i3/mainx.c

#define _GNU_SOURCE
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdbool.h>
#include <assert.h>

#include <xcb/xcb.h>

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

#include "xcb_wm.h"
#include "xcb_aux.h"
#include "xcb_event.h"
#include "xcb_property.h"
#include "xcb_keysyms.h"
#include "data.h"

#include "queue.h"
#include "table.h"
#include "font.h"

#define TERMINAL "/usr/pkg/bin/urxvt"

Display *xkbdpy;

TAILQ_HEAD(bindings_head, Binding) bindings;

static const int TOP = 20;
static const int LEFT = 5;
static const int BOTTOM = 5;
static const int RIGHT = 5;

/* This is the filtered environment which will be passed to opened applications.
 * It contains DISPLAY (naturally) and locales stuff (LC_*, LANG) */
static char **environment;

/* hm, xcb_wm wants us to implement this. */
table_t *byChild = 0;
table_t *byParent = 0;
xcb_window_t root_win;

char *pattern = "-misc-fixed-medium-r-normal--13-120-75-75-C-70-iso8859-1";


int current_col = 0;
int current_row = 0;


int globalc = 0;


static const char *labelError[] = {
    "Success",
    "BadRequest",
    "BadValue",
    "BadWindow",
    "BadPixmap",
    "BadAtom",
    "BadCursor",
    "BadFont",
    "BadMatch",
    "BadDrawable",
    "BadAccess",
    "BadAlloc",
    "BadColor",
    "BadGC",
    "BadIDChoice",
    "BadName",
    "BadLength",
    "BadImplementation",
};

static const char *labelRequest[] = {
    "no request",
    "CreateWindow",
    "ChangeWindowAttributes",
    "GetWindowAttributes",
    "DestroyWindow",
    "DestroySubwindows",
    "ChangeSaveSet",
    "ReparentWindow",
    "MapWindow",
    "MapSubwindows",
    "UnmapWindow",
    "UnmapSubwindows",
    "ConfigureWindow",
    "CirculateWindow",
    "GetGeometry",
    "QueryTree",
    "InternAtom",
    "GetAtomName",
    "ChangeProperty",
    "DeleteProperty",
    "GetProperty",
    "ListProperties",
    "SetSelectionOwner",
    "GetSelectionOwner",
    "ConvertSelection",
    "SendEvent",
    "GrabPointer",
    "UngrabPointer",
    "GrabButton",
    "UngrabButton",
    "ChangeActivePointerGrab",
    "GrabKeyboard",
    "UngrabKeyboard",
    "GrabKey",
    "UngrabKey",
    "AllowEvents",
    "GrabServer",
    "UngrabServer",
    "QueryPointer",
    "GetMotionEvents",
    "TranslateCoords",
    "WarpPointer",
    "SetInputFocus",
    "GetInputFocus",
    "QueryKeymap",
    "OpenFont",
    "CloseFont",
    "QueryFont",
    "QueryTextExtents",
    "ListFonts",
    "ListFontsWithInfo",
    "SetFontPath",
    "GetFontPath",
    "CreatePixmap",
    "FreePixmap",
    "CreateGC",
    "ChangeGC",
    "CopyGC",
    "SetDashes",
    "SetClipRectangles",
    "FreeGC",
    "ClearArea",
    "CopyArea",
    "CopyPlane",
    "PolyPoint",
    "PolyLine",
    "PolySegment",
    "PolyRectangle",
    "PolyArc",
    "FillPoly",
    "PolyFillRectangle",
    "PolyFillArc",
    "PutImage",
    "GetImage",
    "PolyText",
    "PolyText",
    "ImageText",
    "ImageText",
    "CreateColormap",
    "FreeColormap",
    "CopyColormapAndFree",
    "InstallColormap",
    "UninstallColormap",
    "ListInstalledColormaps",
    "AllocColor",
    "AllocNamedColor",
    "AllocColorCells",
    "AllocColorPlanes",
    "FreeColors",
    "StoreColors",
    "StoreNamedColor",
    "QueryColors",
    "LookupColor",
    "CreateCursor",
    "CreateGlyphCursor",
    "FreeCursor",
    "RecolorCursor",
    "QueryBestSize",
    "QueryExtension",
    "ListExtensions",
    "ChangeKeyboardMapping",
    "GetKeyboardMapping",
    "ChangeKeyboardControl",
    "GetKeyboardControl",
    "Bell",
    "ChangePointerControl",
    "GetPointerControl",
    "SetScreenSaver",
    "GetScreenSaver",
    "ChangeHosts",
    "ListHosts",
    "SetAccessControl",
    "SetCloseDownMode",
    "KillClient",
    "RotateProperties",
    "ForceScreenSaver",
    "SetPointerMapping",
    "GetPointerMapping",
    "SetModifierMapping",
    "GetModifierMapping",
    "major 120",
    "major 121",
    "major 122",
    "major 123",
    "major 124",
    "major 125",
    "major 126",
    "NoOperation",
};

