i3
src/util.c
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00001 /*
00002  * vim:ts=8:expandtab
00003  *
00004  * i3 - an improved dynamic tiling window manager
00005  *
00006  * © 2009 Michael Stapelberg and contributors
00007  *
00008  * See file LICENSE for license information.
00009  *
00010  * util.c: Utility functions, which can be useful everywhere.
00011  *
00012  */
00013 #include <stdio.h>
00014 #include <stdlib.h>
00015 #include <unistd.h>
00016 #include <string.h>
00017 #include <sys/wait.h>
00018 #include <stdarg.h>
00019 #include <assert.h>
00020 #include <iconv.h>
00021 #if defined(__OpenBSD__)
00022 #include <sys/cdefs.h>
00023 #endif
00024 
00025 #include <xcb/xcb_icccm.h>
00026 
00027 #include "i3.h"
00028 #include "data.h"
00029 #include "table.h"
00030 #include "layout.h"
00031 #include "util.h"
00032 #include "xcb.h"
00033 #include "client.h"
00034 #include "log.h"
00035 #include "ewmh.h"
00036 #include "manage.h"
00037 #include "workspace.h"
00038 #include "ipc.h"
00039 
00040 static iconv_t conversion_descriptor = 0;
00041 struct keyvalue_table_head by_parent = TAILQ_HEAD_INITIALIZER(by_parent);
00042 struct keyvalue_table_head by_child = TAILQ_HEAD_INITIALIZER(by_child);
00043 
00044 int min(int a, int b) {
00045         return (a < b ? a : b);
00046 }
00047 
00048 int max(int a, int b) {
00049         return (a > b ? a : b);
00050 }
00051 
00052 /*
00053  * Updates *destination with new_value and returns true if it was changed or false
00054  * if it was the same
00055  *
00056  */
00057 bool update_if_necessary(uint32_t *destination, const uint32_t new_value) {
00058         uint32_t old_value = *destination;
00059 
00060         return ((*destination = new_value) != old_value);
00061 }
00062 
00063 /*
00064  * The s* functions (safe) are wrappers around malloc, strdup, …, which exits if one of
00065  * the called functions returns NULL, meaning that there is no more memory available
00066  *
00067  */
00068 void *smalloc(size_t size) {
00069         void *result = malloc(size);
00070         exit_if_null(result, "Error: out of memory (malloc(%zd))\n", size);
00071         return result;
00072 }
00073 
00074 void *scalloc(size_t size) {
00075         void *result = calloc(size, 1);
00076         exit_if_null(result, "Error: out of memory (calloc(%zd))\n", size);
00077         return result;
00078 }
00079 
00080 char *sstrdup(const char *str) {
00081         char *result = strdup(str);
00082         exit_if_null(result, "Error: out of memory (strdup())\n");
00083         return result;
00084 }
00085 
00086 /*
00087  * The table_* functions emulate the behaviour of libxcb-wm, which in libxcb 0.3.4 suddenly
00088  * vanished. Great.
00089  *
00090  */
00091 bool table_put(struct keyvalue_table_head *head, uint32_t key, void *value) {
00092         struct keyvalue_element *element = scalloc(sizeof(struct keyvalue_element));
00093         element->key = key;
00094         element->value = value;
00095 
00096         TAILQ_INSERT_TAIL(head, element, elements);
00097         return true;
00098 }
00099 
00100 void *table_remove(struct keyvalue_table_head *head, uint32_t key) {
00101         struct keyvalue_element *element;
00102 
00103         TAILQ_FOREACH(element, head, elements)
00104                 if (element->key == key) {
00105                         void *value = element->value;
00106                         TAILQ_REMOVE(head, element, elements);
00107                         free(element);
00108                         return value;
00109                 }
00110 
00111         return NULL;
00112 }
00113 
00114 void *table_get(struct keyvalue_table_head *head, uint32_t key) {
00115         struct keyvalue_element *element;
00116 
00117         TAILQ_FOREACH(element, head, elements)
00118                 if (element->key == key)
00119                         return element->value;
00120 
00121         return NULL;
00122 }
00123 
00124 /*
00125  * Starts the given application by passing it through a shell. We use double fork
00126  * to avoid zombie processes. As the started application’s parent exits (immediately),
00127  * the application is reparented to init (process-id 1), which correctly handles
00128  * childs, so we don’t have to do it :-).
00129  *
00130  * The shell is determined by looking for the SHELL environment variable. If it
00131  * does not exist, /bin/sh is used.
