Added an overload of get_next_double_click() that allows the user to find out

which mouse button was double clicked.

dlib/gui_widgets/widgets.cpp

@@ -6096,7 +6096,7 @@ namespace dlib
                 p = p*zoom_out_scale;
 
             if (dlib::get_rect(img).contains(p))
-                image_clicked_handler(p, is_double_click);
+                image_clicked_handler(p, is_double_click, btn);
         }
 
         if (btn == base_window::RIGHT && rect_is_selected)
@@ -6450,6 +6450,7 @@ namespace dlib
         gui_img(*this),
         window_has_closed(false),
         have_last_click(false),
+        mouse_btn(0),
         clicked_signaler(this->wm)
     {
 
@@ -6485,7 +6486,8 @@ namespace dlib
 
     bool image_window::
     get_next_double_click (
-        point& p
+        point& p,
+        unsigned long& mouse_button 
     ) 
     {
         auto_mutex lock(wm);
@@ -6500,6 +6502,7 @@ namespace dlib
         // Mark that we are taking the point click so the next call to get_next_click()
         // will have to wait for another click.
         have_last_click = false;
+        mouse_button = mouse_btn;
         p = last_clicked_point;
         return true;
     }
@@ -6509,13 +6512,15 @@ namespace dlib
     void image_window::
     on_image_clicked (
         const point& p,
-        bool is_double_click
+        bool is_double_click,
+        unsigned long btn
     )
     {
         if (is_double_click)
         {
             have_last_click = true;
             last_clicked_point = p;
+            mouse_btn = btn;
             clicked_signaler.signal();
         }
     }

dlib/gui_widgets/widgets.h

@@ -3435,7 +3435,7 @@ namespace dlib
             >
         void set_image_clicked_handler (
             T& object,
-            void (T::*event_handler_)(const point& p, bool is_double_click)
+            void (T::*event_handler_)(const point& p, bool is_double_click, unsigned long btn)
         )
         {
             auto_mutex M(m);
@@ -3443,7 +3443,7 @@ namespace dlib
         }
 
         void set_image_clicked_handler (
-            const any_function<void(const point& p, bool is_double_click)>& event_handler_
+            const any_function<void(const point& p, bool is_double_click, unsigned long btn)>& event_handler_
         )
         {
             auto_mutex M(m);
@@ -3532,7 +3532,7 @@ namespace dlib
         std::string default_rect_label;
         any_function<void()> event_handler;
         any_function<void(const overlay_rect& orect)> orect_selected_event_handler;
-        any_function<void(const point& p, bool is_double_click)> image_clicked_handler;
+        any_function<void(const point& p, bool is_double_click, unsigned long btn)> image_clicked_handler;
         popup_menu_region parts_menu;
         point last_right_click_pos;
         const int part_width;
@@ -3563,6 +3563,7 @@ namespace dlib
             gui_img(*this), 
             window_has_closed(false),
             have_last_click(false),
+            mouse_btn(0),
             clicked_signaler(this->wm) 
         {  
             gui_img.set_image_clicked_handler(*this, &image_window::on_image_clicked);
@@ -3578,6 +3579,7 @@ namespace dlib
             gui_img(*this), 
             window_has_closed(false),
             have_last_click(false),
+            mouse_btn(0),
             clicked_signaler(this->wm) 
         {  
             gui_img.set_image_clicked_handler(*this, &image_window::on_image_clicked);
@@ -3744,15 +3746,17 @@ namespace dlib
         );
 
         bool get_next_double_click (
-            point& p
+            point& p,
+            unsigned long& mouse_button
         ); 
-        /*!
-            ensures
-                - This function blocks until the user double clicks on the image
-                  or the window is closed by the user.
-                - if (this function returns true) then
-                    - #p == the next place the user clicked
-        !*/
+
+        bool get_next_double_click (
+            point& p
+        ) 
+        {
+            unsigned long mouse_button;
+            return get_next_double_click(p, mouse_btn);
+        }
 
     private:
 
@@ -3764,7 +3768,8 @@ namespace dlib
         
         void on_image_clicked (
             const point& p,
-            bool is_double_click
+            bool is_double_click,
+            unsigned long btn
         );
 
         // restricted functions
@@ -3777,6 +3782,7 @@ namespace dlib
         bool window_has_closed;
         bool have_last_click;
         point last_clicked_point;
+        unsigned long mouse_btn;
         rsignaler clicked_signaler;
     };
 

dlib/gui_widgets/widgets_abstract.h

@@ -3024,12 +3024,27 @@ namespace dlib
         ); 
         /*!
             ensures
-                - This function blocks until the user double left clicks on the image or
-                  the window is closed by the user.
+                - This function blocks until the user double clicks on the image or the
+                  window is closed by the user.
                 - if (this function returns true) then
                     - #p == the next image pixel the user clicked.  
         !*/
 
+        bool get_next_double_click (
+            point& p,
+            unsigned long& mouse_button
+        ); 
+        /*!
+            ensures
+                - This function blocks until the user double clicks on the image or the
+                  window is closed by the user.
+                - if (this function returns true) then
+                    - #p == the next image pixel the user clicked.  
+                    - #mouse_button == the mouse button which was used to double click.
+                      This will be either dlib::base_window::LEFT,
+                      dlib::base_window::MIDDLE, or dlib::base_window::RIGHT
+        !*/
+
     private:
 
         // restricted functions