[render] EventDrawer prepared to request to block event propagation

cnr-isti-vclab · Jan 9, 2025 · 628c83a · 628c83a
1 parent a6a6ea3
commit 628c83a
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Showing 4 changed files with 159 additions and 15 deletions.
diff --git a/tests/render/000-static-asserts/drawers.h b/tests/render/000-static-asserts/drawers.h
@@ -75,15 +75,15 @@ void drawersStaticAsserts()
     static_assert(
         !EventDrawerConcept<PlainDrawer<RendererTypePD>>,
         "PlainDrawer does satisfy the EventDrawerConcept");
-    // static_assert(
-    //     !EventDrawerConcept<const PlainDrawer<RendererTypePD>>,
-    //     "const PlainDrawer does satisfy the EventDrawerConcept");
+    static_assert(
+        !EventDrawerConcept<const PlainDrawer<RendererTypePD>>,
+        "const PlainDrawer does satisfy the EventDrawerConcept");
     static_assert(
         !EventDrawerConcept<PlainDrawer<RendererTypePD>&>,
         "PlainDrawer& does satisfy the EventDrawerConcept");
-    // static_assert(
-    //     !EventDrawerConcept<const PlainDrawer<RendererTypePD>&>,
-    //     "const PlainDrawer& does satisfy the EventDrawerConcept");
+    static_assert(
+        !EventDrawerConcept<const PlainDrawer<RendererTypePD>&>,
+        "const PlainDrawer& does satisfy the EventDrawerConcept");
     static_assert(
         !EventDrawerConcept<PlainDrawer<RendererTypePD>&&>,
         "PlainDrawer&& does satisfy the EventDrawerConcept");
@@ -174,15 +174,15 @@ void drawersStaticAsserts()
     static_assert(
         !EventDrawerConcept<TextDrawer<RendererTypeTD>>,
         "TextDrawer does satisfy the EventDrawerConcept");
-    // static_assert(
-    //     !EventDrawerConcept<const TextDrawer<RendererTypeTD>>,
-    //     "const TextDrawer does satisfy the EventDrawerConcept");
+    static_assert(
+        !EventDrawerConcept<const TextDrawer<RendererTypeTD>>,
+        "const TextDrawer does satisfy the EventDrawerConcept");
     static_assert(
         !EventDrawerConcept<TextDrawer<RendererTypeTD>&>,
         "TextDrawer& does satisfy the EventDrawerConcept");
-    // static_assert(
-    //     !EventDrawerConcept<const TextDrawer<RendererTypeTD>&>,
-    //     "const TextDrawer& does satisfy the EventDrawerConcept");
+    static_assert(
+        !EventDrawerConcept<const TextDrawer<RendererTypeTD>&>,
+        "const TextDrawer& does satisfy the EventDrawerConcept");
     static_assert(
         !EventDrawerConcept<TextDrawer<RendererTypeTD>&&>,
         "TextDrawer&& does satisfy the EventDrawerConcept");

diff --git a/vclib/render/include/vclib/imgui/imgui_drawer.h b/vclib/render/include/vclib/imgui/imgui_drawer.h
@@ -41,7 +41,7 @@
 namespace vcl::imgui {
 
 template<typename DerivedRenderer>
-class ImguiDrawer : public EventDrawer<DerivedRenderer>
+class ImguiDrawer : public EventDrawer<DerivedRenderer, true>
 {
 protected:
     using DRT = DerivedRenderer;

diff --git a/vclib/render/include/vclib/render/concepts/event_drawer.h b/vclib/render/include/vclib/render/concepts/event_drawer.h
@@ -30,7 +30,9 @@
 namespace vcl {
 
 template<typename T>
-concept EventDrawerConcept = DrawerConcept<T> && requires (T&& obj) {
+concept CantBlockEventDrawerConcept = DrawerConcept<T> && requires (T&& obj) {
+    requires RemoveRef<T>::CAN_BLOCK_EVENT_PROPAGATION == false;
+
     // non const requirements
     requires IsConst<T> || requires {
         { obj.onKeyPress(Key::Enum(), KeyModifiers()) } -> std::same_as<void>;
@@ -56,6 +58,39 @@ concept EventDrawerConcept = DrawerConcept<T> && requires (T&& obj) {
     };
 };
 
+template<typename T>
+concept CanBlockEventDrawerConcept = DrawerConcept<T> && requires (T&& obj) {
+    requires RemoveRef<T>::CAN_BLOCK_EVENT_PROPAGATION == true;
+
+    // non const requirements
+    requires IsConst<T> || requires {
+        { obj.onKeyPress(Key::Enum(), KeyModifiers()) } -> std::same_as<bool>;
+        { obj.onKeyRelease(Key::Enum(), KeyModifiers()) } -> std::same_as<bool>;
+        {
+            obj.onMouseMove(double(), double(), KeyModifiers())
+        } -> std::same_as<bool>;
+        {
+            obj.onMousePress(
+                MouseButton::Enum(), double(), double(), KeyModifiers())
+        } -> std::same_as<bool>;
+        {
+            obj.onMouseRelease(
+                MouseButton::Enum(), double(), double(), KeyModifiers())
+        } -> std::same_as<bool>;
+        {
+            obj.onMouseDoubleClick(
+                MouseButton::Enum(), double(), double(), KeyModifiers())
+        } -> std::same_as<bool>;
+        {
+            obj.onMouseScroll(double(), double(), KeyModifiers())
+        } -> std::same_as<bool>;
+    };
+};
+
+template<typename T>
+concept EventDrawerConcept =
+    CanBlockEventDrawerConcept<T> || CantBlockEventDrawerConcept<T>;
+
 } // namespace vcl
 
