i3
src/tree.c
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00001 /*
00002  * vim:ts=4:sw=4:expandtab
00003  *
00004  * i3 - an improved dynamic tiling window manager
00005  * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
00006  *
00007  * tree.c: Everything that primarily modifies the layout tree data structure.
00008  *
00009  */
00010 #include "all.h"
00011 
00012 struct Con *croot;
00013 struct Con *focused;
00014 
00015 struct all_cons_head all_cons = TAILQ_HEAD_INITIALIZER(all_cons);
00016 
00017 /*
00018  * Create the pseudo-output __i3. Output-independent workspaces such as
00019  * __i3_scratch will live there.
00020  *
00021  */
00022 static Con *_create___i3(void) {
00023     Con *__i3 = con_new(croot, NULL);
00024     FREE(__i3->name);
00025     __i3->name = sstrdup("__i3");
00026     __i3->type = CT_OUTPUT;
00027     __i3->layout = L_OUTPUT;
00028     con_fix_percent(croot);
00029     x_set_name(__i3, "[i3 con] pseudo-output __i3");
00030     /* For retaining the correct position/size of a scratchpad window, the
00031      * dimensions of the real outputs should be multiples of the __i3
00032      * pseudo-output. */
00033     __i3->rect.width = 1280;
00034     __i3->rect.height = 1024;
00035 
00036     /* Add a content container. */
00037     DLOG("adding main content container\n");
00038     Con *content = con_new(NULL, NULL);
00039     content->type = CT_CON;
00040     FREE(content->name);
00041     content->name = sstrdup("content");
00042 
00043     x_set_name(content, "[i3 con] content __i3");
00044     con_attach(content, __i3, false);
00045 
00046     /* Attach the __i3_scratch workspace. */
00047     Con *ws = con_new(NULL, NULL);
00048     ws->type = CT_WORKSPACE;
00049     ws->num = -1;
00050     ws->name = sstrdup("__i3_scratch");
00051     con_attach(ws, content, false);
00052     x_set_name(ws, "[i3 con] workspace __i3_scratch");
00053     ws->fullscreen_mode = CF_OUTPUT;
00054 
00055     return __i3;
00056 }
00057 
00058 /*
00059  * Loads tree from 'path' (used for in-place restarts).
00060  *
00061  */
00062 bool tree_restore(const char *path, xcb_get_geometry_reply_t *geometry) {
00063     char *globbed = resolve_tilde(path);
00064 
00065     if (!path_exists(globbed)) {
00066         LOG("%s does not exist, not restoring tree\n", globbed);
00067         free(globbed);
00068         return false;
00069     }
00070 
00071     /* TODO: refactor the following */
00072     croot = con_new(NULL, NULL);
00073     croot->rect = (Rect){
00074         geometry->x,
00075         geometry->y,
00076         geometry->width,
00077         geometry->height
00078     };
00079     focused = croot;
00080 
00081     tree_append_json(globbed);
00082 
00083     printf("appended tree, using new root\n");
00084     croot = TAILQ_FIRST(&(croot->nodes_head));
00085     printf("new root = %p\n", croot);
00086     Con *out = TAILQ_FIRST(&(croot->nodes_head));
00087     printf("out = %p\n", out);
00088     Con *ws = TAILQ_FIRST(&(out->nodes_head));
00089     printf("ws = %p\n", ws);
00090 
00091     /* For in-place restarting into v4.2, we need to make sure the new
00092      * pseudo-output __i3 is present. */
00093     if (strcmp(out->name, "__i3") != 0) {
00094         DLOG("Adding pseudo-output __i3 during inplace restart\n");
00095         Con *__i3 = _create___i3();
00096         /* Ensure that it is the first output, other places in the code make
00097          * that assumption. */
00098         TAILQ_REMOVE(&(croot->nodes_head), __i3, nodes);
00099         TAILQ_INSERT_HEAD(&(croot->nodes_head), __i3, nodes);
00100     }
00101 
00102     return true;
00103 }
00104 
00105 /*
00106  * Initializes the tree by creating the root node. The CT_OUTPUT Cons below the
00107  * root node are created in randr.c for each Output.