00132  *
00133  */
00134 void start_application(const char *command) {
00135         if (fork() == 0) {
00136                 /* Child process */
00137                 if (fork() == 0) {
00138                         /* Stores the path of the shell */
00139                         static const char *shell = NULL;
00140 
00141                         if (shell == NULL)
00142                                 if ((shell = getenv("SHELL")) == NULL)
00143                                         shell = "/bin/sh";
00144 
00145                         /* This is the child */
00146                         execl(shell, shell, "-c", command, (void*)NULL);
00147                         /* not reached */
00148                 }
00149                 exit(0);
00150         }
00151         wait(0);
00152 }
00153 
00154 /*
00155  * Checks a generic cookie for errors and quits with the given message if there
00156  * was an error.
00157  *
00158  */
00159 void check_error(xcb_connection_t *conn, xcb_void_cookie_t cookie, char *err_message) {
00160         xcb_generic_error_t *error = xcb_request_check(conn, cookie);
00161         if (error != NULL) {
00162                 fprintf(stderr, "ERROR: %s (X error %d)\n", err_message , error->error_code);
00163                 xcb_disconnect(conn);
00164                 exit(-1);
00165         }
00166 }
00167 
00168 /*
00169  * Converts the given string to UCS-2 big endian for use with
00170  * xcb_image_text_16(). The amount of real glyphs is stored in real_strlen,
00171  * a buffer containing the UCS-2 encoded string (16 bit per glyph) is
00172  * returned. It has to be freed when done.
00173  *
00174  */
00175 char *convert_utf8_to_ucs2(char *input, int *real_strlen) {
00176         size_t input_size = strlen(input) + 1;
00177         /* UCS-2 consumes exactly two bytes for each glyph */
00178         int buffer_size = input_size * 2;
00179 
00180         char *buffer = smalloc(buffer_size);
00181         size_t output_size = buffer_size;
00182         /* We need to use an additional pointer, because iconv() modifies it */
00183         char *output = buffer;
00184 
00185         /* We convert the input into UCS-2 big endian */
00186         if (conversion_descriptor == 0) {
00187                 conversion_descriptor = iconv_open("UCS-2BE", "UTF-8");
00188                 if (conversion_descriptor == 0) {
00189                         fprintf(stderr, "error opening the conversion context\n");
00190                         exit(1);
00191                 }
00192         }
00193 
00194         /* Get the conversion descriptor back to original state */
00195         iconv(conversion_descriptor, NULL, NULL, NULL, NULL);
00196 
00197         /* Convert our text */
00198         int rc = iconv(conversion_descriptor, (void*)&input, &input_size, &output, &output_size);
00199         if (rc == (size_t)-1) {
00200                 perror("Converting to UCS-2 failed");
00201                 if (real_strlen != NULL)
00202                         *real_strlen = 0;
00203                 return NULL;
00204         }
00205 
00206         if (real_strlen != NULL)
00207                 *real_strlen = ((buffer_size - output_size) / 2) - 1;
00208 
00209         return buffer;
00210 }
00211 
00212 /*
00213  * Returns the client which comes next in focus stack (= was selected before) for
00214  * the given container, optionally excluding the given client.
00215  *
00216  */
00217 Client *get_last_focused_client(xcb_connection_t *conn, Container *container, Client *exclude) {
00218         Client *current;
00219         SLIST_FOREACH(current, &(container->workspace->focus_stack), focus_clients)
00220                 if ((current->container == container) && ((exclude == NULL) || (current != exclude)))
00221                         return current;
00222         return NULL;
00223 }
00224 
00225 
00226 /*
00227  * Sets the given client as focused by updating the data structures correctly,
00228  * updating the X input focus and finally re-decorating both windows (to signalize
00229  * the user the new focus situation)
00230  *
00231  */
00232 void set_focus(xcb_connection_t *conn, Client *client, bool set_anyways) {
00233         /* The dock window cannot be focused, but enter notifies are still handled correctly */
00234         if (client->dock)
00235                 return;
00236 
00237         /* Store the old client */
00238         Client *old_client = SLIST_FIRST(&(c_ws->focus_stack));
00239 
00240         /* Check if the focus needs to be changed at all */
00241         if (!set_anyways && (old_client == client))
00242                 return;
00243 
00244         /* Store current_row/current_col */
00245         c_ws->current_row = current_row;
00246         c_ws->current_col = current_col;
00247         c_ws = client->workspace;
00248         ewmh_update_current_desktop();
00249         /* Load current_col/current_row if we switch to a client without a container */
00250         current_col = c_ws->current_col;
00251         current_row = c_ws->current_row;
00252 
00253         /* Update container */
00254         if (client->container != NULL) {
00255                 client->container->currently_focused = client;
00256 
00257                 current_col = client->container->col;
00258                 current_row = client->container->row;
00259         }
00260 
00261         CLIENT_LOG(client);
00262         /* Set focus to the entered window, and flush xcb buffer immediately */
