Warning, file /education/kmplot/kmplot/kgradientdialog.cpp was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

 /*
     KmPlot - a math. function plotter for the KDE-Desktop
 
     SPDX-FileCopyrightText: 2006 David Saxton <david@bluehaze.org>
 
     This file is part of the KDE Project.
     KmPlot is part of the KDE-EDU Project.
 
     SPDX-License-Identifier: GPL-2.0-or-later
 
 */
 
 #include "kgradientdialog.h"
 
 #include <KLocalizedString>
 
 #include <QApplication>
 #include <QColorDialog>
 #include <QDialogButtonBox>
 #include <QLabel>
 #include <QLinearGradient>
 #include <QPaintEvent>
 #include <QPainter>
 #include <QPointer>
 #include <QStyleOption>
 #include <QStyleOptionButton>
 #include <QTileRules>
 #include <QVBoxLayout>
 
 const double SQRT_3 = 1.732050808;
 const double ArrowLength = 8;
 const double ArrowHalfWidth = ArrowLength / SQRT_3;
 
 // BEGIN class KGradientEditor
 KGradientEditor::KGradientEditor(QWidget *parent)
     : QWidget(parent)
 {
     m_haveArrow = false;
     m_clickOffset = 0;
     m_orientation = Qt::Horizontal;
     findGradientStop();
 }
 
 KGradientEditor::~KGradientEditor()
 {
 }
 
 void KGradientEditor::setGradient(const QGradient &gradient)
 {
     if (m_gradient == gradient)
         return;
     setGradient(gradient.stops());
     findGradientStop();
 }
 
 void KGradientEditor::setColor(const QColor &color)
 {
     // Hmm...why doesn't qvector have some sortof search / replace functionality?
     QGradientStops stops = m_gradient.stops();
     for (int i = 0; i < stops.size(); ++i) {
         if (stops[i] != m_currentStop)
             continue;
 
         if (stops[i].second == color)
             return;
 
         m_currentStop.second = color;
         stops[i] = m_currentStop;
         break;
     }
 
     setGradient(stops);
 }
 
 QSize KGradientEditor::minimumSizeHint() const
 {
     double w = 3 * ArrowHalfWidth;
     double h = 12 + ArrowLength;
 
     if (m_orientation == Qt::Vertical)
         qSwap(w, h);
 
     return QSizeF(w, h).toSize();
 }
 
 void KGradientEditor::paintEvent(QPaintEvent *)
 {
     QPainter painter(this);
 
     // BEGIN draw gradient
     QRectF r;
     QLinearGradient lg;
 
     if (m_orientation == Qt::Horizontal) {
         lg = QLinearGradient(0, 0, width(), 0);
         r = QRectF(ArrowHalfWidth - 1, 0, width() - 2 * ArrowHalfWidth + 1, height() - ArrowLength);
     } else {
         lg = QLinearGradient(0, 0, 0, height());
         r = QRectF(0, ArrowHalfWidth - 1, width() - ArrowLength, height() - 2 * ArrowHalfWidth + 1);
     }
 
     lg.setStops(m_gradient.stops());
     painter.setBrush(lg);
     painter.setPen(QPen(Qt::black, 1));
     painter.drawRect(r);
     // END draw gradient
 
     // BEGIN draw arrows
     painter.setRenderHint(QPainter::Antialiasing, true);
     const QGradientStops stops = m_gradient.stops();
     for (const QGradientStop &stop : stops)
         drawArrow(&painter, stop);
     // END draw arrows
 }
 
 void KGradientEditor::drawArrow(QPainter *painter, const QGradientStop &stop)
 {
     QPolygonF arrow(3);
 
     double mid = toArrowPos(stop.first);
 
