
void deregister_xkb_keyevents() {
    xcb_xkb_select_events(conn,
                          XCB_XKB_ID_USE_CORE_KBD,
                          0,
                          0,
                          0,
                          0xff,
                          0xff,
                          NULL);
}

/*
 * Initialization which depends on 'config' being usable. Called after the
 * configuration has arrived.
 *
 */
void init_xcb_late(char *fontname) {
    if (fontname == NULL)
        fontname = "-misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1";

    /* Load the font */
    font = load_font(fontname, true);
    set_font(&font);
    DLOG("Calculated font height: %d\n", font.height);
    bar_height = font.height + 2 * logical_px(ws_voff_px);
    icon_size = bar_height - 2 * logical_px(config.tray_padding);

    if (config.separator_symbol)
        separator_symbol_width = predict_text_width(config.separator_symbol);

    xcb_flush(xcb_connection);

    if (config.hide_on_modifier == M_HIDE)
        register_xkb_keyevents();
}

/*
 * Inform clients waiting for a new _NET_SYSTEM_TRAY that we took the
 * selection.
 *
 */
static void send_tray_clientmessage(void) {
    uint8_t buffer[32] = {0};
    xcb_client_message_event_t *ev = (xcb_client_message_event_t *)buffer;

    ev->response_type = XCB_CLIENT_MESSAGE;
    ev->window = xcb_root;
    ev->type = atoms[MANAGER];
    ev->format = 32;
    ev->data.data32[0] = XCB_CURRENT_TIME;
    ev->data.data32[1] = tray_reply->atom;
    ev->data.data32[2] = selwin;

    xcb_send_event(xcb_connection,
                   0,
                   xcb_root,
                   0xFFFFFF,
                   (char *)buffer);
}

/*
 * Initializes tray support by requesting the appropriate _NET_SYSTEM_TRAY atom
 * for the X11 display we are running on, then acquiring the selection for this
 * atom. Afterwards, tray clients will send ClientMessages to our window.
 *
 */
void init_tray(void) {
    DLOG("Initializing system tray functionality\n");
    /* request the tray manager atom for the X11 display we are running on */
    char atomname[strlen("_NET_SYSTEM_TRAY_S") + 11];
    snprintf(atomname, strlen("_NET_SYSTEM_TRAY_S") + 11, "_NET_SYSTEM_TRAY_S%d", screen);
    xcb_intern_atom_cookie_t tray_cookie;
    if (tray_reply == NULL)
        tray_cookie = xcb_intern_atom(xcb_connection, 0, strlen(atomname), atomname);

    /* tray support: we need a window to own the selection */
    selwin = xcb_generate_id(xcb_connection);
    uint32_t selmask = XCB_CW_BACK_PIXEL | XCB_CW_BORDER_PIXEL | XCB_CW_OVERRIDE_REDIRECT | XCB_CW_COLORMAP;
    uint32_t selval[] = {root_screen->black_pixel, root_screen->black_pixel, 1, colormap};
    xcb_create_window(xcb_connection,
                      depth,
                      selwin,
                      xcb_root,
                      -1, -1,
                      1, 1,
                      0,
                      XCB_WINDOW_CLASS_INPUT_OUTPUT,
                      visual_type->visual_id,
                      selmask,
                      selval);

    uint32_t orientation = _NET_SYSTEM_TRAY_ORIENTATION_HORZ;
    /* set the atoms */
    xcb_change_property(xcb_connection,
                        XCB_PROP_MODE_REPLACE,
                        selwin,
                        atoms[_NET_SYSTEM_TRAY_ORIENTATION],
                        XCB_ATOM_CARDINAL,
                        32,
                        1,
                        &orientation);
    xcb_change_property(xcb_connection,
                        XCB_PROP_MODE_REPLACE,
                        selwin,
                        atoms[_NET_SYSTEM_TRAY_VISUAL],
                        XCB_ATOM_VISUALID,
                        32,
                        1,
                        &visual_type->visual_id);

    init_tray_colors();

    if (tray_reply == NULL) {
        if (!(tray_reply = xcb_intern_atom_reply(xcb_connection, tray_cookie, NULL))) {
            ELOG("Could not get atom %s\n", atomname);
            exit(EXIT_FAILURE);
        }
    }

    xcb_set_selection_owner(xcb_connection,
                            selwin,
                            tray_reply->atom,
                            XCB_CURRENT_TIME);

