LibGUI: Put a governor on Action activation

Many actions affect Window modality, so let's put a temporary change
governor on activation to stop race conditions.

Fixes being able to spam open/close shortcuts and spawn multiple
FilePickers, among other things.

2 files changed, 9 insertions, 1 deletions

diff --git a/Userland/Libraries/LibGUI/Action.cpp b/Userland/Libraries/LibGUI/Action.cpp
index e55dddc1cf..07de87bccb 100644
--- a/Userland/Libraries/LibGUI/Action.cpp
+++ b/Userland/Libraries/LibGUI/Action.cpp
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/TemporaryChange.h>
 #include <LibGUI/Action.h>
 #include <LibGUI/ActionGroup.h>
 #include <LibGUI/Application.h>
@@ -132,7 +133,7 @@ Action::~Action()
 
 void Action::process_event(Window& window, Event& event)
 {
-    if (is_enabled() && is_visible()) {
+    if (is_enabled() && is_visible() && !is_activating()) {
         flash_menubar_menu(window);
         activate();
         event.accept();
@@ -148,6 +149,10 @@ void Action::process_event(Window& window, Event& event)
 
 void Action::activate(Core::Object* activator)
 {
+    if (is_activating())
+        return;
+    TemporaryChange change { m_activating, true };
+
     if (!on_activation)
         return;
 
diff --git a/Userland/Libraries/LibGUI/Action.h b/Userland/Libraries/LibGUI/Action.h
index f876f0371f..a61c765d05 100644
--- a/Userland/Libraries/LibGUI/Action.h
+++ b/Userland/Libraries/LibGUI/Action.h
@@ -121,6 +121,8 @@ public:
     }
     void set_checked(bool);
 
+    bool is_activating() const { return m_activating; }
+
     bool swallow_key_event_when_disabled() const { return m_swallow_key_event_when_disabled; }
     void set_swallow_key_event_when_disabled(bool swallow) { m_swallow_key_event_when_disabled = swallow; }
 
@@ -157,6 +159,7 @@ private:
     bool m_checkable { false };
     bool m_checked { false };
     bool m_swallow_key_event_when_disabled { false };
+    bool m_activating { false };
     ShortcutScope m_scope { ShortcutScope::None };
 
     HashTable<Button*> m_buttons;