LibGUI: Use new layout system in scrollable widgets

These changes are mainly nessecairy to remove dependence on the
temporary implicit conversions currently still in place.

Userland/Libraries/LibGUI/AbstractScrollableWidget.cpp

@@ -78,17 +78,23 @@ void AbstractScrollableWidget::custom_layout()
     int height_wanted_by_horizontal_scrollbar = m_horizontal_scrollbar->is_visible() ? int(m_horizontal_scrollbar->min_height()) : 0;
     int width_wanted_by_vertical_scrollbar = m_vertical_scrollbar->is_visible() ? int(m_vertical_scrollbar->min_width()) : 0;
 
-    m_vertical_scrollbar->set_relative_rect(
-        inner_rect.right() + 1 - m_vertical_scrollbar->min_width(),
-        inner_rect.top(),
-        m_vertical_scrollbar->min_width(),
-        inner_rect.height() - height_wanted_by_horizontal_scrollbar);
-
-    m_horizontal_scrollbar->set_relative_rect(
-        inner_rect.left(),
-        inner_rect.bottom() + 1 - m_horizontal_scrollbar->min_height(),
-        inner_rect.width() - width_wanted_by_vertical_scrollbar,
-        m_horizontal_scrollbar->min_height());
+    {
+        int vertical_scrollbar_width = m_vertical_scrollbar->effective_min_size().width().as_int();
+        m_vertical_scrollbar->set_relative_rect(
+            inner_rect.right() + 1 - vertical_scrollbar_width,
+            inner_rect.top(),
+            vertical_scrollbar_width,
+            inner_rect.height() - height_wanted_by_horizontal_scrollbar);
+    }
+
+    {
+        int horizontal_scrollbar_height = m_horizontal_scrollbar->effective_min_size().height().as_int();
+        m_horizontal_scrollbar->set_relative_rect(
+            inner_rect.left(),
+            inner_rect.bottom() + 1 - horizontal_scrollbar_height,
+            inner_rect.width() - width_wanted_by_vertical_scrollbar,
+            horizontal_scrollbar_height);
+    }
 
     m_corner_widget->set_visible(m_vertical_scrollbar->is_visible() && m_horizontal_scrollbar->is_visible());
     if (m_corner_widget->is_visible()) {
@@ -106,8 +112,8 @@ void AbstractScrollableWidget::resize_event(ResizeEvent& event)
 Gfx::IntSize AbstractScrollableWidget::available_size() const
 {
     auto inner_size = Widget::content_size();
-    unsigned available_width = max(inner_size.width() - m_size_occupied_by_fixed_elements.width(), 0);
-    unsigned available_height = max(inner_size.height() - m_size_occupied_by_fixed_elements.height(), 0);
+    int available_width = max(inner_size.width() - m_size_occupied_by_fixed_elements.width(), 0);
+    int available_height = max(inner_size.height() - m_size_occupied_by_fixed_elements.height(), 0);
     return { available_width, available_height };
 }
 

Userland/Libraries/LibGUI/ScrollableContainerWidget.cpp

@@ -37,31 +37,25 @@ void ScrollableContainerWidget::update_widget_size()
     if (!m_widget)
         return;
     m_widget->do_layout();
-    auto new_size = Widget::content_size();
-
-    if (m_widget->layout()) {
-        auto preferred_size = m_widget->layout()->preferred_size();
-        if (m_widget->is_shrink_to_fit()) {
-            if (preferred_size.width() != -1)
-                new_size.set_width(preferred_size.width());
-            if (preferred_size.height() != -1)
-                new_size.set_height(preferred_size.height());
-        } else {
-            new_size = Gfx::Size {
-                max(new_size.width(), preferred_size.width()),
-                max(new_size.height(), preferred_size.height())
-            };
-        }
+    if (m_widget->is_shrink_to_fit() && m_widget->layout()) {
+        auto new_size = Widget::content_size();
+        auto preferred_size = m_widget->effective_preferred_size();
+        if (preferred_size.width().is_int())
+            new_size.set_width(preferred_size.width().as_int());
+        if (preferred_size.height().is_int())
+            new_size.set_height(preferred_size.height().as_int());
+        m_widget->resize(new_size);
+        set_content_size(new_size);
+    } else {
+        auto inner_size = Widget::content_size();
+        auto min_size = m_widget->effective_min_size();
+        auto new_size = Gfx::Size {
+            max(inner_size.width(), MUST(min_size.width().shrink_value())),
+            max(inner_size.height(), MUST(min_size.height().shrink_value()))
+        };
+        m_widget->resize(new_size);
+        set_content_size(new_size);
     }
-
-    auto min_size = m_widget->min_size();
-    new_size = Gfx::Size {
-        max(new_size.width(), min_size.width()),
-        max(new_size.height(), min_size.height()),
-    };
-
-    m_widget->resize(new_size);
-    set_content_size(new_size);
 }
 
 void ScrollableContainerWidget::resize_event(GUI::ResizeEvent& event)