    /* Verify that we have the selection */
    xcb_get_selection_owner_cookie_t selcookie;
    xcb_get_selection_owner_reply_t *selreply;

    selcookie = xcb_get_selection_owner(xcb_connection, tray_reply->atom);
    if (!(selreply = xcb_get_selection_owner_reply(xcb_connection, selcookie, NULL))) {
        ELOG("Could not get selection owner for %s\n", atomname);
        exit(EXIT_FAILURE);
    }

    if (selreply->owner != selwin) {
        ELOG("Could not set the %s selection. "
             "Maybe another tray is already running?\n",
             atomname);
        /* NOTE that this error is not fatal. We just can’t provide tray
         * functionality */
        free(selreply);
        return;
    }

    send_tray_clientmessage();
}

/*
 * We need to set the _NET_SYSTEM_TRAY_COLORS atom on the tray selection window
 * to make GTK+ 3 applets with symbolic icons visible. If the colors are unset,
 * they assume a light background.
 * See also https://bugzilla.gnome.org/show_bug.cgi?id=679591
 *
 */
void init_tray_colors(void) {
    /* Convert colors.bar_fg (#rrggbb) to 16-bit RGB */
    const char *bar_fg = (config.colors.bar_fg ? config.colors.bar_fg : "#FFFFFF");

    DLOG("Setting bar_fg = %s as _NET_SYSTEM_TRAY_COLORS\n", bar_fg);

    char strgroups[3][3] = {{bar_fg[1], bar_fg[2], '\0'},
                            {bar_fg[3], bar_fg[4], '\0'},
                            {bar_fg[5], bar_fg[6], '\0'}};
    const uint8_t r = strtol(strgroups[0], NULL, 16);
    const uint8_t g = strtol(strgroups[1], NULL, 16);
    const uint8_t b = strtol(strgroups[2], NULL, 16);

    const uint16_t r16 = ((uint16_t)r << 8) | r;
    const uint16_t g16 = ((uint16_t)g << 8) | g;
    const uint16_t b16 = ((uint16_t)b << 8) | b;

    const uint32_t tray_colors[12] = {
        r16, g16, b16, /* foreground color */
        r16, g16, b16, /* error color */
        r16, g16, b16, /* warning color */
        r16, g16, b16, /* success color */
    };

    xcb_change_property(xcb_connection,
                        XCB_PROP_MODE_REPLACE,
                        selwin,
                        atoms[_NET_SYSTEM_TRAY_COLORS],
                        XCB_ATOM_CARDINAL,
                        32,
                        12,
                        tray_colors);
}

/*
 * Cleanup the xcb stuff.
 * Called once, before the program terminates.
 *
 */
void clean_xcb(void) {
    i3_output *o_walk;
    free_workspaces();
    SLIST_FOREACH(o_walk, outputs, slist) {
        destroy_window(o_walk);
        FREE(o_walk->trayclients);
        FREE(o_walk->workspaces);
        FREE(o_walk->name);
    }
    FREE_SLIST(outputs, i3_output);
    FREE(outputs);

    xcb_free_cursor(xcb_connection, cursor);
    xcb_flush(xcb_connection);
    xcb_aux_sync(xcb_connection);
    xcb_disconnect(xcb_connection);

    ev_check_stop(main_loop, xcb_chk);
    ev_prepare_stop(main_loop, xcb_prep);
    ev_io_stop(main_loop, xcb_io);