00108  *
00109  */
00110 void tree_init(xcb_get_geometry_reply_t *geometry) {
00111     croot = con_new(NULL, NULL);
00112     FREE(croot->name);
00113     croot->name = "root";
00114     croot->type = CT_ROOT;
00115     croot->rect = (Rect){
00116         geometry->x,
00117         geometry->y,
00118         geometry->width,
00119         geometry->height
00120     };
00121 
00122     _create___i3();
00123 }
00124 
00125 /*
00126  * Opens an empty container in the current container
00127  *
00128  */
00129 Con *tree_open_con(Con *con, i3Window *window) {
00130     if (con == NULL) {
00131         /* every focusable Con has a parent (outputs have parent root) */
00132         con = focused->parent;
00133         /* If the parent is an output, we are on a workspace. In this case,
00134          * the new container needs to be opened as a leaf of the workspace. */
00135         if (con->parent->type == CT_OUTPUT && con->type != CT_DOCKAREA) {
00136             con = focused;
00137         }
00138 
00139         /* If the currently focused container is a floating container, we
00140          * attach the new container to the currently focused spot in its
00141          * workspace. */
00142         if (con->type == CT_FLOATING_CON) {
00143             con = con_descend_tiling_focused(con->parent);
00144             if (con->type != CT_WORKSPACE)
00145                 con = con->parent;
00146         }
00147         DLOG("con = %p\n", con);
00148     }
00149 
00150     assert(con != NULL);
00151 
00152     /* 3. create the container and attach it to its parent */
00153     Con *new = con_new(con, window);
00154 
00155     /* 4: re-calculate child->percent for each child */
00156     con_fix_percent(con);
00157 
00158     return new;
00159 }
00160 
00161 static bool _is_con_mapped(Con *con) {
00162     Con *child;
00163 
00164     TAILQ_FOREACH(child, &(con->nodes_head), nodes)
00165         if (_is_con_mapped(child))
00166             return true;
00167 
00168     return con->mapped;
00169 }
00170 
00171 /*
00172  * Closes the given container including all children.
00173  * Returns true if the container was killed or false if just WM_DELETE was sent
00174  * and the window is expected to kill itself.
00175  *
00176  * The dont_kill_parent flag is specified when the function calls itself
00177  * recursively while deleting a containers children.
00178  *
00179  * The force_set_focus flag is specified in the case of killing a floating
00180  * window: tree_close() will be invoked for the CT_FLOATINGCON (the parent
00181  * container) and focus should be set there.
00182  *
00183  */
00184 bool tree_close(Con *con, kill_window_t kill_window, bool dont_kill_parent, bool force_set_focus) {
00185     bool was_mapped = con->mapped;
00186     Con *parent = con->parent;
00187 
00188     if (!was_mapped) {
00189         /* Even if the container itself is not mapped, its children may be
00190          * mapped (for example split containers don't have a mapped window on
00191          * their own but usually contain mapped children). */
00192         was_mapped = _is_con_mapped(con);
00193     }
00194 
00195     /* Get the container which is next focused */
00196     Con *next = con_next_focused(con);
00197     DLOG("next = %p, focused = %p\n", next, focused);
00198 
00199     DLOG("closing %p, kill_window = %d\n", con, kill_window);
00200     Con *child, *nextchild;
00201     bool abort_kill = false;
00202     /* We cannot use TAILQ_FOREACH because the children get deleted
00203      * in their parent’s nodes_head */
00204     for (child = TAILQ_FIRST(&(con->nodes_head)); child; ) {
00205         nextchild = TAILQ_NEXT(child, nodes);
00206         DLOG("killing child=%p\n", child);
00207         if (!tree_close(child, kill_window, true, false))
00208             abort_kill = true;
00209         child = nextchild;
00210     }
00211 
00212     if (abort_kill) {
00213         DLOG("One of the children could not be killed immediately (WM_DELETE sent), aborting.\n");
00214         return false;
00215     }
00216 
00217     if (con->window != NULL) {
00218         if (kill_window != DONT_KILL_WINDOW) {
00219             x_window_kill(con->window->id, kill_window);
00220             return false;
00221         } else {
00222             xcb_void_cookie_t cookie;
00223             /* un-parent the window */
00224             cookie = xcb_reparent_window(conn, con->window->id, root, 0, 0);
00225 
00226             /* Ignore X11 errors for the ReparentWindow request.