static const char *labelEvent[] = {
    "error",
    "reply",
    "KeyPress",
    "KeyRelease",
    "ButtonPress",
    "ButtonRelease",
    "MotionNotify",
    "EnterNotify",
    "LeaveNotify",
    "FocusIn",
    "FocusOut",
    "KeymapNotify",
    "Expose",
    "GraphicsExpose",
    "NoExpose",
    "VisibilityNotify",
    "CreateNotify",
    "DestroyNotify",
    "UnmapNotify",
    "MapNotify",
    "MapRequest",
    "ReparentNotify",
    "ConfigureNotify",
    "ConfigureRequest",
    "GravityNotify",
    "ResizeRequest",
    "CirculateNotify",
    "CirculateRequest",
    "PropertyNotify",
    "SelectionClear",
    "SelectionRequest",
    "SelectionNotify",
    "ColormapNotify",
    "ClientMessage",
    "MappingNotify",
};

static const char *labelSendEvent[] = {
    "",
    " (from SendEvent)",
};

/*
 *
 * TODO: what exactly does this, what happens if we leave stuff out?
 *
 */
void manage_window(xcb_property_handlers_t *prophs, xcb_connection_t *c, xcb_window_t window, window_attributes_t wa)
{
	printf("managing window.\n");
	xcb_drawable_t d = { window };
	xcb_get_geometry_cookie_t geomc;
	xcb_get_geometry_reply_t *geom;
	xcb_get_window_attributes_reply_t *attr = 0;
	if(wa.tag == TAG_COOKIE)
	{
		attr = xcb_get_window_attributes_reply(c, wa.u.cookie, 0);
		if(!attr)
			return;
		if(attr->map_state != XCB_MAP_STATE_VIEWABLE)
		{
			printf("Window 0x%08x is not mapped. Ignoring.\n", window);
			free(attr);
			return;
		}
		wa.tag = TAG_VALUE;
		wa.u.override_redirect = attr->override_redirect;
	}
	if(!wa.u.override_redirect && table_get(byChild, window))
	{
		printf("Window 0x%08x already managed. Ignoring.\n", window);
		free(attr);
		return;
	}
	if(wa.u.override_redirect)
	{
		printf("Window 0x%08x has override-redirect set. Ignoring.\n", window);
		free(attr);
		return;
	}
	geomc = xcb_get_geometry(c, d);
	if(!attr)
	{
		wa.tag = TAG_COOKIE;
		wa.u.cookie = xcb_get_window_attributes(c, window);
		attr = xcb_get_window_attributes_reply(c, wa.u.cookie, 0);
	}
	geom = xcb_get_geometry_reply(c, geomc, 0);
	if(attr && geom)
	{
		reparent_window(c, window, attr->visual, geom->root, geom->depth, geom->x, geom->y, geom->width, geom->height);
		xcb_property_changed(prophs, XCB_PROPERTY_NEW_VALUE, window, WM_NAME);
	}
	free(attr);
	free(geom);
}


/*
 * Returns the colorpixel to use for the given hex color (think of HTML).
 *
 * The hex_color has to start with #, for example #FF00FF.
 *
 * NOTE that get_colorpixel() does _NOT_ check the given color code for validity.
 * This has to be done by the caller.
 *
 */
uint32_t get_colorpixel(xcb_connection_t *conn, xcb_window_t window, char *hex) {
	#define RGB_8_TO_16(i) (65535 * ((i) & 0xFF) / 255)
        char strgroups[3][3] = {{hex[1], hex[2], '\0'},
                                {hex[3], hex[4], '\0'},
                                {hex[5], hex[6], '\0'}};
	int rgb16[3] = {RGB_8_TO_16(strtol(strgroups[0], NULL, 16)),
			RGB_8_TO_16(strtol(strgroups[1], NULL, 16)),
			RGB_8_TO_16(strtol(strgroups[2], NULL, 16))};

	xcb_screen_t *root_screen = xcb_setup_roots_iterator(xcb_get_setup(conn)).data;

	xcb_colormap_t colormapId = xcb_generate_id(conn);
	xcb_create_colormap(conn, XCB_COLORMAP_ALLOC_NONE, colormapId, window, root_screen->root_visual);
	xcb_alloc_color_reply_t *reply = xcb_alloc_color_reply(conn,
			xcb_alloc_color(conn, colormapId, rgb16[0], rgb16[1], rgb16[2]), NULL);

	if (!reply) {
		printf("color fail\n");
		exit(1);
	}

	uint32_t pixel = reply->pixel;
	free(reply);
	xcb_free_colormap(conn, colormapId);
	return pixel;
}

/*
 * (Re-)draws window decorations for a given Client
 *
 */
void decorate_window(xcb_connection_t *conn, Client *client) {
	uint32_t mask = 0;
	uint32_t values[3];
	i3Font *font = load_font(conn, pattern);
	uint32_t background_color,
		 text_color,
		 border_color;

	if (client->container->currently_focused == client) {
		background_color = get_colorpixel(conn, client->frame, "#285577");
		text_color = get_colorpixel(conn, client->frame, "#ffffff");
		border_color = get_colorpixel(conn, client->frame, "#4c7899");
	} else {
		background_color = get_colorpixel(conn, client->frame, "#222222");
		text_color = get_colorpixel(conn, client->frame, "#888888");
		border_color = get_colorpixel(conn, client->frame, "#333333");
	}

