From 571c4d3fb81a64199f94412c078f7dbe6c992236 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Mon, 9 Dec 2019 21:25:48 +0100
Subject: [PATCH] LibGUI: Allow finding the source of a GAction activation

When a GAction is activated by a menu, or by a toolbar button, you can
now use GAction::activator() to get a pointer to whomever activated it.

This can be used to implement context-specific behaviors in situations
where the same action is exposed through multiple paths.

This addresses an issue that was brought up in #826.
---
 Libraries/LibGUI/GAction.cpp                 | 5 ++++-
 Libraries/LibGUI/GAction.h                   | 6 +++++-
 Libraries/LibGUI/GButton.cpp                 | 2 +-
 Libraries/LibGUI/GWindowServerConnection.cpp | 2 +-
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/Libraries/LibGUI/GAction.cpp b/Libraries/LibGUI/GAction.cpp
index a8ba924488d..d62ba660e9d 100644
--- a/Libraries/LibGUI/GAction.cpp
+++ b/Libraries/LibGUI/GAction.cpp
@@ -127,10 +127,13 @@ GAction::~GAction()
         m_widget->unregister_local_shortcut_action({}, *this);
 }
 
-void GAction::activate()
+void GAction::activate(CObject* activator)
 {
+    if (activator)
+        m_activator = activator->make_weak_ptr();
     if (on_activation)
         on_activation(*this);
+    m_activator = nullptr;
 }
 
 void GAction::register_button(Badge<GButton>, GButton& button)
diff --git a/Libraries/LibGUI/GAction.h b/Libraries/LibGUI/GAction.h
index 285df968dba..58cf4a7c10e 100644
--- a/Libraries/LibGUI/GAction.h
+++ b/Libraries/LibGUI/GAction.h
@@ -69,9 +69,12 @@ public:
     const GraphicsBitmap* icon() const { return m_icon.ptr(); }
     void set_icon(const GraphicsBitmap* icon) { m_icon = icon; }
 
+    const CObject* activator() const { return m_activator.ptr(); }
+    CObject* activator() { return m_activator.ptr(); }
+
     Function<void(GAction&)> on_activation;
 
-    void activate();
+    void activate(CObject* activator = nullptr);
 
     bool is_enabled() const { return m_enabled; }
     void set_enabled(bool);
@@ -117,4 +120,5 @@ private:
     HashTable<GMenuItem*> m_menu_items;
     WeakPtr<GWidget> m_widget;
     WeakPtr<GActionGroup> m_action_group;
+    WeakPtr<CObject> m_activator;
 };
diff --git a/Libraries/LibGUI/GButton.cpp b/Libraries/LibGUI/GButton.cpp
index 1170f35ffd8..c35bbdbb6f0 100644
--- a/Libraries/LibGUI/GButton.cpp
+++ b/Libraries/LibGUI/GButton.cpp
@@ -69,7 +69,7 @@ void GButton::click()
     if (on_click)
         on_click(*this);
     if (m_action)
-        m_action->activate();
+        m_action->activate(this);
 }
 
 bool GButton::supports_keyboard_activation() const
diff --git a/Libraries/LibGUI/GWindowServerConnection.cpp b/Libraries/LibGUI/GWindowServerConnection.cpp
index aba2bcdba5b..4867d84954d 100644
--- a/Libraries/LibGUI/GWindowServerConnection.cpp
+++ b/Libraries/LibGUI/GWindowServerConnection.cpp
@@ -209,7 +209,7 @@ void GWindowServerConnection::handle(const WindowClient::MenuItemActivated& mess
         return;
     }
     if (auto* action = menu->action_at(message.identifier()))
-        action->activate();
+        action->activate(menu);
 }
 
 void GWindowServerConnection::handle(const WindowClient::WM_WindowStateChanged& message)