     if (m_orientation == Qt::Horizontal) {
         arrow[0] = QPointF(mid, height() - ArrowLength + 0.5);
         arrow[1] = QPointF(mid + ArrowHalfWidth, height() - 0.5);
         arrow[2] = QPointF(mid - ArrowHalfWidth, height() - 0.5);
     } else {
         arrow[0] = QPointF(width() - ArrowLength + 0.5, mid);
         arrow[1] = QPointF(width() - 0.5, mid + ArrowHalfWidth);
         arrow[2] = QPointF(width() - 0.5, mid - ArrowHalfWidth);
     }
 
     bool selected = (stop == m_currentStop);
     QColor color(selected ? palette().color(QPalette::Dark) : Qt::black);
 
     painter->setPen(color);
     painter->setBrush(stop.second);
     painter->drawPolygon(arrow);
 }
 
 void KGradientEditor::contextMenuEvent(QContextMenuEvent *e)
 {
     // Prevent the "QWhatsThis" menu from popping up when right-clicking
     e->accept();
 }
 
 void KGradientEditor::removeStop()
 {
     QGradientStops stops = m_gradient.stops();
     for (int i = 0; i < stops.size(); ++i) {
         if (stops[i] != m_currentStop)
             continue;
 
         stops.remove(i);
         break;
     }
 
     setGradient(stops);
     findGradientStop();
 }
 
 void KGradientEditor::mousePressEvent(QMouseEvent *e)
 {
     if (!getGradientStop(e->pos()))
         return;
     e->accept();
 
     if (e->button() == Qt::RightButton)
         removeStop();
     else
         m_haveArrow = true;
 }
 
 bool KGradientEditor::getGradientStop(const QPoint &point)
 {
     double dl; // the vertical (for horizontal layout) distance from the tip of the arrows
     if (m_orientation == Qt::Horizontal)
         dl = point.y() - (height() - ArrowLength);
     else
         dl = point.x() - (width() - ArrowLength);
 
     // Is the arrow in the strip?
     if (dl < 0)
         return false;
 
     QGradientStops stops = m_gradient.stops();
 
     // Iterate over stops in reverse as the last stops are displayed on top of
     // the first stops.
     for (int i = stops.size() - 1; i >= 0; --i) {
         QGradientStop stop = stops[i];
 
         double pos = toArrowPos(stop.first);
 
         // Is the click inside the arrow?
         double lower = pos - dl * (ArrowHalfWidth / ArrowLength);
         double upper = pos + dl * (ArrowHalfWidth / ArrowLength);
 
         double x = (m_orientation == Qt::Horizontal) ? point.x() : point.y();
         if (x < lower || x > upper)
             continue;
 
         // Is inside arrow! :)
         m_clickOffset = x - pos;
 
         setCurrentStop(stop);
         return true;
     }
 
     return false;
 }
 
 void KGradientEditor::mouseMoveEvent(QMouseEvent *e)
 {
     if (!m_haveArrow)
         return;
 
     e->accept();
     QPoint point = e->pos();
 
     // Hmm...why doesn't qvector have some sortof search / replace functionality?
     QGradientStops stops = m_gradient.stops();
     for (int i = 0; i < stops.size(); ++i) {
         if (stops[i] != m_currentStop)
             continue;
 
         double x = (m_orientation == Qt::Horizontal) ? point.x() : point.y();
 
         m_currentStop.first = fromArrowPos(x - m_clickOffset);
 
         stops[i] = m_currentStop;
         break;
     }
 
     setGradient(stops);
 }
 
 void KGradientEditor::mouseReleaseEvent(QMouseEvent *)
 {
     m_haveArrow = false;
 }
 
 void KGradientEditor::mouseDoubleClickEvent(QMouseEvent *e)
 {
     e->accept();
 
     if (getGradientStop(e->pos()))
         return;
 
     // Create new stop
     QPoint point = e->pos();
     double pos = fromArrowPos((m_orientation == Qt::Horizontal) ? point.x() : point.y());
 
     QGradientStop stop;
     stop.first = pos;
     stop.second = Qt::red;
 