00227              * X11 Errors are returned when the window was already destroyed */
00228             add_ignore_event(cookie.sequence, 0);
00229 
00230             /* We are no longer handling this window, thus set WM_STATE to
00231              * WM_STATE_WITHDRAWN (see ICCCM 4.1.3.1) */
00232             long data[] = { XCB_ICCCM_WM_STATE_WITHDRAWN, XCB_NONE };
00233             cookie = xcb_change_property(conn, XCB_PROP_MODE_REPLACE,
00234                         con->window->id, A_WM_STATE, A_WM_STATE, 32, 2, data);
00235 
00236             /* Ignore X11 errors for the ReparentWindow request.
00237              * X11 Errors are returned when the window was already destroyed */
00238             add_ignore_event(cookie.sequence, 0);
00239         }
00240         FREE(con->window->class_class);
00241         FREE(con->window->class_instance);
00242         FREE(con->window->name_x);
00243         FREE(con->window->name_json);
00244         free(con->window);
00245     }
00246 
00247     /* kill the X11 part of this container */
00248     x_con_kill(con);
00249 
00250     con_detach(con);
00251     if (con->type != CT_FLOATING_CON) {
00252         /* If the container is *not* floating, we might need to re-distribute
00253          * percentage values for the resized containers. */
00254         con_fix_percent(parent);
00255     }
00256 
00257     if (con_is_floating(con)) {
00258         Con *ws = con_get_workspace(con);
00259         DLOG("Container was floating, killing floating container\n");
00260         tree_close(parent, DONT_KILL_WINDOW, false, (con == focused));
00261         DLOG("parent container killed\n");
00262         if (con == focused) {
00263             DLOG("This is the focused container, i need to find another one to focus. I start looking at ws = %p\n", ws);
00264             /* go down the focus stack as far as possible */
00265             next = con_descend_focused(ws);
00266 
00267             dont_kill_parent = true;
00268             DLOG("Alright, focusing %p\n", next);
00269         } else {
00270             next = NULL;
00271         }
00272     }
00273 
00274     free(con->name);
00275     FREE(con->deco_render_params);
00276     TAILQ_REMOVE(&all_cons, con, all_cons);
00277     free(con);
00278 
00279     /* in the case of floating windows, we already focused another container
00280      * when closing the parent, so we can exit now. */
00281     if (!next) {
00282         DLOG("No next container, i will just exit now\n");
00283         return true;
00284     }
00285 
00286     if (was_mapped || con == focused) {
00287         if ((kill_window != DONT_KILL_WINDOW) || !dont_kill_parent || con == focused) {
00288             DLOG("focusing %p / %s\n", next, next->name);
00289             if (next->type == CT_DOCKAREA) {
00290                 /* Instead of focusing the dockarea, we need to restore focus to the workspace */
00291                 con_focus(con_descend_focused(output_get_content(next->parent)));
00292             } else {
00293                 if (!force_set_focus && con != focused)
00294                     DLOG("not changing focus, the container was not focused before\n");
00295                 else con_focus(next);
00296             }
00297         }
00298         else {
00299             DLOG("not focusing because we're not killing anybody");
00300         }
00301     } else {
00302         DLOG("not focusing, was not mapped\n");
00303     }
00304 
00305     /* check if the parent container is empty now and close it */
00306     if (!dont_kill_parent)
00307         CALL(parent, on_remove_child);
00308 
00309     return true;
00310 }
00311 
00312 /*
00313  * Closes the current container using tree_close().
00314  *
00315  */
00316 void tree_close_con(kill_window_t kill_window) {
00317     assert(focused != NULL);
00318     if (focused->type == CT_WORKSPACE) {
00319         LOG("Cannot close workspace\n");
00320         return;
00321     }
00322 
00323     /* There *should* be no possibility to focus outputs / root container */
00324     assert(focused->type != CT_OUTPUT);
00325     assert(focused->type != CT_ROOT);
00326 
00327     /* Kill con */
00328     tree_close(focused, kill_window, false, false);
00329 }
00330 
00331 /*
00332  * Splits (horizontally or vertically) the given container by creating a new
00333  * container which contains the old one and the future ones.
