Implement the window::floating event

The window::floating event should be emitted when a window transitions
to or from the floating state.

docs/ipc

@@ -722,6 +722,7 @@ This event consists of a single serialized map containing a property
 * +title+ - the window's title has changed
 * +fullscreen_mode+ - the window has entered or exited fullscreen mode
 * +move+ - the window has changed its position in the tree
+* +floating+ - the window has transitioned to or from floating
 
 Additionally a +container (object)+ field will be present, which consists
 of the window's parent container. Be aware that for the "new" event, the

src/floating.c

@@ -298,16 +298,22 @@ void floating_enable(Con *con, bool automatic) {
 
     /* Check if we need to re-assign it to a different workspace because of its
      * coordinates and exit if that was done successfully. */
-    if (floating_maybe_reassign_ws(nc))
+    if (floating_maybe_reassign_ws(nc)) {
+        ipc_send_window_event("floating", con);
         return;
+    }
 
     /* Sanitize coordinates: Check if they are on any output */
-    if (get_output_containing(nc->rect.x, nc->rect.y) != NULL)
+    if (get_output_containing(nc->rect.x, nc->rect.y) != NULL) {
+        ipc_send_window_event("floating", con);
         return;
+    }
 
     ELOG("No output found at destination coordinates, centering floating window on current ws\n");
     nc->rect.x = ws->rect.x + (ws->rect.width / 2) - (nc->rect.width / 2);
     nc->rect.y = ws->rect.y + (ws->rect.height / 2) - (nc->rect.height / 2);
+
+    ipc_send_window_event("floating", con);
 }
 
 void floating_disable(Con *con, bool automatic) {
@@ -351,6 +357,8 @@ void floating_disable(Con *con, bool automatic) {
 
     if (set_focus)
         con_focus(con);
+
+    ipc_send_window_event("floating", con);
 }
 
 /*

testcases/t/231-ipc-floating-event.t

@@ -0,0 +1,59 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • http://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • http://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • http://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Test that the window::floating event works correctly. This event should be
+# emitted when a window transitions to or from the floating state.
+# Bug still in: 4.8-7-gf4a8253
+use i3test;
+
+my $i3 = i3(get_socket_path());
+$i3->connect->recv;
+
+my $cv = AnyEvent->condvar;
+
+$i3->subscribe({
+        window => sub {
+            my ($event) = @_;
+            $cv->send($event) if $event->{change} eq 'floating';
+        }
+    })->recv;
+
+my $t;
+$t = AnyEvent->timer(
+    after => 0.5,
+    cb => sub {
+        $cv->send(0);
+    }
+);
+
+my $win = open_window();
+
+cmd '[id="' . $win->{id} . '"] floating enable';
+my $e = $cv->recv;
+
+isnt($e, 0, 'floating a container should send an ipc window event');
+is($e->{container}->{window}, $win->{id}, 'the event should contain information about the window');
+is($e->{container}->{floating}, 'user_on', 'the container should be floating');
+
+$cv = AnyEvent->condvar;
+cmd '[id="' . $win->{id} . '"] floating disable';
+my $e = $cv->recv;
+
+isnt($e, 0, 'disabling floating on a container should send an ipc window event');
+is($e->{container}->{window}, $win->{id}, 'the event should contain information about the window');
+is($e->{container}->{floating}, 'user_off', 'the container should not be floating');
+
+done_testing;