MWCRectTool.h

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//# MWCRectTool.h: Base class for MultiWorldCanvas event-based rectangle 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_MWCRECTTOOL_H
#define TRIALDISPLAY_MWCRECTTOOL_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 rectangle tools
// </summary>
//
// <use visibility=export>
//
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
//
// <prerequisites>
//   <li> WCTool
// </prerequisites>
//
// <etymology>
// MWCRectTool stands for MultiWorldCanvas Rectangle Tool
// </etymology>
//
// <synopsis>
// This class adds to its base WCTool to provide a tool for drawing,
// resizing and moving rectangles on a WorldCanvas.  While MWCRectTool
// 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
// rectangle respectively.  It is up to the programmer to decide what
// double clicks inside and outside the rectangle 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 rectangle is drawn by dragging the mouse from one corner to 
// the diagonally opposite corner.  Once constructed, the rectangle
// can be resized by dragging its corners, or relocated by dragging
// inside the rectangle.  The rectangle 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 rectangle, and then proceeding to some action with that rectangle.
// A nice example is zooming.
// </motivation>

class MWCRectTool : public MultiWCTool, public DTVisible {
  
 public:
  
  // Constructor
  MWCRectTool(Display::KeySym keysym = Display::K_Pointer_Button1,
              const Bool persistent = False);
  
  // Destructor
  virtual ~MWCRectTool();
  
  // Switch the tool off - this erases the rectangle, if any,
  // and calls the base class disable.
  virtual void disable();

  // reset to non-existent, non-active rectangle.
  // 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 rectangle currently defined?
  virtual Bool rectangleDefined() { return itsRectangleExists;  } 
  
 
 protected:

  // Functions called by the base class event handling operators--and
  // normally only those.  This is the input that controls the rectangle's
  // appearance and action.  When the rectangle 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 rectangle (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 rectangle
  // <group>
  virtual void doubleInside() { };
  virtual void doubleOutside() { };
  // </group>

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


  // Retrieve the rectangle 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 rectangle
  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 rectangle persist after double clicks (until a new one
  // is started)?
  Bool itsRectanglePersistent;

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

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

  // (Linear) coordinates of the rectangle (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