Use the combined geometry of children when setting a split container to floating (+testcase) (Thanks mseed)

Fixes #332

src/floating.c

@@ -98,7 +98,19 @@ void floating_enable(Con *con, bool automatic) {
     int deco_height = font->height + 5;
 
     DLOG("Original rect: (%d, %d) with %d x %d\n", con->rect.x, con->rect.y, con->rect.width, con->rect.height);
+    Rect zero = { 0, 0, 0, 0 };
     nc->rect = con->geometry;
+    /* If the geometry was not set (split containers), we need to determine a
+     * sensible one by combining the geometry of all children */
+    if (memcmp(&(nc->rect), &zero, sizeof(Rect)) == 0) {
+        DLOG("Geometry not set, combining children\n");
+        Con *child;
+        TAILQ_FOREACH(child, &(con->nodes_head), nodes) {
+            DLOG("child geometry: %d x %d\n", child->geometry.width, child->geometry.height);
+            nc->rect.width += child->geometry.width;
+            nc->rect.height = max(nc->rect.height, child->geometry.height);
+        }
+    }
     /* Raise the width/height to at least 75x50 (minimum size for windows) */
     nc->rect.width = max(nc->rect.width, 75);
     nc->rect.height = max(nc->rect.height, 50);

src/x.c

@@ -149,8 +149,7 @@ void x_move_win(Con *src, Con *dest) {
         return;
     }
 
-    Rect zero;
+    Rect zero = { 0, 0, 0, 0 };
-    memset(&zero, 0, sizeof(Rect));
     if (memcmp(&(state_dest->window_rect), &(zero), sizeof(Rect)) == 0) {
         memcpy(&(state_dest->window_rect), &(state_src->window_rect), sizeof(Rect));
         DLOG("COPYING RECT\n");

testcases/t/55-floating-split-size.t

@@ -0,0 +1,70 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Test to see if i3 combines the geometry of all children in a split container
+# when setting the split container to floating
+#
+use X11::XCB qw(:all);
+use Time::HiRes qw(sleep);
+use i3test;
+
+BEGIN {
+    use_ok('X11::XCB::Window');
+}
+
+my $x = X11::XCB::Connection->new;
+my $i3 = i3("/tmp/nestedcons");
+
+my $tmp = get_unused_workspace;
+cmd "workspace $tmp";
+
+#####################################################################
+# open a window with 200x80
+#####################################################################
+
+my $first = $x->root->create_child(
+    class => WINDOW_CLASS_INPUT_OUTPUT,
+    rect => [ 0, 0, 200, 80],
+    background_color => '#FF0000',
+);
+
+$first->map;
+
+sleep 0.25;
+
+#####################################################################
+# Open a second window with 300x90
+#####################################################################
+
+my $second = $x->root->create_child(
+    class => WINDOW_CLASS_INPUT_OUTPUT,
+    rect => [ 0, 0, 300, 90],
+    background_color => '#00FF00',
+);
+
+$second->map;
+
+sleep 0.25;
+
+#####################################################################
+# Set the parent to floating
+#####################################################################
+cmd 'nop setting floating';
+cmd 'level up';
+cmd 'mode floating';
+
+#####################################################################
+# Get geometry of the first floating node (the split container)
+#####################################################################
+
+my @nodes = @{get_ws($tmp)->{floating_nodes}};
+my $rect = $nodes[0]->{rect};
+
+# we compare the width with ± 20 pixels for borders
+cmp_ok($rect->{width}, '>', 500-20, 'width now > 480');
+cmp_ok($rect->{width}, '<', 500+20, 'width now < 520');
+# we compare the height with ± 40 pixels for decorations
+cmp_ok($rect->{height}, '>', 90-40, 'width now > 50');
+cmp_ok($rect->{height}, '<', 90+40, 'width now < 130');
+
+done_testing;