LibGUI: Add support for an alternate keyboard shortcut in Action

This patch adds the alternate_shortcut member to LibGUI::Action, which
enables one Action to have two keyboard shortcuts.

Note that the string used in menus and tooltips only shows the main
shortcut, which is the same behaviour as in Firefox and Chrome.

Userland/Libraries/LibGUI/Action.cpp

@@ -186,9 +186,19 @@ NonnullRefPtr<Action> Action::create(String text, const Shortcut& shortcut, Func
     return adopt_ref(*new Action(move(text), shortcut, move(callback), parent));
 }
 
+NonnullRefPtr<Action> Action::create(String text, const Shortcut& shortcut, const Shortcut& alternate_shortcut, Function<void(Action&)> callback, Core::Object* parent)
+{
+    return adopt_ref(*new Action(move(text), shortcut, alternate_shortcut, move(callback), parent));
+}
+
 NonnullRefPtr<Action> Action::create(String text, const Shortcut& shortcut, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> callback, Core::Object* parent)
 {
-    return adopt_ref(*new Action(move(text), shortcut, move(icon), move(callback), parent));
+    return adopt_ref(*new Action(move(text), shortcut, Shortcut {}, move(icon), move(callback), parent));
+}
+
+NonnullRefPtr<Action> Action::create(String text, const Shortcut& shortcut, const Shortcut& alternate_shortcut, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> callback, Core::Object* parent)
+{
+    return adopt_ref(*new Action(move(text), shortcut, alternate_shortcut, move(icon), move(callback), parent));
 }
 
 NonnullRefPtr<Action> Action::create_checkable(String text, Function<void(Action&)> callback, Core::Object* parent)
@@ -208,30 +218,36 @@ NonnullRefPtr<Action> Action::create_checkable(String text, const Shortcut& shor
 
 NonnullRefPtr<Action> Action::create_checkable(String text, const Shortcut& shortcut, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> callback, Core::Object* parent)
 {
-    return adopt_ref(*new Action(move(text), shortcut, move(icon), move(callback), parent, true));
+    return adopt_ref(*new Action(move(text), shortcut, Shortcut {}, move(icon), move(callback), parent, true));
 }
 
 Action::Action(String text, Function<void(Action&)> on_activation_callback, Core::Object* parent, bool checkable)
-    : Action(move(text), Shortcut {}, nullptr, move(on_activation_callback), parent, checkable)
+    : Action(move(text), Shortcut {}, Shortcut {}, nullptr, move(on_activation_callback), parent, checkable)
 {
 }
 
 Action::Action(String text, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> on_activation_callback, Core::Object* parent, bool checkable)
-    : Action(move(text), Shortcut {}, move(icon), move(on_activation_callback), parent, checkable)
+    : Action(move(text), Shortcut {}, Shortcut {}, move(icon), move(on_activation_callback), parent, checkable)
 {
 }
 
 Action::Action(String text, const Shortcut& shortcut, Function<void(Action&)> on_activation_callback, Core::Object* parent, bool checkable)
-    : Action(move(text), shortcut, nullptr, move(on_activation_callback), parent, checkable)
+    : Action(move(text), shortcut, Shortcut {}, nullptr, move(on_activation_callback), parent, checkable)
+{
+}
+
+Action::Action(String text, const Shortcut& shortcut, const Shortcut& alternate_shortcut, Function<void(Action&)> on_activation_callback, Core::Object* parent, bool checkable)
+    : Action(move(text), shortcut, alternate_shortcut, nullptr, move(on_activation_callback), parent, checkable)
 {
 }
 
-Action::Action(String text, const Shortcut& shortcut, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> on_activation_callback, Core::Object* parent, bool checkable)
+Action::Action(String text, const Shortcut& shortcut, const Shortcut& alternate_shortcut, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> on_activation_callback, Core::Object* parent, bool checkable)
     : Core::Object(parent)
     , on_activation(move(on_activation_callback))
     , m_text(move(text))
     , m_icon(move(icon))
     , m_shortcut(shortcut)
+    , m_alternate_shortcut(alternate_shortcut)
     , m_checkable(checkable)
 {
     if (parent && is<Widget>(*parent)) {

Userland/Libraries/LibGUI/Action.h

@@ -61,7 +61,9 @@ public:
     static NonnullRefPtr<Action> create(String text, Function<void(Action&)> callback, Core::Object* parent = nullptr);
     static NonnullRefPtr<Action> create(String text, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> callback, Core::Object* parent = nullptr);
     static NonnullRefPtr<Action> create(String text, const Shortcut& shortcut, Function<void(Action&)> callback, Core::Object* parent = nullptr);
+    static NonnullRefPtr<Action> create(String text, const Shortcut& shortcut, const Shortcut& alternate_shortcut, Function<void(Action&)> callback, Core::Object* parent = nullptr);
     static NonnullRefPtr<Action> create(String text, const Shortcut& shortcut, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> callback, Core::Object* parent = nullptr);
+    static NonnullRefPtr<Action> create(String text, const Shortcut& shortcut, const Shortcut& alternate_shortcut, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> callback, Core::Object* parent = nullptr);
     static NonnullRefPtr<Action> create_checkable(String text, Function<void(Action&)> callback, Core::Object* parent = nullptr);
     static NonnullRefPtr<Action> create_checkable(String text, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> callback, Core::Object* parent = nullptr);
     static NonnullRefPtr<Action> create_checkable(String text, const Shortcut& shortcut, Function<void(Action&)> callback, Core::Object* parent = nullptr);
@@ -76,6 +78,7 @@ public:
     void set_status_tip(String status_tip) { m_status_tip = move(status_tip); }
 
     Shortcut shortcut() const { return m_shortcut; }
+    Shortcut alternate_shortcut() const { return m_alternate_shortcut; }
     const Gfx::Bitmap* icon() const { return m_icon.ptr(); }
     void set_icon(const Gfx::Bitmap*);
 
@@ -113,7 +116,8 @@ public:
 private:
     Action(String, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
     Action(String, const Shortcut&, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
-    Action(String, const Shortcut&, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
+    Action(String, const Shortcut&, const Shortcut&, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
+    Action(String, const Shortcut&, const Shortcut&, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
     Action(String, RefPtr<Gfx::Bitmap> icon, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
 
     template<typename Callback>
@@ -125,6 +129,7 @@ private:
     String m_status_tip;
     RefPtr<Gfx::Bitmap> m_icon;
     Shortcut m_shortcut;
+    Shortcut m_alternate_shortcut;
     bool m_enabled { true };
     bool m_checkable { false };
     bool m_checked { false };