[bspwm.git] / src / tree.c

/* Copyright (c) 2012, Bastien Dejean
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include "bspwm.h"
#include "desktop.h"
#include "ewmh.h"
#include "history.h"
#include "monitor.h"
#include "query.h"
#include "geometry.h"
#include "subscribe.h"
#include "settings.h"
#include "pointer.h"
#include "stack.h"
#include "window.h"
#include "tree.h"

void arrange(monitor_t *m, desktop_t *d)
{
        if (d->root == NULL) {
                return;
        }

        layout_t l = d->layout;

        if (single_monocle && tiled_count(d->root) <= 1) {
                l = LAYOUT_MONOCLE;
        }

        xcb_rectangle_t rect = m->rectangle;

        if (!paddingless_monocle || l != LAYOUT_MONOCLE) {
                rect.x += m->padding.left + d->padding.left;
                rect.y += m->padding.top + d->padding.top;
                rect.width -= m->padding.left + d->padding.left + d->padding.right + m->padding.right;
                rect.height -= m->padding.top + d->padding.top + d->padding.bottom + m->padding.bottom;
        }

        if (!gapless_monocle || l != LAYOUT_MONOCLE) {
                rect.x += d->window_gap;
                rect.y += d->window_gap;
                rect.width -= d->window_gap;
                rect.height -= d->window_gap;
        }

        apply_layout(m, d, d->root, l, rect, rect);
}

void apply_layout(monitor_t *m, desktop_t *d, node_t *n, layout_t l, xcb_rectangle_t rect, xcb_rectangle_t root_rect)
{
        if (n == NULL) {
                return;
        }

        n->rectangle = rect;

        if (pointer_follows_focus && mon->desk->focus == n) {
                xcb_rectangle_t r = rect;
                r.width -= d->window_gap;
                r.height -= d->window_gap;
                center_pointer(r);
        }

        if (n->presel != NULL) {
                draw_presel_feedback(m, d, n);
        }

        if (is_leaf(n)) {

                if (n->client == NULL) {
                        return;
                }

                unsigned int bw;
                if ((borderless_monocle && l == LAYOUT_MONOCLE && IS_TILED(n->client))
                    || n->client->state == STATE_FULLSCREEN) {
                        bw = 0;
                } else {
                        bw = n->client->border_width;
                }

                xcb_rectangle_t r;
                xcb_rectangle_t cr = get_window_rectangle(n);
                client_state_t s = n->client->state;
                if (s == STATE_TILED || s == STATE_PSEUDO_TILED) {
                        int wg = (gapless_monocle && l == LAYOUT_MONOCLE ? 0 : d->window_gap);
                        /* tiled clients */
                        if (s == STATE_TILED) {
                                r = rect;
                                int bleed = wg + 2 * bw;
                                r.width = (bleed < r.width ? r.width - bleed : 1);
                                r.height = (bleed < r.height ? r.height - bleed : 1);
                        /* pseudo-tiled clients */
                        } else {
                                r = n->client->floating_rectangle;
                                if (center_pseudo_tiled) {
                                        r.x = rect.x - bw + (rect.width - wg - r.width) / 2;
                                        r.y = rect.y - bw + (rect.height - wg - r.height) / 2;
                                } else {
                                        r.x = rect.x;
                                        r.y = rect.y;
                                }
                        }
                        n->client->tiled_rectangle = r;
                /* floating clients */
                } else if (s == STATE_FLOATING) {
                        r = n->client->floating_rectangle;
                /* fullscreen clients */
                } else {
                        r = m->rectangle;
                        n->client->tiled_rectangle = r;
                }

                apply_size_hints(n->client, &r.width, &r.height);

                if (!rect_eq(r, cr)) {
                        window_move_resize(n->id, r.x, r.y, r.width, r.height);
                        if (!grabbing) {
                                put_status(SBSC_MASK_NODE_GEOMETRY, "node_geometry 0x%08X 0x%08X 0x%08X %ux%u+%i+%i\n", m->id, d->id, n->id, r.width, r.height, r.x, r.y);
                        }
                }

                window_border_width(n->id, bw);

        } else {
                xcb_rectangle_t first_rect;
                xcb_rectangle_t second_rect;

                if (l == LAYOUT_MONOCLE || n->first_child->vacant || n->second_child->vacant) {
                        first_rect = second_rect = rect;
                } else {
                        unsigned int fence;
                        if (n->split_type == TYPE_VERTICAL) {
                                fence = rect.width * n->split_ratio;
                                if ((n->first_child->constraints.min_width + n->second_child->constraints.min_width) <= rect.width) {
                                        if (fence < n->first_child->constraints.min_width) {
                                                fence = n->first_child->constraints.min_width;
                                                n->split_ratio = (double) fence / (double) rect.width;
                                        } else if (fence > (uint16_t) (rect.width - n->second_child->constraints.min_width)) {
                                                fence = (rect.width - n->second_child->constraints.min_width);
                                                n->split_ratio = (double) fence / (double) rect.width;
                                        }
                                }
                                first_rect = (xcb_rectangle_t) {rect.x, rect.y, fence, rect.height};
                                second_rect = (xcb_rectangle_t) {rect.x + fence, rect.y, rect.width - fence, rect.height};
                        } else {
                                fence = rect.height * n->split_ratio;
                                if ((n->first_child->constraints.min_height + n->second_child->constraints.min_height) <= rect.height) {
                                        if (fence < n->first_child->constraints.min_height) {
                                                fence = n->first_child->constraints.min_height;
                                                n->split_ratio = (double) fence / (double) rect.height;
                                        } else if (fence > (uint16_t) (rect.height - n->second_child->constraints.min_height)) {
                                                fence = (rect.height - n->second_child->constraints.min_height);
                                                n->split_ratio = (double) fence / (double) rect.height;
                                        }
                                }
                                first_rect = (xcb_rectangle_t) {rect.x, rect.y, rect.width, fence};
                                second_rect = (xcb_rectangle_t) {rect.x, rect.y + fence, rect.width, rect.height - fence};
                        }
                }

                apply_layout(m, d, n->first_child, l, first_rect, root_rect);
                apply_layout(m, d, n->second_child, l, second_rect, root_rect);
        }
}

presel_t *make_presel(void)
{
        presel_t *p = calloc(1, sizeof(presel_t));
        p->split_dir = DIR_EAST;
        p->split_ratio = split_ratio;
        p->feedback = XCB_NONE;
        return p;
}

void set_ratio(node_t *n, double rat)
{
        if (n == NULL) {
                return;
        }

        n->split_ratio = rat;
}

void presel_dir(monitor_t *m, desktop_t *d, node_t *n, direction_t dir)
{
        if (n->presel == NULL) {
                n->presel = make_presel();
        }

        n->presel->split_dir = dir;

        put_status(SBSC_MASK_NODE_PRESEL, "node_presel 0x%08X 0x%08X 0x%08X dir %s\n", m->id, d->id, n->id, SPLIT_DIR_STR(dir));
}

void presel_ratio(monitor_t *m, desktop_t *d, node_t *n, double ratio)
{
        if (n->presel == NULL) {
                n->presel = make_presel();
        }

        n->presel->split_ratio = ratio;

        put_status(SBSC_MASK_NODE_PRESEL, "node_presel 0x%08X 0x%08X 0x%08X ratio %lf\n", m->id, d->id, n->id, ratio);
}

