X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=src%2Fcon.c;h=45021f5f71320cf56cbde11e2a4a392fe653e593;hb=08f64f011d00da966b474d4f93f7f55b78387fb7;hp=00001d4c356f2da46c6fd9da9a75f03c1e15f57a;hpb=c145f7e5297ef06aaf84689762a736d5bc8cbb83;p=i3%2Fi3

diff --git a/src/con.c b/src/con.c
index 00001d4c..45021f5f 100644
--- a/src/con.c
+++ b/src/con.c
@@ -24,56 +24,170 @@ char *colors[] = {
     "#aa00aa"
 };
 
+static void con_on_remove_child(Con *con);
 
+/*
+ * Create a new container (and attach it to the given parent, if not NULL).
+ * This function initializes the data structures and creates the appropriate
+ * X11 IDs using x_con_init().
+ *
+ */
 Con *con_new(Con *parent) {
     Con *new = scalloc(sizeof(Con));
+    new->on_remove_child = con_on_remove_child;
     TAILQ_INSERT_TAIL(&all_cons, new, all_cons);
     new->type = CT_CON;
-    new->name = strdup("");
+    new->border_style = config.default_border;
     static int cnt = 0;
-    LOG("opening window %d\n", cnt);
+    DLOG("opening window %d\n", cnt);
 
     /* TODO: remove window coloring after test-phase */
-    LOG("color %s\n", colors[cnt]);
+    DLOG("color %s\n", colors[cnt]);
     new->name = strdup(colors[cnt]);
-    uint32_t cp = get_colorpixel(colors[cnt]);
+    //uint32_t cp = get_colorpixel(colors[cnt]);
     cnt++;
     if ((cnt % (sizeof(colors) / sizeof(char*))) == 0)
         cnt = 0;
 
     x_con_init(new);
 
-    xcb_change_window_attributes(conn, new->frame, XCB_CW_BACK_PIXEL, &cp);
+    // TODO: this needs to be integrated into src/x.c and updated on config file reloads
+    xcb_change_window_attributes(conn, new->frame, XCB_CW_BACK_PIXEL, &config.client.background);
 
     TAILQ_INIT(&(new->floating_head));
     TAILQ_INIT(&(new->nodes_head));
     TAILQ_INIT(&(new->focus_head));
     TAILQ_INIT(&(new->swallow_head));
 
-    if (parent != NULL)
-        con_attach(new, parent);
+    if (parent != NULL) {
+        /* Set layout of ws if this is the first child of the ws and the user
+         * wanted something different than the default layout. */
+        if (parent->type == CT_WORKSPACE &&
+            con_is_leaf(parent) &&
+            config.default_layout != L_DEFAULT) {
+            con_set_layout(new, config.default_layout);
+            con_attach(new, parent, false);
+            con_set_layout(parent, config.default_layout);
+        } else {
+            con_attach(new, parent, false);
+        }
+    }
 
