wxWidgets/interface/wx/overlay.h

/////////////////////////////////////////////////////////////////////////////
// Name:        overlay.h
// Purpose:     interface of wxOverlay
// Author:      wxWidgets team
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

/**
   @class wxOverlay

   Creates an overlay over an existing window, allowing for manipulations like
   rubberbanding, etc.  On wxOSX the overlay is implemented with native
   platform APIs, on the other platforms it is simulated using wxMemoryDC.

   @library{wxcore}

   @see wxDCOverlay, wxDC
 */
class wxOverlay
{
public:
    wxOverlay();
    ~wxOverlay();

    /**
       Clears the overlay without restoring the former state.  To be done, for
       example, when the window content has been changed and repainted.
    */
    void Reset();
};



/**
   @class wxDCOverlay

   Connects an overlay with a drawing DC.

   @library{wxcore}

   @see wxOverlay, wxDC

 */
class wxDCOverlay
{
public:
    /**
       Connects this overlay to the corresponding drawing dc, if the overlay is
       not initialized yet this call will do so.
    */
    wxDCOverlay(wxOverlay &overlay, wxDC *dc, int x , int y , int width , int height);

    /**
       Convenience wrapper that behaves the same using the entire area of the dc.
    */
    wxDCOverlay(wxOverlay &overlay, wxDC *dc);

    /**
       Removes the connection between the overlay and the dc.
    */
    virtual ~wxDCOverlay();

    /**
       Clears the layer, restoring the state at the last init.
    */
    void Clear();
};