	/* Our plan is the following:
	   - Draw a rect around the whole client in background_color
	   - Draw two lines in a lighter color
	   - Draw the window’s title

	   Note that xcb_image_text apparently adds 1xp border around the font? Can anyone confirm this?
	 */

	/* Draw a green rectangle around the window */
	mask = XCB_GC_FOREGROUND;
	values[0] = background_color;
	xcb_change_gc(conn, client->titlegc, mask, values);

	xcb_rectangle_t rect = {0, 0, client->width, client->height};
	xcb_poly_fill_rectangle(conn, client->frame, client->titlegc, 1, &rect);

	/* Draw the lines */
	/* TODO: this needs to be more beautiful somewhen. maybe stdarg + change_gc(gc, ...) ? */
#define DRAW_LINE(colorpixel, x, y, to_x, to_y) { \
		uint32_t draw_values[1]; \
		draw_values[0] = colorpixel; \
		xcb_change_gc(conn, client->titlegc, XCB_GC_FOREGROUND, draw_values); \
		xcb_point_t points[] = {{x, y}, {to_x, to_y}}; \
		xcb_poly_line(conn, XCB_COORD_MODE_ORIGIN, client->frame, client->titlegc, 2, points); \
	}

	DRAW_LINE(border_color, 2, 0, client->width, 0);
	DRAW_LINE(border_color, 2, font->height + 3, 2 + client->width, font->height + 3);

	/* Draw the font */
	mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;

	values[0] = text_color;
	values[1] = background_color;
	values[2] = font->id;

	xcb_change_gc(conn, client->titlegc, mask, values);

	/* TODO: utf8? */
	char *label;
	asprintf(&label, "gots win %08x", client->frame);
        xcb_void_cookie_t text_cookie = xcb_image_text_8_checked(conn, strlen(label), client->frame,
					client->titlegc, 3 /* X */, font->height /* Y = baseline of font */, label);
	free(label);
}

void render_container(xcb_connection_t *connection, Container *container) {
	Client *client;
	uint32_t values[4];
	uint32_t mask = XCB_CONFIG_WINDOW_X |
			XCB_CONFIG_WINDOW_Y |
			XCB_CONFIG_WINDOW_WIDTH |
			XCB_CONFIG_WINDOW_HEIGHT;
	i3Font *font = load_font(connection, pattern);

	if (container->mode == MODE_DEFAULT) {
		int num_clients = 0;
		CIRCLEQ_FOREACH(client, &(container->clients), clients)
			num_clients++;
		printf("got %d clients in this default container.\n", num_clients);

		int current_client = 0;
		CIRCLEQ_FOREACH(client, &(container->clients), clients) {
			/* TODO: rewrite this block so that the need to puke vanishes :) */
			/* TODO: at the moment, every column/row is 200px. This
			 * needs to be changed to "percentage of the screen" by
			 * default and adjustable by the user if necessary.
			 */
			values[0] = container->col * container->width; /* x */
			values[1] = container->row * container->height +
				(container->height / num_clients) * current_client; /* y */

			if (client->x != values[0] || client->y != values[1]) {
				printf("frame needs to be pushed to %dx%d\n",
						values[0], values[1]);
				client->x = values[0];
				client->y = values[1];
				xcb_configure_window(connection, client->frame,
						XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y, values);
			}
			/* TODO: vertical default layout */
			values[0] = container->width; /* width */
			values[1] = container->height / num_clients; /* height */

			if (client->width != values[0] || client->height != values[1]) {
				client->width = values[0];
				client->height = values[1];
				xcb_configure_window(connection, client->frame,
						XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT, values);
			}

			/* TODO: hmm, only do this for new wins */
			/* The coordinates of the child are relative to its frame, we
			 * add a border of 2 pixel to each value */
			values[0] = 2;
			values[1] = font->height + 2 + 2;
			values[2] -= values[0] + 2;
			values[3] -= values[1] + 2;
			printf("child itself will be at %dx%d with size %dx%d\n",
					values[0], values[1], values[2], values[3]);

			xcb_configure_window(connection, client->child, mask, values);

			decorate_window(connection, client);
			current_client++;
		}
	} else {
		/* TODO: Implement stacking */
	}
}

void render_layout(xcb_connection_t *conn) {
	int cols, rows;
	xcb_screen_t *root_screen = xcb_setup_roots_iterator(xcb_get_setup(conn)).data;
	int width = root_screen->width_in_pixels;
	int height = root_screen->height_in_pixels;

	int num_cols = table_dims.x, num_rows = table_dims.y;

	printf("got %d rows and %d cols\n", num_rows, num_cols);
	printf("each of them therefore is %d px width and %d px height\n",
			width / num_cols, height / num_rows);

	/* Go through the whole table and render what’s necessary */
	for (cols = 0; cols < table_dims.x; cols++)
		for (rows = 0; rows < table_dims.y; rows++)
			if (table[cols][rows] != NULL) {
				Container *con = table[cols][rows];
				printf("container has %d colspan, %d rowspan\n",
						con->colspan, con->rowspan);
				/* Update position of the container */
				con->row = rows;
				con->col = cols;
				con->width = (width / num_cols) * con->colspan;
				con->height = (height / num_rows) * con->rowspan;

