(*
    Copyright 2016-2023 Anton Krotov

    This file is part of fb2read.

    fb2read is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    fb2read 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with fb2read. If not, see <http://www.gnu.org/licenses/>.
*)

MODULE DOM;

IMPORT XML, SU := SysUtils, S := Strings, Font, Window, G := Graph, LibImg,
       RF := ReadFile, File, Ini, K := KOSAPI, sys := SYSTEM,
       V := Vector, Cursor, box_lib, tables, Search;


CONST

  BACK_COLOR*       = 0;
  TEXT_COLOR*       = 1;
  ITALIC_COLOR*     = 2;
  LINK_COLOR*       = 3;
  VISITED_COLOR*    = 4;
  CLICKED_COLOR*    = 5;

  CellPadding       = 5;


TYPE

  TSettings* = RECORD

    Colors*   : ARRAY 6 OF INTEGER;
    FontSize* : INTEGER;
    TwoCol*   : BOOLEAN;
    b_pict*   : BOOLEAN;

    PADDING*   : RECORD Left, Right, Top*, Bottom, ColInter, LRpc*, CInt*: INTEGER END;

    PARAGRAPH*,
    EPIGRAPH*,
    LEVEL,
    SUB,
    SUP,
    InterLin*,
    Picture*,
    picture_fsize*,
    SpaceW: INTEGER

  END;

  StackItem = POINTER TO TStackItem;

  TStackItem = RECORD (XML.DESC_ELEMENT)

    body : XML.TAG;
    Ycur : INTEGER;
    d    : REAL

  END;


VAR

  Settings* : TSettings;
  Canvas_X, Canvas_Y: INTEGER;
  ColLeft, ColRight: Window.tRect;

  Ymin, Ymax, Ycur : INTEGER;

  X, Y, W, LineH, W1, W2: INTEGER;

  epigraph  : INTEGER;
  sup, sub  : INTEGER;
  ref_depth : INTEGER;
  align     : INTEGER;
  code      : INTEGER;
  strong    : INTEGER;
  italic    : INTEGER;
  strike    : INTEGER;
  refer     : INTEGER;

  Text      : ARRAY 100000 OF XML.TEXT;
  TextCount : INTEGER;

  Lines: INTEGER;

  description, contents, mainbody, body, ref, cover, clickRef, hoverRef: XML.TAG;

  MainBody: BOOLEAN;

  f_stk, b_stk, vis_ref: XML.LIST;

  FilePath, FileName: S.STRING;

  done, last, resized, loaded*, mouseDown: BOOLEAN;

  Stack*: ARRAY 1000000 OF CHAR;

  Ycont: INTEGER;

  history: File.FS;

  references: V.VECTOR;
  cursor: INTEGER;

  fsize2, chksum: INTEGER;

  sb: box_lib.scrollbar;
  urlstr* : S.STRING;
  DrawStatus, DrawToolbar: PROCEDURE;
  win_size_x, win_size_y: INTEGER;


PROCEDURE PushRef(ref: XML.TAG);
VAR item: StackItem;
BEGIN
  NEW(item);
  item.body := ref;
  XML.AddItem(vis_ref, item);
END PushRef;


PROCEDURE Push(VAR stk: XML.LIST);
VAR item: StackItem;
BEGIN
  NEW(item);
  item.body := body;
  item.Ycur := Ycur;
  XML.AddItem(stk, item);
  IF body = contents THEN
    Ycont := Ycur
  END
END Push;


PROCEDURE Pop(VAR stk: XML.LIST);
VAR item : StackItem;
BEGIN
  item := stk.last(StackItem);
  IF item # NIL THEN
    body := item.body;
    Ymin := body.Ymin;
    Ymax := body.Ymax;
    Ycur := item.Ycur;
    XML.DelLastItem(stk)
  END
END Pop;


PROCEDURE Clear(VAR stk: XML.LIST);
BEGIN
  REPEAT
    XML.DelLastItem(stk)
  UNTIL stk.last = NIL
END Clear;


PROCEDURE AddToLine(text: XML.TEXT);
BEGIN
  Text[TextCount] := text;
  INC(TextCount)
END AddToLine;


PROCEDURE Epigraph(): INTEGER;
  RETURN ORD(epigraph > 0) * Settings.EPIGRAPH
END Epigraph;


PROCEDURE SpaceWidth(): INTEGER;
VAR Result: INTEGER;
BEGIN
  IF code > 0 THEN
    Result := Font.MonoWidth()
  ELSE
    Result := Settings.SpaceW
  END
  RETURN Result
END SpaceWidth;


PROCEDURE Trim;
VAR n: INTEGER;
BEGIN
  IF TextCount > 0 THEN
    n := TextCount - 1;
    WHILE (n >= 0) & (Text[n] IS XML.SPACE) DO
      Text[n].width := -1;
      DEC(n)
    END;
    TextCount := n + 1
  END
END Trim;


PROCEDURE Align;
VAR
  i, n, sp, d, quo, rem, x: INTEGER;
  text: XML.TEXT;
BEGIN
  IF (TextCount > 0) & (code = 0) & (align # 3) THEN
    sp := 0;
    Trim;
    n := TextCount - 1;
    IF n >= 0 THEN
      d := W - Text[n].X - Text[n].width
    END;
    IF align = 1 THEN
      x := (d + Text[0].X) DIV 2
    ELSIF align = 2 THEN
      x := d + Text[0].X
    ELSIF align = 0 THEN
      x := Text[0].X;
      FOR i := 0 TO n DO
        IF Text[i] IS XML.SPACE THEN
          INC(sp)
        END
      END;
      IF sp > 0 THEN
        quo := d DIV sp;
        rem := d MOD sp;
        FOR i := 0 TO n DO
          IF Text[i] IS XML.SPACE THEN
            text := Text[i];
            text.width := text.width + quo + ORD(rem > 0);
            DEC(rem)
          END
        END
      END
    END;
    FOR i := 0 TO n DO
      text := Text[i];
      text.X := x;
      INC(x, text.width)
    END
  END
END Align;


PROCEDURE NewLine;
BEGIN
  IF align # 0 THEN
    Align
  END;
  X := Epigraph();
  INC(Y, LineH);
  TextCount := 0
END NewLine;


PROCEDURE Sup(open: BOOLEAN);
BEGIN
  IF open THEN
    IF sup = 0 THEN
      DEC(Y, Settings.SUP)
    END;
    INC(sup)
  ELSE
    DEC(sup);
    IF sup = 0 THEN
      INC(Y, Settings.SUP)
    END
  END
END Sup;


PROCEDURE Sub(open: BOOLEAN);
BEGIN
  IF open THEN
    IF sub = 0 THEN
      INC(Y, Settings.SUB)
    END;
    INC(sub)
  ELSE
    DEC(sub);
    IF sub = 0 THEN
      DEC(Y, Settings.SUB)
    END
  END
END Sub;


