struct Edx: EditField{
 	typedef Edx CLASSNAME; 	
	Edx(){};
	virtual void LeftDouble(Point p, dword keyflags)
	{
		PromptOK("ok");
	}
};

GUI_APP_MAIN
{
	TopWindow  app;
	app.SetRect(0, 0, Zx(500), Zy(500));
	Edx text;
        app.Add(text.LeftPos(12,234).TopPos(63,21));
	text.SetText( "double click here");
	app.Run();
}

#include <CtrlLib/CtrlLib.h>

using namespace Upp;

struct Edx: EditField{
	// typedef Edx CLASSNAME; (Not needed in new code)
	
	Edx(){};
	
	// encouraged to use c++11 new language feature
	// in new code to clearly manifest that you are
	// override a parent virtual function
	//
	void LeftDouble(Point p, dword keyflags)override
	{
		WhenLeftDouble(p,keyflags);
		
		// following line should be dispensible in this
		// particular case as I expect it does nothing
		//
		this->EditField::LeftDouble(p,keyflags);
	}
	
	// the following line introduce a new Event
	// and note how it comes to effect by calling it in the
	// overrided virtual.
	//
	Event<Point, dword> WhenLeftDouble;
};

GUI_APP_MAIN
{
	TopWindow  app;
	app.SetRect(0, 0, Zx(500), Zy(500));
	Edx text;
	
	text.WhenLeftDouble<<[=](Point , dword){ PromptOK("ok"); };
    
    app.Add(text.LeftPos(12,234).TopPos(63,21));
	text.SetText( "double click here");
	app.Run();
}

    struct: Label{
	Lb(){};
	void LeftDouble(Point p, dword keyflags)override
	{
		WhenLeftDouble(p,keyflags);
	}
	Event<Point, dword> WhenLeftDouble;
    };

struct Lb: Label{ // Label LeftDouble double-click
	Lb(){ NoIgnoreMouse(); };
	
	void LeftDouble(Point p, dword keyflags)
	{
	    WhenLeftDouble(p,keyflags);
		this->Label::LeftDouble(p,keyflags);
	}
	Event<Point, dword> WhenLeftDouble;
};