				/* Render it */
				render_container(conn, table[cols][rows]);
			}

	xcb_flush(conn);
}

/*
 * Let’s own this window…
 *
 */
void reparent_window(xcb_connection_t *conn, xcb_window_t child,
		xcb_visualid_t visual, xcb_window_t root, uint8_t depth,
		int16_t x, int16_t y, uint16_t width, uint16_t height) {

	Client *new = table_get(byChild, child);
	if (new == NULL) {
		printf("oh, it's new\n");
		new = calloc(sizeof(Client), 1);
	}
	uint32_t mask = 0;
	uint32_t values[3];

	/* Insert into the currently active container */
	CIRCLEQ_INSERT_TAIL(&(CUR_CELL->clients), new, clients);

	printf("currently_focused = %p\n", new);
	CUR_CELL->currently_focused = new;
	new->container = CUR_CELL;

	new->frame = xcb_generate_id(conn);
	new->child = child;
	new->width = width;
	new->height = height;

	/* Don’t generate events for our new window, it should *not* be managed */
	mask |= XCB_CW_OVERRIDE_REDIRECT;
	values[0] = 1;

	/* We want to know when… */
	mask |= XCB_CW_EVENT_MASK;
	values[1] = 	XCB_EVENT_MASK_BUTTON_PRESS | /* …mouse is pressed/released */
			XCB_EVENT_MASK_BUTTON_RELEASE |
			XCB_EVENT_MASK_EXPOSURE | /* …our window needs to be redrawn */
			XCB_EVENT_MASK_ENTER_WINDOW /* …user moves cursor inside our window */;

	printf("Reparenting 0x%08x under 0x%08x.\n", child, new->frame);

	/* Yo dawg, I heard you like windows, so I create a window around your window… */
	xcb_create_window(conn,
			depth,
			new->frame,
			root,
			x,
			y,
			width + LEFT + RIGHT,
			height + TOP + BOTTOM,
			/* border_width */ 0,
			XCB_WINDOW_CLASS_INPUT_OUTPUT,
			visual,
			mask,
			values);
	xcb_change_save_set(conn, XCB_SET_MODE_INSERT, child);

	/* Map the window on the screen (= make it visible) */
	xcb_map_window(conn, new->frame);

	/* Generate a graphics context for the titlebar */
	new->titlegc = xcb_generate_id(conn);
	xcb_create_gc(conn, new->titlegc, new->frame, 0, 0);

	/* Draw decorations */
	decorate_window(conn, new);

	/* Put our data structure (Client) into the table */
	table_put(byParent, new->frame, new);
	table_put(byChild, child, new);

	/* Moves the original window into the new frame we've created for it */
	i3Font *font = load_font(conn, pattern);
	xcb_reparent_window(conn, child, new->frame, 0, font->height);

	/* We are interested in property changes */
	mask = XCB_CW_EVENT_MASK;
	values[0] = 	XCB_EVENT_MASK_PROPERTY_CHANGE |
			XCB_EVENT_MASK_STRUCTURE_NOTIFY |
			XCB_EVENT_MASK_ENTER_WINDOW;
	xcb_change_window_attributes(conn, child, mask, values);

	/* Focus the new window */
	xcb_set_input_focus(conn, XCB_INPUT_FOCUS_NONE, new->child, XCB_CURRENT_TIME);

	render_layout(conn);
}

static bool focus_window_in_container(xcb_connection_t *connection, Container *container,
		direction_t direction) {
	/* If this container is empty, we’re done */
	if (container->currently_focused == NULL)
		return false;

	Client *candidad;
	if (direction == D_UP)
		candidad = CIRCLEQ_PREV(container->currently_focused, clients);
	else if (direction == D_DOWN)
		candidad = CIRCLEQ_NEXT(container->currently_focused, clients);

	/* If we don’t have anything to select, we’re done */
	if (candidad == CIRCLEQ_END(&(container->clients)))
		return false;

	/* Set focus if we could successfully move */
	container->currently_focused = candidad;
	xcb_set_input_focus(connection, XCB_INPUT_FOCUS_NONE, candidad->child, XCB_CURRENT_TIME);
	render_layout(connection);

	return true;
}

static void focus_window(xcb_connection_t *connection, direction_t direction) {
	printf("focusing direction %d\n", direction);
	/* TODO: for horizontal default layout, this has to be expanded to LEFT/RIGHT */
	if (direction == D_UP || direction == D_DOWN) {
		/* Let’s see if we can perform up/down focus in the current container */
		Container *container = CUR_CELL;

		/* There always is a container. If not, current_col or current_row is wrong */
		assert(container != NULL);

		if (focus_window_in_container(connection, container, direction))
			return;
	} else if (direction == D_LEFT || direction == D_RIGHT) {
		if (direction == D_RIGHT && cell_exists(current_col+1, current_row))
			current_col++;
		else if (direction == D_LEFT && cell_exists(current_col-1, current_row))
			current_col--;
		else {
			printf("nah, not possible\n");
			return;
		}
		if (CUR_CELL->currently_focused != NULL) {
			xcb_set_input_focus(connection, XCB_INPUT_FOCUS_NONE,
					CUR_CELL->currently_focused->child, XCB_CURRENT_TIME);
			render_layout(connection);
		}