     return new;
 }
 
-void con_attach(Con *con, Con *parent) {
+/*
+ * Attaches the given container to the given parent. This happens when moving
+ * a container or when inserting a new container at a specific place in the
+ * tree.
+ *
+ * ignore_focus is to just insert the Con at the end (useful when creating a
+ * new split container *around* some containers, that is, detaching and
+ * attaching them in order without wanting to mess with the focus in between).
+ *
+ */
+void con_attach(Con *con, Con *parent, bool ignore_focus) {
     con->parent = parent;
-    TAILQ_INSERT_TAIL(&(parent->nodes_head), con, nodes);
+    Con *loop;
+    Con *current = NULL;
+    struct nodes_head *nodes_head = &(parent->nodes_head);
+
+    /* Workspaces are handled differently: they need to be inserted at the
+     * right position. */
+    if (con->type == CT_WORKSPACE) {
+        DLOG("it's a workspace. num = %d\n", con->num);
+        if (con->num == -1 || TAILQ_EMPTY(nodes_head)) {
+            TAILQ_INSERT_TAIL(nodes_head, con, nodes);
+        } else {
+            current = TAILQ_FIRST(nodes_head);
+            if (con->num < current->num) {
+                /* we need to insert the container at the beginning */
+                TAILQ_INSERT_HEAD(nodes_head, con, nodes);
+            } else {
+                while (current->num != -1 && con->num > current->num) {
+                    current = TAILQ_NEXT(current, nodes);
+                    if (current == TAILQ_END(nodes_head)) {
+                        current = NULL;
+                        break;
+                    }
+                }
+                /* we need to insert con after current, if current is not NULL */
+                if (current)
+                    TAILQ_INSERT_BEFORE(current, con, nodes);
+                else TAILQ_INSERT_TAIL(nodes_head, con, nodes);
+            }
+        }
+        goto add_to_focus_head;
+    }
+
+    if (con->type == CT_FLOATING_CON) {
+        DLOG("Inserting into floating containers\n");
+        TAILQ_INSERT_TAIL(&(parent->floating_head), con, floating_windows);
+    } else {
+        if (!ignore_focus) {
+            /* Get the first tiling container in focus stack */
+            TAILQ_FOREACH(loop, &(parent->focus_head), focused) {
+                if (loop->type == CT_FLOATING_CON)
+                    continue;
+                current = loop;
+                break;
+            }
+        }
+
+        /* Insert the container after the tiling container, if found.
+         * When adding to a CT_OUTPUT, just append one after another. */
+        if (current && parent->type != CT_OUTPUT) {
+            DLOG("Inserting con = %p after last focused tiling con %p\n",
+                 con, current);
+            TAILQ_INSERT_AFTER(nodes_head, current, con, nodes);
+        } else TAILQ_INSERT_TAIL(nodes_head, con, nodes);
+    }
+
+add_to_focus_head:
     /* We insert to the TAIL because con_focus() will correct this.
      * This way, we have the option to insert Cons without having
      * to focus them. */
     TAILQ_INSERT_TAIL(&(parent->focus_head), con, focused);
 }
 
+/*
+ * Detaches the given container from its current parent
+ *
+ */
 void con_detach(Con *con) {
     if (con->type == CT_FLOATING_CON) {
-        /* TODO: remove */
+        TAILQ_REMOVE(&(con->parent->floating_head), con, floating_windows);
+        TAILQ_REMOVE(&(con->parent->focus_head), con, focused);
     } else {
         TAILQ_REMOVE(&(con->parent->nodes_head), con, nodes);
         TAILQ_REMOVE(&(con->parent->focus_head), con, focused);
     }
 }
 
+/*
+ * Sets input focus to the given container. Will be updated in X11 in the next
+ * run of x_push_changes().
+ *
+ */
+void con_focus(Con *con) {
+    assert(con != NULL);
+    DLOG("con_focus = %p\n", con);
+
+    /* 1: set focused-pointer to the new con */
+    /* 2: exchange the position of the container in focus stack of the parent all the way up */
+    TAILQ_REMOVE(&(con->parent->focus_head), con, focused);
+    TAILQ_INSERT_HEAD(&(con->parent->focus_head), con, focused);
+    if (con->parent->parent != NULL)
+        con_focus(con->parent);
+
+    focused = con;
+    if (con->urgent) {
+        con->urgent = false;
+        workspace_update_urgent_flag(con_get_workspace(con));
+    }
+    DLOG("con_focus done = %p\n", con);
+}
+
 /*
  * Returns true when this node is a leaf node (has no children)
  *
@@ -89,8 +203,13 @@ bool con_is_leaf(Con *con) {
  */
 bool con_accepts_window(Con *con) {
     /* 1: workspaces never accept direct windows */
-    if (con->parent->type == CT_OUTPUT)
+    if (con->type == CT_WORKSPACE)
+        return false;
+
+    if (con->orientation != NO_ORIENTATION) {
+        DLOG("container %p does not accepts windows, orientation != NO_ORIENTATION\n", con);
         return false;
+    }
 
     /* TODO: if this is a swallowing container, we need to check its max_clients */
     return (con->window == NULL);
@@ -117,40 +236,86 @@ Con *con_get_output(Con *con) {
  */
 Con *con_get_workspace(Con *con) {
     Con *result = con;
-    while (result != NULL && result->parent->type != CT_OUTPUT)
+    while (result != NULL && result->type != CT_WORKSPACE)
         result = result->parent;
-    assert(result != NULL);
     return result;
 }
 