PROCEDURE Split(word: XML.WORD);
VAR
  i, n, max, len: INTEGER;
  c: CHAR;
  rem: XML.WORD;
BEGIN
  WHILE Font.TextWidth(word.value, max) <= W DO
    INC(max)
  END;
  DEC(max);
  IF max = 0 THEN
    max := 1
  END;
  i := 0;
  n := 0;
  len := word.value.last - word.value.first + 1;
  WHILE (n <= max) & (i < len) DO
    c := S.GetChar(word.value, i);
    INC(n);
    IF (80X <= c) & (c <= 0BFX) THEN
      DEC(n)
    END;
    INC(i)
  END;
  IF n > max THEN
    DEC(i);
    rem := XML.CreateWord();
    rem^ := word^;
    rem.value.first := word.value.first + i;
    word.next := rem;
    word.value.last := rem.value.first - 1;
    word.length := S.Utf8Length(word.value);
    word.width := Font.TextWidth(word.value, word.length)
  END
END Split;


PROCEDURE Depth(tag: XML.ELEMENT): INTEGER;
VAR n: INTEGER;
BEGIN
  n := 0;
  WHILE tag # NIL DO
    IF tag(XML.TAG).value = XML.tag_section THEN
      INC(n)
    END;
    tag := tag.parent
  END
  RETURN n
END Depth;


PROCEDURE shift(tag: XML.TAG; shx, shy: INTEGER);
VAR cur: XML.ELEMENT; t: XML.TAG;
BEGIN
  cur := tag.child.first;
  WHILE cur # NIL DO
    IF cur IS XML.TAG THEN
      t := cur(XML.TAG);
      INC(t.X, shx);
      INC(t.Ymin, shy);
      INC(t.Ymax, shy);
      shift(t, shx, shy)
    ELSIF cur IS XML.TEXT THEN
      INC(cur(XML.TEXT).X, shx);
      INC(cur(XML.TEXT).Y, shy)
    END;
    cur := cur.next
  END
END shift;


PROCEDURE getspan(td: XML.TAG; span: S.STRING): INTEGER;
VAR res: INTEGER;
    attr_value: S.CHARS;
    err: BOOLEAN;
BEGIN
  IF XML.GetAttr(td, span, attr_value) THEN
    res := S.CharsToInt(attr_value, err);
    IF err OR (res <= 0) THEN
      res := 1
    END
  ELSE
    res := 1
  END
  RETURN res
END getspan;


PROCEDURE td(t: tables.Table; tag: XML.TAG);
BEGIN
  tag.cell := t.cells.count;
  tables.td(t, getspan(tag, "colspan"), getspan(tag, "rowspan"))
END td;


PROCEDURE tr(t: tables.Table; tag: XML.TAG);
VAR
  cur       : XML.ELEMENT;
  cell      : XML.TAG;
BEGIN
  tables.tr(t);
  cur := tag.child.first;
  WHILE cur # NIL DO
    IF cur IS XML.TAG THEN
      cell := cur(XML.TAG);
      IF (cell.value = XML.tag_td) OR (cell.value = XML.tag_th) THEN
        cell.table := t;
        td(t, cell)
      END
    END;
    cur := cur.next
  END
END tr;


PROCEDURE table(t: tables.Table; tag: XML.TAG; open: BOOLEAN);
VAR
  cur       : XML.ELEMENT;
  row       : XML.TAG;
BEGIN
  IF open THEN
    tables.table(t, W, TRUE);
    cur := tag.child.first;
    WHILE cur # NIL DO
      IF cur IS XML.TAG THEN
        row := cur(XML.TAG);
        IF row.value = XML.tag_tr THEN
          row.table := t;
          tr(t, row)
        END
      END;
      cur := cur.next
    END;
    tables.table(t, W, FALSE)
  END
END table;


PROCEDURE Image (VAR tag: XML.TAG; destroy: BOOLEAN);
VAR
	note  : BOOLEAN;
	img   : XML.TAG;
	URL   : INTEGER;
	chars : S.CHARS;
	sizeY : INTEGER;
	FName : S.STRING;
	path  : S.STRING;
BEGIN
	LibImg.Destroy(tag.img);
	img := XML.GetRef(tag, note, URL);
	IF img # NIL THEN
		IF img.child.first IS XML.WORD THEN
			chars := img.child.first(XML.WORD).value;
			tag.img := LibImg.GetImg(chars.first, chars.last - chars.first + 1, W, sizeY)
		END
	ELSIF URL # 0 THEN
		S.PtrToString(URL, FName);
		tag.img := LibImg.LoadFromFile(FName, W, sizeY);
		IF tag.img = 0 THEN
			path := FilePath;
			IF FName[0] # "/" THEN
				S.Append(path, "/")
			END;
			S.Append(path, FName);
			tag.img := LibImg.LoadFromFile(path, W, sizeY)
		END
	END;
	IF (tag.img # 0) & destroy THEN
		INC(Y, (sizeY DIV LineH) * LineH);
		NewLine;
		tag.Ymax := Y - Y MOD LineH;
		LibImg.Destroy(tag.img)
	END
END Image;


PROCEDURE layout(body: XML.ELEMENT);
VAR
  cur       : XML.ELEMENT;
  tag       : XML.TAG;
  word      : XML.WORD;
  text      : XML.TEXT;
  tag_value : INTEGER;
  _align    : INTEGER;
  title     : XML.ELEMENT;
  width     : INTEGER;
  height1   : INTEGER;
  height2   : INTEGER;

BEGIN
  cur := body;
  WHILE cur # NIL DO
    IF cur IS XML.TAG THEN
      tag := cur(XML.TAG);
      tag_value := tag.value;
      CASE tag_value OF
      |XML.tag_p, XML.tag_v:
        Trim;
        IF TextCount > 0 THEN
          NewLine
        END;
        X := Settings.PARAGRAPH + Epigraph()
      |XML.tag_epigraph:
        NewLine;
        INC(epigraph)
      |XML.tag_contents_item:
        INC(ref_depth);
        Settings.EPIGRAPH := Settings.LEVEL * Depth(tag);
        _align := align;
        align := 3
      |XML.tag_title:
        INC(strong);
        Font.Bold(TRUE);
        _align := align;
        align := 1;
        IF MainBody THEN
          tag.value := XML.tag_contents_item;
          title := XML.Copy(tag);
          XML.AddChild(contents, title);
          title.parent := tag.parent;
          tag.value := XML.tag_title
        END
      |XML.tag_subtitle:
        NewLine;
        _align := align;
        align := 1
      |XML.tag_text_author, XML.tag_date:
        _align := align;
        align := 2
      |XML.tag_section, XML.tag_body, XML.tag_empty_line, XML.tag_poem, XML.tag_stanza, XML.tag_annotation, XML.tag_cite:
        NewLine
      |XML.tag_a:
        INC(ref_depth);
        IF XML.IsNote(tag) THEN
          Sup(TRUE)
        END
      |XML.tag_sup:
        Sup(TRUE)
      |XML.tag_sub:
        Sub(TRUE)
      |XML.tag_code:
        Font.sysfont(TRUE);
        INC(code)
      |XML.tag_image:
        tag.X := 0;
        NewLine;
        NewLine
      |XML.tag_coverpage:
        cover := tag

