MWCEllipseTool.h

Go to the documentation of this file.

//# MWCEllipseTool.h: Base class for MultiWorldCanvas event-based ellipse tools
//# Copyright (C) 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_MWCELLIPSETOOL_H
#define TRIALDISPLAY_MWCELLIPSETOOL_H

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

namespace casa { //# NAMESPACE CASA - BEGIN

// <summary>
// Base class for MultiWorldCanvas event-based ellipse tools
// </summary>
//
// <use visibility=export>
//
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
//
// <prerequisites>
//   <li> WCTool
// </prerequisites>
//
// <etymology>
// MWCEllipseTool stands for MultiWorldCanvas Ellipse Tool
// </etymology>
//
// <synopsis>
// This class adds to its base WCTool to provide a tool for drawing,
// resizing and moving ellipses on a WorldCanvas.  While MWCEllipseTool
// is not abstract, it performs no useful function.  The programmer
// should derive from this class, and implement the functions
// doubleInside and doubleOutside, which are called when the user
// double-clicks the key or mouse button inside or outside an existing
// ellipse respectively.  It is up to the programmer to decide what
// double clicks inside and outside the ellipse correspond to,
// although it is recommended that a double click inside correspond to
// the main action of the tool, and a double click outside correspond
// to a secondary action of the tool, if indeed a secondary action
// exists.
//
// The ellipse is drawn by dragging the mouse from one corner to
// the diagonally opposite corner.  Once constructed, the ellipse
// can be resized by dragging its corners, or relocated by dragging
// inside the ellipse.  The ellipse 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 ellipse, and then proceeding to some action with that ellipse.
// </motivation>

        class MWCEllipseTool : public MultiWCTool, public DTVisible {

        public:

                // Constructor
                MWCEllipseTool(Display::KeySym keysym = Display::K_Pointer_Button1,
                               const Bool persistent = False);

                // Destructor
                virtual ~MWCEllipseTool();

                // Switch the tool off - this erases the ellipse, if any,
                // and calls the base class disable.
                virtual void disable();

                // reset to non-existent, non-active ellipse.
                // Refreshes if necessary to erase (unless skipRefresh==True  In
                // that case, the caller should do the refresh itself).
                // (Does not unregister from WCs or disable future event handling).
                virtual void reset(Bool skipRefresh=False);

                // Is a ellipse currently defined?
                //virtual Bool rectangleDefined() { return itsRectangleExists;  }
                virtual Bool ellipseDefined() {
                        return itsEllipseExists;
                }


        protected:

                // Functions called by the base class event handling operators--and
                // normally only those.  This is the input that controls the ellipse's
                // appearance and action.  When the ellipse is ready and double-click
                // is received, the doubleInside/Outside routine will be invoked.
                // <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*/);
                // </group>

                // draw the ellipse (if any) on the object's currently active WC.
                // Only to be called by the base class refresh event handler.  Derived
                // objects should use refresh() if they need to redraw, but even that
                // is normally handled automatically.
                virtual void draw(const WCRefreshEvent&/*ev*/, const viewer::region::region_list_type & /*selected_regions*/);

                // Output callback functions--to be overridden in derived class.
                // Called when there is a double click inside/outside the ellipse
                // <group>
                virtual void doubleInside() { };
                virtual void doubleOutside() { };
                // </group>

                // Called when a ellipse is ready and not being
                // edited.  (Unused so far on the glish level (12/01)).
                virtual void ellipseReady() { };
                //virtual void rectangleReady() { };


                // Retrieve the ellipse coordinates, in screen pixels.
                // Anchor (if applicable) is (x1,y1).  Valid during the output callbacks;
                // to be used by them, as well as internally.
                virtual void get(Int &x1, Int &y1, Int &x2, Int &y2) const ;

        private:

                // set the pixel coordinates of the ellipse
                virtual void set(const Int &x1, const Int &y1,
                                 const Int &x2, const Int &y2);

                // get only the anchor point
                virtual void get(Int &x1, Int &y1) const;


                // does the ellipse persist after double clicks (until a new one
                // is started)?
                Bool itsEllipsePersistent;
                //Bool itsRectanglePersistent;

                // do we have a ellipse yet?
                // (if True, itsCurrentWC, itsEmitted, P1, and P2 are valid)
                Bool itsEllipseExists;
                //Bool itsRectangleExists;

                // was the button pressed in the ellipse (or, if none, in an active WC)
                // and not yet released/reset?
                Bool itsActive;

                // (valid only if itsActive==True):
                // True = being moved     False = being resized
                Bool itsMoving;

                // (valid only if itsEllipseExists==True)
                // Has doubleInside/Outside been called for this ellipse?  If so, a
                // key press outside the ellipse will start a new ellipse, as if
                // itsEllipseExists were False.
                // However, a key press inside the ellipse will reset
                // itsEmitted to False, allowing the ellipse to be reused
                // (possibly moved or resized, and emitted again).
                Bool itsEmitted;

                // (Linear) coordinates of the ellipse (invariant over zooms, but not
                // coordinate system changes.  To do: support the WorldCoordinateChange
                // refresh reason, and reset this tool when it occurs).
                Vector<Double> itsP1, itsP2;

                // storage of the handle (pixel) coordinates
                Vector<Int> itsHX, itsHY;

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

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

        };


} //# NAMESPACE CASA - END

#endif