menu.h

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/*
    MIT License

    Copyright (c) 2020,2022, Alexey Dynda

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
*/
#ifndef _LCDGFX_MENU_H_
#define _LCDGFX_MENU_H_

#include "nano_gfx_types.h"
#include "canvas/point.h"
#include "canvas/rect.h"
#include "canvas/font.h"

#ifndef lcd_gfx_min

#define lcd_gfx_min(x, y) ((x) < (y) ? (x) : (y))
#endif

#ifndef lcd_gfx_max

#define lcd_gfx_max(x, y) ((x) > (y) ? (x) : (y))
#endif

class LcdGfxMenu
{
public:
    LcdGfxMenu(const char **items, uint8_t count, const NanoRect &rect = {});

    template <typename D> void show(D &d);

    void down();

    void up();

    uint8_t selection();

    void setSelection(uint8_t s);

    void setRect(const NanoRect &rect = {});

    uint8_t size();

    template <typename D> void updateSize(D &d)
    {
        if ( !menu.width )
        {
            menu.width = d.width() - menu.left;
        }
        if ( !menu.height )
        {
            menu.height = d.height() - menu.top;
        }
    }

private:
    SAppMenu menu;

    template <typename D> uint8_t getMaxScreenItems(D &d)
    {
        return (menu.height - 16) / d.getFont().getHeader().height;
    }

    template <typename D> uint8_t calculateScrollPosition(D &d, uint8_t selection)
    {
        if ( selection < menu.scrollPosition )
        {
            return selection;
        }
        else if ( selection - menu.scrollPosition > getMaxScreenItems(d) - 1 )
        {
            return selection - getMaxScreenItems(d) + 1;
        }
        return menu.scrollPosition;
    }

    template <typename D> void drawMenuItem(D &d, uint8_t index)
    {
        if ( index == menu.selection )
        {
            d.invertColors();
        }
        lcdint_t item_top = 8 + menu.top + (index - menu.scrollPosition) * d.getFont().getHeader().height;
        uint16_t color = d.getColor();
        d.setColor(0x0000);
        d.fillRect(menu.left + 8 + d.getFont().getTextSize(menu.items[index]), item_top, menu.width + menu.left - 9,
                   item_top + d.getFont().getHeader().height - 1);
        d.setColor(color);
        d.printFixed(menu.left + 8, item_top, menu.items[index], STYLE_NORMAL);
        if ( index == menu.selection )
        {
            d.invertColors();
        }
    }

    template <typename D> void drawScrollIndicators(D &d, uint8_t maxItems)
    {
        uint16_t color = d.getColor();
        lcdint_t borderTop = 4 + menu.top;
        lcdint_t borderBot = menu.height + menu.top - 5;
        lcdint_t itemsTop = 8 + menu.top;
        lcdint_t itemsBot = itemsTop + maxItems * d.getFont().getHeader().height;
        lcdint_t cx = menu.left + menu.width / 2;

        // Clear and draw up arrow area
        d.setColor(0x0000);
        d.fillRect(5 + menu.left, borderTop + 1, menu.width + menu.left - 6, itemsTop - 1);
        if ( menu.scrollPosition > 0 )
        {
            d.setColor(color);
            d.drawHLine(cx, borderTop + 1, cx);
            d.drawHLine(cx - 1, borderTop + 2, cx + 1);
            d.drawHLine(cx - 2, borderTop + 3, cx + 2);
        }

        // Clear and draw down arrow area
        d.setColor(0x0000);
        d.fillRect(5 + menu.left, itemsBot, menu.width + menu.left - 6, borderBot - 1);
        if ( menu.scrollPosition + maxItems < menu.count )
        {
            d.setColor(color);
            d.drawHLine(cx - 2, borderBot - 3, cx + 2);
            d.drawHLine(cx - 1, borderBot - 2, cx + 1);
            d.drawHLine(cx, borderBot - 1, cx);
        }

        // Scrollbar track on right edge
        lcdint_t sbX = menu.width + menu.left - 8;
        lcdint_t sbH = itemsBot - itemsTop - 1;
        if ( sbH > 4 )
        {
            lcdint_t thumbH = lcd_gfx_max((lcdint_t)2, (lcdint_t)(sbH * maxItems / menu.count));
            lcdint_t maxScroll = menu.count - maxItems;
            lcdint_t thumbY = itemsTop;
            if ( maxScroll > 0 )
            {
                thumbY = itemsTop + (lcdint_t)((long)(sbH - thumbH) * menu.scrollPosition / maxScroll);
            }
            // Clear track area then draw thumb
            d.setColor(0x0000);
            d.fillRect(sbX, itemsTop, sbX + 1, itemsTop + sbH);
            d.setColor(color);
            d.fillRect(sbX, thumbY, sbX + 1, thumbY + thumbH);
        }
        d.setColor(color);
    }
};

template <typename D> void LcdGfxMenu::show(D &d)
{
    updateSize(d);
    d.drawRect(4 + menu.left, 4 + menu.top, menu.width + menu.left - 5, menu.height + menu.top - 5);
    menu.scrollPosition = this->calculateScrollPosition(d, menu.selection);
    uint8_t maxItems = getMaxScreenItems(d);
    for ( uint8_t i = menu.scrollPosition; i < lcd_gfx_min(menu.count, (menu.scrollPosition + maxItems)); i++ )
    {
        this->drawMenuItem(d, i);
    }
    menu.oldSelection = menu.selection;
    if ( menu.count > maxItems )
    {
        this->drawScrollIndicators(d, maxItems);
    }
}

#endif