LibGUI: Add TabWidget::activate_last_tab()

Userland/Libraries/LibGUI/TabWidget.cpp

@@ -592,6 +592,14 @@ void TabWidget::activate_previous_tab()
     set_active_widget(m_tabs.at(previous_index).widget);
 }
 
+void TabWidget::activate_last_tab()
+{
+    size_t number_of_tabs = m_tabs.size();
+    if (number_of_tabs == 0)
+        return;
+    set_active_widget(m_tabs.at(number_of_tabs - 1).widget);
+}
+
 void TabWidget::keydown_event(KeyEvent& event)
 {
     if (event.ctrl() && event.key() == Key_Tab) {

Userland/Libraries/LibGUI/TabWidget.h

@@ -66,6 +66,7 @@ public:
 
     void activate_next_tab();
     void activate_previous_tab();
+    void activate_last_tab();
 
     void set_text_alignment(Gfx::TextAlignment alignment) { m_text_alignment = alignment; }
     Gfx::TextAlignment text_alignment() const { return m_text_alignment; }