	} else {
		printf("direction unhandled\n");
	}
}

/*
 * Tries to move the window inside its current container.
 *
 * Returns true if the window could be moved, false otherwise.
 *
 */
static bool move_current_window_in_container(xcb_connection_t *connection, Client *client,
		direction_t direction) {
	Client *other = (direction == D_UP ? CIRCLEQ_PREV(client, clients) :
						CIRCLEQ_NEXT(client, clients));

	if (other == CIRCLEQ_END(&(client->container->clients)))
		return false;

	printf("i can do that\n");
	/* We can move the client inside its current container */
	CIRCLEQ_REMOVE(&(client->container->clients), client, clients);
	if (direction == D_UP)
		CIRCLEQ_INSERT_BEFORE(&(client->container->clients), other, client, clients);
	else CIRCLEQ_INSERT_AFTER(&(client->container->clients), other, client, clients);
	render_layout(connection);
	return true;
}

/*
 * Moves the current window to the given direction, creating a column/row if
 * necessary
 *
 */
static void move_current_window(xcb_connection_t *connection, direction_t direction) {
	printf("moving window to direction %d\n", direction);
	/* Get current window */
	Container *container = CUR_CELL,
		  *new;

	/* There has to be a container, see focus_window() */
	assert(container != NULL);

	/* If there is no window, we’re done */
	if (container->currently_focused == NULL)
		return;

	/* As soon as the client is moved away, the next client in the old
	 * container needs to get focus, if any. Therefore, we save it here. */
	Client *current_client = container->currently_focused;
	Client *to_focus = CIRCLEQ_NEXT(current_client, clients);
	if (to_focus == CIRCLEQ_END(&(container->clients)))
		to_focus = NULL;

	switch (direction) {
		case D_LEFT:
			if (current_col == 0)
				return;

			new = table[--current_col][current_row];
			break;
		case D_RIGHT:
			if (current_col == (table_dims.x-1))
				expand_table_cols();

			new = table[++current_col][current_row];
			break;
		case D_UP:
			if (move_current_window_in_container(connection, current_client, D_UP) ||
				current_row == 0)
				return;

			new = table[current_col][--current_row];
			break;
		case D_DOWN:
			if (move_current_window_in_container(connection, current_client, D_DOWN))
				return;

			if (current_row == (table_dims.y-1))
				expand_table_rows();

			new = table[current_col][++current_row];
			break;
	}

	/* Remove it from the old container and put it into the new one */
	CIRCLEQ_REMOVE(&(container->clients), current_client, clients);
	CIRCLEQ_INSERT_TAIL(&(new->clients), current_client, clients);

	/* Update data structures */
	current_client->container = new;
	container->currently_focused = to_focus;
	new->currently_focused = current_client;

	/* TODO: delete all empty columns/rows */

	render_layout(connection);
}

/*
 * "Snaps" the current container (not possible for windows, because it works at table base)
 * to the given direction, that is, adjusts cellspan/rowspan
 *
 */
static void snap_current_container(xcb_connection_t *connection, direction_t direction) {
	printf("snapping container to direction %d\n", direction);

	Container *container = CUR_CELL;
	int i;

	assert(container != NULL);

	switch (direction) {
		case D_LEFT:
			/* Snap to the left is actually a move to the left and then a snap right */
			move_current_window(connection, D_LEFT);
			snap_current_container(connection, D_RIGHT);
			return;
		case D_RIGHT:
			/* Check if the cell is used */
			if (!cell_exists(container->col + 1, container->row) ||
				table[container->col+1][container->row]->currently_focused != NULL) {
				printf("cannot snap to right - the cell is already used\n");
				return;
			}

			/* Check if there are other cells with rowspan, which are in our way.
			 * If so, reduce their rowspan. */
			for (i = container->row-1; i >= 0; i--) {
				printf("we got cell %d, %d with rowspan %d\n",
						container->col+1, i, table[container->col+1][i]->rowspan);
				while ((table[container->col+1][i]->rowspan-1) >= (container->row - i))
					table[container->col+1][i]->rowspan--;
				printf("new rowspan = %d\n", table[container->col+1][i]->rowspan);
			}

			container->colspan++;
			break;
		case D_UP:
			move_current_window(connection, D_UP);
			snap_current_container(connection, D_DOWN);
			return;
		case D_DOWN:
			printf("snapping down\n");
			if (!cell_exists(container->col, container->row+1) ||
				table[container->col][container->row+1]->currently_focused != NULL) {
				printf("cannot snap down - the cell is already used\n");
				return;
			}

			for (i = container->col-1; i >= 0; i--) {
				printf("we got cell %d, %d with colspan %d\n",
						i, container->row+1, table[i][container->row+1]->colspan);
				while ((table[i][container->row+1]->colspan-1) >= (container->col - i))
					table[i][container->row+1]->colspan--;
				printf("new colspan = %d\n", table[i][container->row+1]->colspan);

