Added a method to create a ModalCallbackFunction from a lambda function

modules/juce_gui_basics/components/juce_ModalComponentManager.cpp

@@ -245,6 +245,7 @@ bool ModalComponentManager::cancelAllModalComponents()
     return numModal > 0;
 }
 
+//==============================================================================
 #if JUCE_MODAL_LOOPS_PERMITTED
 class ModalComponentManager::ReturnValueRetriever     : public ModalComponentManager::Callback
 {
@@ -292,3 +293,21 @@ int ModalComponentManager::runEventLoopForCurrentComponent()
     return returnValue;
 }
 #endif
+
+//==============================================================================
+#if JUCE_COMPILER_SUPPORTS_LAMBDAS
+struct LambdaCallback  : public ModalComponentManager::Callback
+{
+    LambdaCallback (std::function<void(int)> fn) noexcept : function (fn) {}
+    void modalStateFinished (int result) override  { function (result); }
+
+    std::function<void(int)> function;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (LambdaCallback)
+};
+
+ModalComponentManager::Callback* ModalCallbackFunction::create (std::function<void(int)> f)
+{
+    return new LambdaCallback (f);
+}
+#endif

modules/juce_gui_basics/components/juce_ModalComponentManager.h

@@ -187,6 +187,17 @@ public:
         return new FunctionCaller1<ParamType> (functionToCall, parameterValue);
     }
 
+   #if JUCE_COMPILER_SUPPORTS_LAMBDAS
+    /** This is a utility function to create a ModalComponentManager::Callback that will
+        call a lambda function.
+        The lambda that you supply must take an integer parameter, which is the result code that
+        was returned when the modal component was dismissed.
+
+        @see ModalComponentManager::Callback
+    */
+    static ModalComponentManager::Callback* create (std::function<void(int)>);
+   #endif
+
     //==============================================================================
     /** This is a utility function to create a ModalComponentManager::Callback that will
         call a static function with two custom parameters.