00263         xcb_set_input_focus(conn, XCB_INPUT_FOCUS_POINTER_ROOT, client->child, XCB_CURRENT_TIME);
00264         ewmh_update_active_window(client->child);
00265         //xcb_warp_pointer(conn, XCB_NONE, client->child, 0, 0, 0, 0, 10, 10);
00266 
00267         if (client->container != NULL) {
00268                 /* Get the client which was last focused in this particular container, it may be a different
00269                    one than old_client */
00270                 Client *last_focused = get_last_focused_client(conn, client->container, NULL);
00271 
00272                 /* In stacking containers, raise the client in respect to the one which was focused before */
00273                 if ((client->container->mode == MODE_STACK || client->container->mode == MODE_TABBED) &&
00274                     client->container->workspace->fullscreen_client == NULL) {
00275                         /* We need to get the client again, this time excluding the current client, because
00276                          * we might have just gone into stacking mode and need to raise */
00277                         Client *last_focused = get_last_focused_client(conn, client->container, client);
00278 
00279                         if (last_focused != NULL) {
00280                                 DLOG("raising above frame %p / child %p\n", last_focused->frame, last_focused->child);
00281                                 uint32_t values[] = { last_focused->frame, XCB_STACK_MODE_ABOVE };
00282                                 xcb_configure_window(conn, client->frame, XCB_CONFIG_WINDOW_SIBLING | XCB_CONFIG_WINDOW_STACK_MODE, values);
00283                         }
00284                 }
00285 
00286                 /* If it is the same one as old_client, we save us the unnecessary redecorate */
00287                 if ((last_focused != NULL) && (last_focused != old_client))
00288                         redecorate_window(conn, last_focused);
00289         }
00290 
00291         /* If the last client was a floating client, we need to go to the next
00292          * tiling client in stack and re-decorate it. */
00293         if (old_client != NULL && client_is_floating(old_client)) {
00294                 DLOG("Coming from floating client, searching next tiling...\n");
00295                 Client *current;
00296                 SLIST_FOREACH(current, &(client->workspace->focus_stack), focus_clients) {
00297                         if (client_is_floating(current))
00298                                 continue;
00299 
00300                         DLOG("Found window: %p / child %p\n", current->frame, current->child);
00301                         redecorate_window(conn, current);
00302                         break;
00303                 }
00304         }
00305 
00306         SLIST_REMOVE(&(client->workspace->focus_stack), client, Client, focus_clients);
00307         SLIST_INSERT_HEAD(&(client->workspace->focus_stack), client, focus_clients);
00308 
00309         /* Clear the urgency flag if set (necessary when i3 sets the flag, for
00310          * example when automatically putting windows on the workspace of their
00311          * leader) */
00312         client->urgent = false;
00313         workspace_update_urgent_flag(client->workspace);
00314 
00315         /* If we’re in stacking mode, this renders the container to update changes in the title
00316            bars and to raise the focused client */
00317         if ((old_client != NULL) && (old_client != client) && !old_client->dock)
00318                 redecorate_window(conn, old_client);
00319 
00320         /* redecorate_window flushes, so we don’t need to */
00321         redecorate_window(conn, client);
00322 }
00323 
00324 /*
00325  * Called when the user switches to another mode or when the container is
00326  * destroyed and thus needs to be cleaned up.
00327  *
00328  */
00329 void leave_stack_mode(xcb_connection_t *conn, Container *container) {
00330         /* When going out of stacking mode, we need to close the window */
00331         struct Stack_Window *stack_win = &(container->stack_win);
00332 
00333         SLIST_REMOVE(&stack_wins, stack_win, Stack_Window, stack_windows);
00334 
00335         xcb_free_gc(conn, stack_win->pixmap.gc);
00336         xcb_free_pixmap(conn, stack_win->pixmap.id);
00337         xcb_destroy_window(conn, stack_win->window);
00338 
00339         stack_win->rect.width = -1;
00340         stack_win->rect.height = -1;
00341 }
00342 
00343 /*
00344  * Switches the layout of the given container taking care of the necessary house-keeping
00345  *
00346  */
00347 void switch_layout_mode(xcb_connection_t *conn, Container *container, int mode) {
00348         if (mode == MODE_STACK || mode == MODE_TABBED) {
00349                 /* When we’re already in stacking mode, nothing has to be done */
00350                 if ((mode == MODE_STACK && container->mode == MODE_STACK) ||
00351                     (mode == MODE_TABBED && container->mode == MODE_TABBED))
00352                         return;
00353 
00354                 if (container->mode == MODE_STACK || container->mode == MODE_TABBED)
00355                         goto after_stackwin;
00356 
00357                 /* When entering stacking mode, we need to open a window on
00358                  * which we can draw the title bars of the clients, it has
00359                  * height 1 because we don’t bother here with calculating the
00360                  * correct height - it will be adjusted when rendering anyways.
