text: /* 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 <limits.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;
  	}
  
  	xcb_rectangle_t rect = m->rectangle;
  
  	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 (d->layout == LAYOUT_MONOCLE) {
  		rect.x += monocle_padding.left;
  		rect.y += monocle_padding.top;
  		rect.width -= monocle_padding.left + monocle_padding.right;
  		rect.height -= monocle_padding.top + monocle_padding.bottom;
  	}
  
  	if (!gapless_monocle || d->layout != 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, rect, rect);
  }
  
  void apply_layout(monitor_t *m, desktop_t *d, node_t *n, xcb_rectangle_t rect, xcb_rectangle_t root_rect)
  {
  	if (n == NULL) {
  		return;
  	}
  
  	n->rectangle = rect;
  
  	if (n->presel != NULL) {
  		draw_presel_feedback(m, d, n);
  	}
  
  	if (is_leaf(n)) {
  		unsigned int br = 0;
  
  		if (n->client == NULL) {
  			return;
  		}
  
  		unsigned int bw;
  		bool the_only_window = !m->prev && !m->next && d->root->client;
  		if ((borderless_monocle && d->layout == LAYOUT_MONOCLE && IS_TILED(n->client))
  		    || (borderless_singleton && the_only_window)
  		    || 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;
  		/* tiled and pseudo-tiled clients */
  		if (s == STATE_TILED || s == STATE_PSEUDO_TILED) {
  			int wg = (gapless_monocle && d->layout == LAYOUT_MONOCLE ? 0 : d->window_gap);
  			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 */
  			if (s == STATE_PSEUDO_TILED) {
  				xcb_rectangle_t f = n->client->floating_rectangle;
  				r.width = MIN(r.width, f.width);
  				r.height = MIN(r.height, f.height);
  				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;
  				}
  			}
  			n->client->tiled_rectangle = r;
  			if (!gapless_monocle || d->layout != LAYOUT_MONOCLE)
  				br = n->client->border_radius;
  		/* floating clients */
  		} else if (s == STATE_FLOATING) {
  			r = n->client->floating_rectangle;
  			br = n->client->border_radius;
  		/* 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);
  			window_rounded_border(n);
  			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);
  
  		n->client->drawn_border_radius = br;
  		window_rounded_border(n);
  
  	} else {
  		xcb_rectangle_t first_rect;
  		xcb_rectangle_t second_rect;
  
  		if (d->layout == 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, first_rect, root_rect);
  		apply_layout(m, d, n->second_child, 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_type(node_t *n, split_type_t typ)
  {
  	if (n == NULL) {
  		return;
  	}
  
  	n->split_type = typ;
  	update_constraints(n);
  	rebuild_constraints_towards_root(n);
  }
  
  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));
  			}
  		}
  		n->parent = c;
  		if (f->presel == NULL) {
  			bool single_tiled = f->client != NULL && IS_TILED(f->client) && tiled_count(d->root, true) == 1;
  			if (p == NULL || automatic_scheme != SCHEME_SPIRAL || single_tiled) {
  				if (p != NULL) {
  					if (is_first_child(f)) {
  						p->first_child = c;
  					} else {
  						p->second_child = c;
  					}
  				} else {
  					d->root = c;
  				}
  				c->parent = p;
  				f->parent = c;
  				if (initial_polarity == FIRST_CHILD) {
  					c->first_child = n;
  					c->second_child = f;
  				} else {
  					c->first_child = f;
  					c->second_child = n;
  				}
  				if (p == NULL || automatic_scheme == SCHEME_LONGEST_SIDE || single_tiled) {
  					if (f->rectangle.width > f->rectangle.height) {
  						c->split_type = TYPE_VERTICAL;
  					} else {
  						c->split_type = TYPE_HORIZONTAL;
  					}
  				} else {
  					node_t *q = p;
  					while (q != NULL && (q->first_child->vacant || q->second_child->vacant)) {
  						q = q->parent;
  					}
  					if (q == NULL) {
  						q = p;
  					}
  					if (q->split_type == TYPE_HORIZONTAL) {
  						c->split_type = TYPE_VERTICAL;
  					} else {
  						c->split_type = TYPE_HORIZONTAL;
  					}
  				}
  			} 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;
  				}
  				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;
  			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);
  			set_marked(m, d, n, false);
  		}
  	}
  