    FREE(xcb_chk);
    FREE(xcb_prep);
    FREE(xcb_io);
}

/*
 * Get the earlier requested atoms and save them in the prepared data structure
 *
 */
void get_atoms(void) {
    xcb_intern_atom_reply_t *reply;
#define ATOM_DO(name)                                                        \
    reply = xcb_intern_atom_reply(xcb_connection, atom_cookies[name], NULL); \
    if (reply == NULL) {                                                     \
        ELOG("Could not get atom %s\n", #name);                              \
        exit(EXIT_FAILURE);                                                  \
    }                                                                        \
    atoms[name] = reply->atom;                                               \
    free(reply);

#include "xcb_atoms.def"
    DLOG("Got atoms\n");
}

/*
 * Reparents all tray clients of the specified output to the root window. This
 * is either used when shutting down, when an output appears (xrandr --output
 * VGA1 --off) or when the primary output changes.
 *
 * Applications using the tray will start the protocol from the beginning again
 * afterwards.
 *
 */
void kick_tray_clients(i3_output *output) {
    if (TAILQ_EMPTY(output->trayclients))
        return;

    trayclient *trayclient;
    while (!TAILQ_EMPTY(output->trayclients)) {
        trayclient = TAILQ_FIRST(output->trayclients);
        /* Unmap, then reparent (to root) the tray client windows */
        xcb_unmap_window(xcb_connection, trayclient->win);
        xcb_reparent_window(xcb_connection,
                            trayclient->win,
                            xcb_root,
                            0,
                            0);

        /* We remove the trayclient right here. We might receive an UnmapNotify
         * event afterwards, but better safe than sorry. */
        TAILQ_REMOVE(output->trayclients, trayclient, tailq);
    }

    /* Fake a DestroyNotify so that Qt re-adds tray icons.
     * We cannot actually destroy the window because then Qt will not restore
     * its event mask on the new window. */
    uint8_t buffer[32] = {0};
    xcb_destroy_notify_event_t *event = (xcb_destroy_notify_event_t *)buffer;

    event->response_type = XCB_DESTROY_NOTIFY;
    event->event = selwin;
    event->window = selwin;

    xcb_send_event(conn, false, selwin, XCB_EVENT_MASK_STRUCTURE_NOTIFY, (char *)event);

    send_tray_clientmessage();
}

/*
 * Destroy the bar of the specified output
 *
 */
void destroy_window(i3_output *output) {
    if (output == NULL) {
        return;
    }
    if (output->bar.id == XCB_NONE) {
        return;
    }

    kick_tray_clients(output);
    xcb_destroy_window(xcb_connection, output->bar.id);
    output->bar.id = XCB_NONE;
}

/* Strut partial tells i3 where to reserve space for i3bar. This is determined
 * by the `position` bar config directive. */
xcb_void_cookie_t config_strut_partial(i3_output *output) {
    /* A local struct to save the strut_partial property */
    struct {
        uint32_t left;
        uint32_t right;
        uint32_t top;
        uint32_t bottom;
        uint32_t left_start_y;
        uint32_t left_end_y;
        uint32_t right_start_y;
        uint32_t right_end_y;
        uint32_t top_start_x;
        uint32_t top_end_x;
        uint32_t bottom_start_x;
        uint32_t bottom_end_x;
    } __attribute__((__packed__)) strut_partial;
    memset(&strut_partial, 0, sizeof(strut_partial));

    switch (config.position) {
        case POS_NONE:
            break;
        case POS_TOP:
            strut_partial.top = bar_height;
            strut_partial.top_start_x = output->rect.x;
            strut_partial.top_end_x = output->rect.x + output->rect.w;
            break;
        case POS_BOT:
            strut_partial.bottom = bar_height;
            strut_partial.bottom_start_x = output->rect.x;
            strut_partial.bottom_end_x = output->rect.x + output->rect.w;
            break;
    }
    return xcb_change_property(xcb_connection,
                               XCB_PROP_MODE_REPLACE,
                               output->bar.id,
                               atoms[_NET_WM_STRUT_PARTIAL],
                               XCB_ATOM_CARDINAL,
                               32,
                               12,
                               &strut_partial);
}