      |XML.tag_table:
        NewLine;
        tables.destroy(tag.table);
        NEW(tag.table);
        table(tag.table, tag, TRUE)
      |XML.tag_td, XML.tag_th:
        IF tag_value = XML.tag_th THEN
          INC(strong);
          Font.Bold(TRUE);
        END;
        SU.ErrorIf(tag.parent(XML.TAG).value # XML.tag_tr, 21);
        NewLine; DEC(Y, LineH);
        tag.Width := tables.get_width(tag.table, tag.cell);
        tag.X := tables.get_x(tag.table, tag.cell);
        width := W;
        W := tag.Width - 2 * CellPadding;
        IF W <= 0 THEN
          W := 1
        END
      |XML.tag_tr:
        SU.ErrorIf(tag.parent(XML.TAG).value # XML.tag_table, 20)

      |XML.tag_strong:
        INC(strong);
        Font.Bold(TRUE)
      ELSE
      END;

      tag.Ymin := Y - Y MOD LineH;
      layout(tag.child.first);
      tag.Ymax := Y - Y MOD LineH;

      CASE tag_value OF
      |XML.tag_epigraph:
        NewLine;
        DEC(epigraph)
      |XML.tag_subtitle:
        NewLine;
        NewLine;
        align := _align
      |XML.tag_title, XML.tag_text_author, XML.tag_date:
        DEC(strong);
        Font.Bold(strong > 0);
        NewLine;
        align := _align
      |XML.tag_contents_item:
        DEC(ref_depth);
        align := _align;
      |XML.tag_section, XML.tag_poem, XML.tag_v, XML.tag_p, XML.tag_annotation, XML.tag_cite:
        NewLine
      |XML.tag_a:
        DEC(ref_depth);
        IF XML.IsNote(tag) THEN
          Sup(FALSE)
        END
      |XML.tag_sup:
        Sup(FALSE)
      |XML.tag_sub:
        Sub(FALSE)
      |XML.tag_code:
        DEC(code);
        Font.sysfont(code > 0)
      |XML.tag_image:
        Image(tag, TRUE)
      |XML.tag_table:
        Y := tag.Ymin + tables.get_table_height(tag.table);
        tag.Ymax := Y - Y MOD LineH;
        NewLine;
      |XML.tag_td, XML.tag_th:
        IF tag_value = XML.tag_th THEN
          DEC(strong);
          Font.Bold(strong > 0)
        END;
        W := width;
        NewLine;
        Y := tag.Ymin + Settings.SUP; //!!!
        height1 := tables.get_height(tag.table, tag.cell);
        height2 := tag.Ymax - tag.Ymin + LineH;
        IF height2 > height1 THEN
          tables.set_height(tag.table, tag.cell, height2)
        END;
        INC(tag.Ymin, tables.get_y(tag.table, tag.cell));
        INC(tag.Ymax, tables.get_height(tag.table, tag.cell));
        shift(tag, tag.X + CellPadding, tables.get_y(tag.table, tag.cell));

      |XML.tag_strong:
        DEC(strong);
        Font.Bold(strong > 0)
      ELSE
      END
    ELSIF cur IS XML.WORD THEN
      word := cur(XML.WORD);
      word.length := S.Utf8Length(word.value);
      word.width := Font.TextWidth(word.value, word.length);
      IF W - X < word.width THEN
        Align;
        NewLine
      END;
      IF W < word.width THEN
        Split(word)
      END
    ELSIF cur IS XML.SPACE THEN
      IF W - X < SpaceWidth() THEN
          cur(XML.SPACE).width := 0
      ELSE
          cur(XML.SPACE).width := SpaceWidth()
      END
    END;
    IF cur IS XML.TEXT THEN
      IF ref_depth > 0 THEN
        V.push(references, cur)
      END;
      text := cur(XML.TEXT);
      text.X := X;
      text.Y := Y;
      INC(X, text.width);
      AddToLine(text)
    END;
    cur := cur.next
  END
END layout;


PROCEDURE layout2(body: XML.ELEMENT);
VAR
  color : INTEGER;
  cur   : XML.ELEMENT;
  text  : XML.TEXT;
  tag   : XML.TAG;
  y, y0 : INTEGER;
  value : INTEGER;

  PROCEDURE DrawText(Col: Window.tRect; min, max, y0, y: INTEGER; right: BOOLEAN; VAR text: XML.TEXT);
  VAR word: XML.WORD;
  BEGIN
    IF (min <= y0) & (y0 <= max) THEN
      Font.sysfont(code > 0);
      IF text IS XML.WORD THEN
        word := text(XML.WORD);
        Font.Text(Col, word.X, y - Col.height * ORD(right), word.value.first, word.length);
      END;
      Font.StrikeText(Col, text.X, y - Col.height * ORD(right), text.width)
    END
  END DrawText;

  PROCEDURE DrawImage(VAR tag: XML.TAG);
  VAR sizeX, sizeY, img, y: INTEGER;
  BEGIN
    IF tag.img # 0 THEN
      y := Ycur;
      LibImg.GetInf(tag.img, sizeX, sizeY, img);
      IF (y <= tag.Ymax) & (tag.Ymin <= y + ColLeft.height) THEN
        G.Image(ColLeft.left + tag.X, tag.Ymin - y + ColLeft.top, sizeX, sizeY, img, ColLeft.top, ColLeft.top + ColLeft.height - 1)
      END;
      IF Settings.TwoCol THEN
        y := Ycur + ColLeft.height;
        IF (y <= tag.Ymax) & (tag.Ymin <= y + ColRight.height) THEN
          G.Image(ColRight.left + tag.X, tag.Ymin - y + ColLeft.top, sizeX, sizeY, img, ColRight.top, ColRight.top + ColRight.height - 1)
        END
      END
    END
  END DrawImage;

  PROCEDURE td(VAR tag: XML.TAG);
  VAR x1, y1, x2, y2, cl: INTEGER;
  BEGIN
    x1 := tag.X + ColLeft.left;
    y1 := tag.Ymin - Ycur + ColLeft.top;
    x2 := x1 + tag.Width;
    y2 := y1 + tables.get_height(tag.table, tag.cell);
    cl := G.GetColor();
    G.SetColor(Settings.Colors[TEXT_COLOR]);
    G.Rect(x1, y1, x2, y2);
    IF Settings.TwoCol THEN
      x1 := x1 - ColLeft.left + ColRight.left;
      x2 := x2 - ColLeft.left + ColRight.left;
      y1 := y1 - ColLeft.height;
      y2 := y2 - ColLeft.height;
      G.Rect(x1, y1, x2, y2)
    END;
    G.SetColor(cl)
  END td;

