git.sur5r.net Git - i3/i3/blob - src/layout.c

   1 /*
   2  * vim:ts=8:expandtab
   3  *
   4  * i3 - an improved dynamic tiling window manager
   5  *
   6  * © 2009 Michael Stapelberg and contributors
   7  *
   8  * See file LICENSE for license information.
   9  *
  10  * layout.c: Functions handling layout/drawing of window decorations
  11  *
  12  */
  13 #include <stdio.h>
  14 #include <string.h>
  15 #include <stdlib.h>
  16 #include <xcb/xcb.h>
  17 #include <assert.h>
  18 #include <math.h>
  19
  20 #include "config.h"
  21 #include "i3.h"
  22 #include "xcb.h"
  23 #include "table.h"
  24 #include "util.h"
  25 #include "xinerama.h"
  26 #include "layout.h"
  27
  28 /*
  29  * Updates *destination with new_value and returns true if it was changed or false
  30  * if it was the same
  31  *
  32  */
  33 static bool update_if_necessary(uint32_t *destination, const uint32_t new_value) {
  34         uint32_t old_value = *destination;
  35
  36         return ((*destination = new_value) != old_value);
  37 }
  38
  39 /*
  40  * Gets the unoccupied space (= space which is available for windows which were resized by the user)
  41  * for the given row. This is necessary to render both, customly resized windows and never touched
  42  * windows correctly, meaning that the aspect ratio will be maintained when opening new windows.
  43  *
  44  */
  45 int get_unoccupied_x(Workspace *workspace) {
  46         int unoccupied = workspace->rect.width;
  47         float default_factor = ((float)workspace->rect.width / workspace->cols) / workspace->rect.width;
  48
  49         LOG("get_unoccupied_x(), starting with %d, default_factor = %f\n", unoccupied, default_factor);
  50
  51         for (int cols = 0; cols < workspace->cols; cols++) {
  52                 LOG("width_factor[%d] = %f\n", cols, workspace->width_factor[cols]);
  53
  54                 if (workspace->width_factor[cols] == 0)
  55                         unoccupied -= workspace->rect.width * default_factor;
  56         }
  57
  58         LOG("unoccupied space: %d\n", unoccupied);
  59         return unoccupied;
  60 }
  61
  62 /* See get_unoccupied_x() */
  63 int get_unoccupied_y(Workspace *workspace, int col) {
  64         int unoccupied = workspace->rect.height;
  65         float default_factor = ((float)workspace->rect.height / workspace->rows) / workspace->rect.height;
  66
  67         LOG("get_unoccupied_y(), starting with %d, default_factor = %f\n", unoccupied, default_factor);
  68
  69         for (int rows = 0; rows < workspace->rows; rows++) {
  70                 LOG("height_factor[%d] = %f\n", rows, workspace->height_factor[rows]);
  71                 if (workspace->height_factor[rows] == 0)
  72                         unoccupied -= workspace->rect.height * default_factor;
  73         }
  74
  75         LOG("unoccupied space: %d\n", unoccupied);
  76         return unoccupied;
  77 }
  78
  79 /*
  80  * Redecorates the given client correctly by checking if it’s in a stacking container and
  81  * re-rendering the stack window or just calling decorate_window if it’s not in a stacking
  82  * container.
  83  *
  84  */
  85 void redecorate_window(xcb_connection_t *conn, Client *client) {
  86         if (client->container->mode == MODE_STACK) {
  87                 render_container(conn, client->container);
  88                 /* We clear the frame to generate exposure events, because the color used
  89                    in drawing may be different */
  90                 xcb_clear_area(conn, true, client->frame, 0, 0, client->rect.width, client->rect.height);
  91         } else decorate_window(conn, client, client->frame, client->titlegc, 0);
  92         xcb_flush(conn);
  93 }
  94
  95 /*
  96  * (Re-)draws window decorations for a given Client onto the given drawable/graphic context.
  97  * When in stacking mode, the window decorations are drawn onto an own window.