     QGradientStops stops = m_gradient.stops();
     stops << stop;
 
     setGradient(stops);
     setCurrentStop(stop);
 }
 
 void KGradientEditor::setOrientation(Qt::Orientation orientation)
 {
     m_orientation = orientation;
     update();
 }
 
 void KGradientEditor::findGradientStop()
 {
     QGradientStops stops = m_gradient.stops();
 
     // The QGradientStops should always have at least one stop in, since
     // QGradient returns a Black->White gradient if its stops are empty.
     Q_ASSERT(!stops.isEmpty());
 
     // Pick a stop in the center
     setCurrentStop(stops[stops.size() / 2]);
 }
 
 void KGradientEditor::setCurrentStop(const QGradientStop &stop)
 {
     if (m_currentStop == stop)
         return;
 
     bool colorChanged = stop.second != m_currentStop.second;
 
     m_currentStop = stop;
     update();
 
     if (colorChanged)
         emit colorSelected(stop.second);
 }
 
 void KGradientEditor::setGradient(const QGradientStops &stops)
 {
     if (stops == m_gradient.stops())
         return;
 
     m_gradient.setStops(stops);
     update();
     emit gradientChanged(m_gradient);
 }
 
 double KGradientEditor::toArrowPos(double stop) const
 {
     double l = (m_orientation == Qt::Horizontal) ? width() : height();
     l -= 2 * ArrowHalfWidth;
     return stop * l + ArrowHalfWidth;
 }
 
 double KGradientEditor::fromArrowPos(double pos) const
 {
     double l = (m_orientation == Qt::Horizontal) ? width() : height();
     l -= 2 * ArrowHalfWidth;
 
     double stop = (pos - ArrowHalfWidth) / l;
 
     if (stop < 0)
         stop = 0;
     else if (stop > 1)
         stop = 1;
 
     return stop;
 }
 // END class KGradientEditor
 
 // BEGIN class KGradientDialog
 KGradientDialog::KGradientDialog(QWidget *parent, bool modal)
     : QDialog(parent)
 {
     QWidget *widget = new QWidget(this);
     m_gradient = new KGradientEditor(widget);
     m_colorDialog = new QColorDialog(widget);
     m_colorDialog->setWindowFlags(Qt::Widget);
     m_colorDialog->setOptions(QColorDialog::DontUseNativeDialog | QColorDialog::NoButtons);
 
     QLabel *label = new QLabel(i18n("(Double-click on the gradient to add a stop)"), widget);
     QPushButton *button = new QPushButton(i18n("Remove stop"), widget);
     connect(button, &QPushButton::clicked, m_gradient, &KGradientEditor::removeStop);
 
     QDialogButtonBox *buttonBox = new QDialogButtonBox(modal ? QDialogButtonBox::Ok | QDialogButtonBox::Cancel : QDialogButtonBox::Close);
     connect(buttonBox, &QDialogButtonBox::accepted, this, &KGradientDialog::accept);
     connect(buttonBox, &QDialogButtonBox::rejected, this, &KGradientDialog::reject);
 
     // BEGIN layout widgets
     QVBoxLayout *layout = new QVBoxLayout(this);
     layout->setContentsMargins(0, 0, 0, 0);
 
     m_gradient->setFixedHeight(24);
     layout->addWidget(m_gradient);
 
     QHBoxLayout *hLayout = new QHBoxLayout;
     hLayout->addWidget(label);
     hLayout->addStretch(1);
     hLayout->addWidget(button);
     layout->addLayout(hLayout);
     layout->addWidget(m_colorDialog);
     layout->addWidget(buttonBox);
     resize(layout->minimumSize());
     // END layout widgets
 
     setWindowTitle(i18nc("@title:window", "Choose a Gradient"));
 
     setModal(modal);
 
     connect(m_gradient, &KGradientEditor::colorSelected, m_colorDialog, &QColorDialog::setCurrentColor);
     connect(m_colorDialog, &QColorDialog::currentColorChanged, m_gradient, &KGradientEditor::setColor);
     connect(m_gradient, &KGradientEditor::gradientChanged, this, &KGradientDialog::gradientChanged);
 