			}

			container->rowspan++;
			break;
	}

	render_layout(connection);
}

int format_event(xcb_generic_event_t *e)
{           
    uint8_t sendEvent;
    uint16_t seqnum;

    sendEvent = (e->response_type & 0x80) ? 1 : 0;
    e->response_type &= ~0x80;
    seqnum = *((uint16_t *) e + 1);

    switch(e->response_type) 
    {   
    case 0:
        printf("Error %s on seqnum %d (%s).\n",
            labelError[*((uint8_t *) e + 1)],
            seqnum,
            labelRequest[*((uint8_t *) e + 10)]);
        break;
    default:
        printf("Event %s following seqnum %d%s.\n",
            labelEvent[e->response_type],
            seqnum,
            labelSendEvent[sendEvent]);
        break;  
    case XCB_KEYMAP_NOTIFY:
        printf("Event %s%s.\n",
            labelEvent[e->response_type],
            labelSendEvent[sendEvent]);
        break;
    }

    fflush(stdout);
    return 1;
}


static int handleEvent(void *ignored, xcb_connection_t *c, xcb_generic_event_t *e)
{
        return format_event(e);
}

/*
 * Starts the given application with the given args.
 *
 */
static void start_application(char *path, char *args) {
	pid_t pid;
	if ((pid = vfork()) == 0) {
		/* This is the child */
		char *argv[2];
		/* TODO: For now, we ignore args. Later on, they should be parsed
		   correctly (like in the shell?) */
		argv[0] = path;
		argv[1] = NULL;
		execve(path, argv, environment);
		/* not reached */
	}
}

/*
 * Due to bindings like Mode_switch + <a>, we need to bind some keys in XCB_GRAB_MODE_SYNC.
 * Therefore, we just replay all key presses.
 *
 */
static int handle_key_release(void *ignored, xcb_connection_t *conn, xcb_key_release_event_t *event) {
	printf("got key release, just passing\n");
	xcb_allow_events(conn, ReplayKeyboard, event->time);
	xcb_flush(conn);
	return 1;
}

/*
 * Parses a command, see file CMDMODE for more information
 *
 */
static void parse_command(xcb_connection_t *conn, const char *command) {
	printf("--- parsing command \"%s\" ---\n", command);
	/* Hmm, just to be sure */
	if (command[0] == '\0')
		return;

	/* Is it an <exec>? */
	if (strncmp(command, "exec ", strlen("exec ")) == 0) {
		printf("starting \"%s\"\n", command + strlen("exec "));
		start_application(command+strlen("exec "), NULL);
		return;
	}

	/* Is it a <with>? */
	if (command[0] == 'w') {
		/* TODO: implement */
		printf("not yet implemented.\n");
		return;
	}

	/* It's a normal <cmd> */
	int times;
	char *rest = NULL;
	enum { ACTION_FOCUS, ACTION_MOVE, ACTION_SNAP } action = ACTION_FOCUS;
	direction_t direction;
	times = strtol(command, &rest, 10);
	if (rest == NULL) {
		printf("Invalid command: Consists only of a movement\n");
		return;
	}
	if (*rest == 'm' || *rest == 's') {
		action = (*rest == 'm' ? ACTION_MOVE : ACTION_SNAP);
		rest++;
	}

	/* Now perform action to <where> */
	while (*rest != '\0') {
		/* TODO: tags */
		if (*rest == 'h')
			direction = D_LEFT;
		else if (*rest == 'j')
			direction = D_DOWN;
		else if (*rest == 'k')
			direction = D_UP;
		else if (*rest == 'l')
			direction = D_RIGHT;
		else {
			printf("unknown direction: %c\n", *rest);
			return;
		}

		if (action == ACTION_FOCUS)
			focus_window(conn, direction);
		else if (action == ACTION_MOVE)
			move_current_window(conn, direction);
		else if (action == ACTION_SNAP)
			snap_current_container(conn, direction);

		rest++;

	}

	printf("--- done ---\n");
}

/*
 * There was a key press. We lookup the key symbol and see if there are any bindings
 * on that. This allows to do things like binding special characters (think of ä) to
 * functions to get one more modifier while not losing AltGr :-)
 * TODO: this description needs to be more understandable
 *
 */
static int handle_key_press(void *ignored, xcb_connection_t *conn, xcb_key_press_event_t *event) {
	printf("Keypress %d\n", event->detail);

	/* We need to get the keysym group (There are group 1 to group 4, each holding
	   two keysyms (without shift and with shift) using Xkb because X fails to
	   provide them reliably (it works in Xephyr, it does not in real X) */
	XkbStateRec state;
	if (XkbGetState(xkbdpy, XkbUseCoreKbd, &state) == Success && (state.group+1) == 2)
		event->state |= 0x2;

	printf("state %d\n", event->state);

	/* Find the binding */
	Binding *bind, *best_match = TAILQ_END(&bindings);
	TAILQ_FOREACH(bind, &bindings, bindings) {
		if (bind->keycode == event->detail &&
			(bind->mods & event->state) == bind->mods) {
			if (best_match == TAILQ_END(&bindings) ||
				bind->mods > best_match->mods)
				best_match = bind;
		}
	}

