text: // Copyright (c) 2011-2017 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #if defined(HAVE_CONFIG_H)
  #include <config/bitcoin-config.h>
  #endif
  
  #include <qt/splashscreen.h>
  
  #include <qt/networkstyle.h>
  
  #include <clientversion.h>
  #include <init.h>
  #include <util.h>
  #include <ui_interface.h>
  #include <version.h>
  
  #ifdef ENABLE_WALLET
  #include <wallet/wallet.h>
  #endif
  
  #include <QApplication>
  #include <QCloseEvent>
  #include <QDesktopWidget>
  #include <QPainter>
  #include <QRadialGradient>
  
  SplashScreen::SplashScreen(Qt::WindowFlags f, const NetworkStyle *networkStyle) :
      QWidget(0, f), curAlignment(0)
  {
      // set reference point, paddings
      int paddingRight            = 50;
      int paddingTop              = 50;
      int titleVersionVSpace      = 17;
      int titleCopyrightVSpace    = 40;
  
      float fontFactor            = 1.0;
      float devicePixelRatio      = 1.0;
  #if QT_VERSION > 0x050100
      devicePixelRatio = ((QGuiApplication*)QCoreApplication::instance())->devicePixelRatio();
  #endif
  
      // define text to place
      QString titleText       = tr(PACKAGE_NAME);
      QString versionText     = QString("Version %1").arg(QString::fromStdString(FormatFullVersion()));
      QString copyrightText   = QString::fromUtf8(CopyrightHolders(strprintf("\xc2\xA9 %u-%u ", 2018, COPYRIGHT_YEAR)).c_str());
      QString titleAddText    = networkStyle->getTitleAddText();
  
      QString font            = "TeXGyreAdventor";
  
      // create a bitmap according to device pixelratio
      QSize splashSize(480*devicePixelRatio,320*devicePixelRatio);
      pixmap = QPixmap(splashSize);
  
  #if QT_VERSION > 0x050100
      // change to HiDPI if it makes sense
      pixmap.setDevicePixelRatio(devicePixelRatio);
  #endif
  
      QPainter pixPaint(&pixmap);
      pixPaint.setPen(QColor(100,100,100));
  
      // draw a slightly radial gradient
      QRadialGradient gradient(QPoint(0,0), splashSize.width()/devicePixelRatio);
      gradient.setColorAt(0, Qt::white);
      gradient.setColorAt(1, QColor(247,247,247));
      QRect rGradient(QPoint(0,0), splashSize);
      pixPaint.fillRect(rGradient, gradient);
  
      // draw the bitcoin icon, expected size of PNG: 1024x1024
      QRect rectIcon(QPoint(-150,-122), QSize(430,430));
  
      const QSize requiredSize(1024,1024);
      QPixmap icon(networkStyle->getAppIcon().pixmap(requiredSize));
  
      pixPaint.drawPixmap(rectIcon, icon);
  
      // check font size and drawing with
      pixPaint.setFont(QFont(font, 33*fontFactor));
      QFontMetrics fm = pixPaint.fontMetrics();
      int titleTextWidth = fm.width(titleText);
      if (titleTextWidth > 176) {
          fontFactor = fontFactor * 176 / titleTextWidth;
      }
  
      pixPaint.setFont(QFont(font, 33*fontFactor));
      fm = pixPaint.fontMetrics();
      titleTextWidth  = fm.width(titleText);
      pixPaint.drawText(pixmap.width()/devicePixelRatio-titleTextWidth-paddingRight,paddingTop,titleText);
  
      pixPaint.setFont(QFont(font, 15*fontFactor));
  
      // if the version string is to long, reduce size
      fm = pixPaint.fontMetrics();
      int versionTextWidth  = fm.width(versionText);
      if(versionTextWidth > titleTextWidth+paddingRight-10) {
          pixPaint.setFont(QFont(font, 10*fontFactor));
          titleVersionVSpace -= 5;
      }
      pixPaint.drawText(pixmap.width()/devicePixelRatio-titleTextWidth-paddingRight+2,paddingTop+titleVersionVSpace,versionText);
  
      // draw copyright stuff
      {
          pixPaint.setFont(QFont(font, 10*fontFactor));
          const int x = pixmap.width()/devicePixelRatio-titleTextWidth-paddingRight;
          const int y = paddingTop+titleCopyrightVSpace;
          QRect copyrightRect(x, y, pixmap.width() - x - paddingRight, pixmap.height() - y);
          pixPaint.drawText(copyrightRect, Qt::AlignLeft | Qt::AlignTop | Qt::TextWordWrap, copyrightText);
      }
  