  	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);
  	put_status(SBSC_MASK_NODE_ADD, "node_add 0x%08X 0x%08X 0x%08X 0x%08X\n", m->id, d->id, n != NULL ? n->id : 0, r->id);
  
  	if (single_monocle && d->layout == LAYOUT_MONOCLE && tiled_count(d->root, true) > 1) {
  		set_layout(m, d, d->user_layout, false);
  	}
  }
  
  bool activate_node(monitor_t *m, desktop_t *d, node_t *n)
  {
  	if (n == NULL && d->root != NULL) {
  		n = d->focus;
  		if (n == 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, false);
  
  	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 *ms, desktop_t *ds, monitor_t *md, desktop_t *dd, node_t *n)
  {
  	if (n == NULL) {
  		return;
  	} else if (n->sticky) {
  		sticky_still = false;
  		transfer_node(ms, ds, n, md, dd, dd->focus, false);
  		sticky_still = true;
  	} 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(ms, ds, md, dd, first_child);
  		transfer_sticky_nodes(ms, ds, md, dd, second_child);
  	}
  }
  
  bool focus_node(monitor_t *m, desktop_t *d, node_t *n)
  {
  	if (m == NULL) {
  		m = mon;
  		if (m == NULL) {
  			m = history_last_monitor(NULL);
  		}
  		if (m == NULL) {
  			m = mon_head;
  		}
  	}
  
  	if (m == NULL) {
  		return false;
  	}
  
  	if (d == NULL) {
  		d = m->desk;
  		if (d == NULL) {
  			d = history_last_desktop(m, NULL);
  		}
  		if (d == NULL) {
  			d = m->desk_head;
  		}
  	}
  
  	if (d == NULL) {
  		return false;
  	}
  
  	bool guess = (n == NULL);
  
  	if (n == NULL && d->root != NULL) {
  		n = d->focus;
  		if (n == 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 && m->desk != NULL && d != m->desk) {
  		if (guess && m->desk->focus != NULL && m->desk->focus->sticky) {
  			n = m->desk->focus;
  		}
  
  		transfer_sticky_nodes(m, m->desk, m, d, m->desk->root);
  
  		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);
  
  	bool desk_changed = (m != mon || m->desk != d);
  	bool has_input_focus = false;
  
  	if (mon != m) {
  		mon = m;
  
  		if (pointer_follows_monitor) {
  			center_pointer(m->rectangle);
  		}
  
  		put_status(SBSC_MASK_MONITOR_FOCUS, "monitor_focus 0x%08X\n", m->id);
  	}
  
  	if (m->desk != d) {
  		show_desktop(d);
  		set_input_focus(n);
  		has_input_focus = true;
  		hide_desktop(m->desk);
  		m->desk = d;
  	}
  
  	if (desk_changed) {
  		ewmh_update_current_desktop();
  		put_status(SBSC_MASK_DESKTOP_FOCUS, "desktop_focus 0x%08X 0x%08X\n", m->id, d->id);
  	}
  
  	d->focus = n;
  	if (!has_input_focus) {
  		set_input_focus(n);
  	}
  	ewmh_update_active_window();
  	history_add(m, d, n, true);
  
  	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);
  
