Simplify tree_close_internal

This commit makes multiple changes in tree_close_internal. I didn't
split them because they are not completely independent.

- Remove force_set_focus parameter
This parameter was always set to `false` throughout the code base except
for one case where it was set to `(con == focused)`, when killing a
floating con's parent (the one with type CT_FLOATING_CON). But this case
is not needed anymore since the special handling of CT_FLOATING_CONs in
con_next_focused was removed in #2941.
- Assume that con_next_focused does not returned a container of type
CT_DOCKAREA. This is reasonable since con_next_focused uses the
focus_head stack and has special handling of CT_DOCKAREA containers.
- Remove is_mapped
This variable was only used in the if block towards the end of
tree_close_internal. Ignoring the, now removed, dockarea code and the
use of force_set_focus this block performed only one useful action:
focus the `next` container when `con == focused`. `con == focused` was a
necessary and sufficient condition for the con_activate call:
if `con != focused` we could reach the inner if blocks because of the
other conditions but would never focus another container. If `con ==
focused` then all other conditions would be irrelevant.
- Remove special handling of floating containers
Since the `next` focused container is calculated through the parent for
floating containers, I moved this code to con_next_focused.
Also, because of the removal of force_set_focus, it appears that we can
call con_on_remove_child for floating containers as well.

include/tree.h

@@ -78,7 +78,7 @@ void tree_next(char way, orientation_t orientation);
  * container) and focus should be set there.
  *
  */
-bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_parent, bool force_set_focus);
+bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_parent);
 
 /**
  * Loads tree from ~/.i3/_restart.json (used for in-place restarts).

src/con.c

@@ -286,14 +286,14 @@ void con_close(Con *con, kill_window_t kill_window) {
         for (child = TAILQ_FIRST(&(con->focus_head)); child;) {
             nextchild = TAILQ_NEXT(child, focused);
             DLOG("killing child = %p.\n", child);
-            tree_close_internal(child, kill_window, false, false);
+            tree_close_internal(child, kill_window, false);
             child = nextchild;
         }
 
         return;
     }
 
-    tree_close_internal(con, kill_window, false, false);
+    tree_close_internal(con, kill_window, false);
 }
 
 /*
@@ -1437,6 +1437,9 @@ Con *con_next_focused(Con *con) {
         DLOG("selecting workspace for dock client\n");
         return con_descend_focused(output_get_content(con->parent->parent));
     }
+    if (con_is_floating(con)) {
+        con = con->parent;
+    }
 
     /* if 'con' is not the first entry in the focus stack, use the first one as
      * it’s currently focused already */
@@ -1955,7 +1958,7 @@ static void con_on_remove_child(Con *con) {
         if (TAILQ_EMPTY(&(con->focus_head)) && !workspace_is_visible(con)) {
             LOG("Closing old workspace (%p / %s), it is empty\n", con, con->name);
             yajl_gen gen = ipc_marshal_workspace_event("empty", con, NULL);
-            tree_close_internal(con, DONT_KILL_WINDOW, false, false);
+            tree_close_internal(con, DONT_KILL_WINDOW, false);
 
             const unsigned char *payload;
             ylength length;
@@ -1976,7 +1979,7 @@ static void con_on_remove_child(Con *con) {
     int children = con_num_children(con);
     if (children == 0) {
         DLOG("Container empty, closing\n");
-        tree_close_internal(con, DONT_KILL_WINDOW, false, false);
+        tree_close_internal(con, DONT_KILL_WINDOW, false);
         return;
     }
 }

src/floating.c

@@ -246,7 +246,7 @@ void floating_enable(Con *con, bool automatic) {
         Con *parent = con->parent;
         /* clear the pointer before calling tree_close_internal in which the memory is freed */
         con->parent = NULL;
-        tree_close_internal(parent, DONT_KILL_WINDOW, false, false);
+        tree_close_internal(parent, DONT_KILL_WINDOW, false);
     }
 
