(*
    Copyright 2021 Anton Krotov

    This file is part of CEdit.

    CEdit 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.

    CEdit 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 CEdit. If not, see <http://www.gnu.org/licenses/>.
*)

MODULE Menu;

IMPORT
    SYSTEM, G := Graph, List, K := KolibriOS;

CONST
    fontHeight = 20;
    fontWidth = 8;

    RIGHT = 16;
    LEFT = 16;
    TOP = 1;

    backColor = 0F0F0F0H;
    foreColor = 0;
    selBackColor = 091C9F7H;
    selForeColor = 0;
    disBackColor = backColor;
    disForeColor = 808080H;
    disSelBackColor = 0E4E4E4H;
    disSelForeColor = disForeColor;


TYPE
    tItem* = POINTER TO RECORD (List.tItem)
        id*, check: INTEGER;
        text: ARRAY 32 OF WCHAR;
        enabled, delim: BOOLEAN
    END;

    tMenu* = POINTER TO RECORD
        tid*: INTEGER;
        winX, winY, width*, height*: INTEGER;
        selItem, cliItem: INTEGER;

        font: G.tFont;
        canvas: G.tCanvas;

        items: List.tList;
        click: PROCEDURE (menu: tMenu; id: INTEGER);
        key: PROCEDURE (menu: tMenu; key: INTEGER): BOOLEAN
    END;

    tClick = PROCEDURE (menu: tMenu; id: INTEGER);
    tKey = PROCEDURE (menu: tMenu; key: INTEGER): BOOLEAN;

VAR
    lastTID*: INTEGER;
    stack: ARRAY 250000 OF INTEGER;


PROCEDURE exit (m: tMenu);
BEGIN
    m.tid := 0;
    K.Exit
END exit;


PROCEDURE repaint (m: tMenu);
VAR
    y, i: INTEGER;
    item: tItem;
    BkColor, TextColor: INTEGER;
    canvas: G.tCanvas;

BEGIN
    canvas := m.canvas;
    G.SetColor(canvas, backColor);
    G.clear(canvas);
    G.SetColor(canvas, ORD((-BITS(backColor))*{0..23}) );
    G.Rect(canvas, 0, 0, m.width, m.height);
    y := TOP;
    i := 0;
    item := m.items.first(tItem);
    WHILE item # NIL DO
        IF item.enabled THEN
            IF i # m.selItem THEN
                BkColor := backColor;
                TextColor := foreColor
            ELSE
                BkColor := selBackColor;
                TextColor := selForeColor
            END
        ELSE
            IF i # m.selItem THEN
                BkColor := disBackColor;
                TextColor := disForeColor
            ELSE
                BkColor := disSelBackColor;
                TextColor := disSelForeColor
            END
        END;
        G.SetColor(canvas, BkColor);
        G.FillRect(canvas, 1, y, m.width - 1, y + fontHeight - 4);
        G.SetTextColor(canvas, TextColor);
        G.SetBkColor(canvas, BkColor);
        G.TextOut2(canvas, LEFT, y + (fontHeight - 16) DIV 2 - 2, item.text, LENGTH(item.text));

        IF item.check = 1 THEN
            G.SetColor(canvas, TextColor);
            G.DLine(canvas, 4, 7, y + (fontHeight - 16) DIV 2 + 5, -1);
            G.DLine(canvas, 4, 7, y + (fontHeight - 16) DIV 2 + 6, -1);
            G.DLine(canvas, 7, 12, y + (fontHeight - 16) DIV 2 + 8, 1);
            G.DLine(canvas, 7, 12, y + (fontHeight - 16) DIV 2 + 9, 1);
        ELSIF item.check = 2 THEN
            G.SetColor(canvas, TextColor);
            G.FillRect(canvas, 6, y + fontHeight DIV 2 - 4, 10, y + fontHeight DIV 2)
        END;

        INC(y, fontHeight);
        IF item.delim THEN
            G.SetColor(canvas, ORD((-BITS(backColor))*{0..23}));
            G.HLine(canvas, y - 2, 1, m.width - 1)
        END;
        INC(i);
        item := item.next(tItem)
    END;
    G.DrawCanvas(canvas, 0, 0)
END repaint;


PROCEDURE draw_window (m: tMenu);
BEGIN
    K.BeginDraw;
    K.CreateWindow(m.winX, m.winY, m.width, m.height, 0, 61H, 0, 1, "");
    repaint(m);
    K.EndDraw
END draw_window;


PROCEDURE mouse (m: tMenu; VAR x, y: INTEGER);
VAR
    mouseX, mouseY: INTEGER;
BEGIN
    K.MousePos(mouseX, mouseY);
    x := mouseX - m.winX;
    y := mouseY - m.winY;
END mouse;


PROCEDURE click (m: tMenu; i: INTEGER);
VAR
    item: List.tItem;
BEGIN
    item := List.getItem(m.items, i);
    IF (item # NIL) & item(tItem).enabled THEN
        m.click(m, item(tItem).id);
        exit(m)
    END
END click;


