squawk/ui/widgets/vcard/omemo/keydelegate.cpp

// Squawk messenger. 
// Copyright (C) 2019  Yury Gubich <blue@macaw.me>
// 
// This program 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.
// 
// This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

#include "keydelegate.h"
#include <QPainter>
#include <QFontDatabase>

#include "keysmodel.h"

constexpr int minHeight = 50;
constexpr int minWidth = 400;
constexpr uint8_t margin = 10;
constexpr uint8_t partSize = 8;
constexpr uint8_t maxSingleLineParts = 3;

UI::KeyDelegate::KeyDelegate(QObject* parent):
    QStyledItemDelegate(parent),
    fingerPrintFont(QFontDatabase::systemFont(QFontDatabase::FixedFont)),
    fingerPrintMetrics(fingerPrintFont),
    spaceWidth(fingerPrintMetrics.horizontalAdvance(" "))
{
}

UI::KeyDelegate::~KeyDelegate() {}


void UI::KeyDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const {
    painter->save();
    painter->setRenderHint(QPainter::Antialiasing, true);

    bool hover = option.state & QStyle::State_MouseOver;
    if (hover) {
        painter->save();
        painter->fillRect(option.rect, option.palette.brush(QPalette::Inactive, QPalette::Highlight));
        painter->restore();
    }

    QVariant fingerPrintV = index.data(UI::KeysModel::FingerPrint);
    if (fingerPrintV.isValid()) {
        painter->save();
        painter->setFont(fingerPrintFont);
        QByteArray fingerPrint = fingerPrintV.toByteArray();
        std::vector<QString> parts = getParts(fingerPrint);
        uint8_t partsLength = parts.size();
        QRect rect = option.rect;
        rect.adjust(margin, margin, 0, 0);
        QRect r;
        uint8_t firstLine;
        if (partsLength > maxSingleLineParts)
            firstLine = partsLength / 2 + partsLength % 2;
        else
            firstLine = partsLength;

        for (uint8_t i = 0; i < partsLength; ++i) {
            if (i == firstLine) {
                rect.setLeft(option.rect.left() + margin);
                rect.adjust(0, r.height() + fingerPrintMetrics.leading(), 0, 0);
            }
            painter->drawText(rect, Qt::AlignLeft | Qt::AlignTop, parts[i], &r);
            rect.adjust(r.width() + spaceWidth ,0, 0, 0);
        }

        painter->restore();
    }
    //painter->drawText(option.rect, option.displayAlignment, index.data().toString());

    painter->restore();
}

QSize UI::KeyDelegate::sizeHint(const QStyleOptionViewItem& option, const QModelIndex& index) const {
    QSize size = QStyledItemDelegate::sizeHint(option, index);

    int mh = margin * 2;
    int mw = margin * 2;
    QVariant fingerPrintV = index.data(UI::KeysModel::FingerPrint);
    if (fingerPrintV.isValid()) {
        QString hex = fingerPrintV.toByteArray().toHex();
        uint8_t parts = hex.size() / partSize;

        mh += fingerPrintMetrics.height();
        if (parts > maxSingleLineParts) {
            mh += fingerPrintMetrics.height() + fingerPrintMetrics.leading();
        }

        uint8_t firstLine;
        if (parts > maxSingleLineParts)
            firstLine = parts / 2 + parts % 2;
        else
            firstLine = parts;

        mw += firstLine * partSize * spaceWidth + (firstLine - 1) * spaceWidth;
    }


    if (size.width() < mw)
        size.setWidth(mw);

    if (size.height() < mh)
        size.setHeight(mh);

    return size;
}

std::vector<QString> UI::KeyDelegate::getParts(const QByteArray& data) {
    QString hex = data.toHex();
    uint8_t parts = hex.size() / partSize;
    std::vector<QString> result(parts);
    for (uint8_t i = 0; i < parts; ++i) {
        uint16_t index = i * partSize;
        uint8_t length = partSize;
        if (index + length > hex.size())
            length = hex.size() - index;
        QStringRef part(&hex, index, length);
        result[i] = part.toString();
    }

    return result;
}