/*
 * Reconfigure all bars and create new bars for recently activated outputs
 *
 */
void reconfig_windows(bool redraw_bars) {
    uint32_t mask;
    uint32_t values[6];
    static bool tray_configured = false;

    i3_output *walk;
    SLIST_FOREACH(walk, outputs, slist) {
        if (!walk->active) {
            /* If an output is not active, we destroy its bar */
            /* FIXME: Maybe we rather want to unmap? */
            DLOG("Destroying window for output %s\n", walk->name);
            destroy_window(walk);
            continue;
        }
        if (walk->bar.id == XCB_NONE) {
            DLOG("Creating window for output %s\n", walk->name);

            xcb_window_t bar_id = xcb_generate_id(xcb_connection);
            xcb_pixmap_t buffer_id = xcb_generate_id(xcb_connection);
            xcb_pixmap_t statusline_buffer_id = xcb_generate_id(xcb_connection);
            mask = XCB_CW_BACK_PIXEL | XCB_CW_BORDER_PIXEL | XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK | XCB_CW_COLORMAP | XCB_CW_CURSOR;

            values[0] = colors.bar_bg.colorpixel;
            values[1] = root_screen->black_pixel;
            /* If hide_on_modifier is set to hide or invisible mode, i3 is not supposed to manage our bar windows */
            values[2] = (config.hide_on_modifier == M_DOCK ? 0 : 1);
            /* We enable the following EventMask fields:
             * EXPOSURE, to get expose events (we have to re-draw then)
             * SUBSTRUCTURE_REDIRECT, to get ConfigureRequests when the tray
             *                        child windows use ConfigureWindow
             * BUTTON_PRESS, to handle clicks on the workspace buttons
             * */
            values[3] = XCB_EVENT_MASK_EXPOSURE |
                        XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT |
                        XCB_EVENT_MASK_BUTTON_PRESS;
            if (config.hide_on_modifier == M_DOCK) {
                /* If the bar is normally visible, catch visibility change events to suspend
                 * the status process when the bar is obscured by full-screened windows.  */
                values[3] |= XCB_EVENT_MASK_VISIBILITY_CHANGE;
                walk->visible = true;
            }
            values[4] = colormap;
            values[5] = cursor;

            xcb_void_cookie_t win_cookie = xcb_create_window_checked(xcb_connection,
                                                                     depth,
                                                                     bar_id,
                                                                     xcb_root,
                                                                     walk->rect.x, walk->rect.y + walk->rect.h - bar_height,
                                                                     walk->rect.w, bar_height,
                                                                     0,
                                                                     XCB_WINDOW_CLASS_INPUT_OUTPUT,
                                                                     visual_type->visual_id,
                                                                     mask,
                                                                     values);

            /* The double-buffer we use to render stuff off-screen */
            xcb_void_cookie_t pm_cookie = xcb_create_pixmap_checked(xcb_connection,
                                                                    depth,
                                                                    buffer_id,
                                                                    bar_id,
                                                                    walk->rect.w,
                                                                    bar_height);

            /* The double-buffer we use to render the statusline before copying to buffer */
            xcb_void_cookie_t slpm_cookie = xcb_create_pixmap_checked(xcb_connection,
                                                                      depth,
                                                                      statusline_buffer_id,
                                                                      bar_id,
                                                                      walk->rect.w,
                                                                      bar_height);

