LibGUI: Remove Layout::try_add_spacer()

And fall back to the infallible add_spacer().

Work towards #20557.

Meta/Lagom/Tools/CodeGenerators/GMLCompiler/main.cpp

@@ -301,7 +301,7 @@ static ErrorOr<void> generate_loader_for_object(GUI::GML::Object const& gml_obje
     TRY(gml_object.try_for_each_child_object([&](auto const& child) -> ErrorOr<void> {
         // Spacer is a pseudo-class that insteads causes a call to `Widget::add_spacer` on the parent object.
         if (child.name() == "GUI::Layout::Spacer"sv) {
-            TRY(append(generator, "TRY(@object_name@->add_spacer());"));
+            TRY(append(generator, "@object_name@->add_spacer();"));
             return {};
         }
 

Userland/Applications/Browser/DownloadWidget.cpp

@@ -69,7 +69,7 @@ DownloadWidget::DownloadWidget(const URL& url)
 
     m_browser_image = animation_container.add<GUI::ImageWidget>();
     m_browser_image->load_from_file("/res/graphics/download-animation.gif"sv);
-    animation_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    animation_container.add_spacer();
 
     auto& source_label = add<GUI::Label>(String::formatted("File: {}", m_url.basename()).release_value_but_fixme_should_propagate_errors());
     source_label.set_text_alignment(Gfx::TextAlignment::CenterLeft);
@@ -102,7 +102,7 @@ DownloadWidget::DownloadWidget(const URL& url)
 
     auto& button_container = add<GUI::Widget>();
     button_container.set_layout<GUI::HorizontalBoxLayout>();
-    button_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    button_container.add_spacer();
     m_cancel_button = button_container.add<GUI::Button>("Cancel"_string);
     m_cancel_button->set_fixed_size(100, 22);
     m_cancel_button->on_click = [this](auto) {

Userland/Applications/Calendar/AddEventDialog.cpp

@@ -88,12 +88,12 @@ AddEventDialog::AddEventDialog(Core::DateTime date_time, EventManager& event_man
     starting_meridiem_combo.set_model(MeridiemListModel::create());
     starting_meridiem_combo.set_selected_index(0);
 
-    widget->add_spacer().release_value_but_fixme_should_propagate_errors();
+    widget->add_spacer();
 
     auto& button_container = widget->add<GUI::Widget>();
     button_container.set_fixed_height(20);
     button_container.set_layout<GUI::HorizontalBoxLayout>();
-    button_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    button_container.add_spacer();
     auto& ok_button = button_container.add<GUI::Button>("OK"_string);
     ok_button.set_fixed_size(80, 20);
     ok_button.on_click = [&](auto) {

Userland/Applications/FileManager/PropertiesWindow.cpp

@@ -82,7 +82,7 @@ ErrorOr<void> PropertiesWindow::create_widgets(bool disable_rename)
     button_widget->set_layout<GUI::HorizontalBoxLayout>(GUI::Margins {}, 5);
     button_widget->set_fixed_height(22);
 
-    TRY(button_widget->add_spacer());
+    button_widget->add_spacer();
 
     auto ok_button = TRY(make_button("OK"_string, button_widget));
     ok_button->on_click = [this](auto) {

Userland/Applications/KeyboardMapper/KeyboardMapperWidget.cpp

@@ -94,7 +94,7 @@ void KeyboardMapperWidget::create_frame()
     add_map_radio_button("alt_map"sv, "Alt"_string);
     add_map_radio_button("shift_altgr_map"sv, "Shift+AltGr"_string);
 
-    bottom_widget.add_spacer().release_value_but_fixme_should_propagate_errors();
+    bottom_widget.add_spacer();
 }
 
 void KeyboardMapperWidget::add_map_radio_button(const StringView map_name, String button_text)

Userland/Applications/Piano/TrackControlsWidget.cpp

@@ -36,7 +36,7 @@ ErrorOr<NonnullRefPtr<TrackControlsWidget>> TrackControlsWidget::try_create(Weak
 
     TRY(widget->m_processor_groups.try_append(mastering_parameters));
 
-    TRY(widget->add_spacer());
+    widget->add_spacer();
 
     for (auto& processor : strong_track->processor_chain()) {
         auto processor_parameters = TRY(widget->try_add<GUI::GroupBox>());

Userland/Applications/PixelPaint/Tools/GradientTool.cpp

@@ -295,7 +295,7 @@ ErrorOr<GUI::Widget*> GradientTool::get_properties_widget()
         auto button_container = TRY(properties_widget->try_add<GUI::Widget>());
         button_container->set_fixed_height(22);
         button_container->set_layout<GUI::HorizontalBoxLayout>();
-        button_container->add_spacer().release_value_but_fixme_should_propagate_errors();
+        button_container->add_spacer();
 
         auto apply_button = TRY(button_container->try_add<GUI::DialogButton>("Apply"_string));
         apply_button->on_click = [this](auto) {