void cancel_presel(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n->presel == NULL) {
                return;
        }

        if (n->presel->feedback != XCB_NONE) {
                xcb_destroy_window(dpy, n->presel->feedback);
        }

        free(n->presel);
        n->presel = NULL;

        put_status(SBSC_MASK_NODE_PRESEL, "node_presel 0x%08X 0x%08X 0x%08X cancel\n", m->id, d->id, n->id);
}

void cancel_presel_in(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        }
        cancel_presel(m, d, n);
        cancel_presel_in(m, d, n->first_child);
        cancel_presel_in(m, d, n->second_child);
}

node_t *find_public(desktop_t *d)
{
        unsigned int b_manual_area = 0;
        unsigned int b_automatic_area = 0;
        node_t *b_manual = NULL;
        node_t *b_automatic = NULL;
        for (node_t *n = first_extrema(d->root); n != NULL; n = next_leaf(n, d->root)) {
                if (n->vacant) {
                        continue;
                }
                unsigned int n_area = node_area(d, n);
                if (n_area > b_manual_area && (n->presel != NULL || !n->private)) {
                        b_manual = n;
                        b_manual_area = n_area;
                }
                if (n_area > b_automatic_area &&
                    n->presel == NULL && !n->private && private_count(n->parent) == 0) {
                        b_automatic = n;
                        b_automatic_area = n_area;
                }
        }
        if (b_automatic != NULL) {
                return b_automatic;
        } else {
                return b_manual;
        }
}

node_t *insert_node(monitor_t *m, desktop_t *d, node_t *n, node_t *f)
{
        if (d == NULL || n == NULL) {
                return NULL;
        }

        /* n: inserted node */
        /* c: new internal node */
        /* f: focus or insertion anchor */
        /* p: parent of focus */
        /* g: grand parent of focus */

        if (f == NULL) {
                f = d->root;
        }

        if (f == NULL) {
                d->root = n;
        } else if (IS_RECEPTACLE(f) && f->presel == NULL) {
                node_t *p = f->parent;
                if (p != NULL) {
                        if (is_first_child(f)) {
                                p->first_child = n;
                        } else {
                                p->second_child = n;
                        }
                } else {
                        d->root = n;
                }
                n->parent = p;
                free(f);
                f = NULL;
        } else {
                node_t *c = make_node(XCB_NONE);
                node_t *p = f->parent;
                if (f->presel == NULL && (f->private || private_count(f->parent) > 0)) {
                        node_t *k = find_public(d);
                        if (k != NULL) {
                                f = k;
                                p = f->parent;
                        }
                        if (f->presel == NULL && (f->private || private_count(f->parent) > 0)) {
                                xcb_rectangle_t rect = get_rectangle(m, d, f);
                                presel_dir(m, d, f, (rect.width >= rect.height ? DIR_EAST : DIR_SOUTH));
                        }
                }
                if (f->presel == NULL && p != NULL && p->vacant) {
                        f = p;
                        p = f->parent;
                }
                n->parent = c;
                c->birth_rotation = f->birth_rotation;
                if (f->presel == NULL) {
                        if (p == NULL) {
                                if (initial_polarity == FIRST_CHILD) {
                                        c->first_child = n;
                                        c->second_child = f;
                                } else {
                                        c->first_child = f;
                                        c->second_child = n;
                                }
                                if (m->rectangle.width > m->rectangle.height) {
                                        c->split_type = TYPE_VERTICAL;
                                } else {
                                        c->split_type = TYPE_HORIZONTAL;
                                }
                                f->parent = c;
                                d->root = c;
                        } else {
                                node_t *g = p->parent;
                                c->parent = g;
                                if (g != NULL) {
                                        if (is_first_child(p)) {
                                                g->first_child = c;
                                        } else {
                                                g->second_child = c;
                                        }
                                } else {
                                        d->root = c;
                                }
                                c->split_type = p->split_type;
                                c->split_ratio = p->split_ratio;
                                p->parent = c;
                                int rot;
                                if (is_first_child(f)) {
                                        c->first_child = n;
                                        c->second_child = p;
                                        rot = 90;
                                } else {
                                        c->first_child = p;
                                        c->second_child = n;
                                        rot = 270;
                                }
                                n->birth_rotation = rot;
                                if (!n->vacant) {
                                        rotate_tree(p, rot);
                                }
                        }
                } else {
                        if (p != NULL) {
                                if (is_first_child(f)) {
                                        p->first_child = c;
                                } else {
                                        p->second_child = c;
                                }
                        }
                        c->split_ratio = f->presel->split_ratio;
                        c->parent = p;
                        f->parent = c;
                        f->birth_rotation = 0;
                        switch (f->presel->split_dir) {
                                case DIR_WEST:
                                        c->split_type = TYPE_VERTICAL;
                                        c->first_child = n;
                                        c->second_child = f;
                                        break;
                                case DIR_EAST:
                                        c->split_type = TYPE_VERTICAL;
                                        c->first_child = f;
                                        c->second_child = n;
                                        break;
                                case DIR_NORTH:
                                        c->split_type = TYPE_HORIZONTAL;
                                        c->first_child = n;
                                        c->second_child = f;
                                        break;
                                case DIR_SOUTH:
                                        c->split_type = TYPE_HORIZONTAL;
                                        c->first_child = f;
                                        c->second_child = n;
                                        break;
                        }
                        if (d->root == f) {
                                d->root = c;
                        }
                        cancel_presel(m, d, f);
                }
        }

        propagate_flags_upward(m, d, n);

        if (d->focus == NULL && is_focusable(n)) {
                d->focus = n;
        }

        return f;
}

void insert_receptacle(monitor_t *m, desktop_t *d, node_t *n)
{
        node_t *r = make_node(XCB_NONE);
        insert_node(m, d, r, n);
}

bool activate_node(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL && d->root != NULL) {
                n = history_last_node(d, NULL);
                if (n == NULL) {
                        n = first_focusable_leaf(d->root);
                }
        }

        if (d == mon->desk || (n != NULL && !is_focusable(n))) {
                return false;
        }

        if (n != NULL) {
                if (d->focus != NULL && n != d->focus) {
                        neutralize_occluding_windows(m, d, n);
                }
                stack(d, n, true);
                if (d->focus != n) {
                        for (node_t *f = first_extrema(d->focus); f != NULL; f = next_leaf(f, d->focus)) {
                                if (f->client != NULL && !is_descendant(f, n)) {
                                        window_draw_border(f->id, get_border_color(false, (m == mon)));
                                }
                        }
                }
                draw_border(n, true, (m == mon));
        }

        d->focus = n;
        history_add(m, d, n);

        put_status(SBSC_MASK_REPORT);

        if (n == NULL) {
                return true;
        }

        put_status(SBSC_MASK_NODE_ACTIVATE, "node_activate 0x%08X 0x%08X 0x%08X\n", m->id, d->id, n->id);

        return true;
}

void transfer_sticky_nodes(monitor_t *m, desktop_t *ds, desktop_t *dd, node_t *n)
{
        if (n == NULL) {
                return;
        } else if (n->sticky) {
                transfer_node(m, ds, n, m, dd, dd->focus, false);
        } else {
                /* we need references to the children because n might be freed after
                 * the first recursive call */
                node_t *first_child = n->first_child;
                node_t *second_child = n->second_child;
                transfer_sticky_nodes(m, ds, dd, first_child);
                transfer_sticky_nodes(m, ds, dd, second_child);
        }
}

