LibGUI: Add ability to hide GUI::TabWidget's tab bar

Libraries/LibGUI/TabWidget.cpp

@@ -147,6 +147,9 @@ Gfx::Rect TabWidget::container_rect() const
 
 void TabWidget::paint_event(PaintEvent& event)
 {
+    if (!m_bar_visible)
+        return;
+
     Painter painter(*this);
     painter.add_clip_rect(event.rect());
 
@@ -206,6 +209,14 @@ int TabWidget::uniform_tab_width() const
     return max(tab_width, minimum_tab_width);
 }
 
+void TabWidget::set_bar_visible(bool bar_visible)
+{
+    m_bar_visible = bar_visible;
+    if (m_active_widget)
+        m_active_widget->set_relative_rect(child_rect_for_size(size()));
+    update_bar();
+}
+
 Gfx::Rect TabWidget::button_rect(int index) const
 {
     int x_offset = 2;
@@ -346,7 +357,7 @@ void TabWidget::activate_previous_tab()
     set_active_widget(m_tabs.at(index).widget);
 }
 
-void TabWidget::keydown_event(KeyEvent & event)
+void TabWidget::keydown_event(KeyEvent& event)
 {
     if (event.ctrl() && event.key() == Key_Tab) {
         if (event.shift())

Libraries/LibGUI/TabWidget.h

@@ -49,7 +49,7 @@ public:
     const Widget* active_widget() const { return m_active_widget.ptr(); }
     void set_active_widget(Widget*);
 
-    int bar_height() const { return 21; }
+    int bar_height() const { return m_bar_visible ? 21 : 0; }
 
     int container_padding() const { return m_container_padding; }
     void set_container_padding(int padding) { m_container_padding = padding; }
@@ -79,6 +79,9 @@ public:
     void set_uniform_tabs(bool uniform_tabs) { m_uniform_tabs = uniform_tabs; }
     int uniform_tab_width() const;
 
+    void set_bar_visible(bool bar_visible);
+    bool is_bar_visible() const { return m_bar_visible; };
+
     Function<void(Widget&)> on_change;
     Function<void(Widget&)> on_middle_click;
 
@@ -114,6 +117,7 @@ private:
     int m_container_padding { 2 };
     Gfx::TextAlignment m_text_alignment { Gfx::TextAlignment::Center };
     bool m_uniform_tabs { false };
+    bool m_bar_visible { true };
 };
 
 }