BEGIN
  cur := body;
  WHILE cur # NIL DO
    IF cur IS XML.TAG THEN
      tag := cur(XML.TAG);
      IF (tag.value = XML.tag_td) OR (tag.value = XML.tag_th) THEN
         tag.Ymax := tag.Ymin + tables.get_height(tag.table, tag.cell)
      END;

      IF (tag.Ymin < Ycur + LineH * Lines * (ORD(Settings.TwoCol) + 1)) & (tag.Ymax >= Ycur) OR (tag.value = XML.tag_tr) THEN

      value := tag.value;
      CASE value OF
      |XML.tag_a:
      	INC(refer);
        color := Font.Font.color;
        IF tag.Clicked THEN
          Font.SetFontColor(Settings.Colors[CLICKED_COLOR])
        ELSE
          IF tag.Visited THEN
            Font.SetFontColor(Settings.Colors[VISITED_COLOR])
          ELSE
            Font.SetFontColor(Settings.Colors[LINK_COLOR])
          END
        END
      |XML.tag_contents_item:
		IF tag.Clicked THEN
			INC(refer);
			color := Font.Font.color;
			Font.SetFontColor(Settings.Colors[CLICKED_COLOR])
		ELSIF tag.Visited THEN
			INC(refer);
			color := Font.Font.color;
			Font.SetFontColor(Settings.Colors[VISITED_COLOR])
		END
      |XML.tag_title, XML.tag_strong, XML.tag_th:
        INC(strong);
        Font.Bold(TRUE)
      |XML.tag_strikethrough:
        INC(strike);
        Font.Strike(TRUE)
      |XML.tag_epigraph, XML.tag_cite, XML.tag_emphasis:
        INC(italic);
        Font.Italic(TRUE, refer = 0)
      |XML.tag_image:
      	Image(tag, FALSE);
        DrawImage(tag);
        LibImg.Destroy(tag.img)
      |XML.tag_code:
        INC(code)
      ELSE
      END;
      layout2(tag.child.first);
      CASE value OF
      |XML.tag_a:
      	DEC(refer);
        Font.SetFontColor(color)
      |XML.tag_contents_item:
		IF tag.Clicked OR tag.Visited THEN
			DEC(refer);
			Font.SetFontColor(color)
		END
      |XML.tag_title, XML.tag_strong:
        DEC(strong);
        Font.Bold(strong > 0)
      |XML.tag_strikethrough:
        DEC(strike);
        Font.Strike(strike > 0)
      |XML.tag_epigraph, XML.tag_cite, XML.tag_emphasis:
        DEC(italic);
        Font.Italic(italic > 0, refer = 0)
      |XML.tag_td:
        td(tag)
      |XML.tag_th:
        DEC(strong);
        Font.Bold(strong > 0);
        td(tag)
      |XML.tag_code:
        DEC(code)
      ELSE
      END

      END
    ELSIF cur IS XML.TEXT THEN
      text := cur(XML.TEXT);
      y  := text.Y - Ycur;
      y0 := y - y MOD LineH;
      DrawText(ColLeft, 0, ColLeft.height - LineH, y0, y, FALSE, text);
      IF Settings.TwoCol THEN
        DrawText(ColRight, ColLeft.height, ColLeft.height + ColRight.height - LineH, y0, y, TRUE, text)
      END
    END;
    cur := cur.next
  END
END layout2;


PROCEDURE DrawFrame (color: INTEGER);
VAR max_X, max_Y: INTEGER;
BEGIN
  max_X := G.Buffer.Width - 1;
  max_Y := G.Buffer.Height - 1;
  G.SetColor(color);
  G.HLine(0, max_X, 0);
  G.HLine(0, max_X, max_Y);
  G.VLine(0, 0, max_Y);
  sb.max_area := (Ymax - Ymin) DIV LineH + 50;
  sb.cur_area := 50;
  sb.position := (Ycur - Ymin) DIV LineH;
  box_lib.scrollbar_v_draw(sb)
END DrawFrame;


PROCEDURE Draw*;
(*VAR max_Y: INTEGER;*)
BEGIN
  (*max_Y := G.Buffer.Height - 1;*)
  IF Settings.b_pict & (Settings.Picture # 0) THEN
      G.Copy(G.BackImg, G.Buffer, 0, G.Buffer.Height, 0)
  ELSE
      G.Fill(G.Buffer, Settings.Colors[BACK_COLOR])
  END;
  Font.SetFontColor(Settings.Colors[TEXT_COLOR]);
  IF ((body = description) OR (body = contents)) & Settings.TwoCol THEN
    Settings.TwoCol := FALSE;
    layout2(body.child.first);
    Settings.TwoCol := TRUE;
    Search.draw(body, ColLeft, ColRight, Ycur, LineH, FALSE)
  ELSE
    layout2(body.child.first);
    Search.draw(body, ColLeft, ColRight, Ycur, LineH, Settings.TwoCol)
  END;
  (*G.Copy(G.BackImg, G.Buffer, 0, ColLeft.top + 1, 0);
  G.Copy(G.BackImg, G.Buffer, max_Y - ColLeft.top, ColLeft.top + 1, max_Y - ColLeft.top);*)
  DrawFrame(0);
  G.Draw(Canvas_X, Canvas_Y);
  DrawToolbar;
  DrawStatus
END Draw;


PROCEDURE BackEnabled* (): BOOLEAN;
	RETURN b_stk.first # NIL
END BackEnabled;


PROCEDURE FrwEnabled* (): BOOLEAN;
	RETURN f_stk.first # NIL
END FrwEnabled;


PROCEDURE ContentsEnabled* (): BOOLEAN;
	RETURN (contents # NIL) (*& (body # contents)*)
END ContentsEnabled;


PROCEDURE DescrEnabled* (): BOOLEAN;
	RETURN (description # NIL) (*& (body # description)*)
END DescrEnabled;


PROCEDURE Back*;
BEGIN
  IF b_stk.first # NIL THEN
    Push(f_stk);
    Pop(b_stk)
  END
END Back;


PROCEDURE Forward*;
BEGIN
  IF f_stk.first # NIL THEN
    Push(b_stk);
    Pop(f_stk)
  END
END Forward;


PROCEDURE Contents*;
BEGIN
  IF (contents # NIL) & (body # contents) THEN
    Push(b_stk);
    Clear(f_stk);
    body := contents;
    Ycur := Ycont;
    Ymin := 0;
    Ymax := body.Ymax
  END
END Contents;


PROCEDURE Descr*;
BEGIN
  IF (description # NIL) & (body # description) THEN
    Push(b_stk);
    Clear(f_stk);
    body := description;
    Ycur := 0;
    Ymin := 0;
    Ymax := body.Ymax
  END
END Descr;


PROCEDURE Scroll* (n: INTEGER);
BEGIN
	INC(Ycur, LineH*n);
	SU.MinMax(Ycur, Ymin, Ymax)
END Scroll;


