/*------------------------------------------------------------*/
/* filename -       exposed.cpp                               */
/*                                                            */
/* function(s)                                                */
/*                  Tview exposed member function             */
/*------------------------------------------------------------*/

/*------------------------------------------------------------*/
/*                                                            */
/*    Turbo Vision -  Version 1.0                             */
/*    Copyright (c) 1991 by Borland International             */
/*    All Rights Reserved.                                    */
/*                                                            */
/*    This file Copyright (c) 1993 by J”rn Sierwald           */
/*                                                            */
/*                                                            */
/*------------------------------------------------------------*/

#define Uses_TView
#define Uses_TGroup
#include <tv.h>


struct StaticVars2 {
  TView*        target;
  short         y;
};

static StaticVars2 staticVars2;

int TView::exposedRec1(short x1, short x2, TView* p ) {
  while (1) {
/*20*/
    p=p->next;
    if (p==staticVars2.target) { // alle durch
      return exposedRec2( x1, x2, p->owner );
    }
    if ( !(p->state & sfVisible) || staticVars2.y<p->origin.y) continue; // keine Verdeckung

    if ( staticVars2.y<p->origin.y+p->size.y ) {
      // šberdeckung m”glich.
      if (x1<p->origin.x) { // f„ngt links vom Object an.
        if (x2<=p->origin.x) continue; // links vorbei
        if (x2>p->origin.x+p->size.x) {
          if (exposedRec1( x1, p->origin.x, p )) return 1;
          x1=p->origin.x+p->size.x;
        }
        else
          x2=p->origin.x;
      } else {
        if ( x1<p->origin.x+p->size.x ) x1=p->origin.x+p->size.x;
        if ( x1>=x2 ) return 0; // komplett verdeckt.
      }
    }

  } // while

}

int TView::exposedRec2( short x1, short x2, TView* p ) {
  if (!(p->state & sfVisible)) return 0;
  if ( !p->owner || p->owner->buffer ) return 1;  // taken from tvunix_6, 02.02.99

  StaticVars2 savedStatics = staticVars2;

  staticVars2.y += p->origin.y;
  x1 += p->origin.x;
  x2 += p->origin.x;
  staticVars2.target=p;

  TGroup* g=p->owner;
  if (staticVars2.y<g->clip.a.y || staticVars2.y >= g->clip.b.y) {
    staticVars2 = savedStatics;
    return 0;
  }
  if (x1<g->clip.a.x) x1 = g->clip.a.x;
  if (x2>g->clip.b.x) x2 = g->clip.b.x;
  if (x1>=x2) {
    staticVars2 = savedStatics;
    return 0;
  }

  int retValue = exposedRec1( x1, x2, g->last );
  staticVars2 = savedStatics;
  return retValue;
}

Boolean TV_CDECL TView::exposed() {
  if ( !(state & sfExposed) || size.x <= 0 || size.y <= 0 ) return Boolean(0);
  for (short y=0; y<size.y; y++) {
    staticVars2.y=y;
    if (exposedRec2( 0, size.x, this )) return Boolean(1);
  }
  return Boolean(0);
}