00361                  * Also, we need to use max(width, 1) because windows cannot
00362                  * be created with either width == 0 or height == 0. */
00363                 Rect rect = {container->x, container->y, max(container->width, 1), 1};
00364 
00365                 uint32_t mask = 0;
00366                 uint32_t values[2];
00367 
00368                 /* Don’t generate events for our new window, it should *not* be managed */
00369                 mask |= XCB_CW_OVERRIDE_REDIRECT;
00370                 values[0] = 1;
00371 
00372                 /* We want to know when… */
00373                 mask |= XCB_CW_EVENT_MASK;
00374                 values[1] =     XCB_EVENT_MASK_ENTER_WINDOW |   /* …mouse is moved into our window */
00375                                 XCB_EVENT_MASK_BUTTON_PRESS |   /* …mouse is pressed */
00376                                 XCB_EVENT_MASK_EXPOSURE;        /* …our window needs to be redrawn */
00377 
00378                 struct Stack_Window *stack_win = &(container->stack_win);
00379                 stack_win->window = create_window(conn, rect, XCB_WINDOW_CLASS_INPUT_OUTPUT, XCB_CURSOR_LEFT_PTR, false, mask, values);
00380 
00381                 stack_win->rect.height = 0;
00382 
00383                 /* Initialize the entry for our cached pixmap. It will be
00384                  * created as soon as it’s needed (see cached_pixmap_prepare). */
00385                 memset(&(stack_win->pixmap), 0, sizeof(struct Cached_Pixmap));
00386                 stack_win->pixmap.referred_rect = &stack_win->rect;
00387                 stack_win->pixmap.referred_drawable = stack_win->window;
00388 
00389                 stack_win->container = container;
00390 
00391                 SLIST_INSERT_HEAD(&stack_wins, stack_win, stack_windows);
00392         } else {
00393                 if (container->mode == MODE_STACK || container->mode == MODE_TABBED)
00394                         leave_stack_mode(conn, container);
00395         }
00396 after_stackwin:
00397         container->mode = mode;
00398 
00399         /* Force reconfiguration of each client */
00400         Client *client;
00401 
00402         CIRCLEQ_FOREACH(client, &(container->clients), clients)
00403                 client->force_reconfigure = true;
00404 
00405         render_layout(conn);
00406 
00407         if (container->currently_focused != NULL) {
00408                 /* We need to make sure that this client is above *each* of the
00409                  * other clients in this container */
00410                 Client *last_focused = get_last_focused_client(conn, container, container->currently_focused);
00411 
00412                 CIRCLEQ_FOREACH(client, &(container->clients), clients) {
00413                         if (client == container->currently_focused || client == last_focused)
00414                                 continue;
00415 
00416                         DLOG("setting %08x below %08x / %08x\n", client->frame, container->currently_focused->frame);
00417                         uint32_t values[] = { container->currently_focused->frame, XCB_STACK_MODE_BELOW };
00418                         xcb_configure_window(conn, client->frame,
00419                                              XCB_CONFIG_WINDOW_SIBLING | XCB_CONFIG_WINDOW_STACK_MODE, values);
00420                 }
00421 
00422                 if (last_focused != NULL) {
00423                         DLOG("Putting last_focused directly underneath the currently focused\n");
00424                         uint32_t values[] = { container->currently_focused->frame, XCB_STACK_MODE_BELOW };
00425                         xcb_configure_window(conn, last_focused->frame,
00426                                              XCB_CONFIG_WINDOW_SIBLING | XCB_CONFIG_WINDOW_STACK_MODE, values);
00427                 }
00428 
00429 
00430                 set_focus(conn, container->currently_focused, true);
00431         }
00432 }
00433 
00434 /*
00435  * Gets the first matching client for the given window class/window title.