  	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 || (!hide_sticky && n->sticky)) {
  		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 = n->marked = false;
  	n->split_ratio = split_ratio;
  	n->split_type = TYPE_VERTICAL;
  	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->border_radius = border_radius;
  	c->urgent = false;
  	c->shown = false;
  	c->sets_own_shape = 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_node(node_t *n)
  {
  	if (n == NULL) {
  		return NULL;
  	}
  
  	if (n->second_child != NULL) {
  		return first_extrema(n->second_child);
  	} else {
  		node_t *p = n;
  		while (is_second_child(p)) {
  			p = p->parent;
  		}
  		if (is_first_child(p)) {
  			return p->parent;
  		} else {
  			return NULL;
  		}
  	}
  }
  
  node_t *prev_node(node_t *n)
  {
  	if (n == NULL) {
  		return NULL;
  	}
  
  	if (n->first_child != NULL) {
  		return second_extrema(n->first_child);
  	} else {
  		node_t *p = n;
  		while (is_first_child(p)) {
  			p = p->parent;
  		}
  		if (is_second_child(p)) {
  			return p->parent;
  		} else {
  			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);
  		}
  	}
  }
  
  void find_any_node(coordinates_t *ref, coordinates_t *dst, node_select_t *sel)
  {
  	for (monitor_t *m = mon_head; m != NULL; m = m->next) {
  		for (desktop_t *d = m->desk_head; d != NULL; d = d->next) {
  			if (find_any_node_in(m, d, d->root, ref, dst, sel)) {
  				return;
  			}
  		}
  	}
  }
  
  bool find_any_node_in(monitor_t *m, desktop_t *d, node_t *n, coordinates_t *ref, coordinates_t *dst, node_select_t *sel)
  {
  	if (n == NULL) {
  		return false;
  	} else {
  		coordinates_t loc = {m, d, n};
  		if (node_matches(&loc, ref, sel)) {
  			*dst = loc;
  			return true;
  		} else {
  			if (find_any_node_in(m, d, n->first_child, ref, dst, sel)) {
  				return true;
  			} else {
  				return find_any_node_in(m, d, n->second_child, ref, dst, sel);
  			}
  		}
  	}
  }
  
  void find_first_ancestor(coordinates_t *ref, coordinates_t *dst, node_select_t *sel)
  {
  	if (ref->node == NULL) {
  		return;
  	}
  
  	coordinates_t loc = {ref->monitor, ref->desktop, ref->node};
  	while ((loc.node = loc.node->parent) != NULL) {
  		if (node_matches(&loc, ref, sel)) {
  			*dst = loc;
  			return;
  		}
  	}
  }
  
  /* 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);
  	uint32_t 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, bool include_receptacles)
  {
  	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 && ((include_receptacles && f->client == NULL) ||
  		                   (f->client != NULL && IS_TILED(f->client)))) {
  			cnt++;
  		}
  	}
  	return cnt;
  }
  
  void find_by_area(area_peak_t ap, coordinates_t *ref, coordinates_t *dst, node_select_t *sel)
  {
  	unsigned int p_area;
  	if (ap == AREA_BIGGEST) {
  		p_area = 0;
  	} else {
  		p_area = UINT_MAX;
  	}
  
  	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->vacant || !node_matches(&loc, ref, sel)) {
  					continue;
  				}
  				unsigned int f_area = node_area(d, f);
  				if ((ap == AREA_BIGGEST && f_area > p_area) || (ap == AREA_SMALLEST && f_area < p_area)) {
  					*dst = loc;
  					p_area = f_area;
  				}
  			}
  		}
  	}
  }
  
  void rotate_tree(node_t *n, int deg)
  {
  	rotate_tree_rec(n, deg);
  	rebuild_constraints_from_leaves(n);
  	rebuild_constraints_towards_root(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 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;
  	}
  }
  