  98  *
  99  */
 100 void decorate_window(xcb_connection_t *conn, Client *client, xcb_drawable_t drawable, xcb_gcontext_t gc, int offset) {
 101         i3Font *font = load_font(conn, config.font);
 102         int decoration_height = font->height + 2 + 2;
 103         uint32_t background_color,
 104                  text_color,
 105                  border_color;
 106
 107         /* Clients without a container (docks) won’t get decorated */
 108         if (client->container == NULL)
 109                 return;
 110
 111         if (client->container->currently_focused == client) {
 112                 /* Distinguish if the window is currently focused… */
 113                 if (CUR_CELL->currently_focused == client)
 114                         background_color = get_colorpixel(conn, "#285577");
 115                 /* …or if it is the focused window in a not focused container */
 116                 else background_color = get_colorpixel(conn, "#555555");
 117
 118                 text_color = get_colorpixel(conn, "#ffffff");
 119                 border_color = get_colorpixel(conn, "#4c7899");
 120         } else {
 121                 background_color = get_colorpixel(conn, "#222222");
 122                 text_color = get_colorpixel(conn, "#888888");
 123                 border_color = get_colorpixel(conn, "#333333");
 124         }
 125
 126         /* Our plan is the following:
 127            - Draw a rect around the whole client in background_color
 128            - Draw two lines in a lighter color
 129            - Draw the window’s title
 130          */
 131
 132         /* Draw a rectangle in background color around the window */
 133         xcb_change_gc_single(conn, gc, XCB_GC_FOREGROUND, background_color);
 134
 135         /* In stacking mode, we only render the rect for this specific decoration */
 136         if (client->container->mode == MODE_STACK) {
 137                 xcb_rectangle_t rect = {0, offset, client->container->width, offset + decoration_height };
 138                 xcb_poly_fill_rectangle(conn, drawable, gc, 1, &rect);
 139         } else {
 140                 /* We need to use the container’s width because it is the more recent value - when
 141                    in stacking mode, clients get reconfigured only on demand (the not active client
 142                    is not reconfigured), so the client’s rect.width would be wrong */
 143                 xcb_rectangle_t rect = {0, 0, client->container->width, client->rect.height};
 144                 xcb_poly_fill_rectangle(conn, drawable, gc, 1, &rect);
 145
 146                 /* Draw the inner background to have a black frame around clients (such as mplayer)
 147                    which cannot be resized exactly in our frames and therefore are centered */
 148                 xcb_change_gc_single(conn, client->titlegc, XCB_GC_FOREGROUND, get_colorpixel(conn, "#000000"));
 149                 xcb_rectangle_t crect = {2, decoration_height,
 150                                          client->rect.width - (2 + 2), client->rect.height - 2 - decoration_height};
 151                 xcb_poly_fill_rectangle(conn, client->frame, client->titlegc, 1, &crect);
 152         }
 153
 154         /* Draw the lines */
 155         xcb_draw_line(conn, drawable, gc, border_color, 2, offset, client->rect.width, offset);
 156         xcb_draw_line(conn, drawable, gc, border_color, 2, offset + font->height + 3,
 157                       2 + client->rect.width, offset + font->height + 3);
 158
 159         /* If the client has a title, we draw it */
 160         if (client->name != NULL) {
 161                 /* Draw the font */
 162                 uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
 163                 uint32_t values[] = { text_color, background_color, font->id };
 164                 xcb_change_gc(conn, gc, mask, values);
 165
 166                 /* name_len == -1 means this is a legacy application which does not specify _NET_WM_NAME,
 167                    and we don’t handle the old window name (COMPOUND_TEXT) but only _NET_WM_NAME, which
 168                    is UTF-8 */
 169                 if (client->name_len == -1)
 170                         xcb_image_text_8(conn, strlen(client->name), drawable, gc, 3 /* X */,
 171                                          offset + font->height /* Y = baseline of font */, client->name);
 172                 else
 173                         xcb_image_text_16(conn, client->name_len, drawable, gc, 3 /* X */,
 174                                           offset + font->height /* Y = baseline of font */, (xcb_char2b_t*)client->name);
 175         }
 176 }
 177
 178 /*
 179  * Pushes the client’s x and y coordinates to X11
 180  *
 181  */
 182 static void reposition_client(xcb_connection_t *conn, Client *client) {
 183         LOG("frame 0x%08x needs to be pushed to %dx%d\n", client->frame, client->rect.x, client->rect.y);
 184         /* Note: We can use a pointer to client->x like an array of uint32_ts
 185            because it is followed by client->y by definition */
 186         xcb_configure_window(conn, client->frame, XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y, &(client->rect.x));
 187 }
 188
 189 /*
 190  * Pushes the client’s width/height to X11 and resizes the child window
 191  *
 192  */
 193 static void resize_client(xcb_connection_t *conn, Client *client) {
 194         i3Font *font = load_font(conn, config.font);
 195
 196         LOG("resizing client 0x%08x to %d x %d\n", client->frame, client->rect.width, client->rect.height);
 197         xcb_configure_window(conn, client->frame,
 198                         XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT,
 199                         &(client->rect.width));
 200
 201         /* Adjust the position of the child inside its frame.