00334  *
00335  */
00336 void tree_split(Con *con, orientation_t orientation) {
00337     /* for a workspace, we just need to change orientation */
00338     if (con->type == CT_WORKSPACE) {
00339         DLOG("Workspace, simply changing orientation to %d\n", orientation);
00340         con->orientation = orientation;
00341         return;
00342     }
00343 
00344     Con *parent = con->parent;
00345 
00346     /* Force re-rendering to make the indicator border visible. */
00347     FREE(con->deco_render_params);
00348     FREE(parent->deco_render_params);
00349 
00350     /* if we are in a container whose parent contains only one
00351      * child (its split functionality is unused so far), we just change the
00352      * orientation (more intuitive than splitting again) */
00353     if (con_num_children(parent) == 1 &&
00354         parent->layout == L_DEFAULT) {
00355         parent->orientation = orientation;
00356         DLOG("Just changing orientation of existing container\n");
00357         return;
00358     }
00359 
00360     DLOG("Splitting in orientation %d\n", orientation);
00361 
00362     /* 2: replace it with a new Con */
00363     Con *new = con_new(NULL, NULL);
00364     TAILQ_REPLACE(&(parent->nodes_head), con, new, nodes);
00365     TAILQ_REPLACE(&(parent->focus_head), con, new, focused);
00366     new->parent = parent;
00367     new->orientation = orientation;
00368 
00369     /* 3: swap 'percent' (resize factor) */
00370     new->percent = con->percent;
00371     con->percent = 0.0;
00372 
00373     /* 4: add it as a child to the new Con */
00374     con_attach(con, new, false);
00375 }
00376 
00377 /*
00378  * Moves focus one level up.
00379  *
00380  */
00381 void level_up(void) {
00382     /* We cannot go up when we are in fullscreen mode at the moment, that would
00383      * be totally not intuitive */
00384     if (focused->fullscreen_mode != CF_NONE) {
00385         LOG("Currently in fullscreen, not going up\n");
00386         return;
00387     }
00388     /* We can focus up to the workspace, but not any higher in the tree */
00389     if ((focused->parent->type != CT_CON &&
00390         focused->parent->type != CT_WORKSPACE) ||
00391         focused->type == CT_WORKSPACE) {
00392         LOG("Cannot go up any further\n");
00393         return;
00394     }
00395     con_focus(focused->parent);
00396 }
00397 
00398 /*
00399  * Moves focus one level down.
00400  *
00401  */
00402 void level_down(void) {
00403     /* Go down the focus stack of the current node */
00404     Con *next = TAILQ_FIRST(&(focused->focus_head));
00405     if (next == TAILQ_END(&(focused->focus_head))) {
00406         printf("cannot go down\n");
00407         return;
00408     }
00409     con_focus(next);
00410 }
00411 
00412 static void mark_unmapped(Con *con) {
00413     Con *current;
00414 
00415     con->mapped = false;
00416     TAILQ_FOREACH(current, &(con->nodes_head), nodes)
00417         mark_unmapped(current);
00418     if (con->type == CT_WORKSPACE) {
00419         /* We need to call mark_unmapped on floating nodes aswell since we can
00420          * make containers floating. */
00421         TAILQ_FOREACH(current, &(con->floating_head), floating_windows)
00422             mark_unmapped(current);
00423     }
00424 }
00425 
00426 /*
00427  * Renders the tree, that is rendering all outputs using render_con() and
00428  * pushing the changes to X11 using x_push_changes().
00429  *
00430  */
00431 void tree_render(void) {
00432     if (croot == NULL)
00433         return;
00434 
00435     DLOG("-- BEGIN RENDERING --\n");
00436     /* Reset map state for all nodes in tree */
00437     /* TODO: a nicer method to walk all nodes would be good, maybe? */
00438     mark_unmapped(croot);
00439     croot->mapped = true;
00440 
00441     render_con(croot, false);
00442 
00443     x_push_changes(croot);
00444     DLOG("-- END RENDERING --\n");
00445 }
00446 
00447 /*
00448  * Recursive function to walk the tree until a con can be found to focus.
