Added two new events to the text_field object. One for detecting when the

user hits enter and another for detecting when input focus is lost.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402279

dlib/gui_widgets/widgets.cpp

@@ -871,6 +871,8 @@ namespace dlib
             highlight_start = 0;
             highlight_end = -1;
 
+            if (focus_lost_handler.is_set())
+                focus_lost_handler();
             parent.invalidate_rectangle(rect);
         }
     }
@@ -1021,6 +1023,11 @@ namespace dlib
                     if (text_modified_handler.is_set())
                         text_modified_handler();
                 }
+                else if (key == '\n')
+                {
+                    if (enter_key_handler.is_set())
+                        enter_key_handler();
+                }
             }
             else if (key == base_window::KEY_BACKSPACE)
             {                

dlib/gui_widgets/widgets.h

@@ -519,6 +519,31 @@ namespace dlib
             text_modified_handler.set(object,event_handler);
         }
 
+        template <
+            typename T
+            >
+        void set_enter_key_handler (
+            T& object,
+            void (T::*event_handler)()
+        )
+        {
+            auto_mutex M(m);
+            enter_key_handler.set(object,event_handler);
+        }
+
+
+        template <
+            typename T
+            >
+        void set_focus_lost_handler (
+            T& object,
+            void (T::*event_handler)()
+        )
+        {
+            auto_mutex M(m);
+            focus_lost_handler.set(object,event_handler);
+        }
+
     private:
 
         void on_user_event (
@@ -590,6 +615,8 @@ namespace dlib
         long highlight_end;
         long shift_pos;
         member_function_pointer<>::kernel_1a_c text_modified_handler;
+        member_function_pointer<>::kernel_1a_c enter_key_handler;
+        member_function_pointer<>::kernel_1a_c focus_lost_handler;
 
 
         timer<text_field>::kernel_2a t;

dlib/gui_widgets/widgets_abstract.h

@@ -701,6 +701,45 @@ namespace dlib
                 - std::bad_alloc
         !*/
 
+        template <
+            typename T
+            >
+        void set_enter_key_handler (
+            T& object,
+            void (T::*event_handler)()
+        );
+        /*!
+            requires
+                - event_handler is a valid pointer to a member function in T 
+            ensures
+                - the event_handler function is called on object when this text field
+                  has input focus and the user hits the enter key on their keyboard.
+                - 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
+        !*/
+
+        template <
+            typename T
+            >
+        void set_focus_lost_handler (
+            T& object,
+            void (T::*event_handler)()
+        );
+        /*!
+            requires
+                - event_handler is a valid pointer to a member function in T 
+            ensures
+                - the event_handler function is called on object when this object
+                  loses input focus due to the user clicking outside the text field
+                - 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:
 

dlib/test/gui/main.cpp

@@ -591,6 +591,8 @@ public:
         tf.set_text("Davis685g@");
         tf.set_width(500);
         tf.set_text_color(rgb_pixel(255,0,0));
+        tf.set_enter_key_handler(*this,&win::on_enter_key);
+        tf.set_focus_lost_handler(*this,&win::on_tf_focus_lost);
         
 
         button_count = 0;
@@ -625,6 +627,18 @@ public:
 
 private:
 
+
+    void on_enter_key()
+    {
+        cout << "enter key pressed" << endl;
+    }
+
+    void on_tf_focus_lost()
+    {
+        cout << "text field lost focus" << endl;
+    }
+
+
     void on_open_file (const std::string& file)
     {
         message_box("file opened",file);