bool focus_node(monitor_t *m, desktop_t *d, node_t *n)
{
        if (m == NULL) {
                m = history_last_monitor(NULL);
                if (m == NULL) {
                        m = mon_head;
                }
        }

        if (m == NULL) {
                return false;
        }

        if (d == NULL) {
                d = history_last_desktop(m, NULL);
                if (d == NULL) {
                        d = m->desk_head;
                }
        }

        if (d == NULL) {
                return false;
        }

        if (n == NULL && d->root != NULL) {
                n = history_last_node(d, NULL);
                if (n == NULL) {
                        n = first_focusable_leaf(d->root);
                }
        }

        if (n != NULL && !is_focusable(n)) {
                return false;
        }

        if ((mon != NULL && mon->desk != d) || n == NULL || n->client == NULL) {
                clear_input_focus();
        }

        if (m->sticky_count > 0 && d != m->desk) {
                sticky_still = false;
                transfer_sticky_nodes(m, m->desk, d, m->desk->root);
                sticky_still = true;
                if (n == NULL && d->focus != NULL) {
                        n = d->focus;
                }
        }

        if (d->focus != NULL && n != d->focus) {
                neutralize_occluding_windows(m, d, n);
        }

        if (n != NULL && n->client != NULL && n->client->urgent) {
                set_urgent(m, d, n, false);
        }

        if (mon != m) {
                if (mon != NULL) {
                        for (desktop_t *e = mon->desk_head; e != NULL; e = e->next) {
                                draw_border(e->focus, true, false);
                        }
                }
                for (desktop_t *e = m->desk_head; e != NULL; e = e->next) {
                        if (e == d) {
                                continue;
                        }
                        draw_border(e->focus, true, true);
                }
        }

        if (d->focus != n) {
                for (node_t *f = first_extrema(d->focus); f != NULL; f = next_leaf(f, d->focus)) {
                        if (f->client != NULL && !is_descendant(f, n)) {
                                window_draw_border(f->id, get_border_color(false, true));
                        }
                }
        }

        draw_border(n, true, true);

        focus_desktop(m, d);

        d->focus = n;
        ewmh_update_active_window();
        history_add(m, d, n);

        put_status(SBSC_MASK_REPORT);

        if (n == NULL) {
                if (focus_follows_pointer) {
                        update_motion_recorder();
                }
                return true;
        }

        put_status(SBSC_MASK_NODE_FOCUS, "node_focus 0x%08X 0x%08X 0x%08X\n", m->id, d->id, n->id);

        stack(d, n, true);
        set_input_focus(n);

        if (pointer_follows_focus) {
                center_pointer(get_rectangle(m, d, n));
        } else if (focus_follows_pointer) {
                update_motion_recorder();
        }

        return true;
}

void hide_node(desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        } else {
                if (!n->hidden) {
                        if (n->presel != NULL && d->layout != LAYOUT_MONOCLE) {
                                window_hide(n->presel->feedback);
                        }
                        if (n->client != NULL) {
                                window_hide(n->id);
                        }
                }
                if (n->client != NULL) {
                        n->client->shown = false;
                }
                hide_node(d, n->first_child);
                hide_node(d, n->second_child);
        }
}

void show_node(desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        } else {
                if (!n->hidden) {
                        if (n->client != NULL) {
                                window_show(n->id);
                        }
                        if (n->presel != NULL && d->layout != LAYOUT_MONOCLE) {
                                window_show(n->presel->feedback);
                        }
                }
                if (n->client != NULL) {
                        n->client->shown = true;
                }
                show_node(d, n->first_child);
                show_node(d, n->second_child);
        }
}

node_t *make_node(uint32_t id)
{
        if (id == XCB_NONE) {
                id = xcb_generate_id(dpy);
        }
        node_t *n = calloc(1, sizeof(node_t));
        n->id = id;
        n->parent = n->first_child = n->second_child = NULL;
        n->vacant = n->hidden = n->sticky = n->private = n->locked = false;
        n->split_ratio = split_ratio;
        n->split_type = TYPE_VERTICAL;
        n->birth_rotation = 0;
        n->constraints = (constraints_t) {MIN_WIDTH, MIN_HEIGHT};
        n->presel = NULL;
        n->client = NULL;
        return n;
}

client_t *make_client(void)
{
        client_t *c = calloc(1, sizeof(client_t));
        c->state = c->last_state = STATE_TILED;
        c->layer = c->last_layer = LAYER_NORMAL;
        snprintf(c->class_name, sizeof(c->class_name), "%s", MISSING_VALUE);
        snprintf(c->instance_name, sizeof(c->instance_name), "%s", MISSING_VALUE);
        c->border_width = border_width;
        c->urgent = false;
        c->shown = false;
        c->wm_flags = 0;
        c->icccm_props.input_hint = true;
        c->icccm_props.take_focus = false;
        c->icccm_props.delete_window = false;
        c->size_hints.flags = 0;
        return c;
}

void initialize_client(node_t *n)
{
        xcb_window_t win = n->id;
        client_t *c = n->client;
        xcb_icccm_get_wm_protocols_reply_t protos;
        if (xcb_icccm_get_wm_protocols_reply(dpy, xcb_icccm_get_wm_protocols(dpy, win, ewmh->WM_PROTOCOLS), &protos, NULL) == 1) {
                for (uint32_t i = 0; i < protos.atoms_len; i++) {
                        if (protos.atoms[i] == WM_TAKE_FOCUS) {
                                c->icccm_props.take_focus = true;
                        } else if (protos.atoms[i] == WM_DELETE_WINDOW) {
                                c->icccm_props.delete_window = true;
                        }
                }
                xcb_icccm_get_wm_protocols_reply_wipe(&protos);
        }
        xcb_ewmh_get_atoms_reply_t wm_state;
        if (xcb_ewmh_get_wm_state_reply(ewmh, xcb_ewmh_get_wm_state(ewmh, win), &wm_state, NULL) == 1) {
                for (unsigned int i = 0; i < wm_state.atoms_len && i < MAX_WM_STATES; i++) {
#define HANDLE_WM_STATE(s) \
                        if (wm_state.atoms[i] == ewmh->_NET_WM_STATE_##s) { \
                                c->wm_flags |= WM_FLAG_##s; continue; \
                        }
                        HANDLE_WM_STATE(MODAL)
                        HANDLE_WM_STATE(STICKY)
                        HANDLE_WM_STATE(MAXIMIZED_VERT)
                        HANDLE_WM_STATE(MAXIMIZED_HORZ)
                        HANDLE_WM_STATE(SHADED)
                        HANDLE_WM_STATE(SKIP_TASKBAR)
                        HANDLE_WM_STATE(SKIP_PAGER)
                        HANDLE_WM_STATE(HIDDEN)
                        HANDLE_WM_STATE(FULLSCREEN)
                        HANDLE_WM_STATE(ABOVE)
                        HANDLE_WM_STATE(BELOW)
                        HANDLE_WM_STATE(DEMANDS_ATTENTION)
#undef HANDLE_WM_STATE
                }
                xcb_ewmh_get_atoms_reply_wipe(&wm_state);
        }
        xcb_icccm_wm_hints_t hints;
        if (xcb_icccm_get_wm_hints_reply(dpy, xcb_icccm_get_wm_hints(dpy, win), &hints, NULL) == 1
                && (hints.flags & XCB_ICCCM_WM_HINT_INPUT)) {
                c->icccm_props.input_hint = hints.input;
        }
        xcb_icccm_get_wm_normal_hints_reply(dpy, xcb_icccm_get_wm_normal_hints(dpy, win), &c->size_hints, NULL);
}