 202          * The coordinates of the child are relative to its frame, we
 203          * add a border of 2 pixel to each value */
 204         uint32_t mask = XCB_CONFIG_WINDOW_X |
 205                         XCB_CONFIG_WINDOW_Y |
 206                         XCB_CONFIG_WINDOW_WIDTH |
 207                         XCB_CONFIG_WINDOW_HEIGHT;
 208         Rect *rect = &(client->child_rect);
 209         switch ((client->container != NULL ? client->container->mode : MODE_DEFAULT)) {
 210                 case MODE_STACK:
 211                         rect->x = 2;
 212                         rect->y = 0;
 213                         rect->width = client->rect.width - (2 + 2);
 214                         rect->height = client->rect.height - 2;
 215                         break;
 216                 default:
 217                         if (client->titlebar_position == TITLEBAR_OFF) {
 218                                 rect->x = 0;
 219                                 rect->y = 0;
 220                                 rect->width = client->rect.width;
 221                                 rect->height = client->rect.height;
 222                         } else {
 223                                 rect->x = 2;
 224                                 rect->y = font->height + 2 + 2;
 225                                 rect->width = client->rect.width - (2 + 2);
 226                                 rect->height = client->rect.height - ((font->height + 2 + 2) + 2);
 227                         }
 228                         break;
 229         }
 230
 231         /* Obey the ratio, if any */
 232         if (client->proportional_height != 0 &&
 233             client->proportional_width != 0) {
 234                 LOG("proportional height = %d, width = %d\n", client->proportional_height, client->proportional_width);
 235                 double new_height = rect->height + 1;
 236                 int new_width = rect->width;
 237
 238                 while (new_height > rect->height) {
 239                         new_height = ((double)client->proportional_height / client->proportional_width) * new_width;
 240
 241                         if (new_height > rect->height)
 242                                 new_width--;
 243                 }
 244                 /* Center the window */
 245                 rect->y += ceil(rect->height / 2) - floor(new_height / 2);
 246                 rect->x += ceil(rect->width / 2) - floor(new_width / 2);
 247
 248                 rect->height = new_height;
 249                 rect->width = new_width;
 250                 LOG("new_height = %f, new_width = %d\n", new_height, new_width);
 251         }
 252
 253         LOG("child will be at %dx%d with size %dx%d\n", rect->x, rect->y, rect->width, rect->height);
 254
 255         xcb_configure_window(conn, client->child, mask, &(rect->x));
 256
 257         /* After configuring a child window we need to fake a configure_notify_event (see ICCCM 4.2.3).
 258          * This is necessary to inform the client of its position relative to the root window,
 259          * not relative to its frame (as done in the configure_notify_event by the x server). */
 260         fake_absolute_configure_notify(conn, client);
 261 }
 262
 263 /*
 264  * Renders the given container. Is called by render_layout() or individually (for example
 265  * when focus changes in a stacking container)
 266  *
 267  */
 268 void render_container(xcb_connection_t *conn, Container *container) {
 269         Client *client;
 270         int num_clients = 0, current_client = 0;
 271
 272         if (container->currently_focused == NULL)
 273                 return;
 274
 275         CIRCLEQ_FOREACH(client, &(container->clients), clients)
 276                 num_clients++;
 277
 278         if (container->mode == MODE_DEFAULT) {
 279                 LOG("got %d clients in this default container.\n", num_clients);
 280                 CIRCLEQ_FOREACH(client, &(container->clients), clients) {
 281                         /* If the client is in fullscreen mode, it does not get reconfigured */
 282                         if (container->workspace->fullscreen_client == client) {
 283                                 current_client++;
 284                                 continue;
 285                         }
 286
 287                         /* Check if we changed client->x or client->y by updating it.