00449  *
00450  */
00451 static bool _tree_next(Con *con, char way, orientation_t orientation, bool wrap) {
00452     /* Stop recursing at workspaces after attempting to switch to next
00453      * workspace if possible. */
00454     if (con->type == CT_WORKSPACE) {
00455         Output *current_output = get_output_containing(con->rect.x, con->rect.y);
00456         Output *next_output;
00457 
00458         if (!current_output)
00459             return false;
00460         DLOG("Current output is %s\n", current_output->name);
00461 
00462         /* Try to find next output */
00463         direction_t direction;
00464         if (way == 'n' && orientation == HORIZ)
00465             direction = D_RIGHT;
00466         else if (way == 'p' && orientation == HORIZ)
00467             direction = D_LEFT;
00468         else if (way == 'n' && orientation == VERT)
00469             direction = D_DOWN;
00470         else if (way == 'p' && orientation == VERT)
00471             direction = D_UP;
00472         else
00473             return false;
00474 
00475         next_output = get_output_next(direction, current_output);
00476         if (!next_output)
00477             return false;
00478         DLOG("Next output is %s\n", next_output->name);
00479 
00480         /* Find visible workspace on next output */
00481         Con *workspace = NULL;
00482         GREP_FIRST(workspace, output_get_content(next_output->con), workspace_is_visible(child));
00483 
00484         /* Show next workspace and focus appropriate container if possible. */
00485         if (!workspace)
00486             return false;
00487 
00488         workspace_show(workspace);
00489         Con *focus = con_descend_direction(workspace, direction);
00490         if (focus) {
00491             con_focus(focus);
00492             x_set_warp_to(&(focus->rect));
00493         }
00494         return true;
00495     }
00496 
00497     Con *parent = con->parent;
00498 
00499     if (con->type == CT_FLOATING_CON) {
00500         /* left/right focuses the previous/next floating container */
00501         if (orientation == HORIZ) {
00502             Con *next;
00503             if (way == 'n')
00504                 next = TAILQ_NEXT(con, floating_windows);
00505             else next = TAILQ_PREV(con, floating_head, floating_windows);
00506 
00507             /* If there is no next/previous container, wrap */
00508             if (!next) {
00509                 if (way == 'n')
00510                     next = TAILQ_FIRST(&(parent->floating_head));
00511                 else next = TAILQ_LAST(&(parent->floating_head), floating_head);
00512             }
00513 
00514             /* Still no next/previous container? bail out */
00515             if (!next)
00516                 return false;
00517 
00518             con_focus(con_descend_focused(next));
00519             return true;
00520         } else {
00521             /* up/down cycles through the Z-index */
00522             /* TODO: implement cycling through the z-index */
00523             return false;
00524         }
00525     }
00526 
00527     /* If the orientation does not match or there is no other con to focus, we
00528      * need to go higher in the hierarchy */
00529     if (con_orientation(parent) != orientation ||
00530         con_num_children(parent) == 1)
00531         return _tree_next(parent, way, orientation, wrap);
00532 
00533     Con *current = TAILQ_FIRST(&(parent->focus_head));
00534     /* TODO: when can the following happen (except for floating windows, which
00535      * are handled above)? */
00536     if (TAILQ_EMPTY(&(parent->nodes_head))) {
00537         DLOG("nothing to focus\n");
00538         return false;
00539     }
00540 
00541     Con *next;
00542     if (way == 'n')
00543         next = TAILQ_NEXT(current, nodes);
00544     else next = TAILQ_PREV(current, nodes_head, nodes);
00545 
00546     if (!next) {
00547         if (!config.force_focus_wrapping) {
00548             /* If there is no next/previous container, we check if we can focus one
00549              * when going higher (without wrapping, though). If so, we are done, if
00550              * not, we wrap */
00551             if (_tree_next(parent, way, orientation, false))
00552                 return true;
00553 
00554             if (!wrap)
00555                 return false;
00556         }
00557 
00558         if (way == 'n')
00559             next = TAILQ_FIRST(&(parent->nodes_head));
00560         else next = TAILQ_LAST(&(parent->nodes_head), nodes_head);
00561     }
00562 
00563     /* 3: focus choice comes in here. at the moment we will go down
00564      * until we find a window */
00565     /* TODO: check for window, atm we only go down as far as possible */
00566     con_focus(con_descend_focused(next));
00567     return true;
00568 }
00569 
00570 /*
00571  * Changes focus in the given way (next/previous) and given orientation
00572  * (horizontal/vertical).