bool is_focusable(node_t *n)
{
        for (node_t *f = first_extrema(n); f != NULL; f = next_leaf(f, n)) {
                if (f->client != NULL && !f->hidden) {
                        return true;
                }
        }
        return false;
}

bool is_leaf(node_t *n)
{
        return (n != NULL && n->first_child == NULL && n->second_child == NULL);
}

bool is_first_child(node_t *n)
{
        return (n != NULL && n->parent != NULL && n->parent->first_child == n);
}

bool is_second_child(node_t *n)
{
        return (n != NULL && n->parent != NULL && n->parent->second_child == n);
}

unsigned int clients_count_in(node_t *n)
{
        if (n == NULL) {
                return 0;
        } else {
                return (n->client != NULL ? 1 : 0) +
                        clients_count_in(n->first_child) +
                        clients_count_in(n->second_child);
        }
}

node_t *brother_tree(node_t *n)
{
        if (n == NULL || n->parent == NULL) {
                return NULL;
        }
        if (is_first_child(n)) {
                return n->parent->second_child;
        } else {
                return n->parent->first_child;
        }
}

node_t *first_extrema(node_t *n)
{
        if (n == NULL) {
                return NULL;
        } else if (n->first_child == NULL) {
                return n;
        } else {
                return first_extrema(n->first_child);
        }
}

node_t *second_extrema(node_t *n)
{
        if (n == NULL) {
                return NULL;
        } else if (n->second_child == NULL) {
                return n;
        } else {
                return second_extrema(n->second_child);
        }
}

node_t *first_focusable_leaf(node_t *n)
{
        for (node_t *f = first_extrema(n); f != NULL; f = next_leaf(f, n)) {
                if (f->client != NULL && !f->hidden) {
                        return f;
                }
        }
        return NULL;
}

node_t *next_leaf(node_t *n, node_t *r)
{
        if (n == NULL) {
                return NULL;
        }
        node_t *p = n;
        while (is_second_child(p) && p != r) {
                p = p->parent;
        }
        if (p == r) {
                return NULL;
        }
        return first_extrema(p->parent->second_child);
}

node_t *prev_leaf(node_t *n, node_t *r)
{
        if (n == NULL) {
                return NULL;
        }
        node_t *p = n;
        while (is_first_child(p) && p != r) {
                p = p->parent;
        }
        if (p == r) {
                return NULL;
        }
        return second_extrema(p->parent->first_child);
}

node_t *next_tiled_leaf(node_t *n, node_t *r)
{
        node_t *next = next_leaf(n, r);
        if (next == NULL || (next->client != NULL && !next->vacant)) {
                return next;
        } else {
                return next_tiled_leaf(next, r);
        }
}

node_t *prev_tiled_leaf(node_t *n, node_t *r)
{
        node_t *prev = prev_leaf(n, r);
        if (prev == NULL || (prev->client != NULL && !prev->vacant)) {
                return prev;
        } else {
                return prev_tiled_leaf(prev, r);
        }
}

/* Returns true if *b* is adjacent to *a* in the direction *dir* */
bool is_adjacent(node_t *a, node_t *b, direction_t dir)
{
        switch (dir) {
                case DIR_EAST:
                        return (a->rectangle.x + a->rectangle.width) == b->rectangle.x;
                        break;
                case DIR_SOUTH:
                        return (a->rectangle.y + a->rectangle.height) == b->rectangle.y;
                        break;
                case DIR_WEST:
                        return (b->rectangle.x + b->rectangle.width) == a->rectangle.x;
                        break;
                case DIR_NORTH:
                        return (b->rectangle.y + b->rectangle.height) == a->rectangle.y;
                        break;
        }
        return false;
}

node_t *find_fence(node_t *n, direction_t dir)
{
        node_t *p;

        if (n == NULL) {
                return NULL;
        }

        p = n->parent;

        while (p != NULL) {
                if ((dir == DIR_NORTH && p->split_type == TYPE_HORIZONTAL && p->rectangle.y < n->rectangle.y) ||
                    (dir == DIR_WEST && p->split_type == TYPE_VERTICAL && p->rectangle.x < n->rectangle.x) ||
                    (dir == DIR_SOUTH && p->split_type == TYPE_HORIZONTAL && (p->rectangle.y + p->rectangle.height) > (n->rectangle.y + n->rectangle.height)) ||
                    (dir == DIR_EAST && p->split_type == TYPE_VERTICAL && (p->rectangle.x + p->rectangle.width) > (n->rectangle.x + n->rectangle.width)))
                        return p;
                p = p->parent;
        }

        return NULL;
}

/* returns *true* if *a* is a child of *b* */
bool is_child(node_t *a, node_t *b)
{
        if (a == NULL || b == NULL) {
                return false;
        }
        return (a->parent != NULL && a->parent == b);
}

/* returns *true* if *a* is a descendant of *b* */
bool is_descendant(node_t *a, node_t *b)
{
        if (a == NULL || b == NULL) {
                return false;
        }
        while (a != b && a != NULL) {
                a = a->parent;
        }
        return a == b;
}

bool find_by_id(uint32_t id, coordinates_t *loc)
{
        for (monitor_t *m = mon_head; m != NULL; m = m->next) {
                for (desktop_t *d = m->desk_head; d != NULL; d = d->next) {
                        node_t *n = find_by_id_in(d->root, id);
                        if (n != NULL) {
                                loc->monitor = m;
                                loc->desktop = d;
                                loc->node = n;
                                return true;
                        }
                }
        }
        return false;
}

node_t *find_by_id_in(node_t *r, uint32_t id)
{
        if (r == NULL) {
                return NULL;
        } else if (r->id == id) {
                return r;
        } else {
                node_t *f = find_by_id_in(r->first_child, id);
                if (f != NULL) {
                        return f;
                } else {
                        return find_by_id_in(r->second_child, id);
                }
        }
}