            /* Set the WM_CLASS and WM_NAME (we don't need UTF-8) atoms */
            xcb_void_cookie_t class_cookie;
            class_cookie = xcb_change_property(xcb_connection,
                                               XCB_PROP_MODE_REPLACE,
                                               bar_id,
                                               XCB_ATOM_WM_CLASS,
                                               XCB_ATOM_STRING,
                                               8,
                                               (strlen("i3bar") + 1) * 2,
                                               "i3bar\0i3bar\0");

            char *name;
            sasprintf(&name, "i3bar for output %s", walk->name);
            xcb_void_cookie_t name_cookie;
            name_cookie = xcb_change_property(xcb_connection,
                                              XCB_PROP_MODE_REPLACE,
                                              bar_id,
                                              XCB_ATOM_WM_NAME,
                                              XCB_ATOM_STRING,
                                              8,
                                              strlen(name),
                                              name);
            free(name);

            /* We want dock windows (for now). When override_redirect is set, i3 is ignoring
             * this one */
            xcb_void_cookie_t dock_cookie = xcb_change_property(xcb_connection,
                                                                XCB_PROP_MODE_REPLACE,
                                                                bar_id,
                                                                atoms[_NET_WM_WINDOW_TYPE],
                                                                XCB_ATOM_ATOM,
                                                                32,
                                                                1,
                                                                (unsigned char *)&atoms[_NET_WM_WINDOW_TYPE_DOCK]);

            draw_util_surface_init(xcb_connection, &walk->bar, bar_id, NULL, walk->rect.w, bar_height);
            draw_util_surface_init(xcb_connection, &walk->buffer, buffer_id, NULL, walk->rect.w, bar_height);
            draw_util_surface_init(xcb_connection, &walk->statusline_buffer, statusline_buffer_id, NULL, walk->rect.w, bar_height);

            xcb_void_cookie_t strut_cookie = config_strut_partial(walk);

            /* We finally map the bar (display it on screen), unless the modifier-switch is on */
            xcb_void_cookie_t map_cookie;
            if (config.hide_on_modifier == M_DOCK) {
                map_cookie = xcb_map_window_checked(xcb_connection, bar_id);
            }

            if (xcb_request_failed(win_cookie, "Could not create window") ||
                xcb_request_failed(pm_cookie, "Could not create pixmap") ||
                xcb_request_failed(slpm_cookie, "Could not create statusline pixmap") ||
                xcb_request_failed(dock_cookie, "Could not set dock mode") ||
                xcb_request_failed(class_cookie, "Could not set WM_CLASS") ||
                xcb_request_failed(name_cookie, "Could not set WM_NAME") ||
                xcb_request_failed(strut_cookie, "Could not set strut") ||
                ((config.hide_on_modifier == M_DOCK) && xcb_request_failed(map_cookie, "Could not map window"))) {
                exit(EXIT_FAILURE);
            }

            /* Unless "tray_output none" was specified, we need to initialize the tray. */
            const char *first = (TAILQ_EMPTY(&(config.tray_outputs))) ? SLIST_FIRST(outputs)->name : TAILQ_FIRST(&(config.tray_outputs))->output;
            if (!tray_configured && strcasecmp(first, "none") != 0) {
                /* We do a sanity check here to ensure that this i3bar instance actually handles
                 * the output on which the tray should appear. For example,
                 * consider tray_output == [VGA-1], but output == [HDMI-1]. */

                /* If no tray_output was specified, we go ahead and initialize the tray as
                 * we will be using the first available output. */
                if (TAILQ_EMPTY(&(config.tray_outputs)))
                    init_tray();

                /* If one or more tray_output assignments were specified, we ensure that at least one of
                 * them is actually an output managed by this instance. */
                tray_output_t *tray_output;
                TAILQ_FOREACH(tray_output, &(config.tray_outputs), tray_outputs) {
                    i3_output *output;
                    bool found = false;
                    SLIST_FOREACH(output, outputs, slist) {
                        if (strcasecmp(output->name, tray_output->output) == 0 ||
                            (strcasecmp(tray_output->output, "primary") == 0 && output->primary)) {
                            found = true;
                            init_tray();
                            break;
                        }
                    }

