Added an event handler for when the user selects an overlay rectangle.

dlib/gui_widgets/widgets.cpp

@@ -5922,6 +5922,8 @@ namespace dlib
             {
                 rect_is_selected = true;
                 selected_rect = best_idx;
+                if (orect_selected_event_handler.is_set())
+                    orect_selected_event_handler(overlay_rects[best_idx]);
             }
 
             if (rect_is_selected || rect_was_selected)

dlib/gui_widgets/widgets.h

@@ -3341,6 +3341,26 @@ namespace dlib
             event_handler = event_handler_;
         }
 
+        template <
+            typename T
+            >
+        void set_overlay_rect_selected_handler (
+            T& object,
+            void (T::*event_handler_)(const overlay_rect& orect)
+        )
+        {
+            auto_mutex M(m);
+            orect_selected_event_handler = make_mfp(object,event_handler_);
+        }
+
+        void set_overlay_rects_changed_handler (
+            const any_function<void(const overlay_rect& orect)>& event_handler_
+        )
+        {
+            auto_mutex M(m);
+            orect_selected_event_handler = event_handler_;
+        }
+
 
     private:
 
@@ -3402,6 +3422,7 @@ namespace dlib
         rgb_alpha_pixel default_rect_color;
         std::string default_rect_label;
         any_function<void()> event_handler;
+        any_function<void(const overlay_rect& orect)> orect_selected_event_handler;
 
         // restricted functions
         image_display(image_display&);        // copy constructor

dlib/gui_widgets/widgets_abstract.h

@@ -2011,7 +2011,7 @@ namespace dlib
             >
         void set_graph_modified_handler (
             T& object,
-            void (T::*event_handler_)()
+            void (T::*event_handler)()
         );
         /*!
             requires
@@ -2550,7 +2550,7 @@ namespace dlib
             >
         void set_overlay_rects_changed_handler (
             T& object,
-            void (T::*event_handler_)()
+            void (T::*event_handler)()
         );
         /*
             requires
@@ -2579,6 +2579,42 @@ namespace dlib
                 - std::bad_alloc
         */
 
+        template <
+            typename T
+            >
+        void set_overlay_rect_selected_handler (
+            T& object,
+            void (T::*event_handler)(const overlay_rect& orect)
+        );
+        /*
+            requires
+                - event_handler is a valid pointer to a member function in T 
+            ensures
+                - The event_handler function is called on object when the user selects
+                  an overlay rectangle by double clicking on it.  The selected rectangle 
+                  will be passed to event_handler().
+                - any previous calls to this function are overridden by this new call.  
+                  (i.e. you can only have one event handler associated with this 
+                  event at a time)
+            throws
+                - std::bad_alloc
+        */
+
+        void set_overlay_rects_changed_handler (
+            const any_function<void(const overlay_rect& orect)>& event_handler
+        );
+        /*
+            ensures
+                - The event_handler function is called when the user selects an overlay 
+                  rectangle by double clicking on it.  The selected rectangle will be 
+                  passed to event_handler().
+                - any previous calls to this function are overridden by this new call.  
+                  (i.e. you can only have one event handler associated with this 
+                  event at a time)
+            throws
+                - std::bad_alloc
+        */
+
     private:
 
         // restricted functions