PROCEDURE PageUp*;
BEGIN
    Scroll(-Lines * (ORD(Settings.TwoCol) + 1))
END PageUp;


PROCEDURE PageDown*;
BEGIN
    Scroll(Lines * (ORD(Settings.TwoCol) + 1))
END PageDown;


PROCEDURE Home*;
BEGIN
  IF Ycur # Ymin THEN
    Push(b_stk);
    Clear(f_stk);
    Ycur := Ymin
  END
END Home;


PROCEDURE End*;
BEGIN
  IF Ycur # Ymax THEN
    Push(b_stk);
    Clear(f_stk);
    Ycur := Ymax
  END
END End;


PROCEDURE ScrollBar*;
BEGIN
  Ycur := sb.position * LineH + Ymin
END ScrollBar;


PROCEDURE GetBody(tag: XML.TAG): XML.TAG;
BEGIN
  WHILE (tag # NIL) & (tag.value # XML.tag_body) DO
    tag := tag.parent(XML.TAG)
  END
  RETURN tag
END GetBody;


PROCEDURE layout3(Body: XML.ELEMENT; X, Y: INTEGER);
VAR
  ptr   : V.ANYPTR;
  text  : XML.TEXT;
  sect  : XML.TAG;
  y     : INTEGER;
  i     : INTEGER;
BEGIN
  i := 0;
  WHILE i < references.count DO
    ptr := V.get(references, i);
    text := ptr(XML.TEXT);
    y  := text.Y - Ycur;
    IF (y <= Y) & (Y <= y + Font.FontH()) & (text.X <= X) & (X <= text.X + text.width) THEN
      sect := text.parent(XML.TAG);
      IF Body = contents THEN
        WHILE (sect # NIL) & (sect.value # XML.tag_contents_item) DO
          sect := sect.parent(XML.TAG)
        END
      ELSE
        WHILE (sect # NIL) & (sect # Body) DO
          IF sect.value = XML.tag_contents_item THEN
            sect := NIL
          ELSE
            sect := sect.parent(XML.TAG)
          END
        END
      END;

      IF sect # NIL THEN
        sect := text.parent(XML.TAG);
        WHILE sect # NIL DO
          IF (sect.value = XML.tag_contents_item) & (Body = contents) OR (sect.value = XML.tag_a) THEN
            ref := sect;
            sect := NIL;
            i := references.count
          ELSE
            sect := sect.parent(XML.TAG)
          END
        END
      END
    END;
    INC(i)
  END
END layout3;


PROCEDURE getRefProp (VAR ref, body: XML.TAG; VAR URL: INTEGER; VAR note: BOOLEAN; VAR Y: INTEGER);
BEGIN
	note := FALSE;
	URL := 0;
	Y := 0;
	IF ref.value = XML.tag_a THEN
		ref := XML.GetRef(ref, note, URL)
	ELSE
		ref := ref.parent(XML.TAG)
	END;
	IF ref # NIL THEN
		Y := ref.Ymin;
	END;
	IF note THEN
	  	body := ref
	ELSE
	  	body := GetBody(ref)
	END
END getRefProp;


PROCEDURE zstreq (s1, s2: INTEGER): BOOLEAN;
VAR
    c1, c2: CHAR;
BEGIN
    REPEAT
        sys.GET(s1, c1); INC(s1);
        sys.GET(s2, c2); INC(s2);
    UNTIL (c1 = 0X) OR (c2 = 0X)

    RETURN c1 = c2
END zstreq;


PROCEDURE refeq (ref1, ref2: XML.TAG): BOOLEAN;
VAR
	body1, body2: XML.TAG;
	URL1, URL2: INTEGER;
	note1, note2: BOOLEAN;
	Y1, Y2: INTEGER;
BEGIN
	getRefProp(ref1, body1, URL1, note1, Y1);
	getRefProp(ref2, body2, URL2, note2, Y2);
	RETURN (ref1 = ref2) & (body1 = body2) & (URL1 = 0) & (URL2 = 0) & (note1 = note2) & (Y1 = Y2) OR
			(URL1 # 0) & (URL2 # 0) & zstreq(URL1, URL2)
END refeq;


PROCEDURE setVisited (ref: XML.TAG);
VAR
	i: INTEGER;
	cur: V.ANYPTR;
BEGIN
	FOR i := 0 TO references.count - 1 DO
		cur := V.get(references, i);
		IF cur IS XML.TEXT THEN
			cur := cur(XML.TEXT).parent;
			IF refeq(cur(XML.TAG), ref) THEN
				cur(XML.TAG).Visited := TRUE
			END
		END
	END
END setVisited;


PROCEDURE MouseDown;
BEGIN
	IF ~mouseDown THEN
		mouseDown := TRUE;
		clickRef := ref;
		IF ref # NIL THEN
			ref.Clicked := TRUE
		END;
		Draw
	END
END MouseDown;


PROCEDURE MouseUp;
VAR
	note : BOOLEAN;
	URL  : INTEGER;
	redraw: BOOLEAN;
BEGIN
	redraw := FALSE;
	mouseDown := FALSE;
	IF (ref # NIL) & (clickRef = ref) & ref.Clicked THEN
		redraw := TRUE;
        ref.Clicked := FALSE;
		note := FALSE;
		URL := 0;
		IF ref.value = XML.tag_a THEN
			ref := XML.GetRef(ref, note, URL)
		ELSE
			ref := ref.parent(XML.TAG)
		END;
		IF ref # NIL THEN
			Push(b_stk);
			Clear(f_stk);
			Ycur := ref.Ymin;
			IF note THEN
			  	body := ref
			ELSE
			  	body := GetBody(ref)
			END;
			Ymax := body.Ymax;
			Ymin := body.Ymin;

			IF ~clickRef.Visited THEN
				setVisited(clickRef);
				clickRef.Visited := TRUE;
				PushRef(clickRef)
			END
		ELSIF URL # 0 THEN
			SU.Run(Ini.Browser, URL);
			IF ~clickRef.Visited THEN
				setVisited(clickRef);
				clickRef.Visited := TRUE;
				PushRef(clickRef)
			END
		END
	END;
	IF clickRef # NIL THEN
		clickRef.Clicked := FALSE;
		clickRef := NIL;
		redraw := TRUE
	END;
	IF hoverRef # NIL THEN
		hoverRef.Clicked := FALSE;
		hoverRef := NIL;
		redraw := TRUE
	END;
	IF redraw THEN
		Draw
	END
END MouseUp;


