/*
 * selection.c: Handle selections on videotext page
 *
 * $Id: selection.c,v 1.1 1997/10/22 23:46:51 mb Exp mb $
 *
 * Copyright (c) 1997 Martin Buck  <martin.buck@bigfoot.com>
 * Read COPYING for more information
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <xview/sel_pkg.h>
#include "vtx_assert.h"
#include "misc.h"
#include "vtxdecode.h"
#include "xevents.h"
#include "selection.h"


static Selection_owner xvsel;
static Selection_item xvsel_item;
static char sel_buf[VTX_PAGESIZE + 24 + 1]; /* Add 24 chars for linefeeds, 1 for '\0' */


static void
lose_proc(Selection_owner owner) {
  /*FIXME: Don't use globals here*/
  selection_hide(&vtxwin);
}


static void
invert_range(vtxpage_t *page, int x1, int y1, int x2, int y2, int rect) {
  int x, y, pos, xmin, xmax, ymin, ymax;
  
  if (rect) {
    xmin = MIN(x1, x2);
    xmax = MAX(x1, x2);
    ymin = MIN(y1, y2);
    ymax = MAX(y1, y2);
    for (y = ymin; y <= ymax; y++) {
      for (x = xmin; x <= xmax; x++) {
        page->attrib[y * 40 + x] ^= VTX_INVERT;
      }
    }
  } else {
    if (y1 < y2 || (y1 == y2 && x1 < x2)) {
      xmin = x1;
      ymin = y1;
      xmax = x2;
      ymax = y2;
    } else {
      xmin = x2;
      ymin = y2;
      xmax = x1;
      ymax = y1;
    }
    for (pos = ymin * 40 + xmin; pos <= ymax * 40 + xmax; pos++) {
      page->attrib[pos] ^= VTX_INVERT;
    }
  }
}


void
selection_start(vtxpgwin_t *vtxwin, int x, int y, int rect, int expand) {
  selection_t *sel = &vtxwin->sel;
  int pos, pos0, pos1;

  x = LIMIT(x, 0, 39);
  y = LIMIT(y, 0, 23);
  if (!expand) {
    selection_hide(vtxwin);
    sel->disp_x[0] = sel->disp_x[1] = x;
    sel->disp_y[0] = sel->disp_y[1] = y;
    sel->expand = -1;
    sel->rect = rect;
  } else {
    if (sel->show) {
      invert_range(vtxwin->page, sel->disp_x[0], sel->disp_y[0], sel->disp_x[1], sel->disp_y[1],
          sel->rect);
    }
    if (!sel->rect) {
      pos0 = sel->sel_x[0] + sel->sel_y[0] * 40;
      pos1 = sel->sel_x[1] + sel->sel_y[1] * 40;
      pos = x + y * 40;
      sel->expand = (pos > (pos0 + pos1) / 2) ^ (pos0 > pos1);
      sel->disp_x[sel->expand] = x;
      sel->disp_y[sel->expand] = y;
      sel->disp_x[!sel->expand] = sel->sel_x[!sel->expand];
      sel->disp_y[!sel->expand] = sel->sel_y[!sel->expand];
    } else {
      sel->expand = ((x > (sel->sel_x[0] + sel->sel_x[1]) / 2) ^ (sel->sel_x[0] > sel->sel_x[1]))
          | (((y > (sel->sel_y[0] + sel->sel_y[1]) / 2) ^ (sel->sel_y[0] > sel->sel_y[1])) << 1);
      sel->disp_x[sel->expand & 1] = x;
      sel->disp_y[sel->expand >> 1] = y;
      sel->disp_x[!(sel->expand & 1)] = sel->sel_x[!(sel->expand & 1)];
      sel->disp_y[!(sel->expand >> 1)] = sel->sel_y[!(sel->expand >> 1)];
    }
    invert_range(vtxwin->page, sel->disp_x[0], sel->disp_y[0], sel->disp_x[1], sel->disp_y[1],
        sel->rect);
    x_vtx_redraw(vtxwin, 0, 0, 39, 23, FALSE);
    sel->show = TRUE;
  }
  sel->last_x = -1;
  sel->init = TRUE;
}


void
selection_drag(vtxpgwin_t *vtxwin, int x, int y) {
  selection_t *sel = &vtxwin->sel;
  int pos, pos0, pos1, newexp;
  