	/* No match? Then it was an actively grabbed key, that is with Mode_switch, and
	   the user did not press Mode_switch, so just pass it… */
	if (best_match == TAILQ_END(&bindings)) {
		xcb_allow_events(conn, ReplayKeyboard, event->time);
		xcb_flush(conn);
		return 1;
	}

	if (event->state & 0x2) {
		printf("that's mode_switch\n");
		parse_command(conn, best_match->command);
		printf("ok, hiding this event.\n");
		xcb_allow_events(conn, SyncKeyboard, event->time);
		xcb_flush(conn);
		return 1;
	}

	parse_command(conn, best_match->command);
	return 1;
}

/*
 * When the user moves the mouse pointer onto a window, this callback gets called.
 *
 */
static int handle_enter_notify(void *ignored, xcb_connection_t *conn, xcb_enter_notify_event_t *event) {
	printf("enter_notify\n");

	/* This was either a focus for a client’s parent (= titlebar)… */
	Client *client = table_get(byParent, event->event),
	       *old_client;
	/* …or the client itself */
	if (client == NULL)
		client = table_get(byChild, event->event);

	/* If not, then this event is not interesting. This should not happen */
	if (client == NULL) {
		printf("DEBUG: Uninteresting enter_notify-event?\n");
		return 1;
	}

	/* Update container */
	old_client = client->container->currently_focused;
	client->container->currently_focused = client;

	current_col = client->container->col;
	current_row = client->container->row;

	/* Set focus to the entered window, and flush xcb buffer immediately */
	xcb_set_input_focus(conn, XCB_INPUT_FOCUS_NONE, client->child, XCB_CURRENT_TIME);
	/* Update last/current client’s titlebar */
	if (old_client != NULL)
		decorate_window(conn, old_client);
	decorate_window(conn, client);
	xcb_flush(conn);

	return 1;
}

int handle_map_notify_event(void *prophs, xcb_connection_t *c, xcb_map_notify_event_t *e)
{
	window_attributes_t wa = { TAG_VALUE };
	wa.u.override_redirect = e->override_redirect;
	printf("MapNotify for 0x%08x.\n", e->window);
	manage_window(prophs, c, e->window, wa);
	return 1;
}

/*
 * Our window decorations were unmapped. That means, the window will be killed now,
 * so we better clean up before.
 *
 */
int handle_unmap_notify_event(void *data, xcb_connection_t *c, xcb_unmap_notify_event_t *e) {
	Client *client = table_remove(byChild, e->event);
	xcb_window_t root;
	printf("UnmapNotify for 0x%08x (received from 0x%08x): ", e->window, e->event);
	if(!client)
	{
		printf("not a managed window. Ignoring.\n");
		return 0;
	}

	int rows, cols;
	Client *con_client;
	for (cols = 0; cols < table_dims.x; cols++)
		for (rows = 0; rows < table_dims.y; rows++)
			CIRCLEQ_FOREACH(con_client, &(table[cols][rows]->clients), clients)
				if (con_client == client) {
					printf("removing from container\n");
					if (client->container->currently_focused == client)
						client->container->currently_focused = NULL;
					CIRCLEQ_REMOVE(&(table[cols][rows]->clients), con_client, clients);
					break;
				}



	root = xcb_setup_roots_iterator(xcb_get_setup(c)).data->root;
	printf("child of 0x%08x.\n", client->frame);
	xcb_reparent_window(c, client->child, root, 0, 0);
	xcb_destroy_window(c, client->frame);
	xcb_flush(c);
	table_remove(byParent, client->frame);
	free(client);

	render_layout(c);

	return 1;
}



static int handleExposeEvent(void *data, xcb_connection_t *c, xcb_expose_event_t *e) {
printf("exposeevent\n");
	Client *client = table_get(byParent, e->window);
	if(!client || e->count != 0)
		return 1;
	decorate_window(c, client);
	return 1;
}
void manage_existing_windows(xcb_connection_t *c, xcb_property_handlers_t *prophs, xcb_window_t root) {
	xcb_query_tree_cookie_t wintree;
	xcb_query_tree_reply_t *rep;
	int i, len;
	xcb_window_t *children;
	xcb_get_window_attributes_cookie_t *cookies;

	wintree = xcb_query_tree(c, root);
	rep = xcb_query_tree_reply(c, wintree, 0);
	if(!rep)
		return;
	len = xcb_query_tree_children_length(rep);
	cookies = malloc(len * sizeof(*cookies));
	if(!cookies)
	{
		free(rep);
		return;
	}
	children = xcb_query_tree_children(rep);
	for(i = 0; i < len; ++i)
		cookies[i] = xcb_get_window_attributes(c, children[i]);
	for(i = 0; i < len; ++i)
	{
		window_attributes_t wa = { TAG_COOKIE, { cookies[i] } };
		manage_window(prophs, c, children[i], wa);
	}
	free(rep);
}

int main(int argc, char *argv[], char *env[]) {
	int i, e = 0;

	for (i = 0; (env[i] != NULL); i++)
		if (strncmp(env[i], "LC_", strlen("LC_")) == 0 ||
			strncmp(env[i], "LANG=", strlen("LANG=")) == 0 ||
			strncmp(env[i], "DISPLAY=", strlen("DISPLAY=")) == 0) {
			printf("Passing environment \"%s\"\n", env[i]);
			environment = realloc(environment, sizeof(char*) * ++e);
			environment[e-1] = env[i];
		}