     char *name;
@@ -372,7 +372,7 @@ void floating_disable(Con *con, bool automatic) {
         Con *parent = con->parent;
         con_detach(con);
         con->parent = NULL;
-        tree_close_internal(parent, DONT_KILL_WINDOW, true, false);
+        tree_close_internal(parent, DONT_KILL_WINDOW, true);
         con_attach(con, tiling_focused, false);
         con->percent = 0.0;
         con_fix_percent(con->parent);

src/handlers.c

@@ -511,7 +511,7 @@ static void handle_unmap_notify_event(xcb_unmap_notify_event_t *event) {
     xcb_delete_property(conn, event->window, A__NET_WM_DESKTOP);
     xcb_delete_property(conn, event->window, A__NET_WM_STATE);
 
-    tree_close_internal(con, DONT_KILL_WINDOW, false, false);
+    tree_close_internal(con, DONT_KILL_WINDOW, false);
     tree_render();
 
 ignore_end:
@@ -884,7 +884,7 @@ static void handle_client_message(xcb_client_message_event_t *event) {
             if (event->data.data32[0])
                 last_timestamp = event->data.data32[0];
 
-            tree_close_internal(con, KILL_WINDOW, false, false);
+            tree_close_internal(con, KILL_WINDOW, false);
             tree_render();
         } else {
             DLOG("Couldn't find con for _NET_CLOSE_WINDOW request. (window = %d)\n", event->window);

src/randr.c

@@ -991,7 +991,7 @@ void randr_disable_output(Output *output) {
             if (current != next && TAILQ_EMPTY(&(current->focus_head))) {
                 /* the workspace is empty and not focused, get rid of it */
                 DLOG("Getting rid of current = %p / %s (empty, unfocused)\n", current, current->name);
-                tree_close_internal(current, DONT_KILL_WINDOW, false, false);
+                tree_close_internal(current, DONT_KILL_WINDOW, false);
                 continue;
             }
             DLOG("Detaching current = %p / %s\n", current, current->name);
@@ -1037,7 +1037,7 @@ void randr_disable_output(Output *output) {
         Con *con = output->con;
         /* clear the pointer before calling tree_close_internal in which the memory is freed */
         output->con = NULL;
-        tree_close_internal(con, DONT_KILL_WINDOW, true, false);
+        tree_close_internal(con, DONT_KILL_WINDOW, true);
         DLOG("Done. Should be fine now\n");
     }
 

src/tree.c

@@ -175,16 +175,6 @@ Con *tree_open_con(Con *con, i3Window *window) {
     return new;
 }
 
-static bool _is_con_mapped(Con *con) {
-    Con *child;
-
-    TAILQ_FOREACH(child, &(con->nodes_head), nodes)
-    if (_is_con_mapped(child))
-        return true;
-
-    return con->mapped;
-}
-
 /*
  * Closes the given container including all children.
  * Returns true if the container was killed or false if just WM_DELETE was sent
@@ -193,33 +183,17 @@ static bool _is_con_mapped(Con *con) {
  * The dont_kill_parent flag is specified when the function calls itself
  * recursively while deleting a containers children.
  *
- * The force_set_focus flag is specified in the case of killing a floating
- * window: tree_close_internal() will be invoked for the CT_FLOATINGCON (the parent
- * container) and focus should be set there.
- *
  */
-bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_parent, bool force_set_focus) {
-    bool was_mapped = con->mapped;
+bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_parent) {
     Con *parent = con->parent;
 
-    if (!was_mapped) {
-        /* Even if the container itself is not mapped, its children may be
-         * mapped (for example split containers don't have a mapped window on
-         * their own but usually contain mapped children). */
-        was_mapped = _is_con_mapped(con);
-    }
-
     /* remove the urgency hint of the workspace (if set) */
     if (con->urgent) {
         con_set_urgency(con, false);
         con_update_parents_urgency(con);
         workspace_update_urgent_flag(con_get_workspace(con));
     }
 