PROCEDURE Click*(X, Y: INTEGER; clicked: BOOLEAN);
VAR
  note : BOOLEAN;
  URL  : INTEGER;
  urlchars: S.CHARS;
  urlstr1 : S.STRING;
BEGIN
  DEC(Y, Settings.PADDING.Top);
  DEC(X, Settings.PADDING.Left);
  IF (0 <= Y) & (Y <= Lines * LineH) THEN
    ref := NIL;
    layout3(body, X, Y);
    IF (ref = NIL) & Settings.TwoCol THEN
      layout3(body, X - ColLeft.width - Settings.PADDING.ColInter, Y + Lines * LineH);
    END;
    hoverRef := ref;
	IF clicked THEN
		MouseDown
	ELSE
		MouseUp
	END;
    IF ref # NIL THEN
      SU.SetCursor(cursor);
      note := FALSE;
      URL := 0;
      IF ref.value = XML.tag_a THEN
        ref := XML.GetRef(ref, note, URL)
      END;
      IF URL # 0 THEN
        S.PtrToString(URL, urlstr1);
        S.StrToChars(urlstr1, urlchars)
      END
    ELSE
      SU.SetCursor(0);
      urlstr1 := ""
    END;
    IF urlstr1 # urlstr THEN
      urlstr := urlstr1;
      DrawStatus
    END
  ELSE
      SU.SetCursor(0);
      urlstr := "";
      ref := NIL;
      DrawStatus
  END
END Click;


PROCEDURE main(fb: XML.ELEMENT; Contents: BOOLEAN);
VAR
  cur: XML.ELEMENT;
  tag: XML.TAG;
  par, epi: INTEGER;


  PROCEDURE lout(body: XML.ELEMENT);
  BEGIN
    TextCount := 0;
    X := 0;
    Y := Settings.SUP;
    layout(body(XML.TAG).child.first);
    body(XML.TAG).Ymax := Y - Settings.SUP
  END lout;

  PROCEDURE lout_one_col(body: XML.ELEMENT);
  BEGIN
    IF body # NIL THEN
      IF Settings.TwoCol THEN
        W := W2;
        Settings.TwoCol := FALSE;
        lout(body);
        Settings.TwoCol := TRUE;
        W := W1
      ELSE
        lout(body)
      END
    END
  END lout_one_col;

BEGIN
  TextCount := 0;
  sup := 0;
  sub := 0;
  epigraph := 0;
  align := 0;
  code := 0;
  strong := 0;
  italic := 0;
  strike := 0;
  refer := 0;
  SU.ErrorIf(fb = NIL, 11);
  MainBody := FALSE;
  description := NIL;
  mainbody := NIL;
  cover := NIL;
  cur := fb;
  cur := cur(XML.TAG).child.first;
  WHILE (cur # NIL) & (mainbody = NIL) DO
    IF cur IS XML.TAG THEN
      tag := cur(XML.TAG);
      IF tag.value = XML.tag_description THEN
        description := tag
      ELSIF tag.value = XML.tag_body THEN
        mainbody := tag
      END
    END;
    cur := cur.next
  END;
  SU.ErrorIf(mainbody = NIL, 12);

  WHILE cur # NIL DO
    IF (cur IS XML.TAG) & (cur(XML.TAG).value = XML.tag_body) THEN
      lout(cur)
    END;
    cur := cur.next
  END;

  IF Contents THEN
    contents := XML.CreateTag();
    MainBody := TRUE;
  END;
  lout(mainbody);
  IF Contents & (contents.child.first = NIL) THEN
    DISPOSE(contents)
  END;
  MainBody := FALSE;
  epigraph := 1;
  par := Settings.PARAGRAPH;
  epi := Settings.EPIGRAPH;
  Settings.PARAGRAPH := 0;
  Settings.EPIGRAPH := 0;
  lout_one_col(contents);
  Settings.EPIGRAPH := epi;
  Settings.PARAGRAPH := par;
  epigraph := 0;
  lout_one_col(description);
  body := mainbody;
  Ymax := body.Ymax;
  Ycur := 0;
  Ymin := 0;
  Ycont := 0
END main;


PROCEDURE Find* (d: INTEGER);
VAR
    y, min, max: INTEGER;

BEGIN
    Search.fnext(body, y, d);
    IF y >= 0 THEN
        DEC(y, y MOD LineH);
        min := Ycur;
        max := min + ColLeft.height - LineH;
        IF Settings.TwoCol THEN
            INC(max, ColRight.height)
        END;

        IF (y < min) OR (y > max) THEN
            Ycur := MAX(y - ColLeft.height DIV 2, 0)
        END;

        DEC(Ycur, Ycur MOD LineH)
    END
END Find;


PROCEDURE OpenSearch*;
BEGIN
    Search.open(Find)
END OpenSearch;


PROCEDURE CloseSearch*;
BEGIN
    Search.close
END CloseSearch;


PROCEDURE found* (): BOOLEAN;
    RETURN Search.found(body)
END found;


PROCEDURE FontSizeChange(fs: INTEGER);
BEGIN
  Settings.SUP               :=  fs DIV 4;
  Settings.SUB               :=  fs DIV 4;
  Settings.SpaceW            :=  fs DIV 2;
  Settings.LEVEL             :=  Settings.PARAGRAPH;
  Settings.PADDING.Bottom    :=  Settings.PADDING.Top;
  Settings.PADDING.Left      :=  G.Buffer.Width * Settings.PADDING.LRpc DIV 100;
  IF Settings.PADDING.Left = 0 THEN
    Settings.PADDING.Left := 1
  END;
  Settings.PADDING.Right     :=  Settings.PADDING.Left;
  Settings.PADDING.ColInter  :=  G.Buffer.Width * Settings.PADDING.CInt DIV 100;

  LineH := Font.FontH() + Settings.SUP + Settings.SUB + Settings.InterLin;
  Window.initRect(
    ColLeft, Settings.PADDING.Left, Settings.PADDING.Top,
    G.Buffer.Width - Settings.PADDING.Left - Settings.PADDING.Right,
    G.Buffer.Height - Settings.PADDING.Top - Settings.PADDING.Bottom);
  IF Settings.TwoCol THEN
    ColLeft.width := (ColLeft.width - Settings.PADDING.ColInter) DIV 2;
    ColRight := ColLeft;
    ColRight.left := ColLeft.left + ColLeft.width + Settings.PADDING.ColInter
  END;
  W := ColLeft.width;
  Lines := ColLeft.height DIV LineH;
  ColLeft.height  := Lines * LineH;
  ColRight.height := ColLeft.height;
END FontSizeChange;


PROCEDURE Resize*(Width, Height: INTEGER);
VAR d: REAL; resize: BOOLEAN; sizeX, sizeY, data, back_picture: INTEGER;

  PROCEDURE stk1(stk: XML.LIST);
  VAR cur: StackItem;
  BEGIN
    cur := stk.first(StackItem);
    WHILE cur # NIL DO
      cur.d := FLT(cur.Ycur - cur.body.Ymin) / FLT(cur.body.Ymax - cur.body.Ymin);
      cur := cur.next(StackItem)
    END
  END stk1;