     m_colorDialog->setCurrentColor(m_gradient->color());
 }
 
 KGradientDialog::~KGradientDialog()
 {
 }
 
 // static
 int KGradientDialog::getGradient(QGradient &gradient, QWidget *parent)
 {
     QPointer<KGradientDialog> dlg = new KGradientDialog(parent, true);
     dlg->setGradient(gradient);
 
     int result = dlg->exec();
     if (result == Accepted)
         gradient = dlg->gradient();
     delete dlg;
     return result;
 }
 
 void KGradientDialog::setGradient(const QGradient &gradient)
 {
     m_gradient->setGradient(gradient);
 }
 
 QGradient KGradientDialog::gradient() const
 {
     return m_gradient->gradient();
 }
 // END class KGradientDialog
 
 // BEGIN class KGradientButton
 KGradientButton::KGradientButton(QWidget *parent)
     : QPushButton(parent)
 {
     connect(this, &KGradientButton::clicked, this, &KGradientButton::chooseGradient);
 }
 
 KGradientButton::~KGradientButton()
 {
 }
 
 void KGradientButton::initStyleOption(QStyleOptionButton *opt) const
 {
     opt->initFrom(this);
     opt->text.clear();
     opt->icon = QIcon();
     opt->features = QStyleOptionButton::None;
 }
 
 QSize KGradientButton::sizeHint() const
 {
     QStyleOptionButton opt;
     initStyleOption(&opt);
     return style()->sizeFromContents(QStyle::CT_PushButton, &opt, QSize(40, 15), this);
 }
 
 void KGradientButton::setGradient(const QGradient &gradient)
 {
     if (m_gradient.stops() == gradient.stops())
         return;
 
     m_gradient.setStops(gradient.stops());
     emit gradientChanged(m_gradient);
 }
 
 void KGradientButton::chooseGradient()
 {
     int result = KGradientDialog::getGradient(m_gradient, this);
     if (result == KGradientDialog::Accepted)
         emit gradientChanged(m_gradient);
 }
 
 void KGradientButton::paintEvent(QPaintEvent *)
 {
     // Mostly copied verbatim from KColorButton - thanks! :)
 
     QPainter painter(this);
 
     // First, we need to draw the bevel.
     QStyleOptionButton butOpt;
     initStyleOption(&butOpt);
     style()->drawControl(QStyle::CE_PushButtonBevel, &butOpt, &painter, this);
 
     // OK, now we can muck around with drawing out pretty little color box
     // First, sort out where it goes
     QRect labelRect = style()->subElementRect(QStyle::SE_PushButtonContents, &butOpt, this);
     int shift = style()->pixelMetric(QStyle::PM_ButtonMargin);
     labelRect.adjust(shift, shift, -shift, -shift);
     int x, y, w, h;
     labelRect.getRect(&x, &y, &w, &h);
 
     if (isChecked() || isDown()) {
         x += style()->pixelMetric(QStyle::PM_ButtonShiftHorizontal);
         y += style()->pixelMetric(QStyle::PM_ButtonShiftVertical);
     }
 
     qDrawShadePanel(&painter, x, y, w, h, palette(), true, 1, NULL);
 
     if (isEnabled()) {
         QLinearGradient lg(x + 1, 0, x + w - 1, 0);
         lg.setStops(m_gradient.stops());
         painter.setBrush(lg);
     } else
         painter.setBrush(palette().color(backgroundRole()));
 
     painter.drawRect(x + 1, y + 1, w - 2, h - 2);
 
     if (hasFocus()) {
         QRect focusRect = style()->subElementRect(QStyle::SE_PushButtonFocusRect, &butOpt, this);
         QStyleOptionFocusRect focusOpt;
         focusOpt.initFrom(this);
         focusOpt.rect = focusRect;
         focusOpt.backgroundColor = palette().window().color();
         style()->drawPrimitive(QStyle::PE_FrameFocusRect, &focusOpt, &painter, this);
     }
 }
 // END class KGradientButton