00436  * If the paramater specific is set to a specific client, only this one
00437  * will be checked.
00438  *
00439  */
00440 Client *get_matching_client(xcb_connection_t *conn, const char *window_classtitle,
00441                             Client *specific) {
00442         char *to_class, *to_title, *to_title_ucs = NULL;
00443         int to_title_ucs_len = 0;
00444         Client *matching = NULL;
00445 
00446         to_class = sstrdup(window_classtitle);
00447 
00448         /* If a title was specified, split both strings at the slash */
00449         if ((to_title = strstr(to_class, "/")) != NULL) {
00450                 *(to_title++) = '\0';
00451                 /* Convert to UCS-2 */
00452                 to_title_ucs = convert_utf8_to_ucs2(to_title, &to_title_ucs_len);
00453         }
00454 
00455         /* If we were given a specific client we only check if that one matches */
00456         if (specific != NULL) {
00457                 if (client_matches_class_name(specific, to_class, to_title, to_title_ucs, to_title_ucs_len))
00458                         matching = specific;
00459                 goto done;
00460         }
00461 
00462         DLOG("Getting clients for class \"%s\" / title \"%s\"\n", to_class, to_title);
00463         Workspace *ws;
00464         TAILQ_FOREACH(ws, workspaces, workspaces) {
00465                 if (ws->output == NULL)
00466                         continue;
00467 
00468                 Client *client;
00469                 SLIST_FOREACH(client, &(ws->focus_stack), focus_clients) {
00470                         DLOG("Checking client with class=%s / %s, name=%s\n", client->window_class_instance,
00471                              client->window_class_class, client->name);
00472                         if (!client_matches_class_name(client, to_class, to_title, to_title_ucs, to_title_ucs_len))
00473                                 continue;
00474 
00475                         matching = client;
00476                         goto done;
00477                 }
00478         }
00479 
00480 done:
00481         free(to_class);
00482         FREE(to_title_ucs);
00483         return matching;
00484 }
00485 
00486 /*
00487  * Goes through the list of arguments (for exec()) and checks if the given argument
00488  * is present. If not, it copies the arguments (because we cannot realloc it) and
00489  * appends the given argument.
00490  *
00491  */
00492 static char **append_argument(char **original, char *argument) {
00493         int num_args;
00494         for (num_args = 0; original[num_args] != NULL; num_args++) {
00495                 DLOG("original argument: \"%s\"\n", original[num_args]);
00496                 /* If the argument is already present we return the original pointer */
00497                 if (strcmp(original[num_args], argument) == 0)
00498                         return original;
00499         }
00500         /* Copy the original array */
00501         char **result = smalloc((num_args+2) * sizeof(char*));
00502         memcpy(result, original, num_args * sizeof(char*));
00503         result[num_args] = argument;
00504         result[num_args+1] = NULL;
00505 
00506         return result;
00507 }
00508 
00509 /*
00510  * Restart i3 in-place
00511  * appends -a to argument list to disable autostart
00512  *
00513  */
00514 void i3_restart() {
00515         restore_geometry(global_conn);
00516 
00517         ipc_shutdown();
00518 
00519         LOG("restarting \"%s\"...\n", start_argv[0]);
00520         /* make sure -a is in the argument list or append it */
00521         start_argv = append_argument(start_argv, "-a");
00522 
00523         execvp(start_argv[0], start_argv);
00524         /* not reached */
00525 }
00526 
00527 #if defined(__OpenBSD__)
00528 
00529 /*
00530  * Taken from FreeBSD
00531  * Find the first occurrence of the byte string s in byte string l.
00532  *
00533  */
00534 void *memmem(const void *l, size_t l_len, const void *s, size_t s_len) {
00535         register char *cur, *last;
00536         const char *cl = (const char *)l;
00537         const char *cs = (const char *)s;
00538 
00539         /* we need something to compare */
00540         if (l_len == 0 || s_len == 0)
00541                 return NULL;
00542 
00543         /* "s" must be smaller or equal to "l" */
00544         if (l_len < s_len)
00545                 return NULL;
00546 
00547         /* special case where s_len == 1 */
00548         if (s_len == 1)
00549                 return memchr(l, (int)*cs, l_len);
00550 
00551         /* the last position where its possible to find "s" in "l" */
00552         last = (char *)cl + l_len - s_len;
00553 
00554         for (cur = (char *)cl; cur <= last; cur++)
00555                 if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
00556                         return cur;
00557 
00558         return NULL;
00559 }
00560 
00561 #endif
00562