Invader sample: Clean up event listeners, see #605

mikke89 · Mar 31, 2024 · 386820b · 386820b
1 parent 0c030e4
commit 386820b
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Showing 4 changed files with 32 additions and 6 deletions.
diff --git a/Samples/invaders/src/ElementGame.cpp b/Samples/invaders/src/ElementGame.cpp
@@ -100,3 +100,15 @@ void ElementGame::OnChildAdd(Rml::Element* element)
 		GetOwnerDocument()->AddEventListener(Rml::EventId::Keyup, this);
 	}
 }
+
+void ElementGame::OnChildRemove(Rml::Element* element)
+{
+	Rml::Element::OnChildRemove(element);
+
+	if (element == this)
+	{
+		GetOwnerDocument()->RemoveEventListener(Rml::EventId::Load, this);
+		GetOwnerDocument()->RemoveEventListener(Rml::EventId::Keydown, this);
+		GetOwnerDocument()->RemoveEventListener(Rml::EventId::Keyup, this);
+	}
+}
diff --git a/Samples/invaders/src/ElementGame.h b/Samples/invaders/src/ElementGame.h
@@ -46,11 +46,12 @@ class ElementGame : public Rml::Element, public Rml::EventListener {
 	/// Intercepts and handles key events.
 	void ProcessEvent(Rml::Event& event) override;
 
-	/// Receive notifications when child elements are added
-	/// This will only get called when we're added to the tree,
-	/// which allows us to bind to onload
+	/// This will get called when we're added to the tree, which allows us to bind to events.
 	void OnChildAdd(Rml::Element* element) override;
 
+	/// This will get called when we're removed from the tree, which allows us to clean up the event listeners previously added.
+	void OnChildRemove(Element* element) override;
+
 protected:
 	/// Updates the game.
 	void OnUpdate() override;

diff --git a/Samples/luainvaders/src/ElementGame.cpp b/Samples/luainvaders/src/ElementGame.cpp
@@ -103,3 +103,15 @@ void ElementGame::OnChildAdd(Rml::Element* element)
 		GetOwnerDocument()->AddEventListener(Rml::EventId::Keyup, this);
 	}
 }
+
+void ElementGame::OnChildRemove(Rml::Element* element)
+{
+	Rml::Element::OnChildRemove(element);
+
+	if (element == this)
+	{
+		GetOwnerDocument()->RemoveEventListener(Rml::EventId::Load, this);
+		GetOwnerDocument()->RemoveEventListener(Rml::EventId::Keydown, this);
+		GetOwnerDocument()->RemoveEventListener(Rml::EventId::Keyup, this);
+	}
+}
diff --git a/Samples/luainvaders/src/ElementGame.h b/Samples/luainvaders/src/ElementGame.h
@@ -46,11 +46,12 @@ class ElementGame : public Rml::Element, public Rml::EventListener {
 	/// Intercepts and handles key events.
 	void ProcessEvent(Rml::Event& event) override;
 
-	/// Receive notifications when child elements are added
-	/// This will only get called when we're added to the tree,
-	/// which allows us to bind to onload
+	/// This will get called when we're added to the tree, which allows us to bind to events.
 	void OnChildAdd(Rml::Element* element) override;
 
+	/// This will get called when we're removed from the tree, which allows us to clean up the event listeners previously added.
+	void OnChildRemove(Element* element) override;
+
 protected:
 	/// Updates the game.
 	void OnUpdate() override;