  /* Adjust the split ratios so that they keep their position
   * despite the potential alteration of their rectangle. */
  void adjust_ratios(node_t *n, xcb_rectangle_t rect)
  {
  	if (n == NULL) {
  		return;
  	}
  
  	double ratio;
  
  	if (n->split_type == TYPE_VERTICAL) {
  		double position = (double) n->rectangle.x + n->split_ratio * (double) n->rectangle.width;
  		ratio = (position - (double) rect.x) / (double) rect.width;
  	} else {
  		double position = (double) n->rectangle.y + n->split_ratio * (double) n->rectangle.height;
  		ratio = (position - (double) rect.y) / (double) rect.height;
  	}
  
  	ratio = MAX(0.0, ratio);
  	ratio = MIN(1.0, ratio);
  	n->split_ratio = ratio;
  
  	xcb_rectangle_t first_rect;
  	xcb_rectangle_t second_rect;
  	unsigned int fence;
  
  	if (n->split_type == TYPE_VERTICAL) {
  		fence = rect.width * n->split_ratio;
  		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;
  		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};
  	}
  
  	adjust_ratios(n->first_child, first_rect);
  	adjust_ratios(n->second_child, second_rect);
  }
  
  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;
  
  		b->parent = g;
  
  		if (g != NULL) {
  			if (is_first_child(p)) {
  				g->first_child = b;
  			} else {
  				g->second_child = b;
  			}
  		} else {
  			d->root = b;
  		}
  
  		if (!n->vacant && removal_adjustment) {
  			if (automatic_scheme == SCHEME_SPIRAL) {
  				if (is_first_child(n)) {
  					rotate_tree(b, 270);
  				} else {
  					rotate_tree(b, 90);
  				}
  			} else if (automatic_scheme == SCHEME_LONGEST_SIDE || g == NULL) {
  				if (p != NULL) {
  					if (p->rectangle.width > p->rectangle.height) {
  						b->split_type = TYPE_VERTICAL;
  					} else {
  						b->split_type = TYPE_HORIZONTAL;
  					}
  				}
  			} else if (automatic_scheme == SCHEME_ALTERNATE) {
  				if (g->split_type == TYPE_HORIZONTAL) {
  					b->split_type = TYPE_VERTICAL;
  				} else {
  					b->split_type = TYPE_HORIZONTAL;
  				}
  			}
  		}
  
  		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;
  	}
  
  	if (IS_RECEPTACLE(n)) {
  		put_status(SBSC_MASK_NODE_REMOVE, "node_remove 0x%08X 0x%08X 0x%08X\n", m->id, d->id, n->id);
  		remove_node(m, d, n);
  	} else {
  		for (node_t *f = first_extrema(n); f != NULL; f = next_leaf(f, n)) {
  			if (f->client != NULL) {
  				xcb_kill_client(dpy, f->id);
  			}
  		}
  	}
  }
  
  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 && d == m->desk) {
  		m->sticky_count -= sticky_count(n);
  	}
  	clients_count -= clients_count_in(n);
  	if (is_descendant(grabbed_node, n)) {
  		grabbed_node = NULL;
  	}
  	free_node(n);
  
  	if (single_monocle && d->layout != LAYOUT_MONOCLE && tiled_count(d->root, true) <= 1) {
  		set_layout(m, d, LAYOUT_MONOCLE, false);
  	}
  
  	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);
  	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;
  
  	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_remove(d1, n1, true);
  		history_remove(d2, n2, true);
  
  		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 (single_monocle) {
  			layout_t l1 = tiled_count(d1->root, true) <= 1 ? LAYOUT_MONOCLE : d1->user_layout;
  			layout_t l2 = tiled_count(d2->root, true) <= 1 ? LAYOUT_MONOCLE : d2->user_layout;
  			set_layout(m1, d1, l1, false);
  			set_layout(m2, d2, l2, false);
  		}
  
  		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 {
  		if (!n1_held_focus) {
  			draw_border(n1, is_descendant(n1, d2->focus), (m2 == mon));
  		}
  		if (!n2_held_focus) {
  			draw_border(n2, is_descendant(n2, d1->focus), (m1 == mon));
  		}
  	}
  
  	arrange(m1, d1);
  
  	if (d1 != d2) {
  		arrange(m2, d2);
  	} else {
  		if (pointer_follows_focus && (n1_held_focus || n2_held_focus)) {
  			center_pointer(get_rectangle(m1, d1, d1->focus));
  		}
  	}
  