-    /* Get the container which is next focused */
-    Con *next = con_next_focused(con);
-    DLOG("next = %p, focused = %p\n", next, focused);
-
     DLOG("closing %p, kill_window = %d\n", con, kill_window);
     Con *child, *nextchild;
     bool abort_kill = false;
@@ -228,8 +202,9 @@ bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_par
     for (child = TAILQ_FIRST(&(con->nodes_head)); child;) {
         nextchild = TAILQ_NEXT(child, nodes);
         DLOG("killing child=%p\n", child);
-        if (!tree_close_internal(child, kill_window, true, false))
+        if (!tree_close_internal(child, kill_window, true)) {
             abort_kill = true;
+        }
         child = nextchild;
     }
 
@@ -281,17 +256,8 @@ bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_par
     Con *ws = con_get_workspace(con);
 
     /* Figure out which container to focus next before detaching 'con'. */
-    if (con_is_floating(con)) {
-        if (con == focused) {
-            DLOG("This is the focused container, i need to find another one to focus. I start looking at ws = %p\n", ws);
-            next = con_next_focused(parent);
-
-            dont_kill_parent = true;
-            DLOG("Alright, focusing %p\n", next);
-        } else {
-            next = NULL;
-        }
-    }
+    Con *next = (con == focused) ? con_next_focused(con) : NULL;
+    DLOG("next = %p, focused = %p\n", next, focused);
 
     /* Detach the container so that it will not be rendered anymore. */
     con_detach(con);
@@ -324,12 +290,6 @@ bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_par
     /* kill the X11 part of this container */
     x_con_kill(con);
 
-    if (con_is_floating(con)) {
-        DLOG("Container was floating, killing floating container\n");
-        tree_close_internal(parent, DONT_KILL_WINDOW, false, (con == focused));
-        DLOG("parent container killed\n");
-    }
-
     if (ws == con) {
         DLOG("Closing a workspace container, updating EWMH atoms\n");
         ewmh_update_number_of_desktops();
@@ -339,30 +299,10 @@ bool tree_close_internal(Con *con, kill_window_t kill_window, bool dont_kill_par
 
     con_free(con);
 
-    /* in the case of floating windows, we already focused another container
-     * when closing the parent, so we can exit now. */
-    if (!next) {
-        DLOG("No next container, i will just exit now\n");
-        return true;
-    }
-
-    if (was_mapped || con == focused) {
-        if ((kill_window != DONT_KILL_WINDOW) || !dont_kill_parent || con == focused) {
-            DLOG("focusing %p / %s\n", next, next->name);
-            if (next->type == CT_DOCKAREA) {
-                /* Instead of focusing the dockarea, we need to restore focus to the workspace */
-                con_activate(con_descend_focused(output_get_content(next->parent)));
-            } else {
-                if (!force_set_focus && con != focused)
-                    DLOG("not changing focus, the container was not focused before\n");
-                else
-                    con_activate(next);
-            }
-        } else {
-            DLOG("not focusing because we're not killing anybody\n");
-        }
+    if (next) {
+        con_activate(next);
     } else {
-        DLOG("not focusing, was not mapped\n");
+        DLOG("not changing focus, the container was not focused before\n");
     }
 
     /* check if the parent container is empty now and close it */
@@ -755,7 +695,7 @@ void tree_flatten(Con *con) {
 
     /* 4: close the redundant cons */
     DLOG("closing redundant cons\n");
-    tree_close_internal(con, DONT_KILL_WINDOW, true, false);
+    tree_close_internal(con, DONT_KILL_WINDOW, true);
 
     /* Well, we got to abort the recursion here because we destroyed the
      * container. However, if tree_flatten() is called sufficiently often,

src/workspace.c

@@ -496,7 +496,7 @@ void workspace_show(Con *workspace) {
         if (!workspace_is_visible(old)) {
             LOG("Closing old workspace (%p / %s), it is empty\n", old, old->name);
             yajl_gen gen = ipc_marshal_workspace_event("empty", old, NULL);
-            tree_close_internal(old, DONT_KILL_WINDOW, false, false);
+            tree_close_internal(old, DONT_KILL_WINDOW, false);
 
             const unsigned char *payload;
             ylength length;