+/*
+ * Searches parenst of the given 'con' until it reaches one with the specified
+ * 'orientation'. Aborts when it comes across a floating_con.
+ *
+ */
+Con *con_parent_with_orientation(Con *con, orientation_t orientation) {
+    DLOG("Searching for parent of Con %p with orientation %d\n", con, orientation);
+    Con *parent = con->parent;
+    if (parent->type == CT_FLOATING_CON)
+        return NULL;
+    while (con_orientation(parent) != orientation) {
+        DLOG("Need to go one level further up\n");
+        parent = parent->parent;
+        /* Abort when we reach a floating con */
+        if (parent && parent->type == CT_FLOATING_CON)
+            parent = NULL;
+        if (parent == NULL)
+            break;
+    }
+    DLOG("Result: %p\n", parent);
+    return parent;
+}
+
+/*
+ * helper data structure for the breadth-first-search in
+ * con_get_fullscreen_con()
+ *
+ */
+struct bfs_entry {
+    Con *con;
+
+    TAILQ_ENTRY(bfs_entry) entries;
+};
+
 /*
  * Returns the first fullscreen node below this node.
  *
  */
 Con *con_get_fullscreen_con(Con *con) {
-    Con *current;
+    Con *current, *child;
 
-    LOG("looking for fullscreen node\n");
     /* TODO: is breadth-first-search really appropriate? (check as soon as
      * fullscreen levels and fullscreen for containers is implemented) */
-    Con **queue = NULL;
-    int queue_len = 0;
-    TAILQ_FOREACH(current, &(con->nodes_head), nodes) {
-        queue_len++;
-        queue = srealloc(queue, queue_len * sizeof(Con*));
-        queue[queue_len-1] = current;
-    }
-
-    while (queue_len > 0) {
-        current = queue[queue_len-1];
-        LOG("checking %p\n", current);
-        if (current->fullscreen_mode != CF_NONE) {
-            free(queue);
+    TAILQ_HEAD(bfs_head, bfs_entry) bfs_head = TAILQ_HEAD_INITIALIZER(bfs_head);
+    struct bfs_entry *entry = smalloc(sizeof(struct bfs_entry));
+    entry->con = con;
+    TAILQ_INSERT_TAIL(&bfs_head, entry, entries);
+
+    while (!TAILQ_EMPTY(&bfs_head)) {
+        entry = TAILQ_FIRST(&bfs_head);
+        current = entry->con;
+        if (current != con && current->fullscreen_mode != CF_NONE) {
+            /* empty the queue */
+            while (!TAILQ_EMPTY(&bfs_head)) {
+                entry = TAILQ_FIRST(&bfs_head);
+                TAILQ_REMOVE(&bfs_head, entry, entries);
+                free(entry);
+            }
             return current;
         }
-        LOG("deleting from queue\n");
-        queue_len--;
-        queue = realloc(queue, queue_len * sizeof(Con*));
+
+        TAILQ_REMOVE(&bfs_head, entry, entries);
+        free(entry);
+
+        TAILQ_FOREACH(child, &(current->nodes_head), nodes) {
+            entry = smalloc(sizeof(struct bfs_entry));
+            entry->con = child;
+            TAILQ_INSERT_TAIL(&bfs_head, entry, entries);
+        }
+
+        TAILQ_FOREACH(child, &(current->floating_head), floating_windows) {
+            entry = smalloc(sizeof(struct bfs_entry));
+            entry->con = child;
+            TAILQ_INSERT_TAIL(&bfs_head, entry, entries);
+        }
     }
 
     return NULL;
@@ -162,10 +327,34 @@ Con *con_get_fullscreen_con(Con *con) {
  */
 bool con_is_floating(Con *con) {
     assert(con != NULL);
-    LOG("checking if con %p is floating\n", con);
+    DLOG("checking if con %p is floating\n", con);
     return (con->floating >= FLOATING_AUTO_ON);
 }
 
+/*
+ * Checks if the given container is either floating or inside some floating
+ * container. It returns the FLOATING_CON container.
+ *
+ */
+Con *con_inside_floating(Con *con) {
+    assert(con != NULL);
+    if (con->type == CT_FLOATING_CON)
+        return con;
+
+    if (con->floating >= FLOATING_AUTO_ON)
+        return con->parent;
+
+    if (con->type == CT_WORKSPACE || con->type == CT_OUTPUT)
+        return NULL;
+
+    return con_inside_floating(con->parent);
+}
+
+/*
+ * Returns the container with the given client window ID or NULL if no such
+ * container exists.
+ *
+ */
 Con *con_by_window_id(xcb_window_t window) {
     Con *con;
     TAILQ_FOREACH(con, &all_cons, all_cons)
@@ -174,6 +363,11 @@ Con *con_by_window_id(xcb_window_t window) {
     return NULL;
 }
 