PROCEDURE [stdcall] window (m: tMenu);
VAR
    x, y: INTEGER;
    key: INTEGER;
    msState: SET;
BEGIN
    m.selItem := -1;
    m.cliItem := -1;
    K.SetEventsMask({0, 1, 5});
    WHILE TRUE DO
        CASE K.WaitForEvent() OF
        |1:
            draw_window(m)
        |2:
            key := K.GetKey();
            IF key DIV 65536 = 72 THEN
                DEC(m.selItem);
                IF m.selItem < 0 THEN
                    m.selItem := 0
                END
            ELSIF key DIV 65536 = 80 THEN
                INC(m.selItem);
                IF m.selItem >= m.items.count THEN
                    m.selItem := m.items.count - 1
                END
            ELSIF key DIV 65536 = 28 THEN
                IF m.selItem >= 0 THEN
                    click(m, m.selItem)
                END;
                m.cliItem := -1
            ELSE
                IF m.key(m, key) THEN
                    exit(m)
                END
            END;
            repaint(m)
        |6:
            msState := K.MouseState();
            mouse(m, x, y);
            IF (0 <= x) & (x < m.width) & (0 <= y) & (y < m.height) THEN
                m.selItem := (y - TOP) DIV fontHeight;
                IF 8 IN msState THEN
                    m.cliItem := (y - TOP) DIV fontHeight
                END;
                IF 16 IN msState THEN
                    IF m.cliItem = m.selItem THEN
                        click(m, m.cliItem)
                    END;
                    m.cliItem := -1
                END
            ELSE
                m.cliItem := -1;
                IF {8, 9, 10} * msState # {} THEN
                    exit(m)
                END
            END;
            repaint(m)
        END
    END
END window;


PROCEDURE AddMenuItem* (items: List.tList; id: INTEGER; s: ARRAY OF WCHAR);
VAR
    item: tItem;
BEGIN
    NEW(item);
    item.id := id;
    item.text := s;
    item.enabled := TRUE;
    item.delim := FALSE;
    List.append(items, item);
END AddMenuItem;


PROCEDURE delimiter* (items: List.tList);
BEGIN
    items.last(tItem).delim := TRUE
END delimiter;


PROCEDURE getItem (m: tMenu; id: INTEGER): tItem;
VAR
    item: tItem;
BEGIN
    item := m.items.first(tItem);
    WHILE (item # NIL) & (item.id # id) DO
        item := item.next(tItem)
    END
    RETURN item
END getItem;


PROCEDURE setEnabled* (m: tMenu; id: INTEGER; value: BOOLEAN);
VAR
    item: tItem;
BEGIN
    item := getItem(m, id);
    IF item # NIL THEN
        item.enabled := value
    END
END setEnabled;


PROCEDURE setCheck* (m: tMenu; id: INTEGER; value: INTEGER);
VAR
    item: tItem;
BEGIN
    item := getItem(m, id);
    IF item # NIL THEN
        item.check := value
    END
END setCheck;


PROCEDURE isEnabled* (m: tMenu; id: INTEGER): BOOLEAN;
VAR
    item: tItem;
BEGIN
    item := getItem(m, id)
    RETURN (item # NIL) & item.enabled
END isEnabled;


PROCEDURE opened* (m: tMenu): BOOLEAN;
    RETURN m.tid # 0
END opened;


PROCEDURE open* (m: tMenu; x, y: INTEGER);
BEGIN
    IF m.tid = 0 THEN
        m.winX := x;
        m.winY := y;
        SYSTEM.PUT(SYSTEM.ADR(stack[LEN(stack) - 1]), m);
        lastTID := K.CreateThread(SYSTEM.ADR(window), stack);
        m.tid := lastTID
    END
END open;


PROCEDURE close* (m: tMenu);
BEGIN
    IF m.tid # 0 THEN
        K.ExitID(m.tid);
        m.tid := 0
    END
END close;


PROCEDURE create* (items: List.tList; click: tClick; key: tKey): tMenu;
VAR
    m: tMenu;
    maxLength: INTEGER;
    item: tItem;
BEGIN
    NEW(m);
    m.tid := 0;
    m.items  := items;
    m.click := click;
    m.key := key;
    maxLength := 0;
    item := items.first(tItem);
    WHILE item # NIL DO
        maxLength := MAX(maxLength, LENGTH(item.text));
        item := item.next(tItem)
    END;
    m.width  := maxLength*fontWidth + LEFT + RIGHT;
    m.height := items.count*fontHeight - 2;
    m.font := G.CreateFont(1, "", {});
    m.canvas := G.CreateCanvas(m.width + 1, m.height + 1);
    G.SetFont(m.canvas, m.font);
    RETURN m
END create;


BEGIN
    lastTID := 0
END Menu.