/* Based on https://github.com/ntrrgc/right-window */
void find_nearest_neighbor(coordinates_t *ref, coordinates_t *dst, direction_t dir, node_select_t sel)
{
        xcb_rectangle_t rect = get_rectangle(ref->monitor, ref->desktop, ref->node);
        double md = UINT32_MAX, mr = UINT32_MAX;

        for (monitor_t *m = mon_head; m != NULL; m = m->next) {
                desktop_t *d = m->desk;
                for (node_t *f = first_extrema(d->root); f != NULL; f = next_leaf(f, d->root)) {
                        coordinates_t loc = {m, d, f};
                        xcb_rectangle_t r = get_rectangle(m, d, f);
                        if (f == ref->node ||
                            f->client == NULL ||
                            f->hidden ||
                            is_descendant(f, ref->node) ||
                            !node_matches(&loc, ref, sel) ||
                            !on_dir_side(rect, r, dir)) {
                                continue;
                        }
                        uint32_t fd = boundary_distance(rect, r, dir);
                        uint32_t fr = history_rank(f);
                        if (fd < md || (fd == md && fr < mr)) {
                                md = fd;
                                mr = fr;
                                *dst = loc;
                        }
                }
        }
}

unsigned int node_area(desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return 0;
        }
        return area(get_rectangle(NULL, d, n));
}

int tiled_count(node_t *n)
{
        if (n == NULL) {
                return 0;
        }
        int cnt = 0;
        for (node_t *f = first_extrema(n); f != NULL; f = next_leaf(f, n)) {
                if (!f->hidden && f->client != NULL && IS_TILED(f->client)) {
                        cnt++;
                }
        }
        return cnt;
}

void find_biggest(coordinates_t *ref, coordinates_t *dst, node_select_t sel)
{
        unsigned int b_area = 0;

        for (monitor_t *m = mon_head; m != NULL; m = m->next) {
                for (desktop_t *d = m->desk_head; d != NULL; d = d->next) {
                        for (node_t *f = first_extrema(d->root); f != NULL; f = next_leaf(f, d->root)) {
                                coordinates_t loc = {m, d, f};
                                if (f->client == NULL || f->vacant || !node_matches(&loc, ref, sel)) {
                                        continue;
                                }
                                unsigned int f_area = node_area(d, f);
                                if (f_area > b_area) {
                                        *dst = loc;
                                        b_area = f_area;
                                }
                        }
                }
        }
}

void rotate_tree(node_t *n, int deg)
{
        rotate_tree_rec(n, deg);
        rebuild_constraints(n);
}

void rotate_tree_rec(node_t *n, int deg)
{
        if (n == NULL || is_leaf(n) || deg == 0) {
                return;
        }

        node_t *tmp;

        if ((deg == 90 && n->split_type == TYPE_HORIZONTAL) ||
            (deg == 270 && n->split_type == TYPE_VERTICAL) ||
            deg == 180) {
                tmp = n->first_child;
                n->first_child = n->second_child;
                n->second_child = tmp;
                n->split_ratio = 1.0 - n->split_ratio;
        }

        if (deg != 180) {
                if (n->split_type == TYPE_HORIZONTAL) {
                        n->split_type = TYPE_VERTICAL;
                } else if (n->split_type == TYPE_VERTICAL) {
                        n->split_type = TYPE_HORIZONTAL;
                }
        }

        rotate_tree_rec(n->first_child, deg);
        rotate_tree_rec(n->second_child, deg);
}

void rotate_brother(node_t *n)
{
        rotate_tree(brother_tree(n), n->birth_rotation);
}

void unrotate_tree(node_t *n, int rot)
{
        if (rot == 0) {
                return;
        }
        rotate_tree(n, 360 - rot);
}

void unrotate_brother(node_t *n)
{
        unrotate_tree(brother_tree(n), n->birth_rotation);
}

void flip_tree(node_t *n, flip_t flp)
{
        if (n == NULL || is_leaf(n)) {
                return;
        }

        node_t *tmp;

        if ((flp == FLIP_HORIZONTAL && n->split_type == TYPE_HORIZONTAL) ||
            (flp == FLIP_VERTICAL && n->split_type == TYPE_VERTICAL)) {
                tmp = n->first_child;
                n->first_child = n->second_child;
                n->second_child = tmp;
                n->split_ratio = 1.0 - n->split_ratio;
        }

        flip_tree(n->first_child, flp);
        flip_tree(n->second_child, flp);
}

void equalize_tree(node_t *n)
{
        if (n == NULL || n->vacant) {
                return;
        } else {
                n->split_ratio = split_ratio;
                equalize_tree(n->first_child);
                equalize_tree(n->second_child);
        }
}

int balance_tree(node_t *n)
{
        if (n == NULL || n->vacant) {
                return 0;
        } else if (is_leaf(n)) {
                return 1;
        } else {
                int b1 = balance_tree(n->first_child);
                int b2 = balance_tree(n->second_child);
                int b = b1 + b2;
                if (b1 > 0 && b2 > 0) {
                        n->split_ratio = (double) b1 / b;
                }
                return b;
        }
}

void unlink_node(monitor_t *m, desktop_t *d, node_t *n)
{
        if (d == NULL || n == NULL) {
                return;
        }

        node_t *p = n->parent;

        if (p == NULL) {
                d->root = NULL;
                d->focus = NULL;
        } else {
                if (d->focus == p || is_descendant(d->focus, n)) {
                        d->focus = NULL;
                }

                history_remove(d, p, false);
                cancel_presel(m, d, p);
                if (p->sticky) {
                        m->sticky_count--;
                }

                node_t *b = brother_tree(n);
                node_t *g = p->parent;

                if (!n->vacant) {
                        unrotate_tree(b, n->birth_rotation);
                }

                b->parent = g;

                if (g != NULL) {
                        if (is_first_child(p)) {
                                g->first_child = b;
                        } else {
                                g->second_child = b;
                        }
                } else {
                        d->root = b;
                }

                b->birth_rotation = p->birth_rotation;

                free(p);
                n->parent = NULL;

                propagate_flags_upward(m, d, b);
        }
}

void close_node(node_t *n)
{
        if (n == NULL) {
                return;
        } else if (n->client != NULL) {
                if (n->client->icccm_props.delete_window) {
                        send_client_message(n->id, ewmh->WM_PROTOCOLS, WM_DELETE_WINDOW);
                } else {
                        xcb_kill_client(dpy, n->id);
                }
        } else {
                close_node(n->first_child);
                close_node(n->second_child);
        }
}

void kill_node(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        }

        for (node_t *f = first_extrema(n); f != NULL; f = next_leaf(f, n)) {
                if (f->client != NULL) {
                        xcb_kill_client(dpy, f->id);
                }
        }

        remove_node(m, d, n);
}

void remove_node(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        }

        unlink_node(m, d, n);
        history_remove(d, n, true);
        remove_stack_node(n);
        cancel_presel_in(m, d, n);
        if (m->sticky_count > 0) {
                m->sticky_count -= sticky_count(n);
        }
        clients_count -= clients_count_in(n);
        if (is_descendant(grabbed_node, n)) {
                grabbed_node = NULL;
        }
        free_node(n);

        ewmh_update_client_list(false);
        ewmh_update_client_list(true);

        if (mon != NULL && d->focus == NULL) {
                if (d == mon->desk) {
                        focus_node(m, d, NULL);
                } else {
                        activate_node(m, d, NULL);
                }
        }
}

void free_node(node_t *n)
{
        if (n == NULL) {
                return;
        }
        node_t *first_child = n->first_child;
        node_t *second_child = n->second_child;
        free(n->client);
        free(n);
        free_node(first_child);
        free_node(second_child);
}

bool swap_nodes(monitor_t *m1, desktop_t *d1, node_t *n1, monitor_t *m2, desktop_t *d2, node_t *n2, bool follow)
{
        if (n1 == NULL || n2 == NULL || n1 == n2 || is_descendant(n1, n2) || is_descendant(n2, n1) ||
            (d1 != d2 && ((m1->sticky_count > 0 && sticky_count(n1) > 0) ||
                          (m2->sticky_count > 0 && sticky_count(n2) > 0)))) {
                return false;
        }

        put_status(SBSC_MASK_NODE_SWAP, "node_swap 0x%08X 0x%08X 0x%08X 0x%08X 0x%08X 0x%08X\n", m1->id, d1->id, n1->id, m2->id, d2->id, n2->id);