 288                          * Note the bitwise OR instead of logical OR to force evaluation of both statements */
 289                         if (client->force_reconfigure |
 290                             update_if_necessary(&(client->rect.x), container->x) |
 291                             update_if_necessary(&(client->rect.y), container->y +
 292                                         (container->height / num_clients) * current_client))
 293                                 reposition_client(conn, client);
 294
 295                         /* TODO: vertical default layout */
 296                         if (client->force_reconfigure |
 297                             update_if_necessary(&(client->rect.width), container->width) |
 298                             update_if_necessary(&(client->rect.height), container->height / num_clients))
 299                                 resize_client(conn, client);
 300
 301                         client->force_reconfigure = false;
 302
 303                         current_client++;
 304                 }
 305         } else {
 306                 i3Font *font = load_font(conn, config.font);
 307                 int decoration_height = (font->height + 2 + 2);
 308                 struct Stack_Window *stack_win = &(container->stack_win);
 309
 310                 /* Check if we need to remap our stack title window, it gets unmapped when the container
 311                    is empty in src/handlers.c:unmap_notify() */
 312                 if (stack_win->rect.height == 0)
 313                         xcb_map_window(conn, stack_win->window);
 314
 315                 /* Check if we need to reconfigure our stack title window */
 316                 if (update_if_necessary(&(stack_win->rect.x), container->x) |
 317                     update_if_necessary(&(stack_win->rect.y), container->y) |
 318                     update_if_necessary(&(stack_win->rect.width), container->width) |
 319                     update_if_necessary(&(stack_win->rect.height), decoration_height * num_clients)) {
 320
 321                         /* Configuration can happen in two slightly different ways:
 322
 323                            If there is no client in fullscreen mode, 5 parameters are passed
 324                            (x, y, width, height, stack mode is set to above which means top-most position).
 325
 326                            If there is a fullscreen client, the fourth parameter is set to to the
 327                            fullscreen window as sibling and the stack mode is set to below, which means
 328                            that the stack_window will be placed just below the sibling, that is, under
 329                            the fullscreen window.
 330                          */
 331                         uint32_t values[] = { stack_win->rect.x, stack_win->rect.y,
 332                                               stack_win->rect.width, stack_win->rect.height,
 333                                               XCB_STACK_MODE_ABOVE, XCB_STACK_MODE_BELOW };
 334                         uint32_t mask = XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y |
 335                                         XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT |
 336                                         XCB_CONFIG_WINDOW_STACK_MODE;
 337
 338                         /* If there is no fullscreen client, we raise the stack window */
 339                         if (container->workspace->fullscreen_client != NULL) {
 340                                 mask |= XCB_CONFIG_WINDOW_SIBLING;
 341                                 values[4] = container->workspace->fullscreen_client->frame;
 342                         }
 343
 344                         xcb_configure_window(conn, stack_win->window, mask, values);
 345                 }
 346
 347                 /* Reconfigure the currently focused client, if necessary. It is the only visible one */
 348                 client = container->currently_focused;
 349
 350                 /* Render the decorations of all clients */
 351                 CIRCLEQ_FOREACH(client, &(container->clients), clients) {
 352                         /* If the client is in fullscreen mode, it does not get reconfigured */
 353                         if (container->workspace->fullscreen_client == client) {
 354                                 current_client++;
 355                                 continue;
 356                         }
 357
 358                         /* Check if we changed client->x or client->y by updating it.