  	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;
  	}
  
  	unsigned int sc = (ms->sticky_count > 0 && ds == ms->desk) ? sticky_count(ns) : 0;
  	if (sticky_still && sc > 0 && dd != md->desk) {
  		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) {
  		if (ns->client == NULL || monitor_from_client(ns->client) != md) {
  			adapt_geometry(&ms->rectangle, &md->rectangle, ns);
  		}
  		ms->sticky_count -= sc;
  		md->sticky_count += sc;
  	}
  
  	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_remove(ds, ns, true);
  	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 (single_monocle) {
  			if (ds->layout != LAYOUT_MONOCLE && tiled_count(ds->root, true) <= 1) {
  				set_layout(ms, ds, LAYOUT_MONOCLE, false);
  			}
  			if (dd->layout == LAYOUT_MONOCLE && tiled_count(dd->root, true) > 1) {
  				set_layout(md, dd, dd->user_layout, false);
  			}
  		}
  		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_node(n) : next_node(n));
  
  #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 (node_matches(&loc, ref, sel)) {
  			*dst = loc;
  			return true;
  		}
  		n = (dir == CYCLE_PREV ? prev_node(n) : next_node(n));
  		HANDLE_BOUNDARIES(m, d, n);
  		if (ref->node == NULL && d == ref->desktop) {
  			break;
  		}
  	}
  #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, false) < 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) {
  		cancel_presel(m, d, 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;
  
  	bool was_tiled = IS_TILED(c);
  
  	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);
  	}
  
  	if (single_monocle && was_tiled != IS_TILED(c)) {
  		if (was_tiled && d->layout != LAYOUT_MONOCLE && tiled_count(d->root, true) <= 1) {
  			set_layout(m, d, LAYOUT_MONOCLE, false);
  		} else if (!was_tiled && d->layout == LAYOUT_MONOCLE && tiled_count(d->root, true) > 1) {
  			set_layout(m, d, d->user_layout, false);
  		}
  	}
  
  	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);
  	if (!n->hidden) {
  		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);
  	if (!n->hidden) {
  		set_vacant(m, d, n, value);
  	}
  
  	if (value) {
  		c->wm_flags |= WM_FLAG_FULLSCREEN;
  	} else {
  		c->wm_flags &= ~WM_FLAG_FULLSCREEN;
  		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_from_leaves(node_t *n)
  {
  	if (n == NULL || is_leaf(n)) {
  		return;
  	} else {
  		rebuild_constraints_from_leaves(n->first_child);
  		rebuild_constraints_from_leaves(n->second_child);
  		update_constraints(n);
  	}
  }
  
  void rebuild_constraints_towards_root(node_t *n)
  {
  	if (n == NULL) {
  		return;
  	}
  
  	node_t *p = n->parent;
  
  	if (p != NULL) {
  		update_constraints(p);
  	}
  
  	rebuild_constraints_towards_root(p);
  }
  
  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);
  		}
  	}
  
  	if (single_monocle) {
  		if (value && d->layout != LAYOUT_MONOCLE && tiled_count(d->root, true) <= 1) {
  			set_layout(m, d, LAYOUT_MONOCLE, false);
  		} else if (!value && d->layout == LAYOUT_MONOCLE && tiled_count(d->root, true) > 1) {
  			set_layout(m, d, d->user_layout, false);
  		}
  	}
  }
  
  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_marked(monitor_t *m, desktop_t *d, node_t *n, bool value)
  {
  	if (n == NULL || n->marked == value) {
  		return;
  	}
  
  	n->marked = value;
  
  	put_status(SBSC_MASK_NODE_FLAG, "node_flag 0x%08X 0x%08X 0x%08X marked %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);
  }
  
  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 && d->layout == LAYOUT_MONOCLE ? 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
  