ZtRubberSlRect.H

/* ZtRubberSlRect.H */
/* $Id: ZtRubberSlRect.H,v 3.4 2004/02/17 13:53:38 vlad Exp $ */
#ifndef __ZtRubberSlRect_H
#define __ZtRubberSlRect_H


#include <zm/ZtRubberRect.H>


/*************************************************************
 * Object for drawing slanted rubber box.  Useful for
 * arbitrary slanting rectangle selection.
 *************************************************************/
class ZtRubberSlRect : public ZtRubberRect
{
public:

  ZtRubberSlRect (ZtMain* pManager,
          ZGroupId pxid, ZGroupId pyid,
          ZGroupId nxid, ZGroupId nyid);

  /* Callback for end of selection pass n=4 corner points (x,y) */
  virtual void  box (int pnts_n, float xcor[], float ycor[]);

  /* Event processing status:
     ziProcessed - if event processing has been finished (ungrab input);
     ziGrabInput - if event processing must be continued (grab input);
     ziSkipped - if this event is not processed. */
  virtual ZInputStatus  input (const XEvent* xev);

  /* Draw last selected rectangle */
  virtual void  redraw ();

  /* Set draw flag */
  virtual void  draw_last_box (Logic draw_flag);

  /* Set help lines allocated statically */
  void      set_help_msgs (const char* msg1 = NULL,
                   const char* msg2 = NULL);

  /* Graphics environment of permanent area drawing */
  ZGEnv     geLastBox;

  virtual const char*   class_id () const;

protected:

  /* Calculate distance between line (p1,p2) and point p0 */
  float distance_point_to_line (ZPoint& p0, ZPoint& p1, ZPoint& p2);

  /* Calculate corner coords for 2 points and half of width value */
  void  slanting_rect_corners (ZPoint& p1, ZPoint& p2, float hw,
                   float xc[4], float yc[4]);

  /* Draw slanting rectangle unconditionally */
  void  draw_slanting_rect (ZPoint& p1, ZPoint& p2, float hw);

  /* Draw closed tetragonal figure with clipping */
  void  draw_clipped (ZGEnv& genv, float xcor[4], float ycor[4]);

private:

  Logic     bDrawn; /* rubber rect need to be erased */
  int       state;  /* 1 - first point is to be selected;
               2 - second point is to be selected;
               3 - half-width is to be selected. */
  ZPoint    zp1;    /* first point selected (or current value) */
  ZPoint    zp2;    /* second point selected (or current value) */
  const char    *szHelp[2]; /* supply user with online state-dep.help */
  float     half_width; /* half of width */
  float     xc[4], yc[4];   /* last selected corner natural coords */
  Logic     bDrawLast;  /* draw last selection or don't? */

};



#endif /* ZtRubberSlRect.H */