                    if (found)
                        break;
                }

                tray_configured = true;
            }
        } else {
            /* We already have a bar, so we just reconfigure it */
            mask = XCB_CONFIG_WINDOW_X |
                   XCB_CONFIG_WINDOW_Y |
                   XCB_CONFIG_WINDOW_WIDTH |
                   XCB_CONFIG_WINDOW_HEIGHT |
                   XCB_CONFIG_WINDOW_STACK_MODE;
            values[0] = walk->rect.x;
            if (config.position == POS_TOP)
                values[1] = walk->rect.y;
            else
                values[1] = walk->rect.y + walk->rect.h - bar_height;
            values[2] = walk->rect.w;
            values[3] = bar_height;
            values[4] = XCB_STACK_MODE_ABOVE;

            DLOG("Reconfiguring strut partial property for output %s\n", walk->name);
            xcb_void_cookie_t strut_cookie = config_strut_partial(walk);

            DLOG("Destroying buffer for output %s\n", walk->name);
            xcb_free_pixmap(xcb_connection, walk->buffer.id);

            DLOG("Destroying statusline buffer for output %s\n", walk->name);
            xcb_free_pixmap(xcb_connection, walk->statusline_buffer.id);

            DLOG("Reconfiguring window for output %s to %d,%d\n", walk->name, values[0], values[1]);
            xcb_void_cookie_t cfg_cookie = xcb_configure_window_checked(xcb_connection,
                                                                        walk->bar.id,
                                                                        mask,
                                                                        values);

            mask = XCB_CW_OVERRIDE_REDIRECT;
            values[0] = (config.hide_on_modifier == M_DOCK ? 0 : 1);
            DLOG("Changing window attribute override_redirect for output %s to %d\n", walk->name, values[0]);
            xcb_void_cookie_t chg_cookie = xcb_change_window_attributes(xcb_connection,
                                                                        walk->bar.id,
                                                                        mask,
                                                                        values);

            DLOG("Recreating buffer for output %s\n", walk->name);
            xcb_void_cookie_t pm_cookie = xcb_create_pixmap_checked(xcb_connection,
                                                                    depth,
                                                                    walk->buffer.id,
                                                                    walk->bar.id,
                                                                    walk->rect.w,
                                                                    bar_height);

            DLOG("Recreating statusline buffer for output %s\n", walk->name);
            xcb_void_cookie_t slpm_cookie = xcb_create_pixmap_checked(xcb_connection,
                                                                      depth,
                                                                      walk->statusline_buffer.id,
                                                                      walk->bar.id,
                                                                      walk->rect.w,
                                                                      bar_height);

            draw_util_surface_free(xcb_connection, &(walk->bar));
            draw_util_surface_free(xcb_connection, &(walk->buffer));
            draw_util_surface_free(xcb_connection, &(walk->statusline_buffer));
            draw_util_surface_init(xcb_connection, &(walk->bar), walk->bar.id, NULL, walk->rect.w, bar_height);
            draw_util_surface_init(xcb_connection, &(walk->buffer), walk->buffer.id, NULL, walk->rect.w, bar_height);
            draw_util_surface_init(xcb_connection, &(walk->statusline_buffer), walk->statusline_buffer.id, NULL, walk->rect.w, bar_height);

            xcb_void_cookie_t map_cookie, umap_cookie;
            if (redraw_bars) {
                /* Unmap the window, and draw it again when in dock mode */
                umap_cookie = xcb_unmap_window_checked(xcb_connection, walk->bar.id);
                if (config.hide_on_modifier == M_DOCK) {
                    cont_child();
                    map_cookie = xcb_map_window_checked(xcb_connection, walk->bar.id);
                } else {
                    stop_child();
                }

                if (config.hide_on_modifier == M_HIDE) {
                    /* Switching to hide mode, register for keyevents */
                    register_xkb_keyevents();
                } else {
                    /* Switching to dock/invisible mode, deregister from keyevents */
                    deregister_xkb_keyevents();
                }
            }