Userland/Applications/Spreadsheet/CellTypeDialog.cpp

@@ -55,7 +55,7 @@ CellTypeDialog::CellTypeDialog(Vector<Position> const& positions, Sheet& sheet,
     auto& buttonbox = main_widget->add<GUI::Widget>();
     buttonbox.set_shrink_to_fit(true);
     buttonbox.set_layout<GUI::HorizontalBoxLayout>(GUI::Margins {}, 10);
-    buttonbox.add_spacer().release_value_but_fixme_should_propagate_errors();
+    buttonbox.add_spacer();
     auto& ok_button = buttonbox.add<GUI::Button>("OK"_string);
     ok_button.set_fixed_width(80);
     ok_button.on_click = [&](auto) { done(ExecResult::OK); };

Userland/Libraries/LibGUI/ColorPicker.cpp

@@ -226,7 +226,7 @@ void ColorPicker::build_ui()
     auto& button_container = root_container->add<Widget>();
     button_container.set_preferred_height(GUI::SpecialDimension::Fit);
     button_container.set_layout<HorizontalBoxLayout>(4);
-    button_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    button_container.add_spacer();
 
     auto& ok_button = button_container.add<DialogButton>();
     ok_button.set_text("OK"_string);
@@ -327,7 +327,7 @@ void ColorPicker::build_ui_custom(Widget& root_container)
     // Preview selected color
     m_preview_widget = preview_container.add<ColorPreview>(m_color);
 
-    vertical_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    vertical_container.add_spacer();
 
     // HTML
     auto& html_container = vertical_container.add<GUI::Widget>();

Userland/Libraries/LibGUI/InputBox.cpp

@@ -159,7 +159,7 @@ ErrorOr<void> InputBox::build()
 
     auto button_container = TRY(main_widget->try_add<Widget>());
     button_container->set_layout<HorizontalBoxLayout>(0, 6);
-    TRY(button_container->add_spacer());
+    button_container->add_spacer();
 
     m_ok_button = TRY(button_container->try_add<DialogButton>("OK"_string));
     m_ok_button->on_click = [this](auto) {

Userland/Libraries/LibGUI/Layout.cpp

@@ -73,15 +73,9 @@ void Layout::add_entry(Entry&& entry)
     MUST(try_add_entry(move(entry)));
 }
 
-ErrorOr<void> Layout::try_add_spacer()
-{
-    TRY(try_add_entry(Entry { .type = Entry::Type::Spacer }));
-    return {};
-}
-
 void Layout::add_spacer()
 {
-    MUST(try_add_spacer());
+    add_entry(Entry { .type = Entry::Type::Spacer });
 }
 
 void Layout::add_layout(OwnPtr<Layout>&& layout)

Userland/Libraries/LibGUI/Layout.h

@@ -40,7 +40,6 @@ public:
 
     ErrorOr<void> try_add_widget(Widget&);
     ErrorOr<void> try_insert_widget_before(Widget& widget, Widget& before_widget);
-    ErrorOr<void> try_add_spacer();
 
     void remove_widget(Widget&);
 

Userland/Libraries/LibGUI/MessageBox.cpp

@@ -179,7 +179,7 @@ ErrorOr<void> MessageBox::build()
         return button;
     };
 
-    TRY(button_container->add_spacer());
+    button_container->add_spacer();
     if (should_include_ok_button())
         m_ok_button = TRY(add_button("OK"_string, ExecResult::OK));
     if (should_include_yes_button())
@@ -188,7 +188,7 @@ ErrorOr<void> MessageBox::build()
         m_no_button = TRY(add_button("No"_string, ExecResult::No));
     if (should_include_cancel_button())
         m_cancel_button = TRY(add_button("Cancel"_string, ExecResult::Cancel));
-    TRY(button_container->add_spacer());
+    button_container->add_spacer();
 
     return {};
 }

Userland/Libraries/LibGUI/ProcessChooser.cpp

@@ -49,7 +49,7 @@ ProcessChooser::ProcessChooser(StringView window_title, String button_label, Gfx
     auto& button_container = widget->add<GUI::Widget>();
     button_container.set_fixed_height(30);
     button_container.set_layout<GUI::HorizontalBoxLayout>(GUI::Margins { 0, 4, 0 });
-    button_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    button_container.add_spacer();
 
     auto& select_button = button_container.add<GUI::Button>(m_button_label);
     select_button.set_fixed_width(80);

Userland/Libraries/LibGUI/SettingsWindow.cpp

@@ -49,7 +49,7 @@ ErrorOr<NonnullRefPtr<SettingsWindow>> SettingsWindow::create(DeprecatedString t
         };
     }
 
