WCPolyTool.h

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//# WCPolyTool.h: Base class for WorldCanvas event-based polygon tools
//# Copyright (C) 1999,2000
//# 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_WCPOLYTOOL_H
#define TRIALDISPLAY_WCPOLYTOOL_H

#include <casa/aips.h>
#include <display/DisplayEvents/WCTool.h>
#include <display/DisplayEvents/DTVisible.h>

namespace casa { //# NAMESPACE CASA - BEGIN

// <summary>
// Base class for WorldCanvas event-based polygon tools
// </summary>
//
// <use visibility=export>
//
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
//
// <prerequisites>
//   <li><linkto>WCTool</linkto>
// </prerequisites>
//
// <etymology>
// WCPolyTool stands for WorldCanvas Polygon Tool
// </etymology>
//
// <synopsis>
// This class adds to its base WCTool to provide a tool for drawing,
// reshaping and moving polygons on a WorldCanvas.  While WCPolyTool
// is not abstract, it performs no useful function.  The programmer
// should derive from this class and override the functions doubleInside
// and doubleOutside at the very least.  These are called when the user
// double-clicks a particular key or mouse button inside or outside an
// existing polygon respectively.  It is up to the programmer to decide
// what these events mean, but it is recommended that an internal double-
// click correspond to the main action of the tool, eg. emitting the
// polygon vertices to the application, and that an external double-click
// correspond to a secondary action of the tool, if indeed there are
// additional actions suitable to the tool.
//
// The polygon is drawn by clicking at each of the vertices, and
// clicking on the last or first vertices to complete the polygon.
// Once drawn, the vertices can be moved by dragging their handles,
// and the entire polygon relocated by dragging inside the polygon.
// The polygon is removed from the display when the Esc key is
// pressed.
// </synopsis>
//
// <example>
// </example>
//
// <motivation>
// Many activities on the WorldCanvas will be based on the user drawing
// a polygon and using the polygon in some operation.
// </motivation>
//
// <todo asof="1999/02/24">
//   <li> Add time constraint to double click detection
// </todo>

        class WCPolyTool : public WCTool, public DTVisible {

        public:

                // Constructor
                WCPolyTool(WorldCanvas *wcanvas,
                           Display::KeySym keysym = Display::K_Pointer_Button1,
                           const casacore::Bool persistent = false);

                // Destructor
                virtual ~WCPolyTool();

                // Switch the tool off - this calls the base class disable,
                // and then erases the polygon if it's around
                virtual void disable();

                // Functions called by the local event handling operators -
                // these handle the drawing of the polygon.  In special
                // conditions, namely double clicking the key, they will
                // pass control on to the doubleInside and doubleOutside
                // functions
                // <group>
                virtual void keyPressed(const WCPositionEvent &ev);
                virtual void keyReleased(const WCPositionEvent &ev);
                virtual void otherKeyPressed(const WCPositionEvent &ev);
                virtual void moved(const WCMotionEvent &ev, const viewer::region::region_list_type & /*selected_regions*/);
                virtual void refresh(const WCRefreshEvent &ev);
                // </group>

                // Functions special to the polygon event handling - called when
                // there is a double click inside/outside the polygon
                // <group>
                virtual void doubleInside() { };
                virtual void doubleOutside() { };
                // </group>

                // Functions called when a polygon is ready and not being
                // editted, and when this status changes
                // <group>
                virtual void polygonReady() { };
                virtual void polygonNotReady() { };
                // </group>

                // Retrive the polygon vertices
                virtual void get(casacore::Vector<casacore::Int> &x, casacore::Vector<casacore::Int> &y);

        private:

                // do the polygons persist after double clicks?
                casacore::Bool itsPolygonPersistent;

                // is the polygon on screen?
                casacore::Bool itsOnScreen;

                // are we actively drawing?
                casacore::Bool itsActive;

                // have we moved?
                casacore::Bool itsMoved;

                // do we have a polygon yet?
                casacore::Bool itsPolygonExists;

                // adjustment mode
                enum AdjustMode {
                    Off,
                    Move,
                    Handle
                };
                WCPolyTool::AdjustMode itsAdjustMode;

                // Number of points
                casacore::uInt itsNPoints;

                // Polygon points
                // ... pixels
                casacore::Vector<casacore::Int> itsX, itsY;
                // ... world
                casacore::Vector<casacore::Double> itsStoredWorldX, itsStoredWorldY;

                // Point operations
                // <group>
                void pushPoint(casacore::uInt x1, casacore::uInt y1);
                void popPoint();
                // </group>

                // preserve/restore the world coordinates
                // <group>
                void preserve();
                void restore();
                // </group>

                // draw the polygon on a PixelCanvas
                void draw(casacore::Bool drawHandles = false);

                // reset this drawer
                void reset();

                // size in pixels of the handles
                casacore::uInt itsHandleSize;

                // are we within the specified handle?
                casacore::Bool inHandle(const casacore::uInt &pt, const casacore::uInt &x, const casacore::uInt &y) const;

                // which handle to modify?
                casacore::uInt itsSelectedHandle;

                // are we inside the polygon?
                casacore::Bool inPolygon(const casacore::uInt &x, const casacore::uInt &y) const;

                // position that move started from
                casacore::Int itsBaseMoveX, itsBaseMoveY;

                // position of last press event
                casacore::Int itsLastPressX, itsLastPressY;
                casacore::Int its2ndLastPressX, its2ndLastPressY;

                // position of last release event
                casacore::Int itsLastReleaseX, itsLastReleaseY;

                // store the times of the last two presses here:
                casacore::Double itsLastPressTime, its2ndLastPressTime;

        };


} //# NAMESPACE CASA - END

#endif