 #endif // CONCEPTS_EVENT_DRAWER_H
diff --git a/vclib/render/include/vclib/render/drawers/event_drawer.h b/vclib/render/include/vclib/render/drawers/event_drawer.h
@@ -29,10 +29,44 @@
 
 namespace vcl {
 
+/**
+ * @brief The EventDrawer class is a base class for all drawers that handle
+ * events.
+ *
+ * The EventDrawer class is a CRTP class that is templated on the derived
+ * renderer class. It provides the interface for handling events produced by the
+ * DerivedRenderer class.
+ *
+ * The EventDrawer class is specialized for two cases:
+ * - CAN_BLOCK_EVENT_PROPAGATION = false: The drawer cannot request to block the
+ *   event propagation. All the event functions do not return any value. @see
+ *   EventDrawer<DerivedRenderer, false>.
+ * - CAN_BLOCK_EVENT_PROPAGATION = true: The drawer can request to block the
+ *   event propagation. All the event functions return a boolean value that
+ *   indicates if the event propagation is blocked. @see
+ *   EventDrawer<DerivedRenderer, true>.
+ *
+ * @tparam DerivedRenderer The type of the derived renderer class.
+ * @tparam CAN_BLOCK_EVENT_PROPAGATION: A boolean flag that indicates if the
+ * drawer can request to block the event propagation.
+ */
+template<typename, bool CAN_BLOCK_EVENT_PROPAGATION = false>
+class EventDrawer
+{
+};
+
+/**
+ * @brief Default specialization of the EventDrawer class for the case where the
+ * drawer cannot request to block the event propagation.
+ *
+ * @tparam DerivedRenderer The type of the derived renderer class.
+ */
 template<typename DerivedRenderer>
-class EventDrawer : public PlainDrawer<DerivedRenderer>
+class EventDrawer<DerivedRenderer, false> : public PlainDrawer<DerivedRenderer>
 {
 public:
+    static const bool CAN_BLOCK_EVENT_PROPAGATION = false;
+
     EventDrawer() = default;
 
     EventDrawer(uint, uint) {}
@@ -77,6 +111,81 @@ class EventDrawer : public PlainDrawer<DerivedRenderer>
     }
 };
 
+/**
+ * @brief Specialization of the EventDrawer class for the case where the drawer
+ * can request to block the event propagation.
+ *
+ * A drawer that inherits from this class can request to block the event
+ * propagation, and (if requested) the event will not be propagated to the other
+ * drawer arguments of the Renderer class.
+ *
+ * All the event functions of this class return a boolean value. If the function
+ * returns true, the DerivedRenderer will block event propagation to other
+ * drawers; otherwise, the event is propagated to the other drawers.
+ *
+ * @tparam DerivedRenderer The type of the derived renderer class.
+ */
+template<typename DerivedRenderer>
+class EventDrawer<DerivedRenderer, true> : public PlainDrawer<DerivedRenderer>
+{
+public:
+    static const bool CAN_BLOCK_EVENT_PROPAGATION = true;
+
+    EventDrawer() = default;
+
+    EventDrawer(uint, uint) {}
+
+    virtual bool onKeyPress(Key::Enum key, const KeyModifiers& modifiers)
+    {
+        return false;
+    }
+
+    virtual bool onKeyRelease(Key::Enum key, const KeyModifiers& modifiers)
+    {
+        return false;
+    }
+
+    virtual bool onMouseMove(double x, double y, const KeyModifiers& modifiers)
+    {
+        return false;
+    }
+
+    virtual bool onMousePress(
+        MouseButton::Enum   button,
+        double              x,
+        double              y,
+        const KeyModifiers& modifiers)
+    {
+        return false;
+    }
+
+    virtual bool onMouseRelease(
+        MouseButton::Enum   button,
+        double              x,
+        double              y,
+        const KeyModifiers& modifiers)
+    {
+        return false;
+    }
+
+    virtual bool onMouseDoubleClick(
+        MouseButton::Enum   button,
+        double              x,
+        double              y,
+        const KeyModifiers& modifiers)
+    {
+        return false;
+    }
+
+    virtual bool onMouseScroll(
+        double              x,
+        double              y,
+        const KeyModifiers& modifiers)
+    {
+        return false;
+    }
+};
+
 } // namespace vcl
 
 #endif // EVENT_DRAWER_H