+/*
+ * Returns the container with the given frame ID or NULL if no such container
+ * exists.
+ *
+ */
 Con *con_by_frame_id(xcb_window_t frame) {
     Con *con;
     TAILQ_FOREACH(con, &all_cons, all_cons)
@@ -182,67 +376,574 @@ Con *con_by_frame_id(xcb_window_t frame) {
     return NULL;
 }
 
-static bool match_matches_window(Match *match, i3Window *window) {
-    /* TODO: pcre, full matching, … */
-    if (match->class != NULL && strcasecmp(match->class, window->class) == 0) {
-        LOG("match made by window class (%s)\n", window->class);
-        return true;
-    }
-
-    if (match->id != XCB_NONE && window->id == match->id) {
-        LOG("match made by window id (%d)\n", window->id);
-        return true;
-    }
-
-    LOG("window %d (%s) could not be matched\n", window->id, window->class);
-
-    return false;
-}
-
 /*
- * Returns the first container which wants to swallow this window
+ * Returns the first container below 'con' which wants to swallow this window
  * TODO: priority
  *
  */
-Con *con_for_window(i3Window *window, Match **store_match) {
-    Con *con;
+Con *con_for_window(Con *con, i3Window *window, Match **store_match) {
+    Con *child;
     Match *match;
-    LOG("searching con for window %p\n", window);
-    LOG("class == %s\n", window->class);
+    DLOG("searching con for window %p starting at con %p\n", window, con);
+    DLOG("class == %s\n", window->class_class);
 
-    TAILQ_FOREACH(con, &all_cons, all_cons)
-        TAILQ_FOREACH(match, &(con->swallow_head), matches) {
+    TAILQ_FOREACH(child, &(con->nodes_head), nodes) {
+        TAILQ_FOREACH(match, &(child->swallow_head), matches) {
             if (!match_matches_window(match, window))
                 continue;
             if (store_match != NULL)
                 *store_match = match;
-            return con;
+            return child;
+        }
+        Con *result = con_for_window(child, window, store_match);
+        if (result != NULL)
+            return result;
+    }
+
+    TAILQ_FOREACH(child, &(con->floating_head), floating_windows) {
+        TAILQ_FOREACH(match, &(child->swallow_head), matches) {
+            if (!match_matches_window(match, window))
+                continue;
+            if (store_match != NULL)
+                *store_match = match;
+            return child;
         }
+        Con *result = con_for_window(child, window, store_match);
+        if (result != NULL)
+            return result;
+    }
 
     return NULL;
 }
 
 /*
- * Updates the percent attribute of the children of the given container. This
- * function needs to be called when a window is added or removed from a
- * container.
+ * Returns the number of children of this container.
  *
  */
-void con_fix_percent(Con *con, int action) {
+int con_num_children(Con *con) {
     Con *child;
     int children = 0;
+
     TAILQ_FOREACH(child, &(con->nodes_head), nodes)
         children++;
-    /* TODO: better document why this math works */
-    double fix;
-    if (action == WINDOW_ADD)
-        fix = (1.0 - (1.0 / (children+1)));
-    else
-        fix = 1.0 / (1.0 - (1.0 / (children+1)));
 
