DisplayMethod.h

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//# DisplayMethod.h: Base class for drawing data in the Display Library
//# Copyright (C) 1996,1997,1998,1999,2000,2001,2002
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library is distributed in the hope that it will be useful, but WITHOUT
//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//#        Internet email: aips2-request@nrao.edu.
//#        Postal address: AIPS++ Project Office
//#                        National Radio Astronomy Observatory
//#                        520 Edgemont Road
//#                        Charlottesville, VA 22903-2475 USA
//#
//# $Id$

#ifndef TRIALDISPLAY_DISPLAYMETHOD_H
#define TRIALDISPLAY_DISPLAYMETHOD_H

//# aips includes:
#include <casa/aips.h>

//# display library includes:
#include <display/Display/DisplayEnums.h>
#include <display/Display/AttributeBuffer.h>

namespace casa { //# NAMESPACE CASA - BEGIN

//# forwards:
        class WorldCanvasHolder;
        class Attribute;
        class DisplayData;

// <summary>
// Base class for drawing a particular element (view) of a DisplayData.
// </summary>
//
// <synopsis>
// This base class defines an interface for drawing a single view of a
// DisplayData object.  The fundamental idea is that a DisplayData
// class will manage one or more DisplayMethod objects, and request
// the individual objects to draw as necessary.
// </synopsis>

        class DisplayMethod {
        public:

                // Constructor.  DisplayMethods need to know who their parent
                // DisplayData is.
                DisplayMethod(DisplayData *parentDisplayData);

                // Destructor.
                virtual ~DisplayMethod();

                // Draw on the provided WorldCanvasHolder.
                virtual void draw(Display::RefreshReason reason,
                                  WorldCanvasHolder &wcHolder) = 0;

                // clear drawlist state.
                // dk note 11/03:  Only used by the PrincipleAxesDM branch, where the
                // implementation has been moved.  Implementation should remain null
                // on the CachingDD/DM branch, which uses different interface (purgeCache)
                // and state for this.
                virtual void cleanup();

                // Set & remove restrictions
                // <group>
                void addRestriction(Attribute& newAt, Bool permanent);
                void addRestrictions(AttributeBuffer& newBuf);
                void setRestriction(Attribute& newAt);
                void setRestrictions(AttributeBuffer& newBuf);
                void removeRestriction(const String& name);
                Bool existRestriction(const String& name);
                void clearRestrictions();
                // </group>

                // match restriction
                // <group>
                Bool matches(Attribute& at);
                Bool matches(AttributeBuffer& atBuf);
                // </group>


                // Allow DisplayData objects to find out about restrictions in
                // DisplayMethod elements...
                friend class DisplayData;

        protected:

                AttributeBuffer  restrictions;

                // (Required) default constructor.
                DisplayMethod();

                // (Required) copy constructor.
                DisplayMethod(const DisplayMethod &other);

                // (Required) copy assignment.
                void operator=(const DisplayMethod &other);

                // Return the parent DisplayData.
                DisplayData *parentDisplayData() {
                        return itsParentDisplayData;
                }

        private:

                DisplayData *itsParentDisplayData;

        };


} //# NAMESPACE CASA - END

#endif