  PROCEDURE stk2(stk: XML.LIST);
  VAR cur: StackItem;
  BEGIN
    cur := stk.first(StackItem);
    WHILE cur # NIL DO
      cur.Ycur := FLOOR(FLT(cur.body.Ymax - cur.body.Ymin) * cur.d) + cur.body.Ymin;
      cur.Ycur := cur.Ycur - cur.Ycur MOD LineH;
      SU.MinMax(cur.Ycur, cur.body.Ymin, cur.body.Ymax);
      cur := cur.next(StackItem)
    END
  END stk2;

BEGIN
  resize := (Width # G.Buffer.Width) OR resized;
  G.Resize(Width, Height);
  IF (Settings.Picture # 0) & Settings.b_pict THEN
  	back_picture := LibImg.GetImg(Settings.Picture, Settings.picture_fsize, 1000000, sizeY);
  	IF back_picture # 0 THEN
	    LibImg.GetInf(back_picture, sizeX, sizeY, data);
    	G.CreateBackImg;
	    G.BackImage(sizeX, sizeY, data);
    	LibImg.Destroy(back_picture)
    END
  ELSE
    G.DestroyBackImg;
    G.Fill(G.Buffer, Settings.Colors[BACK_COLOR]);
    //G.Fill(G.BackImg, Settings.Colors[BACK_COLOR])
  END;

  IF Font.FontH() # 0 THEN
    FontSizeChange(Font.FontH());
  ELSE
    FontSizeChange(Settings.FontSize);
  END;

  ColLeft.width  := G.Buffer.Width - Settings.PADDING.Left - Settings.PADDING.Right;
  IF Settings.TwoCol THEN
    ColLeft.width  := (ColLeft.width - Settings.PADDING.ColInter) DIV 2;
    ColRight.width := ColLeft.width;
    ColRight.left  := ColLeft.left + ColLeft.width + Settings.PADDING.ColInter
  END;
  ColLeft.height  := G.Buffer.Height - Settings.PADDING.Top  - Settings.PADDING.Bottom;
  Lines           := ColLeft.height DIV LineH;
  ColLeft.height  := Lines * LineH;
  ColRight.height := ColLeft.height;

  IF done & resize THEN
    resized := FALSE;
    Push(b_stk);
    stk1(b_stk);
    stk1(f_stk);
    IF contents # NIL THEN
      d := FLT(Ycont) / FLT(contents.Ymax)
    END;
    W := ColLeft.width;
    W2 := ColLeft.width + ColRight.width + Settings.PADDING.ColInter;
    W1 := W;
    main(XML.FB, FALSE);
    Search.resize;
    stk2(b_stk);
    stk2(f_stk);
    IF contents # NIL THEN
      Ycont := FLOOR(FLT(contents.Ymax) * d);
      Ycont := Ycont - Ycont MOD LineH;
      SU.MinMax(Ycont, 0, contents.Ymax)
    END;
    Pop(b_stk);
  END
END Resize;


PROCEDURE SetColors*;
BEGIN
  Settings.Colors[BACK_COLOR]     := Ini.GetColor("back",    Settings.Colors[BACK_COLOR]);
  Settings.Colors[TEXT_COLOR]     := Ini.GetColor("text",    Settings.Colors[TEXT_COLOR]);
  Settings.Colors[ITALIC_COLOR]   := Ini.GetColor("italic",  Settings.Colors[ITALIC_COLOR]);
  Settings.Colors[LINK_COLOR]     := Ini.GetColor("link",    Settings.Colors[LINK_COLOR]);
  Settings.Colors[VISITED_COLOR]  := Ini.GetColor("visited", Settings.Colors[LINK_COLOR]);
END SetColors;


PROCEDURE Resized(set1, set2: TSettings): BOOLEAN;
  RETURN (set1.FontSize # set2.FontSize) OR (set1.TwoCol # set2.TwoCol) OR
         (set1.PARAGRAPH # set2.PARAGRAPH) OR (set1.EPIGRAPH # set2.EPIGRAPH) OR
         (set1.PADDING.LRpc # set2.PADDING.LRpc) OR (set1.PADDING.CInt # set2.PADDING.CInt)
         OR (set1.InterLin # set2.InterLin)
END Resized;


PROCEDURE SetSettings*(NewSet: TSettings);
BEGIN
  resized := Resized(Settings, NewSet) OR resized;
  Settings := NewSet;
  Font.Init(Settings.Colors[ITALIC_COLOR], Settings.Colors[TEXT_COLOR], Settings.FontSize);
  Resize(G.Buffer.Width, G.Buffer.Height)
END SetSettings;


PROCEDURE Init*(Left, Top, Width, Height: INTEGER);
BEGIN
  G.Resize(Width, Height);
  Canvas_X := Left;
  Canvas_Y := Top
END Init;


PROCEDURE Start;
BEGIN
  XML.Open(FileName);
  main(XML.FB, TRUE);
  done := TRUE;
  SU.Halt
END Start;


PROCEDURE CleanHistory*(fname: S.STRING);
VAR F: File.FS; pos, pos2, fsize, size, buf, buf2: INTEGER; c: CHAR;
BEGIN
  F := File.Open(fname);
  IF F # NIL THEN
    fsize := File.Seek(F, 0, 2);
    pos := File.Seek(F, 0, 0);
    buf := K.malloc(fsize + 1024);
    buf2 := K.malloc(fsize + 1024);
    pos := File.Read(F, buf, fsize);
    File.Close(F);
    pos := 0;
    pos2 := 0;
    WHILE pos < fsize DO
      sys.GET(buf + pos, size);
      sys.GET(buf + pos + 4, c);
      IF c = 0X THEN
        sys.MOVE(buf + pos, buf2 + pos2, size);
        pos2 := pos2 + size
      END;
      pos := pos + size
    END;
    F := File.Create(fname);
    pos := File.Write(F, buf2, pos2);
    File.Close(F);
    buf := K.free(buf);
    buf2 := K.free(buf2)
  END
END CleanHistory;


PROCEDURE Save;
VAR history: File.FS; size, pos: INTEGER;

  PROCEDURE WriteInt(history: File.FS; x: INTEGER);
  BEGIN
    IF File.WriteInt(history, x) THEN END
  END WriteInt;

  PROCEDURE WriteStk(history: File.FS; VAR stk: XML.LIST; links: BOOLEAN);
  VAR
      cur: StackItem;
  BEGIN
    WriteInt(history, XML.ListCount(stk));
    cur := stk.first(StackItem);
    WHILE cur # NIL DO
      WriteInt(history, cur.body.num);
      IF ~links THEN
      	WriteInt(history, cur.Ycur)
      END;
      cur := cur.next(StackItem)
    END
  END WriteStk;