+    return children;
+}
+
+/*
+ * Updates the percent attribute of the children of the given container. This
+ * function needs to be called when a window is added or removed from a
+ * container.
+ *
+ */
+void con_fix_percent(Con *con) {
+    Con *child;
+    int children = con_num_children(con);
+
+    // calculate how much we have distributed and how many containers
+    // with a percentage set we have
+    double total = 0.0;
+    int children_with_percent = 0;
     TAILQ_FOREACH(child, &(con->nodes_head), nodes) {
-        if (child->percent <= 0.0)
-            continue;
-        child->percent *= fix;
+        if (child->percent > 0.0) {
+            total += child->percent;
+            ++children_with_percent;
+        }
+    }
+
+    // if there were children without a percentage set, set to a value that
+    // will make those children proportional to all others
+    if (children_with_percent != children) {
+        TAILQ_FOREACH(child, &(con->nodes_head), nodes) {
+            if (child->percent <= 0.0) {
+                if (children_with_percent == 0)
+                    total += (child->percent = 1.0);
+                else total += (child->percent = total / children_with_percent);
+            }
+        }
+    }
+
+    // if we got a zero, just distribute the space equally, otherwise
+    // distribute according to the proportions we got
+    if (total == 0.0) {
+        TAILQ_FOREACH(child, &(con->nodes_head), nodes)
+            child->percent = 1.0 / children;
+    } else if (total != 1.0) {
+        TAILQ_FOREACH(child, &(con->nodes_head), nodes)
+            child->percent /= total;
     }
 }
+
+/*
+ * Toggles fullscreen mode for the given container. Fullscreen mode will not be
+ * entered when there already is a fullscreen container on this workspace.
+ *
+ */
+void con_toggle_fullscreen(Con *con) {
+    Con *workspace, *fullscreen;
+
+    if (con->type == CT_WORKSPACE) {
+        DLOG("You cannot make a workspace fullscreen.\n");
+        return;
+    }
+
+    DLOG("toggling fullscreen for %p / %s\n", con, con->name);
+    if (con->fullscreen_mode == CF_NONE) {
+        /* 1: check if there already is a fullscreen con */
+        workspace = con_get_workspace(con);
+        if ((fullscreen = con_get_fullscreen_con(workspace)) != NULL) {
+            LOG("Not entering fullscreen mode, container (%p/%s) "
+                "already is in fullscreen mode\n",
+                fullscreen, fullscreen->name);
+        } else {
+            /* 2: enable fullscreen */
+            con->fullscreen_mode = CF_OUTPUT;
+        }
+    } else {
+        /* 1: disable fullscreen */
+        con->fullscreen_mode = CF_NONE;
+    }
+    DLOG("mode now: %d\n", con->fullscreen_mode);
+
+    /* update _NET_WM_STATE if this container has a window */
+    /* TODO: when a window is assigned to a container which is already
+     * fullscreened, this state needs to be pushed to the client, too */
+    if (con->window == NULL)
+        return;
+
+    uint32_t values[1];
+    unsigned int num = 0;
+
+    if (con->fullscreen_mode != CF_NONE)
+        values[num++] = A__NET_WM_STATE_FULLSCREEN;
+
+    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, con->window->id,
+                        A__NET_WM_STATE, A_ATOM, 32, num, values);
+}
+
+/*
+ * Moves the given container to the currently focused container on the given
+ * workspace.
+ * TODO: is there a better place for this function?
+ *
+ */
+void con_move_to_workspace(Con *con, Con *workspace) {
+    if (con->type == CT_WORKSPACE) {
+        DLOG("Moving workspaces is not yet implemented.\n");
+        return;
+    }
+
+    if (con_is_floating(con)) {
+        DLOG("Using FLOATINGCON instead\n");
+        con = con->parent;
+    }
+
+    Con *source_output = con_get_output(con),
+        *dest_output = con_get_output(workspace);
+
+    /* 1: save the container which is going to be focused after the current
+     * container is moved away */
+    Con *focus_next = con_next_focused(con);
+
+    /* 2: get the focused container of this workspace */
+    Con *next = con_descend_focused(workspace);
+
+    /* 3: we go up one level, but only when next is a normal container */
+    if (next->type != CT_WORKSPACE) {
+        DLOG("next originally = %p / %s / type %d\n", next, next->name, next->type);
+        next = next->parent;
+    }
+
+    /* 4: if the target container is floating, we get the workspace instead.
