dde-dock/frame/util/themeappicon.cpp

/*
 * Copyright (C) 2011 ~ 2018 Deepin Technology Co., Ltd.
 *
 * Author:     sbw <sbw@sbw.so>
 *
 * Maintainer: sbw <sbw@sbw.so>
 *
 * 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
 * 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 "themeappicon.h"

#include <QIcon>
#include <QFile>
#include <QDebug>
#include <QApplication>
#include <QPixmapCache>

ThemeAppIcon::ThemeAppIcon(QObject *parent) : QObject(parent)
{

}

ThemeAppIcon::~ThemeAppIcon()
{

}

const QPixmap ThemeAppIcon::getIcon(const QString iconName, const int size)
{
    QPixmap pixmap;

    const auto ratio = qApp->devicePixelRatio();

    QString key;

    if (iconName.startsWith("data:image/")) {
        key = QString("%1x%2x%3") \
                .arg(size) \
                .arg(ratio) \
                .arg(iconName.mid(0, 20)); // incase the iconName is too long.

        // FIXME(hualet): The cache can reduce memory usage,
        // that is ~2M on HiDPI enabled machine with 9 icons loaded,
        // but I don't know why since QIcon has its own cache and all of the
        // icons loaded are loaded by QIcon::fromTheme, really strange here.
        if (QPixmapCache::find(key, &pixmap))
            return pixmap;
    }

    const int s = int(size * ratio) & ~1;

    do {

        if (iconName.startsWith("data:image/"))
        {
            const QStringList strs = iconName.split("base64,");
            if (strs.size() == 2)
                pixmap.loadFromData(QByteArray::fromBase64(strs.at(1).toLatin1()));

            if (!pixmap.isNull())
                break;
        }

        if (QFile::exists(iconName))
        {
            pixmap = QPixmap(iconName);
            if (!pixmap.isNull())
                break;
        }

        const QIcon icon = QIcon::fromTheme(iconName, QIcon::fromTheme("application-x-desktop"));
        pixmap = icon.pixmap(QSize(s, s));
        if (!pixmap.isNull())
            break;

        pixmap = QPixmap(":/icons/resources/application-x-desktop.svg");
        if (!pixmap.isNull())
            break;

        Q_UNREACHABLE();

    } while (false);

    pixmap = pixmap.scaled(s, s, Qt::KeepAspectRatio, Qt::SmoothTransformation);
    pixmap.setDevicePixelRatio(ratio);

    QPixmapCache::insert(key, pixmap);

    return pixmap;
}