00573  *
00574  */
00575 void tree_next(char way, orientation_t orientation) {
00576     _tree_next(focused, way, orientation, true);
00577 }
00578 
00579 /*
00580  * tree_flatten() removes pairs of redundant split containers, e.g.:
00581  *       [workspace, horizontal]
00582  *   [v-split]           [child3]
00583  *   [h-split]
00584  * [child1] [child2]
00585  * In this example, the v-split and h-split container are redundant.
00586  * Such a situation can be created by moving containers in a direction which is
00587  * not the orientation of their parent container. i3 needs to create a new
00588  * split container then and if you move containers this way multiple times,
00589  * redundant chains of split-containers can be the result.
00590  *
00591  */
00592 void tree_flatten(Con *con) {
00593     Con *current, *child, *parent = con->parent;
00594     DLOG("Checking if I can flatten con = %p / %s\n", con, con->name);
00595 
00596     /* We only consider normal containers without windows */
00597     if (con->type != CT_CON || con->window != NULL)
00598         goto recurse;
00599 
00600     /* Ensure it got only one child */
00601     child = TAILQ_FIRST(&(con->nodes_head));
00602     if (child == NULL || TAILQ_NEXT(child, nodes) != NULL)
00603         goto recurse;
00604 
00605     /* The child must have a different orientation than the con but the same as
00606      * the con’s parent to be redundant */
00607     if (con->orientation == NO_ORIENTATION ||
00608         child->orientation == NO_ORIENTATION ||
00609         con->orientation == child->orientation ||
00610         child->orientation != parent->orientation)
00611         goto recurse;
00612 
00613     DLOG("Alright, I have to flatten this situation now. Stay calm.\n");
00614     /* 1: save focus */
00615     Con *focus_next = TAILQ_FIRST(&(child->focus_head));
00616 
00617     DLOG("detaching...\n");
00618     /* 2: re-attach the children to the parent before con */
00619     while (!TAILQ_EMPTY(&(child->nodes_head))) {
00620         current = TAILQ_FIRST(&(child->nodes_head));
00621         DLOG("detaching current=%p / %s\n", current, current->name);
00622         con_detach(current);
00623         DLOG("re-attaching\n");
00624         /* We don’t use con_attach() here because for a CT_CON, the special
00625          * case handling of con_attach() does not trigger. So all it would do
00626          * is calling TAILQ_INSERT_AFTER, but with the wrong container. So we
00627          * directly use the TAILQ macros. */
00628         current->parent = parent;
00629         TAILQ_INSERT_BEFORE(con, current, nodes);
00630         DLOG("attaching to focus list\n");
00631         TAILQ_INSERT_TAIL(&(parent->focus_head), current, focused);
00632         current->percent = con->percent;
00633     }
00634     DLOG("re-attached all\n");
00635 
00636     /* 3: restore focus, if con was focused */
00637     if (focus_next != NULL &&
00638         TAILQ_FIRST(&(parent->focus_head)) == con) {
00639         DLOG("restoring focus to focus_next=%p\n", focus_next);
00640         TAILQ_REMOVE(&(parent->focus_head), focus_next, focused);
00641         TAILQ_INSERT_HEAD(&(parent->focus_head), focus_next, focused);
00642         DLOG("restored focus.\n");
00643     }
00644 
00645     /* 4: close the redundant cons */
00646     DLOG("closing redundant cons\n");
00647     tree_close(con, DONT_KILL_WINDOW, true, false);
00648 
00649     /* Well, we got to abort the recursion here because we destroyed the
00650      * container. However, if tree_flatten() is called sufficiently often,
00651      * there can’t be the situation of having two pairs of redundant containers
00652      * at once. Therefore, we can safely abort the recursion on this level
00653      * after flattening. */
00654     return;
00655 
00656 recurse:
00657     /* We cannot use normal foreach here because tree_flatten might close the
00658      * current container. */
00659     current = TAILQ_FIRST(&(con->nodes_head));
00660     while (current != NULL) {
00661         Con *next = TAILQ_NEXT(current, nodes);
00662         tree_flatten(current);
00663         current = next;
00664     }
00665 
00666     current = TAILQ_FIRST(&(con->floating_head));
00667     while (current != NULL) {
00668         Con *next = TAILQ_NEXT(current, floating_windows);
00669         tree_flatten(current);
00670         current = next;
00671     }
00672 }