+     * Only tiling windows need to get inserted next to the current container.
+     * */
+    Con *floatingcon = con_inside_floating(next);
+    if (floatingcon != NULL) {
+        DLOG("floatingcon, going up even further\n");
+        next = floatingcon->parent;
+    }
+
+    if (con->type == CT_FLOATING_CON) {
+        Con *ws = con_get_workspace(next);
+        DLOG("This is a floating window, using workspace %p / %s\n", ws, ws->name);
+        next = ws;
+    }
+
+    DLOG("Re-attaching container to %p / %s\n", next, next->name);
+    /* 5: re-attach the con to the parent of this focused container */
+    Con *parent = con->parent;
+    con_detach(con);
+    con_attach(con, next, false);
+
+    /* 6: fix the percentages */
+    con_fix_percent(parent);
+    con->percent = 0.0;
+    con_fix_percent(next);
+
+    /* 7: focus the con on the target workspace (the X focus is only updated by
+     * calling tree_render(), so for the "real" focus this is a no-op) */
+    con_focus(con);
+
+    /* 8: when moving to a visible workspace on a different output, we keep the
+     * con focused. Otherwise, we leave the focus on the current workspace as we
+     * don’t want to focus invisible workspaces */
+    if (source_output != dest_output &&
+        workspace_is_visible(workspace)) {
+        DLOG("Moved to a different output, focusing target\n");
+    } else {
+        con_focus(focus_next);
+    }
+
+    CALL(parent, on_remove_child);
+}
+
+/*
+ * Returns the orientation of the given container (for stacked containers,
+ * vertical orientation is used regardless of the actual orientation of the
+ * container).
+ *
+ */
+int con_orientation(Con *con) {
+    /* stacking containers behave like they are in vertical orientation */
+    if (con->layout == L_STACKED)
+        return VERT;
+
+    if (con->layout == L_TABBED)
+        return HORIZ;
+
+    return con->orientation;
+}
+
+/*
+ * Returns the container which will be focused next when the given container
+ * is not available anymore. Called in tree_close and con_move_to_workspace
+ * to properly restore focus.
+ *
+ */
+Con *con_next_focused(Con *con) {
+    Con *next;
+    /* floating containers are attached to a workspace, so we focus either the
+     * next floating container (if any) or the workspace itself. */
+    if (con->type == CT_FLOATING_CON) {
+        DLOG("selecting next for CT_FLOATING_CON\n");
+        next = TAILQ_NEXT(con, floating_windows);
+        if (next == TAILQ_END(&(parent->floating_head))) {
+            Con *ws = con_get_workspace(con);
+            next = ws;
+            DLOG("no more floating containers for next = %p, restoring workspace focus\n", next);
+            while (next != TAILQ_END(&(ws->focus_head)) && !TAILQ_EMPTY(&(next->focus_head))) {
+                next = TAILQ_FIRST(&(next->focus_head));
+                if (next == con) {
+                    DLOG("skipping container itself, we want the next client\n");
+                    next = TAILQ_NEXT(next, focused);
+                }
+            }
+            if (next == TAILQ_END(&(ws->focus_head))) {
+                DLOG("Focus list empty, returning ws\n");
+                next = ws;
+            }
+        } else {
+            /* Instead of returning the next CT_FLOATING_CON, we descend it to
+             * get an actual window to focus. */
+            next = con_descend_focused(next);
+        }
+        return next;
+    }
+
+    /* dock clients cannot be focused, so we focus the workspace instead */
+    if (con->parent->type == CT_DOCKAREA) {
+        DLOG("selecting workspace for dock client\n");
+        return con_descend_focused(output_get_content(con->parent->parent));
+    }
+
+    /* if 'con' is not the first entry in the focus stack, use the first one as
+     * it’s currently focused already */
+    Con *first = TAILQ_FIRST(&(con->parent->focus_head));
+    if (first != con) {
+        DLOG("Using first entry %p\n", first);
+        next = first;
+    } else {
+        /* try to focus the next container on the same level as this one or fall
+         * back to its parent */
+        if (!(next = TAILQ_NEXT(con, focused)))
+            next = con->parent;
+    }
+
+    /* now go down the focus stack as far as
+     * possible, excluding the current container */
+    while (!TAILQ_EMPTY(&(next->focus_head)) &&
+           TAILQ_FIRST(&(next->focus_head)) != con)
+        next = TAILQ_FIRST(&(next->focus_head));
+
+    return next;
+}
+
+/*