            if (xcb_request_failed(cfg_cookie, "Could not reconfigure window") ||
                xcb_request_failed(chg_cookie, "Could not change window") ||
                xcb_request_failed(pm_cookie, "Could not create pixmap") ||
                xcb_request_failed(slpm_cookie, "Could not create statusline pixmap") ||
                xcb_request_failed(strut_cookie, "Could not set strut") ||
                (redraw_bars && (xcb_request_failed(umap_cookie, "Could not unmap window") ||
                                 (config.hide_on_modifier == M_DOCK && xcb_request_failed(map_cookie, "Could not map window"))))) {
                exit(EXIT_FAILURE);
            }
        }
    }
}

/*
 * Render the bars, with buttons and statusline
 *
 */
void draw_bars(bool unhide) {
    DLOG("Drawing bars...\n");

    uint32_t full_statusline_width = predict_statusline_length(false);
    uint32_t short_statusline_width = predict_statusline_length(true);

    i3_output *outputs_walk;
    SLIST_FOREACH(outputs_walk, outputs, slist) {
        int workspace_width = 0;

        if (!outputs_walk->active) {
            DLOG("Output %s inactive, skipping...\n", outputs_walk->name);
            continue;
        }
        if (outputs_walk->bar.id == XCB_NONE) {
            /* Oh shit, an active output without an own bar. Create it now! */
            reconfig_windows(false);
        }

        bool use_focus_colors = output_has_focus(outputs_walk);

        /* First things first: clear the backbuffer */
        draw_util_clear_surface(xcb_connection, &(outputs_walk->buffer),
                                (use_focus_colors ? colors.focus_bar_bg : colors.bar_bg));

        if (!config.disable_ws) {
            i3_ws *ws_walk;
            TAILQ_FOREACH(ws_walk, outputs_walk->workspaces, tailq) {
                DLOG("Drawing button for WS %s at x = %d, len = %d\n",
                     i3string_as_utf8(ws_walk->name), workspace_width, ws_walk->name_width);
                color_t fg_color = colors.inactive_ws_fg;
                color_t bg_color = colors.inactive_ws_bg;
                color_t border_color = colors.inactive_ws_border;
                if (ws_walk->visible) {
                    if (!ws_walk->focused) {
                        fg_color = colors.active_ws_fg;
                        bg_color = colors.active_ws_bg;
                        border_color = colors.active_ws_border;
                    } else {
                        fg_color = colors.focus_ws_fg;
                        bg_color = colors.focus_ws_bg;
                        border_color = colors.focus_ws_border;
                    }
                }
                if (ws_walk->urgent) {
                    DLOG("WS %s is urgent!\n", i3string_as_utf8(ws_walk->name));
                    fg_color = colors.urgent_ws_fg;
                    bg_color = colors.urgent_ws_bg;
                    border_color = colors.urgent_ws_border;
                    unhide = true;
                }

                /* Draw the border of the button. */
                draw_util_rectangle(xcb_connection, &(outputs_walk->buffer), border_color,
                                    workspace_width,
                                    logical_px(1),
                                    ws_walk->name_width + 2 * logical_px(ws_hoff_px) + 2 * logical_px(1),
                                    font.height + 2 * logical_px(ws_voff_px) - 2 * logical_px(1));

                /* Draw the inside of the button. */
                draw_util_rectangle(xcb_connection, &(outputs_walk->buffer), bg_color,
                                    workspace_width + logical_px(1),
                                    2 * logical_px(1),
                                    ws_walk->name_width + 2 * logical_px(ws_hoff_px),
                                    font.height + 2 * logical_px(ws_voff_px) - 4 * logical_px(1));

                draw_util_text(ws_walk->name, &(outputs_walk->buffer), fg_color, bg_color,
                               workspace_width + logical_px(ws_hoff_px) + logical_px(1),
                               logical_px(ws_voff_px),
                               ws_walk->name_width);