  sel->drag = TRUE;
  x = LIMIT(x, 0, 39);
  y = LIMIT(y, 0, 23);
  if (x != sel->last_x || y != sel->last_y) {
    if (sel->show) {
      invert_range(vtxwin->page, sel->disp_x[0], sel->disp_y[0], sel->disp_x[1], sel->disp_y[1],
          sel->rect);
    }
    if (sel->expand < 0) {
      sel->disp_x[1] = x;
      sel->disp_y[1] = y;
    } else {
      if (!sel->rect) {
        pos0 = sel->sel_x[0] + sel->sel_y[0] * 40;
        pos1 = sel->sel_x[1] + sel->sel_y[1] * 40;
        pos = x + y * 40;
        newexp = -1;
        if (pos < MIN(pos0, pos1)) {
          newexp = pos1 < pos0;
        }
        if (pos > MAX(pos0, pos1)) {
          newexp = pos1 > pos0;
        }
        if (newexp >= 0 && newexp != sel->expand) {
          sel->disp_x[sel->expand] = sel->sel_x[sel->expand];
          sel->disp_y[sel->expand] = sel->sel_y[sel->expand];
          sel->expand = newexp;
        }
        sel->disp_x[sel->expand] = x;
        sel->disp_y[sel->expand] = y;
      } else {
        newexp = -1;
        if (x < MIN(sel->sel_x[0], sel->sel_x[1])) {
          newexp = sel->sel_x[1] < sel->sel_x[0];
        }
        if (x > MAX(sel->sel_x[0], sel->sel_x[1])) {
          newexp = sel->sel_x[1] > sel->sel_x[0];
        }
        if (newexp >= 0 && newexp != (sel->expand & 1)) {
          sel->disp_x[sel->expand & 1] = sel->sel_x[sel->expand & 1];
          sel->expand = (sel->expand & ~1) | newexp;
        }
        sel->disp_x[sel->expand & 1] = x;
        newexp = -1;
        if (y < MIN(sel->sel_y[0], sel->sel_y[1])) {
          newexp = (sel->sel_y[1] < sel->sel_y[0]) << 1;
        }
        if (y > MAX(sel->sel_y[0], sel->sel_y[1])) {
          newexp = (sel->sel_y[1] > sel->sel_y[0]) << 1;
        }
        if (newexp >= 0 && newexp != (sel->expand & 2)) {
          sel->disp_y[sel->expand >> 1] = sel->sel_y[sel->expand >> 1];
          sel->expand = (sel->expand & ~2) | newexp;
        }
        sel->disp_y[sel->expand >> 1] = y;
      }
    }
    invert_range(vtxwin->page, sel->disp_x[0], sel->disp_y[0], sel->disp_x[1], sel->disp_y[1],
        sel->rect);
    x_vtx_redraw(vtxwin, 0, 0, 39, 23, FALSE);
    sel->last_x = x;
    sel->last_y = y;
  }
  if (!sel->show && xvsel) {
    xv_set(xvsel, SEL_OWN, FALSE, NULL);
  }
  sel->show = TRUE;
}


void
selection_finish(vtxpgwin_t *vtxwin) {
  selection_t *sel = &vtxwin->sel;
  int sofs;
  
  if (!sel->init) {
    return;
  }
  if (sel->show) {
    sel->sel_x[0] = sel->disp_x[0];
    sel->sel_y[0] = sel->disp_y[0];
    sel->sel_x[1] = sel->disp_x[1];
    sel->sel_y[1] = sel->disp_y[1];
    if (!xvsel) {
      xvsel = xv_create(vtxwin->canvas, SELECTION_OWNER,
          SEL_LOSE_PROC, lose_proc,
          NULL);
      xvsel_item = xv_create(xvsel, SELECTION_ITEM, NULL);
    }
    sofs = 0;
    if (sel->rect) {
      int sxmin = MIN(sel->sel_x[0], sel->sel_x[1]);
      int sxmax = MAX(sel->sel_x[0], sel->sel_x[1]);
      int symin = MIN(sel->sel_y[0], sel->sel_y[1]);
      int symax = MAX(sel->sel_y[0], sel->sel_y[1]);
      int sx, sy;
      
      for (sy = symin; sy <= symax; sy++) {
        for (sx = sxmin; sx <= sxmax; sx++) {
          if ((vtxwin->page->attrib[sy * 40 + sx] & VTX_HIDDEN) && vtxwin->hidden) {
            sel_buf[sofs++] = ' ';
          } else {
            sel_buf[sofs++] = vtx2iso_table[vtxwin->page->chr[sy * 40 + sx]];
          }
        }
        if (symin != symax) {
          sel_buf[sofs++] = '\n';
        }
      }
    } else {
      int start, end, pos;
      
      if (sel->sel_y[0] < sel->sel_y[1]
          || (sel->sel_y[0] == sel->sel_y[1] && sel->sel_x[0] < sel->sel_x[1])) {
        start = sel->sel_y[0] * 40 + sel->sel_x[0];
        end = sel->sel_y[1] * 40 + sel->sel_x[1];
      } else {
        start = sel->sel_y[1] * 40 + sel->sel_x[1];
        end = sel->sel_y[0] * 40 + sel->sel_x[0];
      }
      for (pos = start; pos <= end; pos++) {
        if ((vtxwin->page->attrib[pos] & VTX_HIDDEN) && vtxwin->hidden) {
          sel_buf[sofs++] = ' ';
        } else {
          sel_buf[sofs++] = vtx2iso_table[vtxwin->page->chr[pos]];
        }
        if (pos % 40 == 39 && sel->sel_y[0] != sel->sel_y[1]) {
          sel_buf[sofs++] = '\n';
        }
      }
    }
    sel_buf[sofs++] = '\0';

    xv_set(xvsel_item,
        SEL_DATA, sel_buf,
        SEL_LENGTH, strlen(sel_buf),
        NULL);
    xv_set(xvsel, SEL_OWN, TRUE, NULL);
  }
  sel->drag = sel->init = FALSE;
}


void
selection_hide(vtxpgwin_t *vtxwin) {
  selection_t *sel = &vtxwin->sel;
  
  if (!sel->show) {
    return;
  }
  invert_range(vtxwin->page, sel->disp_x[0], sel->disp_y[0], sel->disp_x[1], sel->disp_y[1],
      sel->rect);
  x_vtx_redraw(vtxwin, 0, 0, 39, 23, FALSE);
  sel->show = sel->init = sel->drag = FALSE;
}