-    TRY(button_container->add_spacer());
+    button_container->add_spacer();
 
     window->m_ok_button = TRY(button_container->try_add<GUI::DialogButton>("OK"_string));
     window->m_ok_button->on_click = [window = window->make_weak_ptr<SettingsWindow>()](auto) {

Userland/Libraries/LibGUI/Toolbar.cpp

@@ -174,7 +174,7 @@ ErrorOr<void> Toolbar::create_overflow_objects()
     m_overflow_action->set_status_tip("Show hidden toolbar actions"_string);
     m_overflow_action->set_enabled(false);
 
-    TRY(add_spacer());
+    add_spacer();
 
     m_overflow_button = TRY(try_add_action(*m_overflow_action));
     m_overflow_button->set_visible(false);

Userland/Libraries/LibGUI/Widget.cpp

@@ -1199,7 +1199,7 @@ ErrorOr<void> Widget::load_from_gml_ast(NonnullRefPtr<GUI::GML::Node const> ast,
             if (!this->layout()) {
                 return Error::from_string_literal("Specified GUI::Layout::Spacer in GML, but the parent has no Layout.");
             }
-            this->layout()->add_spacer();
+            add_spacer();
         } else {
             RefPtr<Core::EventReceiver> child;
             if (auto* registration = GUI::ObjectClassRegistration::find(class_name)) {
@@ -1259,10 +1259,10 @@ bool Widget::is_visible_for_timer_purposes() const
     return is_visible() && Object::is_visible_for_timer_purposes();
 }
 
-ErrorOr<void> Widget::add_spacer()
+void Widget::add_spacer()
 {
     VERIFY(layout());
-    return layout()->try_add_spacer();
+    return layout()->add_spacer();
 }
 
 }

Userland/Libraries/LibGUI/Widget.h

@@ -356,7 +356,7 @@ public:
     // In order for others to be able to call this, it needs to be public.
     virtual ErrorOr<void> load_from_gml_ast(NonnullRefPtr<GUI::GML::Node const> ast, UnregisteredChildHandler);
 
-    ErrorOr<void> add_spacer();
+    void add_spacer();
 
 protected:
     Widget();

Userland/Libraries/LibGUI/Wizards/WizardDialog.cpp

@@ -39,7 +39,7 @@ ErrorOr<void> WizardDialog::build()
     auto nav_container_widget = TRY(main_widget->try_add<Widget>());
     nav_container_widget->set_layout<HorizontalBoxLayout>(Margins { 0, 10 }, 0);
     nav_container_widget->set_fixed_height(42);
-    TRY(nav_container_widget->add_spacer());
+    nav_container_widget->add_spacer();
 
     m_back_button = TRY(nav_container_widget->try_add<DialogButton>("< Back"_string));
     m_back_button->on_click = [&](auto) {

Userland/Libraries/LibGUI/Wizards/WizardPage.cpp

@@ -39,7 +39,7 @@ ErrorOr<void> WizardPage::build(String title, String subtitle)
     m_subtitle_label = TRY(header_widget->try_add<Label>(move(subtitle)));
     m_subtitle_label->set_text_alignment(Gfx::TextAlignment::TopLeft);
     m_subtitle_label->set_fixed_height(m_subtitle_label->font().pixel_size_rounded_up());
-    TRY(header_widget->add_spacer());
+    header_widget->add_spacer();
 
     auto separator = TRY(try_add<SeparatorWidget>(Gfx::Orientation::Horizontal));
     separator->set_fixed_height(2);

Userland/Services/Taskbar/ClockWidget.cpp

@@ -101,7 +101,7 @@ ClockWidget::ClockWidget()
     auto& settings_container = root_container->add<GUI::Widget>();
     settings_container.set_fixed_height(24);
     settings_container.set_layout<GUI::HorizontalBoxLayout>(GUI::Margins { 2 });
-    settings_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    settings_container.add_spacer();
 
     m_jump_to_button = settings_container.add<GUI::Button>();
     m_jump_to_button->set_button_style(Gfx::ButtonStyle::Coolbar);

Userland/Services/Taskbar/ShutdownDialog.cpp

@@ -86,12 +86,12 @@ ShutdownDialog::ShutdownDialog()
         }
     }
 
-    right_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    right_container.add_spacer();
 
     auto& button_container = right_container.add<GUI::Widget>();
     button_container.set_fixed_height(23);
     button_container.set_layout<GUI::HorizontalBoxLayout>(GUI::Margins {}, 5);
-    button_container.add_spacer().release_value_but_fixme_should_propagate_errors();
+    button_container.add_spacer();
     auto& ok_button = button_container.add<GUI::Button>("OK"_string);
     ok_button.set_fixed_size(80, 23);
     ok_button.on_click = [this](auto) {