	/* environment has to be NULL-terminated */
	environment = realloc(environment, sizeof(char*) * ++e);
	environment[e-1] = NULL;

	init_table();

	xcb_connection_t *c;
	xcb_event_handlers_t evenths;
	xcb_property_handlers_t prophs;
	xcb_window_t root;

	int screens;

	memset(&evenths, 0, sizeof(xcb_event_handlers_t));
	memset(&prophs, 0, sizeof(xcb_property_handlers_t));

	byChild = alloc_table();
	byParent = alloc_table();

	TAILQ_INIT(&bindings);

	c = xcb_connect(NULL, &screens);

	printf("x screen is %d\n", screens);

	/* TODO: this has to be more beautiful somewhen */
	int major, minor, error;

	major = XkbMajorVersion;
	minor = XkbMinorVersion;

	int evBase, errBase;

	if ((xkbdpy = XkbOpenDisplay(getenv("DISPLAY"), &evBase, &errBase, &major, &minor, &error)) == NULL) {
		fprintf(stderr, "XkbOpenDisplay() failed\n");
		return 1;
	}

	int i1;
	if (!XkbQueryExtension(xkbdpy,&i1,&evBase,&errBase,&major,&minor)) {
		fprintf(stderr, "XKB not supported by X-server\n");
		return 1;
	}
	/* end of ugliness */

	xcb_event_handlers_init(c, &evenths);
	for(i = 2; i < 128; ++i)
		xcb_event_set_handler(&evenths, i, handleEvent, 0);

	for(i = 0; i < 256; ++i)
		xcb_event_set_error_handler(&evenths, i, (xcb_generic_error_handler_t) handleEvent, 0);

	/* Expose = an Application should redraw itself. That is, we have to redraw our
	 * contents (= top/bottom bar, titlebars for each window) */
	xcb_event_set_expose_handler(&evenths, handleExposeEvent, 0);

	/* Key presses/releases are pretty obvious, I think */
	xcb_event_set_key_press_handler(&evenths, handle_key_press, 0);
	xcb_event_set_key_release_handler(&evenths, handle_key_release, 0);

	/* Enter window = user moved his mouse over the window */
	xcb_event_set_enter_notify_handler(&evenths, handle_enter_notify, 0);

	xcb_event_set_unmap_notify_handler(&evenths, handle_unmap_notify_event, 0);

	xcb_property_handlers_init(&prophs, &evenths);
	xcb_event_set_map_notify_handler(&evenths, handle_map_notify_event, &prophs);

	root = xcb_aux_get_screen(c, screens)->root;
	root_win = root;

	uint32_t mask = XCB_CW_EVENT_MASK;
	uint32_t values[] = { XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_PROPERTY_CHANGE };
	xcb_change_window_attributes(c, root, mask, values);

	#define BIND(key, modifier, cmd) { \
		Binding *new = malloc(sizeof(Binding)); \
		new->keycode = key; \
		new->mods = modifier; \
		new->command = cmd; \
		TAILQ_INSERT_TAIL(&bindings, new, bindings); \
	}

	/* 38 = 'a' */
	BIND(38, BIND_MODE_SWITCH, "foo");

	BIND(30, 0, "exec /usr/pkg/bin/urxvt");

	BIND(44, BIND_MOD_1, "h");
	BIND(45, BIND_MOD_1, "j");
	BIND(46, BIND_MOD_1, "k");
	BIND(47, BIND_MOD_1, "l");

	BIND(44, BIND_MOD_1 | BIND_CONTROL, "sh");
	BIND(45, BIND_MOD_1 | BIND_CONTROL, "sj");
	BIND(46, BIND_MOD_1 | BIND_CONTROL, "sk");
	BIND(47, BIND_MOD_1 | BIND_CONTROL, "sl");

	BIND(44, BIND_MOD_1 | BIND_SHIFT, "mh");
	BIND(45, BIND_MOD_1 | BIND_SHIFT, "mj");
	BIND(46, BIND_MOD_1 | BIND_SHIFT, "mk");
	BIND(47, BIND_MOD_1 | BIND_SHIFT, "ml");

	Binding *bind;
	TAILQ_FOREACH(bind, &bindings, bindings) {
		printf("Grabbing %d\n", bind->keycode);
		if (bind->mods & BIND_MODE_SWITCH)
			xcb_grab_key(c, 0, root, 0, bind->keycode, XCB_GRAB_MODE_SYNC, XCB_GRAB_MODE_SYNC);
		else xcb_grab_key(c, 0, root, bind->mods, bind->keycode, XCB_GRAB_MODE_SYNC, XCB_GRAB_MODE_ASYNC);
	}

	start_application(TERMINAL, NULL);

	xcb_flush(c);

	manage_existing_windows(c, &prophs, root);

	xcb_event_wait_for_event_loop(&evenths);

	/* not reached */
	return 0;
}