Userland+LibGUI: Add shorthand versions of the Margins constructor

This allows for typing [8] instead of [8, 8, 8, 8] to specify the same
margin on all edges, for example. The constructors follow CSS' style of
specifying margins. The added constructors are:

- Margins(int all): Sets the same margin on all edges.
- Margins(int vertical, int horizontal): Sets the first argument to top
  and bottom margins, and the second argument to left and right margins.
- Margins(int top, int vertical, int bottom): Sets the first argument to
  the top margin, the second argument to the left and right margins,
  and the third argument to the bottom margin.

Userland/Applications/Spreadsheet/CellTypeDialog.cpp

@@ -46,7 +46,7 @@ CellTypeDialog::CellTypeDialog(const Vector<Position>& positions, Sheet& sheet,
     resize(285, 360);
 
     auto& main_widget = set_main_widget<GUI::Widget>();
-    main_widget.set_layout<GUI::VerticalBoxLayout>().set_margins({ 4, 4, 4, 4 });
+    main_widget.set_layout<GUI::VerticalBoxLayout>().set_margins(4);
     main_widget.set_fill_with_background_color(true);
 
     auto& tab_widget = main_widget.add<GUI::TabWidget>();
@@ -130,7 +130,7 @@ void CellTypeDialog::setup_tabs(GUI::TabWidget& tabs, const Vector<Position>& po
     }
 
     auto& type_tab = tabs.add_tab<GUI::Widget>("Type");
-    type_tab.set_layout<GUI::HorizontalBoxLayout>().set_margins({ 4, 4, 4, 4 });
+    type_tab.set_layout<GUI::HorizontalBoxLayout>().set_margins(4);
     {
         auto& left_side = type_tab.add<GUI::Widget>();
         left_side.set_layout<GUI::VerticalBoxLayout>();
@@ -192,14 +192,14 @@ void CellTypeDialog::setup_tabs(GUI::TabWidget& tabs, const Vector<Position>& po
     }
 
     auto& alignment_tab = tabs.add_tab<GUI::Widget>("Alignment");
-    alignment_tab.set_layout<GUI::VerticalBoxLayout>().set_margins({ 4, 4, 4, 4 });
+    alignment_tab.set_layout<GUI::VerticalBoxLayout>().set_margins(4);
     {
         // FIXME: Frame?
         // Horizontal alignment
         {
             auto& horizontal_alignment_selection_container = alignment_tab.add<GUI::Widget>();
             horizontal_alignment_selection_container.set_layout<GUI::HorizontalBoxLayout>();
-            horizontal_alignment_selection_container.layout()->set_margins({ 4, 0, 0, 0 });
+            horizontal_alignment_selection_container.layout()->set_margins({ 4, 0, 0 });
             horizontal_alignment_selection_container.set_fixed_height(22);
 
             auto& horizontal_alignment_label = horizontal_alignment_selection_container.add<GUI::Label>();
@@ -231,7 +231,7 @@ void CellTypeDialog::setup_tabs(GUI::TabWidget& tabs, const Vector<Position>& po
         {
             auto& vertical_alignment_container = alignment_tab.add<GUI::Widget>();
             vertical_alignment_container.set_layout<GUI::HorizontalBoxLayout>();
-            vertical_alignment_container.layout()->set_margins({ 0, 4, 0, 0 });
+            vertical_alignment_container.layout()->set_margins({ 4, 0, 0 });
             vertical_alignment_container.set_fixed_height(22);
 
             auto& vertical_alignment_label = vertical_alignment_container.add<GUI::Label>();
@@ -261,7 +261,7 @@ void CellTypeDialog::setup_tabs(GUI::TabWidget& tabs, const Vector<Position>& po
     }
 
     auto& colors_tab = tabs.add_tab<GUI::Widget>("Color");
-    colors_tab.set_layout<GUI::VerticalBoxLayout>().set_margins({ 4, 4, 4, 4 });
+    colors_tab.set_layout<GUI::VerticalBoxLayout>().set_margins(4);
     {
         // Static formatting
         {
@@ -273,7 +273,7 @@ void CellTypeDialog::setup_tabs(GUI::TabWidget& tabs, const Vector<Position>& po
                 // FIXME: Somehow allow unsetting these.
                 auto& foreground_container = static_formatting_container.add<GUI::Widget>();
                 foreground_container.set_layout<GUI::HorizontalBoxLayout>();
-                foreground_container.layout()->set_margins({ 4, 0, 0, 0 });
+                foreground_container.layout()->set_margins({ 4, 0, 0 });
                 foreground_container.set_shrink_to_fit(true);
 
                 auto& foreground_label = foreground_container.add<GUI::Label>();
@@ -293,7 +293,7 @@ void CellTypeDialog::setup_tabs(GUI::TabWidget& tabs, const Vector<Position>& po
                 // FIXME: Somehow allow unsetting these.
                 auto& background_container = static_formatting_container.add<GUI::Widget>();
                 background_container.set_layout<GUI::HorizontalBoxLayout>();
-                background_container.layout()->set_margins({ 4, 0, 0, 0 });
+                background_container.layout()->set_margins({ 4, 0, 0 });
                 background_container.set_shrink_to_fit(true);
 
                 auto& background_label = background_container.add<GUI::Label>();

