Qt 5.9 | Qt SVG | SVG Viewer Example | exportdialog.cpp Example File

Qt 5.9.2 Reference Documentation

# exportdialog.cpp Example File

svgviewer/exportdialog.cpp

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      #include "exportdialog.h"

      #include <QApplication>
      #include <QDesktopWidget>
      #include <QDialogButtonBox>
      #include <QFileDialog>
      #include <QFormLayout>
      #include <QHBoxLayout>
      #include <QMessageBox>
      #include <QLabel>
      #include <QLineEdit>
      #include <QPushButton>
      #include <QSpinBox>
      #include <QToolButton>
      #include <QVBoxLayout>

      #include <QImageWriter>

      #include <QDebug>

      #include <QDir>
      #include <QFileInfo>

      enum { exportMinimumSize = 1, exportMaximumSize = 2000 };

      ExportDialog::ExportDialog(QWidget *parent)
          : QDialog(parent)
          , m_fileNameLineEdit(new QLineEdit(this))
          , m_widthSpinBox(new QSpinBox(this))
          , m_heightSpinBox(new QSpinBox(this))
          , m_aspectRatio(1)
      {
          typedef void (QSpinBox::*QSpinBoxIntSignal)(int);

          setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
          setWindowTitle(tr("Export"));

          QFormLayout *formLayout = new QFormLayout(this);

          QHBoxLayout *fileLayout = new QHBoxLayout;
          fileLayout->addWidget(m_fileNameLineEdit);
          m_fileNameLineEdit->setMinimumWidth(QApplication::desktop()->availableGeometry(this).width() / 6);
          QPushButton *browseButton = new QPushButton(tr("Browse..."), this);
          fileLayout->addWidget(browseButton);
          connect(browseButton, &QAbstractButton::clicked, this, &ExportDialog::browse);
          formLayout->addRow(tr("File:"), fileLayout);

          QHBoxLayout *sizeLayout = new QHBoxLayout;
          sizeLayout->addStretch();
          m_widthSpinBox->setMinimum(exportMinimumSize);
          m_widthSpinBox->setMaximum(exportMaximumSize);
          connect(m_widthSpinBox, static_cast<QSpinBoxIntSignal>(&QSpinBox::valueChanged),
                  this, &ExportDialog::exportWidthChanged);
          sizeLayout->addWidget(m_widthSpinBox);
          //: Multiplication, as in 32x32
          sizeLayout->addWidget(new QLabel(tr("x")));
          m_heightSpinBox->setMinimum(exportMinimumSize);
          m_heightSpinBox->setMaximum(exportMaximumSize);
          connect(m_heightSpinBox, static_cast<QSpinBoxIntSignal>(&QSpinBox::valueChanged),
                  this, &ExportDialog::exportHeightChanged);
          sizeLayout->addWidget(m_heightSpinBox);
          QToolButton *resetButton = new QToolButton(this);
          resetButton->setIcon(QIcon(":/qt-project.org/styles/commonstyle/images/refresh-32.png"));
          sizeLayout->addWidget(resetButton);
          connect(resetButton, &QAbstractButton::clicked, this, &ExportDialog::resetExportSize);
          formLayout->addRow(tr("Size:"), sizeLayout);

          QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, this);
          connect(buttonBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
          connect(buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject);
          formLayout->addRow(buttonBox);
      }

      void ExportDialog::accept()
      {
          const QString fileName = exportFileName();
          if (fileName.isEmpty()) {
              QMessageBox::warning(this, windowTitle(), tr("Please enter a file name"));
              return;
          }
          QFileInfo fi(fileName);
          if (fi.exists()) {
              const QString question = tr("%1 already exists.\nWould you like to overwrite it?").arg(QDir::toNativeSeparators(fileName));
              if (QMessageBox::question(this, windowTitle(), question, QMessageBox::Yes | QMessageBox::No) !=  QMessageBox::Yes)
                  return;
          }
          QDialog::accept();
      }

      QSize ExportDialog::exportSize() const
      {
          return QSize(m_widthSpinBox->value(), m_heightSpinBox->value());
      }

      void ExportDialog::setExportSize(const QSize &size)
      {
          m_defaultSize = size;
          QSizeF defaultSizeF(m_defaultSize);
          m_aspectRatio = defaultSizeF.width() / defaultSizeF.height();
          setExportWidthBlocked(size.width());
          setExportHeightBlocked(size.height());
      }

      void ExportDialog::resetExportSize()
      {
          setExportWidthBlocked(m_defaultSize.width());
          setExportHeightBlocked(m_defaultSize.height());
      }

      void ExportDialog::setExportWidthBlocked(int width)
      {
          if (m_widthSpinBox->value() != width) {
              const bool blockSignals = m_widthSpinBox->blockSignals(true);
              m_widthSpinBox->setValue(width);
              m_widthSpinBox->blockSignals(blockSignals);
          }
      }

      void ExportDialog::setExportHeightBlocked(int height)
      {
          if (m_heightSpinBox->value() != height) {
              const bool blockSignals = m_heightSpinBox->blockSignals(true);
              m_heightSpinBox->setValue(height);
              m_heightSpinBox->blockSignals(blockSignals);
          }
      }

      void ExportDialog::exportWidthChanged(int width)
      {
          const bool square = m_defaultSize.width() == m_defaultSize.height();
          setExportHeightBlocked(square ? width : qRound(qreal(width) / m_aspectRatio));
      }

      void ExportDialog::exportHeightChanged(int height)
      {
          const bool square = m_defaultSize.width() == m_defaultSize.height();
          setExportWidthBlocked(square ? height : qRound(qreal(height) * m_aspectRatio));
      }

      QString ExportDialog::exportFileName() const
      {
          return QDir::cleanPath(m_fileNameLineEdit->text().trimmed());
      }

      void ExportDialog::setExportFileName(const QString &f)
      {
          m_fileNameLineEdit->setText(QDir::toNativeSeparators(f));
      }

      void ExportDialog::browse()
      {
          QFileDialog fileDialog(this);
          fileDialog.setAcceptMode(QFileDialog::AcceptSave);
          const QString fileName = exportFileName();
          if (!fileName.isEmpty())
              fileDialog.setDirectory(QFileInfo(fileName).absolutePath());
          QStringList mimeTypes;
          const auto supportedMimeTypes = QImageWriter::supportedMimeTypes();
          for (const QByteArray &mimeType : supportedMimeTypes)
              mimeTypes.append(QLatin1String(mimeType));
          fileDialog.setMimeTypeFilters(mimeTypes);
          const int pngIndex = mimeTypes.indexOf("image/png");
          if (pngIndex >= 0) {
              fileDialog.selectMimeTypeFilter(mimeTypes.at(pngIndex));
              fileDialog.setDefaultSuffix("png");
          }
          if (fileDialog.exec() == QDialog::Accepted)
              setExportFileName(fileDialog.selectedFiles().constFirst());
      }