+ * Get the next/previous container in the specified orientation. This may
+ * travel up until it finds a container with suitable orientation.
+ *
+ */
+Con *con_get_next(Con *con, char way, orientation_t orientation) {
+    DLOG("con_get_next(way=%c, orientation=%d)\n", way, orientation);
+    /* 1: get the first parent with the same orientation */
+    Con *cur = con;
+    while (con_orientation(cur->parent) != orientation) {
+        DLOG("need to go one level further up\n");
+        if (cur->parent->type == CT_WORKSPACE) {
+            LOG("that's a workspace, we can't go further up\n");
+            return NULL;
+        }
+        cur = cur->parent;
+    }
+
+    /* 2: chose next (or previous) */
+    Con *next;
+    if (way == 'n') {
+        next = TAILQ_NEXT(cur, nodes);
+        /* if we are at the end of the list, we need to wrap */
+        if (next == TAILQ_END(&(parent->nodes_head)))
+            return NULL;
+    } else {
+        next = TAILQ_PREV(cur, nodes_head, nodes);
+        /* if we are at the end of the list, we need to wrap */
+        if (next == TAILQ_END(&(cur->nodes_head)))
+            return NULL;
+    }
+    DLOG("next = %p\n", next);
+
+    return next;
+}
+
+/*
+ * Returns the focused con inside this client, descending the tree as far as
+ * possible. This comes in handy when attaching a con to a workspace at the
+ * currently focused position, for example.
+ *
+ */
+Con *con_descend_focused(Con *con) {
+    Con *next = con;
+    while (!TAILQ_EMPTY(&(next->focus_head)))
+        next = TAILQ_FIRST(&(next->focus_head));
+    return next;
+}
+
+/*
+ * Returns the focused con inside this client, descending the tree as far as
+ * possible. This comes in handy when attaching a con to a workspace at the
+ * currently focused position, for example.
+ *
+ * Works like con_descend_focused but considers only tiling cons.
+ *
+ */
+Con *con_descend_tiling_focused(Con *con) {
+    Con *next = con;
+    Con *before;
+    Con *child;
+    do {
+        before = next;
+        TAILQ_FOREACH(child, &(next->focus_head), focused) {
+            if (child->type == CT_FLOATING_CON)
+                continue;
+
+            next = child;
+            break;
+        }
+    } while (before != next);
+    return next;
+}
+
+
+/*
+ * Returns a "relative" Rect which contains the amount of pixels that need to
+ * be added to the original Rect to get the final position (obviously the
+ * amount of pixels for normal, 1pixel and borderless are different).
+ *
+ */
+Rect con_border_style_rect(Con *con) {
+    switch (con_border_style(con)) {
+    case BS_NORMAL:
+        return (Rect){2, 0, -(2 * 2), -2};
+
+    case BS_1PIXEL:
+        return (Rect){1, 1, -2, -2};
+
+    case BS_NONE:
+        return (Rect){0, 0, 0, 0};
+
+    default:
+        assert(false);
+    }
+}
+
+/*
+ * Use this function to get a container’s border style. This is important
+ * because when inside a stack, the border style is always BS_NORMAL.
+ * For tabbed mode, the same applies, with one exception: when the container is
+ * borderless and the only element in the tabbed container, the border is not
+ * rendered.
+ *
+ * For children of a CT_DOCKAREA, the border style is always none.
+ *
+ */
+int con_border_style(Con *con) {
+    Con *fs = con_get_fullscreen_con(con->parent);
+    if (fs == con) {
+        DLOG("this one is fullscreen! overriding BS_NONE\n");
+        return BS_NONE;
+    }
+
+    if (con->parent->layout == L_STACKED)
+        return (con_num_children(con->parent) == 1 ? con->border_style : BS_NORMAL);
+
+    if (con->parent->layout == L_TABBED && con->border_style != BS_NORMAL)
+        return (con_num_children(con->parent) == 1 ? con->border_style : BS_NORMAL);
+
+    if (con->parent->type == CT_DOCKAREA)
+        return BS_NONE;
+
+    return con->border_style;
+}
+
+/*
+ * This function changes the layout of a given container. Use it to handle
+ * special cases like changing a whole workspace to stacked/tabbed (creates a
+ * new split container before).
+ *
+ */
+void con_set_layout(Con *con, int layout) {
+    /* When the container type is CT_WORKSPACE, the user wants to change the
+     * whole workspace into stacked/tabbed mode. To do this and still allow
+     * intuitive operations (like level-up and then opening a new window), we
+     * need to create a new split container. */
+    if (con->type == CT_WORKSPACE) {
+        DLOG("Creating new split container\n");
+        /* 1: create a new split container */
