xholder_shared implementation (#149)

xholder_shared implementation
jupyter-xeus · Jul 9, 2018 · fdc9a74 · fdc9a74
1 parent 6c7db5f
commit fdc9a74
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diff --git a/include/xwidgets/xholder.hpp b/include/xwidgets/xholder.hpp
@@ -9,6 +9,7 @@
 #ifndef XWIDGETS_HOLDER_HPP
 #define XWIDGETS_HOLDER_HPP
 
+#include <memory>
 #include <stdexcept>
 #include <unordered_map>
 #include <utility>
@@ -90,6 +91,12 @@ namespace xw
     template <template <class> class CRTP>
     xholder<CRTP> make_id_holder(xeus::xguid id);
 
+    template <template <class> class CRTP, class D, class... Args>
+    xholder<CRTP> make_shared_holder(Args&&... args);
+
+    template <template <class> class CRTP, class D>
+    xholder<CRTP> make_shared_holder(CRTP<D>* ptr);
+
     /*************************************
      * to_json and from_json declaration *
      *************************************/
@@ -487,6 +494,10 @@ namespace xw
         return it->second;
     }
 
+    /*****************************
+     * xholder_id implementation *
+     *****************************/
+
     namespace detail
     {
         template <template <class> class CRTP>
@@ -547,6 +558,78 @@ namespace xw
         return xholder<CRTP>(new detail::xholder_id<CRTP>(id));
     }
 
+    /*********************************
+     * xholder_shared implementation *
+     *********************************/
+
+    namespace detail
+    {
+        template <template <class> class CRTP, class D>
+        class xholder_shared : public xholder_impl<CRTP>
+        {
+        public:
+
+            using base_type = xholder_impl<CRTP>;
+            using pointer = std::shared_ptr<D>;
+
+            xholder_shared(pointer ptr)
+                : base_type(),
+                  p_value(ptr)
+            {
+            }
+
+            xholder_shared(CRTP<D>* ptr)
+                : base_type(),
+                  p_value(&(ptr->derived_cast()))
+            {
+            }
+
+            virtual ~xholder_shared() = default;
+            virtual base_type* clone() const override
+            {
+                return new xholder_shared(*this);
+            }
+
+            virtual void display() const override
+            {
+                p_value->display();
+            }
+
+            virtual xeus::xguid id() const override
+            {
+                return p_value->id();
+            }
+
+            virtual xtl::any value() & override
+            {
+                return xtl::closure(*p_value);
+            }
+
+            virtual const xtl::any value() const & override
+            {
+                return xtl::closure(*p_value);
+            }
+
+        private:
+
+            pointer p_value;
+        };
+    }
+
+    template <template <class> class CRTP, class D, class... Args>
+    inline xholder<CRTP> make_shared_holder(Args&&... args)
+    {
+        using impl_type = detail::xholder_shared<CRTP, D>;
+        return xholder<CRTP>(new impl_type(std::make_shared<D>(std::forward<Args>(args)...)));
+    }
+
+    template <template <class> class CRTP, class D>
+    inline xholder<CRTP> make_shared_holder(CRTP<D>* ptr)
+    {
+        using impl_type = detail::xholder_shared<CRTP, D>;
+        return xholder<CRTP>(new impl_type(ptr));
+    }
+
     /**********************************************************
      * Specialization of mime_bundle_repr for Jupyter Widgets *
      **********************************************************/

diff --git a/test/test_xholder.cpp b/test/test_xholder.cpp
@@ -25,4 +25,72 @@ namespace xw
         std::string res = hm["x"].template get<button>().description();
         ASSERT_EQ(desc, res);
     }
+
+    class button_tester : public xwidget<button_tester>
+    {
+    public:
+
+        button_tester(int value = 0)
+            : m_value(value)
+        {
+            ++m_instance_count;
+        }
+
+        ~button_tester()
+        {
+            --m_instance_count;
+        }
+
+        button_tester(const button_tester& rhs)
+            : m_value(rhs.m_value)
+        {
+            ++m_instance_count;
+        }
+
+        button_tester(button_tester&& rhs)
+            : m_value(rhs.m_value)
+        {
+            ++m_instance_count;
+        }
+
+        button_tester& operator=(const button_tester&) = default;
+        button_tester& operator=(button_tester&&) = default;
+
+        int value() const { return m_value; }
+
+        static int instance_count() { return m_instance_count; }
+
+    private:
+
+        int m_value;
+        static int m_instance_count;
+    };
+
+    int button_tester::m_instance_count = 0;
+
+    TEST(xholder, shared)
+    {
+        using map_type = std::map<std::string, xholder<xwidget>>;
+        map_type hm1, hm2;
+        button_tester* b = new button_tester;
+        hm1["x"] = make_shared_holder<xwidget>(b);
+        hm2["x"] = hm1["x"];
+        ASSERT_EQ(hm1["x"].id(), hm2["x"].id());
+        ASSERT_EQ(button_tester::instance_count(), 1);
+
+        hm1["y"] = make_shared_holder<xwidget, button_tester>(4);;
+        hm2["y"] = hm1["y"];
+        ASSERT_EQ(hm1["y"].template get<button_tester>().value(), hm2["y"].template get<button_tester>().value());
+        ASSERT_EQ(button_tester::instance_count(), 2);
+
+        hm1.erase("x");
+        ASSERT_EQ(button_tester::instance_count(), 2);
+        hm2.erase("x");
+        ASSERT_EQ(button_tester::instance_count(), 1);
+
+        hm1.erase("y");
+        ASSERT_EQ(button_tester::instance_count(), 1);
+        hm2.erase("y");
+        ASSERT_EQ(button_tester::instance_count(), 0);
+    }
 }