        node_t *pn1 = n1->parent;
        node_t *pn2 = n2->parent;
        bool n1_first_child = is_first_child(n1);
        bool n2_first_child = is_first_child(n2);
        int br1 = n1->birth_rotation;
        int br2 = n2->birth_rotation;
        bool n1_held_focus = is_descendant(d1->focus, n1);
        bool n2_held_focus = is_descendant(d2->focus, n2);
        node_t *last_d1_focus = d1->focus;
        node_t *last_d2_focus = d2->focus;

        if (pn1 != NULL) {
                if (n1_first_child) {
                        pn1->first_child = n2;
                } else {
                        pn1->second_child = n2;
                }
        }

        if (pn2 != NULL) {
                if (n2_first_child) {
                        pn2->first_child = n1;
                } else {
                        pn2->second_child = n1;
                }
        }

        n1->parent = pn2;
        n2->parent = pn1;
        n1->birth_rotation = br2;
        n2->birth_rotation = br1;

        propagate_flags_upward(m2, d2, n1);
        propagate_flags_upward(m1, d1, n2);

        if (d1 != d2) {
                if (d1->root == n1) {
                        d1->root = n2;
                }

                if (d2->root == n2) {
                        d2->root = n1;
                }

                if (n1_held_focus) {
                        d1->focus = n2_held_focus ? last_d2_focus : n2;
                }

                if (n2_held_focus) {
                        d2->focus = n1_held_focus ? last_d1_focus : n1;
                }

                if (m1 != m2) {
                        adapt_geometry(&m2->rectangle, &m1->rectangle, n2);
                        adapt_geometry(&m1->rectangle, &m2->rectangle, n1);
                }

                ewmh_set_wm_desktop(n1, d2);
                ewmh_set_wm_desktop(n2, d1);

                history_swap_nodes(m1, d1, n1, m2, d2, n2);

                bool d1_was_focused = (d1 == mon->desk);
                bool d2_was_focused = (d2 == mon->desk);

                if (m1->desk != d1 && m2->desk == d2) {
                        show_node(d2, n1);
                        if (!follow || !d2_was_focused || !n2_held_focus) {
                                hide_node(d2, n2);
                        }
                } else if (m1->desk == d1 && m2->desk != d2) {
                        if (!follow || !d1_was_focused || !n1_held_focus) {
                                hide_node(d1, n1);
                        }
                        show_node(d1, n2);
                }

                if (n1_held_focus) {
                        if (d1_was_focused) {
                                if (follow) {
                                        focus_node(m2, d2, last_d1_focus);
                                } else {
                                        focus_node(m1, d1, d1->focus);
                                }
                        } else {
                                activate_node(m1, d1, d1->focus);
                        }
                } else {
                        draw_border(n2, is_descendant(n2, d1->focus), (m1 == mon));
                }

                if (n2_held_focus) {
                        if (d2_was_focused) {
                                if (follow) {
                                        focus_node(m1, d1, last_d2_focus);
                                } else {
                                        focus_node(m2, d2, d2->focus);
                                }
                        } else {
                                activate_node(m2, d2, d2->focus);
                        }
                } else {
                        draw_border(n1, is_descendant(n1, d2->focus), (m2 == mon));
                }
        } else {
                draw_border(n1, is_descendant(n1, d2->focus), (m2 == mon));
                draw_border(n2, is_descendant(n2, d1->focus), (m1 == mon));
        }

        arrange(m1, d1);

        if (d1 != d2) {
                arrange(m2, d2);
        }

        return true;
}

bool transfer_node(monitor_t *ms, desktop_t *ds, node_t *ns, monitor_t *md, desktop_t *dd, node_t *nd, bool follow)
{
        if (ns == NULL || ns == nd || is_child(ns, nd) || is_descendant(nd, ns)) {
                return false;
        }

        if (sticky_still && ds != dd && ms->sticky_count > 0 && sticky_count(ns) > 0) {
                return false;
        }

        put_status(SBSC_MASK_NODE_TRANSFER, "node_transfer 0x%08X 0x%08X 0x%08X 0x%08X 0x%08X 0x%08X\n", ms->id, ds->id, ns->id, md->id, dd->id, nd!=NULL?nd->id:0);

        bool held_focus = is_descendant(ds->focus, ns);
        /* avoid ending up with a dangling pointer (because of unlink_node) */
        node_t *last_ds_focus = is_child(ns, ds->focus) ? NULL : ds->focus;
        bool ds_was_focused = (ds == mon->desk);

        if (held_focus && ds_was_focused) {
                clear_input_focus();
        }

        unlink_node(ms, ds, ns);
        insert_node(md, dd, ns, nd);

        if (md != ms && (ns->client == NULL || monitor_from_client(ns->client) != md)) {
                adapt_geometry(&ms->rectangle, &md->rectangle, ns);
        }

        if (ds != dd) {
                ewmh_set_wm_desktop(ns, dd);
                if (sticky_still) {
                        if (ds == ms->desk && dd != md->desk) {
                                hide_node(ds, ns);
                        } else if (ds != ms->desk && dd == md->desk) {
                                show_node(dd, ns);
                        }
                }
        }

        history_transfer_node(md, dd, ns);
        stack(dd, ns, false);

        if (ds == dd) {
                if (held_focus) {
                        if (ds_was_focused) {
                                focus_node(ms, ds, last_ds_focus);
                        } else {
                                activate_node(ms, ds, last_ds_focus);
                        }
                } else {
                        draw_border(ns, is_descendant(ns, ds->focus), (ms == mon));
                }
        } else {
                if (held_focus) {
                        if (follow) {
                                if (ds_was_focused) {
                                        focus_node(md, dd, last_ds_focus);
                                }
                                activate_node(ms, ds, ds->focus);
                        } else {
                                if (ds_was_focused) {
                                        focus_node(ms, ds, ds->focus);
                                } else {
                                        activate_node(ms, ds, ds->focus);
                                }
                        }
                }
                if (!held_focus || !follow || !ds_was_focused) {
                        if (dd->focus == ns) {
                                if (dd == mon->desk) {
                                        focus_node(md, dd, held_focus ? last_ds_focus : ns);
                                } else {
                                        activate_node(md, dd, held_focus ? last_ds_focus : ns);
                                }
                        } else {
                                draw_border(ns, is_descendant(ns, dd->focus), (md == mon));
                        }
                }
        }

        arrange(ms, ds);

        if (ds != dd) {
                arrange(md, dd);
        }

        return true;
}

bool find_closest_node(coordinates_t *ref, coordinates_t *dst, cycle_dir_t dir, node_select_t sel)
{
        monitor_t *m = ref->monitor;
        desktop_t *d = ref->desktop;
        node_t *n = ref->node;
        n = (dir == CYCLE_PREV ? prev_leaf(n, d->root) : next_leaf(n, d->root));