                workspace_width += 2 * logical_px(ws_hoff_px) + 2 * logical_px(1) + ws_walk->name_width;
                if (TAILQ_NEXT(ws_walk, tailq) != NULL)
                    workspace_width += logical_px(ws_spacing_px);
            }
        }

        if (binding.name && !config.disable_binding_mode_indicator) {
            workspace_width += logical_px(ws_spacing_px);

            color_t fg_color = colors.binding_mode_fg;
            color_t bg_color = colors.binding_mode_bg;

            draw_util_rectangle(xcb_connection, &(outputs_walk->buffer), colors.binding_mode_border,
                                workspace_width,
                                logical_px(1),
                                binding.width + 2 * logical_px(ws_hoff_px) + 2 * logical_px(1),
                                font.height + 2 * logical_px(ws_voff_px) - 2 * logical_px(1));

            draw_util_rectangle(xcb_connection, &(outputs_walk->buffer), bg_color,
                                workspace_width + logical_px(1),
                                2 * logical_px(1),
                                binding.width + 2 * logical_px(ws_hoff_px),
                                font.height + 2 * logical_px(ws_voff_px) - 4 * logical_px(1));

            draw_util_text(binding.name, &(outputs_walk->buffer), fg_color, bg_color,
                           workspace_width + logical_px(ws_hoff_px) + logical_px(1),
                           logical_px(ws_voff_px),
                           binding.width);

            unhide = true;
            workspace_width += 2 * logical_px(ws_hoff_px) + 2 * logical_px(1) + binding.width;
        }

        if (!TAILQ_EMPTY(&statusline_head)) {
            DLOG("Printing statusline!\n");

            int tray_width = get_tray_width(outputs_walk->trayclients);
            uint32_t max_statusline_width = outputs_walk->rect.w - workspace_width - tray_width - 2 * logical_px(sb_hoff_px);
            uint32_t clip_left = 0;
            uint32_t statusline_width = full_statusline_width;
            bool use_short_text = false;

            if (statusline_width > max_statusline_width) {
                statusline_width = short_statusline_width;
                use_short_text = true;
                if (statusline_width > max_statusline_width) {
                    clip_left = statusline_width - max_statusline_width;
                }
            }

            int16_t visible_statusline_width = MIN(statusline_width, max_statusline_width);
            int x_dest = outputs_walk->rect.w - tray_width - logical_px(sb_hoff_px) - visible_statusline_width;

            draw_statusline(outputs_walk, clip_left, use_focus_colors, use_short_text);
            draw_util_copy_surface(xcb_connection, &outputs_walk->statusline_buffer, &outputs_walk->buffer, 0, 0,
                                   x_dest, 0, visible_statusline_width, (int16_t)bar_height);

            outputs_walk->statusline_width = statusline_width;
            outputs_walk->statusline_short_text = use_short_text;
        }
    }

    /* Assure the bar is hidden/unhidden according to the specified hidden_state and mode */
    if (mod_pressed ||
        config.hidden_state == S_SHOW ||
        unhide) {
        unhide_bars();
    } else if (config.hide_on_modifier == M_HIDE) {
        hide_bars();
    }

    redraw_bars();
}

/*
 * Redraw the bars, i.e. simply copy the buffer to the barwindow
 *
 */
void redraw_bars(void) {
    i3_output *outputs_walk;
    SLIST_FOREACH(outputs_walk, outputs, slist) {
        if (!outputs_walk->active) {
            continue;
        }

        draw_util_copy_surface(xcb_connection, &(outputs_walk->buffer), &(outputs_walk->bar), 0, 0,
                               0, 0, outputs_walk->rect.w, outputs_walk->rect.h);
        xcb_flush(xcb_connection);
    }
}

/*
 * Set the current binding mode
 *
 */
void set_current_mode(struct mode *current) {
    I3STRING_FREE(binding.name);
    binding = *current;
    activated_mode = binding.name != NULL;
    return;
}