MouseSettings: Add "Natural scrolling" toggle

Author: https://github.com/filiphsps
Commit: https://github.com/SerenityOS/serenity/commit/2e3efd34c3
Pull-request: https://github.com/SerenityOS/serenity/pull/16265
Reviewed-by: https://github.com/AtkinsSJ ✅
Reviewed-by: https://github.com/linusg

Userland/Applications/MouseSettings/Mouse.gml

@@ -53,7 +53,7 @@
     }
 
     @GUI::GroupBox {
-        title: "Scroll Wheel Step Size"
+        title: "Scroll Wheel"
         fixed_height: 106
         layout: @GUI::VerticalBoxLayout {
             margins: [6]
@@ -79,7 +79,7 @@
 
         @GUI::Widget {
             layout: @GUI::HorizontalBoxLayout {
-                margins: [8]
+                margins: [4, 0, 2, 8]
                 spacing: 8
             }
 
@@ -97,10 +97,19 @@
                 min: 0
                 max: 100
                 value: 50
-                fixed_width: 100
+                preferred_width: "opportunistic_grow"
             }
 
-            @GUI::Layout::Spacer {}
+            @GUI::Widget {
+                fixed_width: 16
+            }
+
+            @GUI::CheckBox {
+                name: "natural_scroll_checkbox"
+                text: "Natural scrolling"
+                tooltip: "Content follows motion instead of the viewport,\nalso commonly referred to as \"reverse scrolling\"."
+                preferred_width: 108
+            }
         }
     }
 

Userland/Applications/MouseSettings/MouseWidget.cpp

@@ -57,6 +57,12 @@ MouseWidget::MouseWidget()
         set_modified(true);
     };
 
+    m_natural_scroll_checkbox = *find_descendant_of_type_named<GUI::CheckBox>("natural_scroll_checkbox");
+    m_natural_scroll_checkbox->set_checked(GUI::ConnectionToWindowServer::the().is_natural_scroll(), GUI::AllowCallback::No);
+    m_natural_scroll_checkbox->on_checked = [&](auto) {
+        set_modified(true);
+    };
+
     update_speed_label();
     update_double_click_speed_label();
     m_double_click_arrow_widget->set_double_click_speed(m_double_click_speed_slider->value());
@@ -69,6 +75,7 @@ void MouseWidget::apply_settings()
     GUI::ConnectionToWindowServer::the().async_set_scroll_step_size(m_scroll_length_spinbox->value());
     GUI::ConnectionToWindowServer::the().async_set_double_click_speed(m_double_click_speed_slider->value());
     GUI::ConnectionToWindowServer::the().async_set_buttons_switched(m_switch_buttons_checkbox->is_checked());
+    GUI::ConnectionToWindowServer::the().async_set_natural_scroll(m_natural_scroll_checkbox->is_checked());
 }
 
 void MouseWidget::reset_default_values()
@@ -77,6 +84,7 @@ void MouseWidget::reset_default_values()
     m_scroll_length_spinbox->set_value(default_scroll_length);
     m_double_click_speed_slider->set_value(double_click_speed_default);
     m_switch_buttons_checkbox->set_checked(false);
+    m_natural_scroll_checkbox->set_checked(false);
 }
 
 void MouseWidget::update_speed_label()

Userland/Applications/MouseSettings/MouseWidget.h

@@ -31,5 +31,6 @@ private:
     RefPtr<GUI::HorizontalSlider> m_double_click_speed_slider;
     RefPtr<GUI::Label> m_double_click_speed_label;
     RefPtr<GUI::CheckBox> m_switch_buttons_checkbox;
+    RefPtr<GUI::CheckBox> m_natural_scroll_checkbox;
     RefPtr<MouseSettings::DoubleClickArrowWidget> m_double_click_arrow_widget;
 };