#define HANDLE_BOUNDARIES(m, d, n)  \
        while (n == NULL) { \
                d = (dir == CYCLE_PREV ? d->prev : d->next); \
                if (d == NULL) { \
                        m = (dir == CYCLE_PREV ? m->prev : m->next); \
                        if (m == NULL) { \
                                m = (dir == CYCLE_PREV ? mon_tail : mon_head); \
                        } \
                        d = (dir == CYCLE_PREV ? m->desk_tail : m->desk_head); \
                } \
                n = (dir == CYCLE_PREV ? second_extrema(d->root) : first_extrema(d->root)); \
                if (ref->node == NULL && d == ref->desktop) { \
                        break; \
                } \
        }
        HANDLE_BOUNDARIES(m, d, n);

        while (n != ref->node) {
                coordinates_t loc = {m, d, n};
                if (n->client != NULL && !n->hidden && node_matches(&loc, ref, sel)) {
                        *dst = loc;
                        return true;
                }
                n = (dir == CYCLE_PREV ? prev_leaf(n, d->root) : next_leaf(n, d->root));
                HANDLE_BOUNDARIES(m, d, n);
        }
#undef HANDLE_BOUNDARIES
        return false;
}

void circulate_leaves(monitor_t *m, desktop_t *d, node_t *n, circulate_dir_t dir)
{
        if (tiled_count(n) < 2) {
                return;
        }
        node_t *p = d->focus->parent;
        bool focus_first_child = is_first_child(d->focus);
        if (dir == CIRCULATE_FORWARD) {
                node_t *e = second_extrema(n);
                while (e != NULL && (e->client == NULL || !IS_TILED(e->client))) {
                        e = prev_leaf(e, n);
                }
                for (node_t *s = e, *f = prev_tiled_leaf(s, n); f != NULL; s = prev_tiled_leaf(f, n), f = prev_tiled_leaf(s, n)) {
                        swap_nodes(m, d, f, m, d, s, false);
                }
        } else {
                node_t *e = first_extrema(n);
                while (e != NULL && (e->client == NULL || !IS_TILED(e->client))) {
                        e = next_leaf(e, n);
                }
                for (node_t *f = e, *s = next_tiled_leaf(f, n); s != NULL; f = next_tiled_leaf(s, n), s = next_tiled_leaf(f, n)) {
                        swap_nodes(m, d, f, m, d, s, false);
                }
        }
        if (p != NULL) {
                node_t *f = focus_first_child ? p->first_child : p->second_child;
                if (is_leaf(f)) {
                        if (d == mon->desk) {
                                focus_node(m, d, f);
                        } else {
                                activate_node(m, d, f);
                        }
                }
        }
}

void set_vacant(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n->vacant == value) {
                return;
        }

        propagate_vacant_downward(m, d, n, value);
        propagate_vacant_upward(m, d, n);
}

void set_vacant_local(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n->vacant == value) {
                return;
        }

        n->vacant = value;

        if (value) {
                unrotate_brother(n);
                cancel_presel(m, d, n);
        } else {
                rotate_brother(n);
        }
}

void propagate_vacant_downward(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL) {
                return;
        }

        set_vacant_local(m, d, n, value);

        propagate_vacant_downward(m, d, n->first_child, value);
        propagate_vacant_downward(m, d, n->second_child, value);
}

void propagate_vacant_upward(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        }

        node_t *p = n->parent;

        if (p != NULL) {
                set_vacant_local(m, d, p, (p->first_child->vacant && p->second_child->vacant));
        }

        propagate_vacant_upward(m, d, p);
}

bool set_layer(monitor_t *m, desktop_t *d, node_t *n, stack_layer_t l)
{
        if (n == NULL || n->client == NULL || n->client->layer == l) {
                return false;
        }

        n->client->last_layer = n->client->layer;
        n->client->layer = l;

        if (l == LAYER_ABOVE) {
                n->client->wm_flags |= WM_FLAG_ABOVE;
                n->client->wm_flags &= ~WM_FLAG_BELOW;
        } else if (l == LAYER_BELOW) {
                n->client->wm_flags |= WM_FLAG_BELOW;
                n->client->wm_flags &= ~WM_FLAG_ABOVE;
        } else {
                n->client->wm_flags &= ~(WM_FLAG_ABOVE | WM_FLAG_BELOW);
        }

        ewmh_wm_state_update(n);

        put_status(SBSC_MASK_NODE_LAYER, "node_layer 0x%08X 0x%08X 0x%08X %s\n", m->id, d->id, n->id, LAYER_STR(l));

        if (d->focus == n) {
                neutralize_occluding_windows(m, d, n);
        }

        stack(d, n, (d->focus == n));

        return true;
}

bool set_state(monitor_t *m, desktop_t *d, node_t *n, client_state_t s)
{
        if (n == NULL || n->client == NULL || n->client->state == s) {
                return false;
        }

        client_t *c = n->client;

        c->last_state = c->state;
        c->state = s;

        switch (c->last_state) {
                case STATE_TILED:
                case STATE_PSEUDO_TILED:
                        break;
                case STATE_FLOATING:
                        set_floating(m, d, n, false);
                        break;
                case STATE_FULLSCREEN:
                        set_fullscreen(m, d, n, false);
                        break;
        }

        put_status(SBSC_MASK_NODE_STATE, "node_state 0x%08X 0x%08X 0x%08X %s off\n", m->id, d->id, n->id, STATE_STR(c->last_state));

        switch (c->state) {
                case STATE_TILED:
                case STATE_PSEUDO_TILED:
                        break;
                case STATE_FLOATING:
                        set_floating(m, d, n, true);
                        break;
                case STATE_FULLSCREEN:
                        set_fullscreen(m, d, n, true);
                        break;
        }

        put_status(SBSC_MASK_NODE_STATE, "node_state 0x%08X 0x%08X 0x%08X %s on\n", m->id, d->id, n->id, STATE_STR(c->state));

        if (n == m->desk->focus) {
                put_status(SBSC_MASK_REPORT);
        }

        return true;
}

void set_floating(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL) {
                return;
        }

        cancel_presel(m, d, n);
        set_vacant(m, d, n, value);

        if (!value && d->focus == n) {
                neutralize_occluding_windows(m, d, n);
        }

        stack(d, n, (d->focus == n));
}

void set_fullscreen(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL) {
                return;
        }

        client_t *c = n->client;

        cancel_presel(m, d, n);
        set_vacant(m, d, n, value);

        if (value) {
                c->wm_flags |= WM_FLAG_FULLSCREEN;
                c->last_layer = c->layer;
                c->layer = LAYER_ABOVE;
        } else {
                c->wm_flags &= ~WM_FLAG_FULLSCREEN;
                c->layer = c->last_layer;
                if (d->focus == n) {
                        neutralize_occluding_windows(m, d, n);
                }
        }

        ewmh_wm_state_update(n);
        stack(d, n, (d->focus == n));
}

void neutralize_occluding_windows(monitor_t *m, desktop_t *d, node_t *n)
{
        bool changed = false;
        for (node_t *f = first_extrema(n); f != NULL; f = next_leaf(f, n)) {
                for (node_t *a = first_extrema(d->root); a != NULL; a = next_leaf(a, d->root)) {
                        if (a != f && a->client != NULL && f->client != NULL &&
                            IS_FULLSCREEN(a->client) && stack_cmp(f->client, a->client) < 0) {
                                set_state(m, d, a, a->client->last_state);
                                changed = true;
                        }
                }
        }
        if (changed) {
                arrange(m, d);
        }
}

void rebuild_constraints(node_t *n)
{
        if (n == NULL || is_leaf(n)) {
                return;
        } else {
                rebuild_constraints(n->first_child);
                rebuild_constraints(n->second_child);
                update_constraints(n);
        }
}

