LibGUI: Allow GActions to be scoped either globally or widget-locally.

This makes it possible for e.g GTextEditor to create a bunch of actions
with popular shortcuts like Ctrl+C, etc, without polluting the global
shortcut namespace. Widget-local actions will only activate while their
corresponding widget has focus. :^)

LibGUI/GAction.cpp

@@ -3,44 +3,55 @@
 #include <LibGUI/GButton.h>
 #include <LibGUI/GMenuItem.h>
 
-GAction::GAction(const String& text, const String& custom_data, Function<void(const GAction&)> on_activation_callback)
+GAction::GAction(const String& text, const String& custom_data, Function<void(const GAction&)> on_activation_callback, GWidget* widget)
     : on_activation(move(on_activation_callback))
     , m_text(text)
     , m_custom_data(custom_data)
+    , m_widget(widget ? widget->make_weak_ptr() : nullptr)
 {
 }
 
-GAction::GAction(const String& text, Function<void(const GAction&)> on_activation_callback)
-    : GAction(text, String(), move(on_activation_callback))
+GAction::GAction(const String& text, Function<void(const GAction&)> on_activation_callback, GWidget* widget)
+    : GAction(text, String(), move(on_activation_callback), widget)
 {
 }
 
-GAction::GAction(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> on_activation_callback)
+GAction::GAction(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> on_activation_callback, GWidget* widget)
     : on_activation(move(on_activation_callback))
     , m_text(text)
     , m_icon(move(icon))
+    , m_widget(widget ? widget->make_weak_ptr() : nullptr)
 {
 }
 
-GAction::GAction(const String& text, const GShortcut& shortcut, Function<void(const GAction&)> on_activation_callback)
-    : GAction(text, shortcut, nullptr, move(on_activation_callback))
+GAction::GAction(const String& text, const GShortcut& shortcut, Function<void(const GAction&)> on_activation_callback, GWidget* widget)
+    : GAction(text, shortcut, nullptr, move(on_activation_callback), widget)
 {
 }
 
 
-GAction::GAction(const String& text, const GShortcut& shortcut, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> on_activation_callback)
+GAction::GAction(const String& text, const GShortcut& shortcut, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> on_activation_callback, GWidget* widget)
     : on_activation(move(on_activation_callback))
     , m_text(text)
     , m_icon(move(icon))
     , m_shortcut(shortcut)
+    , m_widget(widget ? widget->make_weak_ptr() : nullptr)
 {
-    GApplication::the().register_shortcut_action(Badge<GAction>(), *this);
+    if (m_widget) {
+        m_scope = ShortcutScope::WidgetLocal;
+        m_widget->register_local_shortcut_action(Badge<GAction>(), *this);
+    } else {
+        m_scope = ShortcutScope::ApplicationGlobal;
+        GApplication::the().register_global_shortcut_action(Badge<GAction>(), *this);
+    }
 }
 
 GAction::~GAction()
 {
-    if (m_shortcut.is_valid())
-        GApplication::the().unregister_shortcut_action(Badge<GAction>(), *this);
+    if (m_shortcut.is_valid() && m_scope == ShortcutScope::ApplicationGlobal)
+        GApplication::the().unregister_global_shortcut_action(Badge<GAction>(), *this);
+    if (m_widget && m_scope == ShortcutScope::WidgetLocal)
+        m_widget->unregister_local_shortcut_action(Badge<GAction>(), *this);
 }
 
 void GAction::activate()

LibGUI/GAction.h

@@ -5,6 +5,7 @@
 #include <AK/Retainable.h>
 #include <AK/Retained.h>
 #include <AK/Weakable.h>
+#include <AK/WeakPtr.h>
 #include <AK/Badge.h>
 #include <AK/HashTable.h>
 #include <SharedGraphics/GraphicsBitmap.h>
@@ -12,31 +13,40 @@
 
 class GButton;
 class GMenuItem;
+class GWidget;
 
 class GAction : public Retainable<GAction>, public Weakable<GAction> {
 public:
-    static Retained<GAction> create(const String& text, Function<void(const GAction&)> callback)
+    enum class ShortcutScope {
+        None,
+        ApplicationGlobal,
+        WidgetLocal,
+    };
+    static Retained<GAction> create(const String& text, Function<void(const GAction&)> callback, GWidget* widget = nullptr)
     {
-        return adopt(*new GAction(text, move(callback)));
+        return adopt(*new GAction(text, move(callback), widget));
     }
-    static Retained<GAction> create(const String& text, const String& custom_data, Function<void(const GAction&)> callback)
+    static Retained<GAction> create(const String& text, const String& custom_data, Function<void(const GAction&)> callback, GWidget* widget = nullptr)
     {
-        return adopt(*new GAction(text, custom_data, move(callback)));
+        return adopt(*new GAction(text, custom_data, move(callback), widget));
     }
-    static Retained<GAction> create(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> callback)
+    static Retained<GAction> create(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> callback, GWidget* widget = nullptr)
     {
-        return adopt(*new GAction(text, move(icon), move(callback)));
+        return adopt(*new GAction(text, move(icon), move(callback), widget));
     }
-    static Retained<GAction> create(const String& text, const GShortcut& shortcut, Function<void(const GAction&)> callback)
+    static Retained<GAction> create(const String& text, const GShortcut& shortcut, Function<void(const GAction&)> callback, GWidget* widget = nullptr)
     {
-        return adopt(*new GAction(text, shortcut, move(callback)));
+        return adopt(*new GAction(text, shortcut, move(callback), widget));
     }
-    static Retained<GAction> create(const String& text, const GShortcut& shortcut, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> callback)
+    static Retained<GAction> create(const String& text, const GShortcut& shortcut, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> callback, GWidget* widget = nullptr)
     {
-        return adopt(*new GAction(text, shortcut, move(icon), move(callback)));
+        return adopt(*new GAction(text, shortcut, move(icon), move(callback), widget));
     }
     ~GAction();
 