 359                          * Note the bitwise OR instead of logical OR to force evaluation of both statements */
 360                         if (client->force_reconfigure |
 361                             update_if_necessary(&(client->rect.x), container->x) |
 362                             update_if_necessary(&(client->rect.y), container->y + (decoration_height * num_clients)))
 363                                 reposition_client(conn, client);
 364
 365                         if (client->force_reconfigure |
 366                             update_if_necessary(&(client->rect.width), container->width) |
 367                             update_if_necessary(&(client->rect.height), container->height - (decoration_height * num_clients)))
 368                                 resize_client(conn, client);
 369
 370                         client->force_reconfigure = false;
 371
 372                         decorate_window(conn, client, stack_win->window, stack_win->gc,
 373                                         current_client++ * decoration_height);
 374                 }
 375         }
 376 }
 377
 378 static void render_bars(xcb_connection_t *conn, Workspace *r_ws, int width, int *height) {
 379         Client *client;
 380         SLIST_FOREACH(client, &(r_ws->screen->dock_clients), dock_clients) {
 381                 LOG("client is at %d, should be at %d\n", client->rect.y, *height);
 382                 if (client->force_reconfigure |
 383                     update_if_necessary(&(client->rect.x), 0) |
 384                     update_if_necessary(&(client->rect.y), *height))
 385                         reposition_client(conn, client);
 386
 387                 if (client->force_reconfigure |
 388                     update_if_necessary(&(client->rect.width), width) |
 389                     update_if_necessary(&(client->rect.height), client->desired_height))
 390                         resize_client(conn, client);
 391
 392                 client->force_reconfigure = false;
 393                 LOG("desired_height = %d\n", client->desired_height);
 394                 *height += client->desired_height;
 395         }
 396 }
 397
 398 static void render_internal_bar(xcb_connection_t *conn, Workspace *r_ws, int width, int height) {
 399         LOG("Rendering internal bar\n");
 400         i3Font *font = load_font(conn, config.font);
 401         i3Screen *screen = r_ws->screen;
 402         enum { SET_NORMAL = 0, SET_FOCUSED = 1 };
 403         uint32_t background_color[2],
 404                  text_color[2],
 405                  border_color[2],
 406                  black;
 407         char label[3];
 408
 409         black = get_colorpixel(conn, "#000000");
 410
 411         background_color[SET_NORMAL] = get_colorpixel(conn, "#222222");
 412         text_color[SET_NORMAL] = get_colorpixel(conn, "#888888");
 413         border_color[SET_NORMAL] = get_colorpixel(conn, "#333333");
 414
 415         background_color[SET_FOCUSED] = get_colorpixel(conn, "#285577");
 416         text_color[SET_FOCUSED] = get_colorpixel(conn, "#ffffff");
 417         border_color[SET_FOCUSED] = get_colorpixel(conn, "#4c7899");
 418
 419         /* Fill the whole bar in black */
 420         xcb_change_gc_single(conn, screen->bargc, XCB_GC_FOREGROUND, black);
 421         xcb_rectangle_t rect = {0, 0, width, height};
 422         xcb_poly_fill_rectangle(conn, screen->bar, screen->bargc, 1, &rect);
 423
 424         /* Set font */
 425         xcb_change_gc_single(conn, screen->bargc, XCB_GC_FONT, font->id);
 426
 427         int drawn = 0;
 428         for (int c = 0; c < 10; c++) {
 429                 if (workspaces[c].screen != screen)
 430                         continue;
 431
 432                 int set = (screen->current_workspace == c ? SET_FOCUSED : SET_NORMAL);
 433
 434                 xcb_draw_rect(conn, screen->bar, screen->bargc, border_color[set],
 435                               drawn * height, 1, height - 2, height - 2);
 436                 xcb_draw_rect(conn, screen->bar, screen->bargc, background_color[set],
 437                               drawn * height + 1, 2, height - 4, height - 4);
 438
 439                 snprintf(label, sizeof(label), "%d", c+1);
 440                 xcb_change_gc_single(conn, screen->bargc, XCB_GC_FOREGROUND, text_color[set]);
 441                 xcb_change_gc_single(conn, screen->bargc, XCB_GC_BACKGROUND, background_color[set]);
 442                 xcb_image_text_8(conn, strlen(label), screen->bar, screen->bargc, drawn * height + 5 /* X */,
 443                                                 font->height + 1 /* Y = baseline of font */, label);
 444                 drawn++;
 445         }
 446
 447         LOG("done rendering internal\n");
 448 }
 449
 450 /*
 451  * Modifies the event mask of all clients on the given workspace to either ignore or to handle
 452  * enter notifies. It is handy to ignore notifies because they will be sent when a window is mapped
 453  * under the cursor, thus when the user didn’t enter the window actively at all.