void update_constraints(node_t *n)
{
        if (n == NULL || is_leaf(n)) {
                return;
        }
        if (n->split_type == TYPE_VERTICAL) {
                n->constraints.min_width = n->first_child->constraints.min_width + n->second_child->constraints.min_width;
                n->constraints.min_height = MAX(n->first_child->constraints.min_height, n->second_child->constraints.min_height);
        } else {
                n->constraints.min_width = MAX(n->first_child->constraints.min_width, n->second_child->constraints.min_width);
                n->constraints.min_height = n->first_child->constraints.min_height + n->second_child->constraints.min_height;
        }
}

void propagate_flags_upward(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        }

        node_t *p = n->parent;

        if (p != NULL) {
                set_vacant_local(m, d, p, (p->first_child->vacant && p->second_child->vacant));
                set_hidden_local(m, d, p, (p->first_child->hidden && p->second_child->hidden));
                update_constraints(p);
        }

        propagate_flags_upward(m, d, p);
}

void set_hidden(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL || n->hidden == value) {
                return;
        }

        bool held_focus = is_descendant(d->focus, n);

        propagate_hidden_downward(m, d, n, value);
        propagate_hidden_upward(m, d, n);

        put_status(SBSC_MASK_NODE_FLAG, "node_flag 0x%08X 0x%08X 0x%08X hidden %s\n", m->id, d->id, n->id, ON_OFF_STR(value));

        if (held_focus || d->focus == NULL) {
                if (d->focus != NULL) {
                        d->focus = NULL;
                        draw_border(n, false, (mon == m));
                }
                if (d == mon->desk) {
                        focus_node(m, d, d->focus);
                } else {
                        activate_node(m, d, d->focus);
                }
        }
}

void set_hidden_local(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n->hidden == value) {
                return;
        }

        n->hidden = value;

        if (n->client != NULL) {
                if (n->client->shown) {
                        window_set_visibility(n->id, !value);
                }

                if (IS_TILED(n->client)) {
                        set_vacant(m, d, n, value);
                }

                if (value) {
                        n->client->wm_flags |= WM_FLAG_HIDDEN;
                } else {
                        n->client->wm_flags &= ~WM_FLAG_HIDDEN;
                }

                ewmh_wm_state_update(n);
        }
}

void propagate_hidden_downward(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL) {
                return;
        }

        set_hidden_local(m, d, n, value);

        propagate_hidden_downward(m, d, n->first_child, value);
        propagate_hidden_downward(m, d, n->second_child, value);
}

void propagate_hidden_upward(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return;
        }

        node_t *p = n->parent;

        if (p != NULL) {
                set_hidden_local(m, d, p, p->first_child->hidden && p->second_child->hidden);
        }

        propagate_hidden_upward(m, d, p);
}

void set_sticky(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL || n->sticky == value) {
                return;
        }

        if (d != m->desk) {
                transfer_node(m, d, n, m, m->desk, m->desk->focus, false);
        }

        n->sticky = value;

        if (value) {
                m->sticky_count++;
        } else {
                m->sticky_count--;
        }

        if (n->client != NULL) {
                if (value) {
                        n->client->wm_flags |= WM_FLAG_STICKY;
                } else {
                        n->client->wm_flags &= ~WM_FLAG_STICKY;
                }
                ewmh_wm_state_update(n);
        }

        put_status(SBSC_MASK_NODE_FLAG, "node_flag 0x%08X 0x%08X 0x%08X sticky %s\n", m->id, d->id, n->id, ON_OFF_STR(value));

        if (n == m->desk->focus) {
                put_status(SBSC_MASK_REPORT);
        }
}

void set_private(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL || n->private == value) {
                return;
        }

        n->private = value;

        put_status(SBSC_MASK_NODE_FLAG, "node_flag 0x%08X 0x%08X 0x%08X private %s\n", m->id, d->id, n->id, ON_OFF_STR(value));

        if (n == m->desk->focus) {
                put_status(SBSC_MASK_REPORT);
        }
}

void set_locked(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (n == NULL || n->locked == value) {
                return;
        }

        n->locked = value;

        put_status(SBSC_MASK_NODE_FLAG, "node_flag 0x%08X 0x%08X 0x%08X locked %s\n", m->id, d->id, n->id, ON_OFF_STR(value));

        if (n == m->desk->focus) {
                put_status(SBSC_MASK_REPORT);
        }
}

void set_urgent(monitor_t *m, desktop_t *d, node_t *n, bool value)
{
        if (value && mon->desk->focus == n) {
                return;
        }

        n->client->urgent = value;

        if (value) {
                n->client->wm_flags |= WM_FLAG_DEMANDS_ATTENTION;
        } else {
                n->client->wm_flags &= ~WM_FLAG_DEMANDS_ATTENTION;
        }

        ewmh_wm_state_update(n);

        put_status(SBSC_MASK_NODE_FLAG, "node_flag 0x%08X 0x%08X 0x%08X urgent %s\n", m->id, d->id, n->id, ON_OFF_STR(value));
        put_status(SBSC_MASK_REPORT);
}

/* Returns true if a contains b */
bool contains(xcb_rectangle_t a, xcb_rectangle_t b)
{
        return (a.x <= b.x && (a.x + a.width) >= (b.x + b.width) &&
                a.y <= b.y && (a.y + a.height) >= (b.y + b.height));
}

xcb_rectangle_t get_rectangle(monitor_t *m, desktop_t *d, node_t *n)
{
        if (n == NULL) {
                return m->rectangle;
        }
        client_t *c = n->client;
        if (c != NULL) {
                if (IS_FLOATING(c)) {
                        return c->floating_rectangle;
                } else {
                        return c->tiled_rectangle;
                }
        } else {
                int wg = (d == NULL ? 0 : (gapless_monocle && IS_MONOCLE(d) ? 0 : d->window_gap));
                xcb_rectangle_t rect = n->rectangle;
                rect.width -= wg;
                rect.height -= wg;
                return rect;
        }
}

void listen_enter_notify(node_t *n, bool enable)
{
        uint32_t mask = CLIENT_EVENT_MASK | (enable ? XCB_EVENT_MASK_ENTER_WINDOW : 0);
        for (node_t *f = first_extrema(n); f != NULL; f = next_leaf(f, n)) {
                if (f->client == NULL) {
                        continue;
                }
                xcb_change_window_attributes(dpy, f->id, XCB_CW_EVENT_MASK, &mask);
                if (f->presel != NULL) {
                        xcb_change_window_attributes(dpy, f->presel->feedback, XCB_CW_EVENT_MASK, &mask);
                }
        }
}

void regenerate_ids_in(node_t *n)
{
        if (n == NULL || n->client != NULL) {
                return;
        }
        n->id = xcb_generate_id(dpy);
        regenerate_ids_in(n->first_child);
        regenerate_ids_in(n->second_child);
}

#define DEF_FLAG_COUNT(flag) \
        unsigned int flag##_count(node_t *n) \
        { \
                if (n == NULL) { \
                        return 0; \
                } else { \
                        return ((n->flag ? 1 : 0) + \
                                flag##_count(n->first_child) + \
                                flag##_count(n->second_child)); \
                } \
        }
        DEF_FLAG_COUNT(sticky)
        DEF_FLAG_COUNT(private)
        DEF_FLAG_COUNT(locked)
#undef DEF_FLAG_COUNT