+    GWidget* widget() { return m_widget.ptr(); }
+    const GWidget* widget() const { return m_widget.ptr(); }
+
     String text() const { return m_text; }
     GShortcut shortcut() const { return m_shortcut; }
     String custom_data() const { return m_custom_data; }
@@ -55,11 +65,11 @@ public:
     void unregister_menu_item(Badge<GMenuItem>, GMenuItem&);
 
 private:
-    GAction(const String& text, Function<void(const GAction&)> = nullptr);
-    GAction(const String& text, const GShortcut&, Function<void(const GAction&)> = nullptr);
-    GAction(const String& text, const GShortcut&, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> = nullptr);
-    GAction(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> = nullptr);
-    GAction(const String& text, const String& custom_data = String(), Function<void(const GAction&)> = nullptr);
+    GAction(const String& text, Function<void(const GAction&)> = nullptr, GWidget* = nullptr);
+    GAction(const String& text, const GShortcut&, Function<void(const GAction&)> = nullptr, GWidget* = nullptr);
+    GAction(const String& text, const GShortcut&, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> = nullptr, GWidget* = nullptr);
+    GAction(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> = nullptr, GWidget* = nullptr);
+    GAction(const String& text, const String& custom_data = String(), Function<void(const GAction&)> = nullptr, GWidget* = nullptr);
 
     template<typename Callback> void for_each_toolbar_button(Callback);
     template<typename Callback> void for_each_menu_item(Callback);
@@ -69,8 +79,9 @@ private:
     RetainPtr<GraphicsBitmap> m_icon;
     GShortcut m_shortcut;
     bool m_enabled { true };
+    ShortcutScope m_scope { ShortcutScope::None };
 
     HashTable<GButton*> m_buttons;
     HashTable<GMenuItem*> m_menu_items;
+    WeakPtr<GWidget> m_widget;
 };
-

LibGUI/GApplication.cpp

@@ -52,20 +52,20 @@ void GApplication::set_menubar(OwnPtr<GMenuBar>&& menubar)
         m_menubar->notify_added_to_application(Badge<GApplication>());
 }
 
-void GApplication::register_shortcut_action(Badge<GAction>, GAction& action)
+void GApplication::register_global_shortcut_action(Badge<GAction>, GAction& action)
 {
-    m_shortcut_actions.set(action.shortcut(), &action);
+    m_global_shortcut_actions.set(action.shortcut(), &action);
 }
 
-void GApplication::unregister_shortcut_action(Badge<GAction>, GAction& action)
+void GApplication::unregister_global_shortcut_action(Badge<GAction>, GAction& action)
 {
-    m_shortcut_actions.remove(action.shortcut());
+    m_global_shortcut_actions.remove(action.shortcut());
 }
 
 GAction* GApplication::action_for_key_event(const GKeyEvent& event)
 {
-    auto it = m_shortcut_actions.find(GShortcut(event.modifiers(), (KeyCode)event.key()));
-    if (it == m_shortcut_actions.end())
+    auto it = m_global_shortcut_actions.find(GShortcut(event.modifiers(), (KeyCode)event.key()));
+    if (it == m_global_shortcut_actions.end())
         return nullptr;
     return (*it).value;
 }

LibGUI/GApplication.h

@@ -23,8 +23,8 @@ public:
     void set_menubar(OwnPtr<GMenuBar>&&);
     GAction* action_for_key_event(const GKeyEvent&);
 
-    void register_shortcut_action(Badge<GAction>, GAction&);
-    void unregister_shortcut_action(Badge<GAction>, GAction&);
+    void register_global_shortcut_action(Badge<GAction>, GAction&);
+    void unregister_global_shortcut_action(Badge<GAction>, GAction&);
 
     void show_tooltip(const String&, const Point& screen_location);
     void hide_tooltip();
@@ -32,7 +32,7 @@ public:
 private:
     OwnPtr<GEventLoop> m_event_loop;
     OwnPtr<GMenuBar> m_menubar;
-    HashMap<GShortcut, GAction*> m_shortcut_actions;
+    HashMap<GShortcut, GAction*> m_global_shortcut_actions;
     class TooltipWindow;
     TooltipWindow* m_tooltip_window { nullptr };
 };