+        Con *new = con_new(NULL);
+        new->parent = con;
+
+        /* 2: set the requested layout on the split con */
+        new->layout = layout;
+
+        /* 3: While the layout is irrelevant in stacked/tabbed mode, it needs
+         * to be set. Otherwise, this con will not be interpreted as a split
+         * container. */
+        if (config.default_orientation == NO_ORIENTATION) {
+            new->orientation = (con->rect.height > con->rect.width) ? VERT : HORIZ;
+        } else {
+            new->orientation = config.default_orientation;
+        }
+
+        Con *old_focused = TAILQ_FIRST(&(con->focus_head));
+        if (old_focused == TAILQ_END(&(con->focus_head)))
+            old_focused = NULL;
+
+        /* 4: move the existing cons of this workspace below the new con */
+        DLOG("Moving cons\n");
+        Con *child;
+        while (!TAILQ_EMPTY(&(con->nodes_head))) {
+            child = TAILQ_FIRST(&(con->nodes_head));
+            con_detach(child);
+            con_attach(child, new, true);
+        }
+
+        /* 4: attach the new split container to the workspace */
+        DLOG("Attaching new split to ws\n");
+        con_attach(new, con, false);
+
+        if (old_focused)
+            con_focus(old_focused);
+
+        tree_flatten(croot);
+
+        return;
+    }
+
+    con->layout = layout;
+}
+
+/*
+ * Callback which will be called when removing a child from the given con.
+ * Kills the container if it is empty and replaces it with the child if there
+ * is exactly one child.
+ *
+ */
+static void con_on_remove_child(Con *con) {
+    DLOG("on_remove_child\n");
+
+    /* Every container 'above' (in the hierarchy) the workspace content should
+     * not be closed when the last child was removed */
+    if (con->type == CT_WORKSPACE ||
+        con->type == CT_OUTPUT ||
+        con->type == CT_ROOT ||
+        con->type == CT_DOCKAREA) {
+        DLOG("not handling, type = %d\n", con->type);
+        return;
+    }
+
+    /* TODO: check if this container would swallow any other client and
+     * don’t close it automatically. */
+    int children = con_num_children(con);
+    if (children == 0) {
+        DLOG("Container empty, closing\n");
+        tree_close(con, DONT_KILL_WINDOW, false);
+        return;
+    }
+}
+
+/*
+ * Determines the minimum size of the given con by looking at its children (for
+ * split/stacked/tabbed cons). Will be called when resizing floating cons
+ *
+ */
+Rect con_minimum_size(Con *con) {
+    DLOG("Determining minimum size for con %p\n", con);
+
+    if (con_is_leaf(con)) {
+        DLOG("leaf node, returning 75x50\n");
+        return (Rect){ 0, 0, 75, 50 };
+    }
+
+    if (con->type == CT_FLOATING_CON) {
+        DLOG("floating con\n");
+        Con *child = TAILQ_FIRST(&(con->nodes_head));
+        return con_minimum_size(child);
+    }
+
+    if (con->layout == L_STACKED || con->layout == L_TABBED) {
+        uint32_t max_width = 0, max_height = 0, deco_height = 0;
+        Con *child;
+        TAILQ_FOREACH(child, &(con->nodes_head), nodes) {
+            Rect min = con_minimum_size(child);
+            deco_height += child->deco_rect.height;
+            max_width = max(max_width, min.width);
+            max_height = max(max_height, min.height);
+        }
+        DLOG("stacked/tabbed now, returning %d x %d + deco_rect = %d\n",
+             max_width, max_height, deco_height);
+        return (Rect){ 0, 0, max_width, max_height + deco_height };
+    }
+
+    /* For horizontal/vertical split containers we sum up the width (h-split)
+     * or height (v-split) and use the maximum of the height (h-split) or width
+     * (v-split) as minimum size. */
+    if (con->orientation == HORIZ || con->orientation == VERT) {
+        uint32_t width = 0, height = 0;
+        Con *child;
+        TAILQ_FOREACH(child, &(con->nodes_head), nodes) {
+            Rect min = con_minimum_size(child);
+            if (con->orientation == HORIZ) {
+                width += min.width;
+                height = max(height, min.height);
+            } else {
+                height += min.height;
+                width = max(width, min.width);
+            }
+        }
+        DLOG("split container, returning width = %d x height = %d\n", width, height);
+        return (Rect){ 0, 0, width, height };
+    }
+
+    ELOG("Unhandled case, type = %d, layout = %d, orientation = %d\n",
+         con->type, con->layout, con->orientation);
+    assert(false);
+}