      // draw additional text if special network
      if(!titleAddText.isEmpty()) {
          QFont boldFont = QFont(font, 10*fontFactor);
          boldFont.setWeight(QFont::Bold);
          pixPaint.setFont(boldFont);
          fm = pixPaint.fontMetrics();
          int titleAddTextWidth  = fm.width(titleAddText);
          pixPaint.drawText(pixmap.width()/devicePixelRatio-titleAddTextWidth-10,15,titleAddText);
      }
  
      pixPaint.end();
  
      // Set window title
      setWindowTitle(titleText + " " + titleAddText);
  
      // Resize window and move to center of desktop, disallow resizing
      QRect r(QPoint(), QSize(pixmap.size().width()/devicePixelRatio,pixmap.size().height()/devicePixelRatio));
      resize(r.size());
      setFixedSize(r.size());
      move(QApplication::desktop()->screenGeometry().center() - r.center());
  
      subscribeToCoreSignals();
      installEventFilter(this);
  }
  
  SplashScreen::~SplashScreen()
  {
      unsubscribeFromCoreSignals();
  }
  
  bool SplashScreen::eventFilter(QObject * obj, QEvent * ev) {
      if (ev->type() == QEvent::KeyPress) {
          QKeyEvent *keyEvent = static_cast<QKeyEvent *>(ev);
          if(keyEvent->text()[0] == 'q') {
              StartShutdown();
          }
      }
      return QObject::eventFilter(obj, ev);
  }
  
  void SplashScreen::slotFinish(QWidget *mainWin)
  {
      Q_UNUSED(mainWin);
  
      /* If the window is minimized, hide() will be ignored. */
      /* Make sure we de-minimize the splashscreen window before hiding */
      if (isMinimized())
          showNormal();
      hide();
      deleteLater(); // No more need for this
  }
  
  static void InitMessage(SplashScreen *splash, const std::string &message)
  {
      QMetaObject::invokeMethod(splash, "showMessage",
          Qt::QueuedConnection,
          Q_ARG(QString, QString::fromStdString(message)),
          Q_ARG(int, Qt::AlignBottom|Qt::AlignHCenter),
          Q_ARG(QColor, QColor(55,55,55)));
  }
  
  static void ShowProgress(SplashScreen *splash, const std::string &title, int nProgress, bool resume_possible)
  {
      InitMessage(splash, title + std::string("\n") +
              (resume_possible ? _("(press q to shutdown and continue later)")
                                  : _("press q to shutdown")) +
              strprintf("\n%d", nProgress) + "%");
  }
  
  #ifdef ENABLE_WALLET
  void SplashScreen::ConnectWallet(CWallet* wallet)
  {
      wallet->ShowProgress.connect(boost::bind(ShowProgress, this, _1, _2, false));
      connectedWallets.push_back(wallet);
  }
  #endif
  
  void SplashScreen::subscribeToCoreSignals()
  {
      // Connect signals to client
      uiInterface.InitMessage.connect(boost::bind(InitMessage, this, _1));
      uiInterface.ShowProgress.connect(boost::bind(ShowProgress, this, _1, _2, _3));
  #ifdef ENABLE_WALLET
      uiInterface.LoadWallet.connect(boost::bind(&SplashScreen::ConnectWallet, this, _1));
  #endif
  }
  
  void SplashScreen::unsubscribeFromCoreSignals()
  {
      // Disconnect signals from client
      uiInterface.InitMessage.disconnect(boost::bind(InitMessage, this, _1));
      uiInterface.ShowProgress.disconnect(boost::bind(ShowProgress, this, _1, _2, _3));
  #ifdef ENABLE_WALLET
      for (CWallet* const & pwallet : connectedWallets) {
          pwallet->ShowProgress.disconnect(boost::bind(ShowProgress, this, _1, _2, false));
      }
  #endif
  }
  
  void SplashScreen::showMessage(const QString &message, int alignment, const QColor &color)
  {
      curMessage = message;
      curAlignment = alignment;
      curColor = color;
      update();
  }
  
  void SplashScreen::paintEvent(QPaintEvent *event)
  {
      QPainter painter(this);
      painter.drawPixmap(0, 0, pixmap);
      QRect r = rect().adjusted(5, 5, -5, -5);
      painter.setPen(curColor);
      painter.drawText(r, curAlignment, curMessage);
  }
  
  void SplashScreen::closeEvent(QCloseEvent *event)
  {
      StartShutdown(); // allows an "emergency" shutdown during startup
      event->ignore();
  }
  