LibGUI/GEventLoop.cpp

@@ -7,6 +7,7 @@
 #include <LibCore/CNotifier.h>
 #include <LibGUI/GMenu.h>
 #include <LibGUI/GDesktop.h>
+#include <LibGUI/GWidget.h>
 #include <LibC/unistd.h>
 #include <LibC/stdio.h>
 #include <LibC/fcntl.h>
@@ -124,6 +125,15 @@ void GEventLoop::handle_key_event(const WSAPI_ServerMessage& event, GWindow& win
         key_event->m_text = String(&event.key.character, 1);
 
     if (event.type == WSAPI_ServerMessage::Type::KeyDown) {
+        if (auto* focused_widget = window.focused_widget()) {
+            if (auto* action = focused_widget->action_for_key_event(*key_event)) {
+                if (action->is_enabled()) {
+                    action->activate();
+                    return;
+                }
+            }
+        }
+
         if (auto* action = GApplication::the().action_for_key_event(*key_event)) {
             if (action->is_enabled()) {
                 action->activate();

LibGUI/GTextEditor.cpp

@@ -35,27 +35,27 @@ void GTextEditor::create_actions()
 {
     m_undo_action = GAction::create("Undo", { Mod_Ctrl, Key_Z }, GraphicsBitmap::load_from_file("/res/icons/16x16/undo.png"), [&] (const GAction&) {
         // FIXME: Undo
-    });
+    }, this);
 
     m_redo_action = GAction::create("Redo", { Mod_Ctrl, Key_Y }, GraphicsBitmap::load_from_file("/res/icons/16x16/redo.png"), [&] (const GAction&) {
         // FIXME: Redo
-    });
+    }, this);
 
     m_cut_action = GAction::create("Cut", { Mod_Ctrl, Key_X }, GraphicsBitmap::load_from_file("/res/icons/cut16.png"), [&] (const GAction&) {
         cut();
-    });
+    }, this);
 
     m_copy_action = GAction::create("Copy", { Mod_Ctrl, Key_C }, GraphicsBitmap::load_from_file("/res/icons/16x16/edit-copy.png"), [&] (const GAction&) {
         copy();
-    });
+    }, this);
 
     m_paste_action = GAction::create("Paste", { Mod_Ctrl, Key_V }, GraphicsBitmap::load_from_file("/res/icons/paste16.png"), [&] (const GAction&) {
         paste();
-    });
+    }, this);
 
     m_delete_action = GAction::create("Delete", { 0, Key_Delete }, GraphicsBitmap::load_from_file("/res/icons/16x16/delete.png"), [&] (const GAction&) {
         do_delete();
-    });
+    }, this);
 }
 
 void GTextEditor::set_text(const String& text)

LibGUI/GWidget.cpp

@@ -5,6 +5,7 @@
 #include <LibGUI/GLayout.h>
 #include <AK/Assertions.h>
 #include <SharedGraphics/GraphicsBitmap.h>
+#include <LibGUI/GAction.h>
 #include <LibGUI/GPainter.h>
 #include <LibGUI/GApplication.h>
 #include <LibGUI/GMenu.h>
@@ -487,3 +488,21 @@ bool GWidget::is_backmost() const
         return true;
     return parent->children().first() == this;
 }
+
+GAction* GWidget::action_for_key_event(const GKeyEvent& event)
+{
+    auto it = m_local_shortcut_actions.find(GShortcut(event.modifiers(), (KeyCode)event.key()));
+    if (it == m_local_shortcut_actions.end())
+        return nullptr;
+    return (*it).value;
+}
+
+void GWidget::register_local_shortcut_action(Badge<GAction>, GAction& action)
+{
+    m_local_shortcut_actions.set(action.shortcut(), &action);
+}
+
+void GWidget::unregister_local_shortcut_action(Badge<GAction>, GAction& action)
+{
+    m_local_shortcut_actions.remove(action.shortcut());
+}

LibGUI/GWidget.h

@@ -2,14 +2,17 @@
 
 #include <LibCore/CElapsedTimer.h>
 #include <LibGUI/GEvent.h>
+#include <LibGUI/GShortcut.h>
 #include <LibCore/CObject.h>
 #include <SharedGraphics/Rect.h>
 #include <SharedGraphics/Color.h>
 #include <SharedGraphics/Font.h>
 #include <AK/Badge.h>
 #include <AK/AKString.h>
+#include <AK/HashMap.h>
 
 class GraphicsBitmap;
+class GAction;
 class GLayout;
 class GMenu;
 class GWindow;
@@ -172,6 +175,11 @@ public:
     bool is_frontmost() const;
     bool is_backmost() const;
 
+    GAction* action_for_key_event(const GKeyEvent&);
+
+    void register_local_shortcut_action(Badge<GAction>, GAction&);
+    void unregister_local_shortcut_action(Badge<GAction>, GAction&);
+
 private:
     virtual bool is_widget() const final { return true; }
 
@@ -203,4 +211,6 @@ private:
     bool m_layout_dirty { false };
 
     CElapsedTimer m_click_clock;
+
+    HashMap<GShortcut, GAction*> m_local_shortcut_actions;
 };