Component: Ensure that mouseEnter and mouseExit calls are balanced when entering/leaving modal state

modules/juce_gui_basics/components/juce_Component.cpp

@@ -470,6 +470,24 @@ struct Component::ComponentHelpers
         for (auto* child : c.childComponentList)
             releaseAllCachedImageResources (*child);
     }
+
+    //==============================================================================
+    static bool modalWouldBlockComponent (const Component& maybeBlocked, Component* modal)
+    {
+        return modal != nullptr
+            && modal != &maybeBlocked
+            && ! modal->isParentOf (&maybeBlocked)
+            && ! modal->canModalEventBeSentToComponent (&maybeBlocked);
+    }
+
+    template <typename Function>
+    static void sendMouseEventToComponentsThatAreBlockedByModal (Component& modal, Function&& function)
+    {
+        for (auto& ms : Desktop::getInstance().getMouseSources())
+            if (auto* c = ms.getComponentUnderMouse())
+                if (modalWouldBlockComponent (*c, &modal))
+                    (c->*function) (ms, ms.getScreenPosition(), Time::getCurrentTime());
+    }
 };
 
 //==============================================================================
@@ -1720,6 +1738,11 @@ void Component::enterModalState (bool shouldTakeKeyboardFocus,
 
     if (! isCurrentlyModal (false))
     {
+        // While this component is in modal state it may block other components from receiving
+        // mouseExit events. To keep mouseEnter and mouseExit calls balanced on these components,
+        // we must manually force the mouse to "leave" blocked components.
+        ComponentHelpers::sendMouseEventToComponentsThatAreBlockedByModal (*this, &Component::internalMouseExit);
+
         auto& mcm = *ModalComponentManager::getInstance();
         mcm.startModal (this, deleteWhenDismissed);
         mcm.attachCallback (this, callback);
@@ -1746,10 +1769,10 @@ void Component::exitModalState (int returnValue)
             mcm.endModal (this, returnValue);
             mcm.bringModalComponentsToFront();
 
-            // If any of the mouse sources are over another Component when we exit the modal state then send a mouse enter event
-            for (auto& ms : Desktop::getInstance().getMouseSources())
-                if (auto* c = ms.getComponentUnderMouse())
-                    c->internalMouseEnter (ms, ms.getScreenPosition(), Time::getCurrentTime());
+            // While this component is in modal state it may block other components from receiving
+            // mouseEnter events. To keep mouseEnter and mouseExit calls balanced on these components,
+            // we must manually force the mouse to "enter" blocked components.
+            ComponentHelpers::sendMouseEventToComponentsThatAreBlockedByModal (*this, &Component::internalMouseEnter);
         }
         else
         {
@@ -1772,10 +1795,7 @@ bool Component::isCurrentlyModal (bool onlyConsiderForemostModalComponent) const
 
 bool Component::isCurrentlyBlockedByAnotherModalComponent() const
 {
-    auto* mc = getCurrentlyModalComponent();
-
-    return ! (mc == nullptr || mc == this || mc->isParentOf (this)
-               || mc->canModalEventBeSentToComponent (this));
+    return ComponentHelpers::modalWouldBlockComponent (*this, getCurrentlyModalComponent());
 }
 
 int JUCE_CALLTYPE Component::getNumCurrentlyModalComponents() noexcept