 454  *
 455  */
 456 void ignore_enter_notify_forall(xcb_connection_t *conn, Workspace *workspace, bool ignore_enter_notify) {
 457         Client *client;
 458         uint32_t values[1];
 459
 460         LOG("Ignore enter_notify = %d\n", ignore_enter_notify);
 461
 462         FOR_TABLE(workspace)
 463                 CIRCLEQ_FOREACH(client, &(workspace->table[cols][rows]->clients), clients) {
 464                         /* Change event mask for the decorations */
 465                         values[0] = FRAME_EVENT_MASK;
 466                         if (ignore_enter_notify)
 467                                 values[0] &= ~(XCB_EVENT_MASK_ENTER_WINDOW);
 468                         xcb_change_window_attributes(conn, client->frame, XCB_CW_EVENT_MASK, values);
 469
 470                         /* Change event mask for the child itself */
 471                         values[0] = CHILD_EVENT_MASK;
 472                         if (ignore_enter_notify)
 473                                 values[0] &= ~(XCB_EVENT_MASK_ENTER_WINDOW);
 474                         xcb_change_window_attributes(conn, client->child, XCB_CW_EVENT_MASK, values);
 475                 }
 476 }
 477
 478 /*
 479  * Renders the given workspace on the given screen
 480  *
 481  */
 482 void render_workspace(xcb_connection_t *conn, i3Screen *screen, Workspace *r_ws) {
 483         i3Font *font = load_font(conn, config.font);
 484         int width = r_ws->rect.width;
 485         int height = r_ws->rect.height;
 486
 487         /* Reserve space for dock clients */
 488         Client *client;
 489         SLIST_FOREACH(client, &(screen->dock_clients), dock_clients)
 490                 height -= client->desired_height;
 491
 492         /* Space for the internal bar */
 493         height -= (font->height + 6);
 494
 495         LOG("got %d rows and %d cols\n", r_ws->rows, r_ws->cols);
 496
 497         int xoffset[r_ws->rows];
 498         int yoffset[r_ws->cols];
 499         /* Initialize offsets */
 500         for (int cols = 0; cols < r_ws->cols; cols++)
 501                 yoffset[cols] = r_ws->rect.y;
 502         for (int rows = 0; rows < r_ws->rows; rows++)
 503                 xoffset[rows] = r_ws->rect.x;
 504
 505         dump_table(conn, r_ws);
 506
 507         ignore_enter_notify_forall(conn, r_ws, true);
 508
 509         /* Go through the whole table and render what’s necessary */
 510         FOR_TABLE(r_ws) {
 511                 Container *container = r_ws->table[cols][rows];
 512                 int single_width, single_height;
 513                 LOG("\n");
 514                 LOG("========\n");
 515                 LOG("container has %d colspan, %d rowspan\n",
 516                                 container->colspan, container->rowspan);
 517                 LOG("container at %d, %d\n", xoffset[rows], yoffset[cols]);
 518                 /* Update position of the container */
 519                 container->row = rows;
 520                 container->col = cols;
 521                 container->x = xoffset[rows];
 522                 container->y = yoffset[cols];
 523
 524                 if (r_ws->width_factor[cols] == 0)
 525                         container->width = (width / r_ws->cols);
 526                 else container->width = get_unoccupied_x(r_ws) * r_ws->width_factor[cols];
 527                 single_width = container->width;
 528                 container->width *= container->colspan;
 529
 530                 //if (container->height_factor == 0)
 531                         container->height = (height / r_ws->rows);
 532                 //else container->height = get_unoccupied_y(r_ws, cols) * container->height_factor;
 533                 single_height = container->height;
 534                 container->height *= container->rowspan;
 535
 536                 /* Render the container if it is not empty */
 537                 render_container(conn, container);
 538
 539                 xoffset[rows] += single_width;
 540                 yoffset[cols] += single_height;
 541                 LOG("==========\n");
 542         }
 543
 544         ignore_enter_notify_forall(conn, r_ws, false);
 545
 546         render_bars(conn, r_ws, width, &height);
 547         render_internal_bar(conn, r_ws, width, font->height + 6);
 548 }
 549
 550 /*
 551  * Renders the whole layout, that is: Go through each screen, each workspace, each container
 552  * and render each client. This also renders the bars.
 553  *
 554  * If you don’t need to render *everything*, you should call render_container on the container
 555  * you want to refresh.
 556  *
 557  */
 558 void render_layout(xcb_connection_t *conn) {
 559         i3Screen *screen;
 560
 561         TAILQ_FOREACH(screen, virtual_screens, screens) {
 562                 LOG("Rendering screen %d\n", screen->num);
 563                 render_workspace(conn, screen, &(workspaces[screen->current_workspace]));
 564         }
 565
 566         xcb_flush(conn);
 567 }