BEGIN
  Ini.Save(Settings.Colors, Settings.b_pict);
  history := File.Open(Ini.History);
  IF history = NIL THEN
    history := File.Create(Ini.History)
  ELSE
    pos := File.Seek(history, 0 , 2)
  END;
  size := 1 + 18*4 + 1 + 8*(XML.ListCount(b_stk) + XML.ListCount(f_stk)) + 4*XML.ListCount(vis_ref) + 12;
  WriteInt(history, size);
  IF File.WriteChar(history, 0X) THEN END;
  WriteInt(history, fsize2);
  WriteInt(history, chksum);
  WriteInt(history, win_size_x);
  WriteInt(history, win_size_y);
  WriteInt(history, Settings.PADDING.LRpc);
  WriteInt(history, Settings.PADDING.Top);
  WriteInt(history, Settings.PADDING.CInt);
  WriteInt(history, Settings.PARAGRAPH);
  WriteInt(history, Settings.EPIGRAPH);
  WriteInt(history, Settings.InterLin);

  IF File.WriteBool(history, Settings.TwoCol) THEN END;

  WriteInt(history, Settings.FontSize);
  WriteInt(history, body.num);
  WriteInt(history, Ymin);
  WriteInt(history, Ymax);
  WriteInt(history, Ycur);
  WriteInt(history, Ycont);

  WriteStk(history, b_stk, FALSE);
  WriteStk(history, f_stk, FALSE);
  WriteStk(history, vis_ref, TRUE);

  WriteInt(history, size);

  File.Close(history);
  CleanHistory(Ini.History)
END Save;


PROCEDURE ReadInt(VAR x: INTEGER);
BEGIN
  IF File.ReadInt(history, x) THEN END
END ReadInt;


PROCEDURE Load;
VAR body_num, ycur, size, pos: INTEGER;

  PROCEDURE ReadStk(VAR stk: XML.LIST);
  VAR n, num: INTEGER;
  BEGIN
    ReadInt(n);
    WHILE n > 0 DO
      ReadInt(num);
      body := XML.GetTagByNum(num);
      ReadInt(Ycur);
      Push(stk);
      DEC(n)
    END
  END ReadStk;

	PROCEDURE ReadRef;
	VAR
		n, num: INTEGER;
		ref: XML.TAG;
	BEGIN
		ReadInt(n);
		WHILE n > 0 DO
			ReadInt(num);
			ref := XML.GetTagByNum(num);
			IF ref # NIL THEN
				setVisited(ref);
				ref.Visited := TRUE;
				PushRef(ref)
			END;
			DEC(n)
		END
	END ReadRef;

BEGIN
  ReadInt(Settings.PADDING.LRpc);
  ReadInt(Settings.PADDING.Top);
  ReadInt(Settings.PADDING.CInt);
  ReadInt(Settings.PARAGRAPH);
  ReadInt(Settings.EPIGRAPH);
  ReadInt(Settings.InterLin);
  IF File.ReadBool(history, Settings.TwoCol) THEN END;
  ReadInt(Settings.FontSize);

  SetSettings(Settings);

  ReadInt(body_num);
  ReadInt(Ymin);
  ReadInt(Ymax);
  ReadInt(ycur);
  ReadInt(Ycont);

  ReadStk(b_stk);
  ReadStk(f_stk);
  ReadRef;

  ReadInt(size);
  pos := File.Seek(history, -size, 1);
  pos := File.Seek(history, 4, 1);
  IF File.WriteChar(history, 1X) THEN END;

  Ycur := ycur;
  body := XML.GetTagByNum(body_num);
  File.Close(history)
END Load;


PROCEDURE GetWinSize*(hist_fn: S.STRING; VAR win_size_x, win_size_y: INTEGER);
VAR c: CHAR; size, pos, x, y, fsize, _chksum: INTEGER; found: BOOLEAN;
BEGIN
  fsize2 := RF.FileSize(hist_fn);
  chksum := RF.ChkSum(hist_fn);
  found := FALSE;
  history := File.Open(Ini.History);
  pos := File.Seek(history, -4, 2);
  last := FALSE;
  WHILE pos >= 0 DO
    IF File.ReadInt(history, size) THEN
      pos := File.Seek(history, -size + 4, 1);
    END;
    IF File.ReadChar(history, c) THEN END;
    ReadInt(fsize);
    ReadInt(_chksum);
    IF (c = 0X) & (fsize = fsize2) & (_chksum = chksum) THEN
      found := TRUE;
      IF File.ReadInt(history, x) & File.ReadInt(history, y) THEN
        win_size_x := x;
        win_size_y := y;
      ELSE
        found := FALSE
      END;
      pos := -1
    ELSE
      IF ~last THEN
        last := TRUE;
        ReadInt(x);
        ReadInt(y);
        ReadInt(Settings.PADDING.LRpc);
        ReadInt(Settings.PADDING.Top);
        ReadInt(Settings.PADDING.CInt);
        ReadInt(Settings.PARAGRAPH);
        ReadInt(Settings.EPIGRAPH);
        ReadInt(Settings.InterLin);
        IF File.ReadBool(history, Settings.TwoCol) THEN END;
        ReadInt(Settings.FontSize);
      END;
      pos := File.Seek(history, pos - 8, 0)
    END
  END;
  IF ~found THEN
    File.Close(history)
  END
END GetWinSize;


PROCEDURE Open*(FName: S.STRING; DrawWindow, _DrawStatus, _DrawToolbar: SU.ENTRY);
VAR PID, event: INTEGER;
BEGIN
  DrawStatus := _DrawStatus;
  DrawToolbar := _DrawToolbar;
  cursor := SU.LoadCursor(Cursor.GetCursor());
  references := V.create(1024);
  ref_depth := 0;
  done := FALSE;
  loaded := FALSE;
  FilePath := FName;
  FileName := FName;
  S.GetPath(FilePath);
  W  := ColLeft.width;
  W1 := W;
  W2 := ColLeft.width + ColRight.width + Settings.PADDING.ColInter;
  Lines := ColLeft.height DIV LineH;
  ColLeft.height := Lines * LineH;
  PID := SU.NewThread(Start, Stack);
  WHILE ~SU.IsTerminated(PID) DO
    event := SU.CheckEvent();
    IF event = 3 THEN
      SU.TerminateThreadId(PID);
      SU.Halt
    END;
    G.Progress(RF.Progress());
    G.Draw(Canvas_X, Canvas_Y);
    DrawWindow;
    SU.Pause(30)
  END;
  IF ~done THEN
    SU.Halt
  END;
  loaded := TRUE;
  resized := TRUE;
  IF history # NIL THEN
    Load
  ELSE
    SetSettings(Settings)
  END
END Open;


PROCEDURE Close*;
BEGIN
  SU.DelCursor(cursor);
  Save;
  SU.Halt
END Close;


PROCEDURE SetScrollBar*(_sb: box_lib.scrollbar);
BEGIN
  sb := _sb
END SetScrollBar;


PROCEDURE Set_b_pict*(b_pict: BOOLEAN);
BEGIN
  Settings.b_pict := b_pict
END Set_b_pict;


PROCEDURE SetWinSize* (x, y: INTEGER);
BEGIN
	win_size_x := x;
	win_size_y := y
END SetWinSize;


BEGIN
	clickRef := NIL;
	hoverRef := NIL;
	mouseDown := FALSE
END DOM.