LibGUI: Automatically scroll to a new column on adding it in ColumnsView

Userland/Libraries/LibGUI/AbstractScrollableWidget.cpp

@@ -303,6 +303,11 @@ void AbstractScrollableWidget::scroll_to_bottom()
     scroll_into_view({ 0, content_height(), 0, 0 }, Orientation::Vertical);
 }
 
+void AbstractScrollableWidget::scroll_to_right()
+{
+    scroll_into_view({ content_width(), 0, 0, 0 }, Orientation::Horizontal);
+}
+
 void AbstractScrollableWidget::set_automatic_scrolling_timer_active(bool active)
 {
     if (active == m_active_scrolling_enabled)

Userland/Libraries/LibGUI/AbstractScrollableWidget.h

@@ -56,6 +56,7 @@ public:
 
     void scroll_to_top();
     void scroll_to_bottom();
+    void scroll_to_right();
     void update_scrollbar_ranges();
 
     void set_automatic_scrolling_timer_active(bool);

Userland/Libraries/LibGUI/ColumnsView.cpp

@@ -205,6 +205,10 @@ void ColumnsView::push_column(ModelIndex const& parent_index)
     dbgln("Adding a new column");
     m_columns.append({ parent_index, 0 });
     update_column_sizes();
+
+    // FIXME: Find a way not to jump the view so much when changing folders within the same directory.
+    scroll_to_right();
+
     update();
 }