Userland/Applications/Spreadsheet/CondFormatting.gml

@@ -3,7 +3,7 @@
     fill_with_background_color: true
 
     layout: @GUI::VerticalBoxLayout {
-        margins: [4, 4, 4, 4]
+        margins: [4]
         spacing: 4
     }
 

Userland/Applications/Spreadsheet/SpreadsheetView.cpp

@@ -151,7 +151,7 @@ SpreadsheetView::SpreadsheetView(Sheet& sheet)
     : m_sheet(sheet)
     , m_sheet_model(SheetModel::create(*m_sheet))
 {
-    set_layout<GUI::VerticalBoxLayout>().set_margins({ 2, 2, 2, 2 });
+    set_layout<GUI::VerticalBoxLayout>().set_margins(2);
     m_table_view = add<InfinitelyScrollableTableView>();
     m_table_view->set_grid_style(GUI::TableView::GridStyle::Both);
     m_table_view->set_selection_behavior(GUI::AbstractView::SelectionBehavior::SelectItems);

Userland/Applications/Spreadsheet/SpreadsheetWidget.cpp

@@ -26,7 +26,7 @@ SpreadsheetWidget::SpreadsheetWidget(NonnullRefPtrVector<Sheet>&& sheets, bool s
     : m_workbook(make<Workbook>(move(sheets)))
 {
     set_fill_with_background_color(true);
-    set_layout<GUI::VerticalBoxLayout>().set_margins({ 2, 2, 2, 2 });
+    set_layout<GUI::VerticalBoxLayout>().set_margins(2);
     auto& container = add<GUI::VerticalSplitter>();
 
     auto& top_bar = container.add<GUI::Frame>();
@@ -71,7 +71,7 @@ SpreadsheetWidget::SpreadsheetWidget(NonnullRefPtrVector<Sheet>&& sheets, bool s
     m_inline_documentation_window->set_resizable(false);
     auto& inline_widget = m_inline_documentation_window->set_main_widget<GUI::Frame>();
     inline_widget.set_fill_with_background_color(true);
-    inline_widget.set_layout<GUI::VerticalBoxLayout>().set_margins({ 4, 4, 4, 4 });
+    inline_widget.set_layout<GUI::VerticalBoxLayout>().set_margins(4);
     inline_widget.set_frame_shape(Gfx::FrameShape::Box);
     m_inline_documentation_label = inline_widget.add<GUI::Label>();
     m_inline_documentation_label->set_fill_with_background_color(true);

Userland/Applications/Spreadsheet/csv_export.gml

@@ -1,6 +1,6 @@
 @GUI::Widget {
     layout: @GUI::VerticalBoxLayout {
-        margins: [20, 20, 20, 20]
+        margins: [20]
     }
 
     @GUI::HorizontalSplitter {
@@ -19,7 +19,7 @@
 
                     layout: @GUI::VerticalBoxLayout {
                         // FIXME: This is working around the fact that group boxes don't allocate space for their title and border!
-                        margins: [20, 10, 10, 10]
+                        margins: [20, 10, 10]
                     }
 
                     @GUI::RadioButton {
@@ -70,7 +70,7 @@
 
                     layout: @GUI::VerticalBoxLayout {
                         // FIXME: This is working around the fact that group boxes don't allocate space for their title and border!
-                        margins: [20, 10, 10, 10]
+                        margins: [20, 10, 10]
                     }
 
                     @GUI::RadioButton {
@@ -152,7 +152,7 @@
 
             layout: @GUI::VerticalBoxLayout {
                 // FIXME: This is working around the fact that group boxes don't allocate space for their title and border!
-                margins: [20, 10, 10, 10]
+                margins: [20, 10, 10]
             }
 
             @GUI::TextEditor {

Userland/Applications/Spreadsheet/csv_import.gml

@@ -1,6 +1,6 @@
 @GUI::Widget {
     layout: @GUI::VerticalBoxLayout {
-        margins: [20, 20, 20, 20]
+        margins: [20]
     }
 
     @GUI::HorizontalSplitter {
@@ -19,7 +19,7 @@
 
                     layout: @GUI::VerticalBoxLayout {
                         // FIXME: This is working around the fact that group boxes don't allocate space for their title and border!
-                        margins: [20, 10, 10, 10]
+                        margins: [20, 10, 10]
                     }
 
                     @GUI::RadioButton {
@@ -70,7 +70,7 @@
 
                     layout: @GUI::VerticalBoxLayout {
                         // FIXME: This is working around the fact that group boxes don't allocate space for their title and border!
-                        margins: [20, 10, 10, 10]
+                        margins: [20, 10, 10]
                     }
 
                     @GUI::RadioButton {
@@ -133,7 +133,7 @@
                 fixed_height: 40
 
                 layout: @GUI::VerticalBoxLayout {
-                    margins: [6, 6, 0, 6]
+                    margins: [6, 6, 0]
                 }
 
                 @GUI::Widget {
@@ -165,7 +165,7 @@
 
             layout: @GUI::VerticalBoxLayout {
                 // FIXME: This is working around the fact that group boxes don't allocate space for their title and border!
-                margins: [20, 10, 10, 10]
+                margins: [20, 10, 10]
             }
 
             @GUI::StackWidget {

Userland/Applications/Spreadsheet/select_format_page.gml

@@ -2,7 +2,7 @@
     name: "select_format"
 
     layout: @GUI::VerticalBoxLayout {
-        margins: [20, 20, 20, 20]
+        margins: [20]
     }
 
     @GUI::Label {