Encryption settings dialog

Pdf4QtViewer/pdfencryptionstrengthhintwidget.cpp

@@ -0,0 +1,172 @@
+//    Copyright (C) 2021 Jakub Melka
+//
+//    This file is part of Pdf4Qt.
+//
+//    Pdf4Qt is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    with the written consent of the copyright owner, any later version.
+//
+//    Pdf4Qt 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 Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with Pdf4Qt.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "pdfencryptionstrengthhintwidget.h"
+#include "pdfwidgetutils.h"
+#include "pdfutils.h"
+
+#include <QPainter>
+#include <QFontMetrics>
+
+namespace pdfviewer
+{
+
+PDFEncryptionStrengthHintWidget::PDFEncryptionStrengthHintWidget(QWidget* parent) :
+    BaseClass(parent),
+    m_minValue(0),
+    m_maxValue(100),
+    m_currentValue(50)
+{
+    m_levels = {
+        Level{ Qt::red, tr("Very weak") },
+        Level{ QColor::fromRgbF(1.0, 0.5, 0.0, 1.0), tr("Weak") },
+        Level{ Qt::yellow, tr("Moderate") },
+        Level{ QColor::fromRgbF(0.0, 1.0, 0.5, 1.0), tr("Strong") },
+        Level{ Qt::green, tr("Very strong") }
+    };
+}
+
+QSize PDFEncryptionStrengthHintWidget::sizeHint() const
+{
+    const QSize markSize = getMarkSize();
+    const QSize textSize = getTextSizeHint();
+    const int markSpacing = getMarkSpacing();
+    const int levels = int(m_levels.size());
+
+    const int width = levels * (markSize.width() + markSpacing) + textSize.width() + markSpacing;
+    const int height = qMax(markSize.height(), textSize.height());
+
+    return QSize(width, height);
+}
+
+QSize PDFEncryptionStrengthHintWidget::minimumSizeHint() const
+{
+    return sizeHint();
+}
+
+void PDFEncryptionStrengthHintWidget::paintEvent(QPaintEvent* event)
+{
+    QPainter painter(this);
+
+    Q_UNUSED(event);
+
+    const QSize markSize = getMarkSize();
+    const int markSpacing = getMarkSpacing();
+    const int xAdvance = markSize.width() + markSpacing;
+
+    QRect rect = this->rect();
+    painter.fillRect(rect, Qt::lightGray);
+
+    painter.translate(markSpacing, 0);
+
+    int currentLevel = qFloor(pdf::interpolate(m_currentValue, m_minValue, m_maxValue, 0, m_levels.size()));
+    if (currentLevel == m_levels.size())
+    {
+        --currentLevel;
+    }
+
+    Q_ASSERT(currentLevel >= 0);
+    Q_ASSERT(currentLevel < m_levels.size());
+
+    QColor fillColor = m_levels[currentLevel].color;
+    QColor invalidColor = Qt::darkGray;
+
+    QRect markRect(QPoint(0, (rect.height() - markSize.height()) / 2), markSize);
+
+    painter.save();
+    for (size_t i = 0; i < m_levels.size(); ++i)
+    {
+        QColor color = (i <= currentLevel) ? fillColor : invalidColor;
+        painter.fillRect(markRect, color);
+        painter.translate(xAdvance, 0);
+        rect.setLeft(rect.left() + xAdvance);
+    }
+    painter.restore();
+
+    painter.drawText(rect, Qt::TextSingleLine | Qt::TextDontClip | Qt::AlignLeft | Qt::AlignVCenter, m_levels[currentLevel].text);
+}
+
+void PDFEncryptionStrengthHintWidget::correctValue()
+{
+    setCurrentValue(qBound(m_minValue, m_currentValue, m_maxValue));
+}
+
+QSize PDFEncryptionStrengthHintWidget::getMarkSize() const
+{
+    return pdf::PDFWidgetUtils::scaleDPI(this, QSize(15, 5));
+}
+
+int PDFEncryptionStrengthHintWidget::getMarkSpacing() const
+{
+    return pdf::PDFWidgetUtils::scaleDPI_x(this, 5);
+}
+
+QSize PDFEncryptionStrengthHintWidget::getTextSizeHint() const
+{
+    QFontMetrics fontMetrics(font(), this);
+
+    const int height = fontMetrics.lineSpacing() + pdf::PDFWidgetUtils::scaleDPI_y(this, 4);
+    int width = 0;
+
+    for (const auto& levelItem : m_levels)
+    {
+        width = qMax(width, fontMetrics.width(levelItem.text));
+    }
+
+    return QSize(width, height);
+}
+
+int PDFEncryptionStrengthHintWidget::getMaxValue() const
+{
+    return m_maxValue;
+}
+
+void PDFEncryptionStrengthHintWidget::setMaxValue(int maxValue)
+{
+    m_maxValue = maxValue;
+    correctValue();
+}
+
+int PDFEncryptionStrengthHintWidget::getMinValue() const
+{
+    return m_minValue;
+}
+
+void PDFEncryptionStrengthHintWidget::setMinValue(int minValue)
+{
+    m_minValue = minValue;
+    correctValue();
+}
+
+int PDFEncryptionStrengthHintWidget::getCurrentValue() const
+{
+    return m_currentValue;
+}
+
+void PDFEncryptionStrengthHintWidget::setCurrentValue(int currentValue)
+{
+    const int adjustedValue = qBound(m_minValue, currentValue, m_maxValue);
+
+    if (m_currentValue != adjustedValue)
+    {
+        m_currentValue = adjustedValue;
+        update();
+    }
+}
+
+}   // namespace pdfviewer
+