LibGUI: Subtract layout margin when placing items along secondary axis

While space distribution along the primary axis of a BoxLayout is
pretty sophisticated, the secondary axis is very simple: we simply
center the widget.

However, this doesn't always look very nice if we don't take margins
into account, so make sure we subtract them from the rect we do all
the centering within.

1 files changed, 8 insertions, 2 deletions

diff --git a/Userland/Libraries/LibGUI/BoxLayout.cpp b/Userland/Libraries/LibGUI/BoxLayout.cpp
index b9abc69309..74e0f3c2fd 100644
--- a/Userland/Libraries/LibGUI/BoxLayout.cpp
+++ b/Userland/Libraries/LibGUI/BoxLayout.cpp
@@ -198,6 +198,12 @@ void BoxLayout::run(Widget& widget)
     int current_x = margins().left();
     int current_y = margins().top();
 
+    auto widget_rect_with_margins_subtracted = widget.rect();
+    widget_rect_with_margins_subtracted.take_from_left(margins().left());
+    widget_rect_with_margins_subtracted.take_from_top(margins().top());
+    widget_rect_with_margins_subtracted.take_from_right(margins().right());
+    widget_rect_with_margins_subtracted.take_from_bottom(margins().bottom());
+
     for (auto& item : items) {
         Gfx::IntRect rect { current_x, current_y, 0, 0 };
 
@@ -220,9 +226,9 @@ void BoxLayout::run(Widget& widget)
             rect.set_secondary_size_for_orientation(orientation(), secondary);
 
             if (orientation() == Gfx::Orientation::Horizontal)
-                rect.center_vertically_within(widget.rect());
+                rect.center_vertically_within(widget_rect_with_margins_subtracted);
             else
-                rect.center_horizontally_within(widget.rect());
+                rect.center_horizontally_within(widget_rect_with_margins_subtracted);
 
             item.widget->set_relative_rect(rect);
         }