gradients.cpp Example File

painting/gradients/gradients.cpp
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#include "gradients.h" #include "hoverpoints.h" #include <algorithm> ShadeWidget::ShadeWidget(ShadeType type, QWidget *parent) : QWidget(parent), m_shade_type(type), m_alpha_gradient(QLinearGradient(0, 0, 0, 0)) { // Checkers background if (m_shade_type == ARGBShade) { QPixmap pm(20, 20); QPainter pmp(&pm); pmp.fillRect(0, 0, 10, 10, Qt::lightGray); pmp.fillRect(10, 10, 10, 10, Qt::lightGray); pmp.fillRect(0, 10, 10, 10, Qt::darkGray); pmp.fillRect(10, 0, 10, 10, Qt::darkGray); pmp.end(); QPalette pal = palette(); pal.setBrush(backgroundRole(), QBrush(pm)); setAutoFillBackground(true); setPalette(pal); } else { setAttribute(Qt::WA_NoBackground); } QPolygonF points; points << QPointF(0, sizeHint().height()) << QPointF(sizeHint().width(), 0); m_hoverPoints = new HoverPoints(this, HoverPoints::CircleShape); // m_hoverPoints->setConnectionType(HoverPoints::LineConnection); m_hoverPoints->setPoints(points); m_hoverPoints->setPointLock(0, HoverPoints::LockToLeft); m_hoverPoints->setPointLock(1, HoverPoints::LockToRight); m_hoverPoints->setSortType(HoverPoints::XSort); setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed); connect(m_hoverPoints, &HoverPoints::pointsChanged, this, &ShadeWidget::colorsChanged); } QPolygonF ShadeWidget::points() const { return m_hoverPoints->points(); } uint ShadeWidget::colorAt(int x) { generateShade(); QPolygonF pts = m_hoverPoints->points(); for (int i=1; i < pts.size(); ++i) { if (pts.at(i-1).x() <= x && pts.at(i).x() >= x) { QLineF l(pts.at(i-1), pts.at(i)); l.setLength(l.length() * ((x - l.x1()) / l.dx())); return m_shade.pixel(qRound(qMin(l.x2(), (qreal(m_shade.width() - 1)))), qRound(qMin(l.y2(), qreal(m_shade.height() - 1)))); } } return 0; } void ShadeWidget::setGradientStops(const QGradientStops &stops) { if (m_shade_type == ARGBShade) { m_alpha_gradient = QLinearGradient(0, 0, width(), 0); for (int i=0; i<stops.size(); ++i) { QColor c = stops.at(i).second; m_alpha_gradient.setColorAt(stops.at(i).first, QColor(c.red(), c.green(), c.blue())); } m_shade = QImage(); generateShade(); update(); } } void ShadeWidget::paintEvent(QPaintEvent *) { generateShade(); QPainter p(this); p.drawImage(0, 0, m_shade); p.setPen(QColor(146, 146, 146)); p.drawRect(0, 0, width() - 1, height() - 1); } void ShadeWidget::generateShade() { if (m_shade.isNull() || m_shade.size() != size()) { if (m_shade_type == ARGBShade) { m_shade = QImage(size(), QImage::Format_ARGB32_Premultiplied); m_shade.fill(0); QPainter p(&m_shade); p.fillRect(rect(), m_alpha_gradient); p.setCompositionMode(QPainter::CompositionMode_DestinationIn); QLinearGradient fade(0, 0, 0, height()); fade.setColorAt(0, QColor(0, 0, 0, 255)); fade.setColorAt(1, QColor(0, 0, 0, 0)); p.fillRect(rect(), fade); } else { m_shade = QImage(size(), QImage::Format_RGB32); QLinearGradient shade(0, 0, 0, height()); shade.setColorAt(1, Qt::black); if (m_shade_type == RedShade) shade.setColorAt(0, Qt::red); else if (m_shade_type == GreenShade) shade.setColorAt(0, Qt::green); else shade.setColorAt(0, Qt::blue); QPainter p(&m_shade); p.fillRect(rect(), shade); } } } GradientEditor::GradientEditor(QWidget *parent) : QWidget(parent) { QVBoxLayout *vbox = new QVBoxLayout(this); vbox->setSpacing(1); vbox->setMargin(1); m_red_shade = new ShadeWidget(ShadeWidget::RedShade, this); m_green_shade = new ShadeWidget(ShadeWidget::GreenShade, this); m_blue_shade = new ShadeWidget(ShadeWidget::BlueShade, this); m_alpha_shade = new ShadeWidget(ShadeWidget::ARGBShade, this); vbox->addWidget(m_red_shade); vbox->addWidget(m_green_shade); vbox->addWidget(m_blue_shade); vbox->addWidget(m_alpha_shade); connect(m_red_shade, &ShadeWidget::colorsChanged, this, &GradientEditor::pointsUpdated); connect(m_green_shade, &ShadeWidget::colorsChanged, this, &GradientEditor::pointsUpdated); connect(m_blue_shade, &ShadeWidget::colorsChanged, this, &GradientEditor::pointsUpdated); connect(m_alpha_shade, &ShadeWidget::colorsChanged, this, &GradientEditor::pointsUpdated); } inline static bool x_less_than(const QPointF &p1, const QPointF &p2) { return p1.x() < p2.x(); } void GradientEditor::pointsUpdated() { qreal w = m_alpha_shade->width(); QGradientStops stops; QPolygonF points; points += m_red_shade->points(); points += m_green_shade->points(); points += m_blue_shade->points(); points += m_alpha_shade->points(); std::sort(points.begin(), points.end(), x_less_than); for (int i = 0; i < points.size(); ++i) { qreal x = int(points.at(i).x()); if (i + 1 < points.size() && x == points.at(i + 1).x()) continue; QColor color((0x00ff0000 & m_red_shade->colorAt(int(x))) >> 16, (0x0000ff00 & m_green_shade->colorAt(int(x))) >> 8, (0x000000ff & m_blue_shade->colorAt(int(x))), (0xff000000 & m_alpha_shade->colorAt(int(x))) >> 24); if (x / w > 1) return; stops << QGradientStop(x / w, color); } m_alpha_shade->setGradientStops(stops); emit gradientStopsChanged(stops); } static void set_shade_points(const QPolygonF &points, ShadeWidget *shade) { shade->hoverPoints()->setPoints(points); shade->hoverPoints()->setPointLock(0, HoverPoints::LockToLeft); shade->hoverPoints()->setPointLock(points.size() - 1, HoverPoints::LockToRight); shade->update(); } void GradientEditor::setGradientStops(const QGradientStops &stops) { QPolygonF pts_red, pts_green, pts_blue, pts_alpha; qreal h_red = m_red_shade->height(); qreal h_green = m_green_shade->height(); qreal h_blue = m_blue_shade->height(); qreal h_alpha = m_alpha_shade->height(); for (int i = 0; i < stops.size(); ++i) { qreal pos = stops.at(i).first; QRgb color = stops.at(i).second.rgba(); pts_red << QPointF(pos * m_red_shade->width(), h_red - qRed(color) * h_red / 255); pts_green << QPointF(pos * m_green_shade->width(), h_green - qGreen(color) * h_green / 255); pts_blue << QPointF(pos * m_blue_shade->width(), h_blue - qBlue(color) * h_blue / 255); pts_alpha << QPointF(pos * m_alpha_shade->width(), h_alpha - qAlpha(color) * h_alpha / 255); } set_shade_points(pts_red, m_red_shade); set_shade_points(pts_green, m_green_shade); set_shade_points(pts_blue, m_blue_shade); set_shade_points(pts_alpha, m_alpha_shade); } GradientWidget::GradientWidget(QWidget *parent) : QWidget(parent) { setWindowTitle(tr("Gradients")); m_renderer = new GradientRenderer(this); QGroupBox *mainGroup = new QGroupBox(this); mainGroup->setTitle(tr("Gradients")); QGroupBox *editorGroup = new QGroupBox(mainGroup); editorGroup->setTitle(tr("Color Editor")); m_editor = new GradientEditor(editorGroup); QGroupBox *typeGroup = new QGroupBox(mainGroup); typeGroup->setTitle(tr("Gradient Type")); m_linearButton = new QRadioButton(tr("Linear Gradient"), typeGroup); m_radialButton = new QRadioButton(tr("Radial Gradient"), typeGroup); m_conicalButton = new QRadioButton(tr("Conical Gradient"), typeGroup); QGroupBox *spreadGroup = new QGroupBox(mainGroup); spreadGroup->setTitle(tr("Spread Method")); m_padSpreadButton = new QRadioButton(tr("Pad Spread"), spreadGroup); m_reflectSpreadButton = new QRadioButton(tr("Reflect Spread"), spreadGroup); m_repeatSpreadButton = new QRadioButton(tr("Repeat Spread"), spreadGroup); QGroupBox *presetsGroup = new QGroupBox(mainGroup); presetsGroup->setTitle(tr("Presets")); QPushButton *prevPresetButton = new QPushButton(tr("<"), presetsGroup); m_presetButton = new QPushButton(tr("(unset)"), presetsGroup); QPushButton *nextPresetButton = new QPushButton(tr(">"), presetsGroup); updatePresetName(); QGroupBox *defaultsGroup = new QGroupBox(mainGroup); defaultsGroup->setTitle(tr("Examples")); QPushButton *default1Button = new QPushButton(tr("1"), defaultsGroup); QPushButton *default2Button = new QPushButton(tr("2"), defaultsGroup); QPushButton *default3Button = new QPushButton(tr("3"), defaultsGroup); QPushButton *default4Button = new QPushButton(tr("Reset"), editorGroup); QPushButton *showSourceButton = new QPushButton(mainGroup); showSourceButton->setText(tr("Show Source")); #if QT_CONFIG(opengl) QPushButton *enableOpenGLButton = new QPushButton(mainGroup); enableOpenGLButton->setText(tr("Use OpenGL")); enableOpenGLButton->setCheckable(true); enableOpenGLButton->setChecked(m_renderer->usesOpenGL()); #endif QPushButton *whatsThisButton = new QPushButton(mainGroup); whatsThisButton->setText(tr("What's This?")); whatsThisButton->setCheckable(true); // Layouts QHBoxLayout *mainLayout = new QHBoxLayout(this); mainLayout->addWidget(m_renderer); mainLayout->addWidget(mainGroup); mainGroup->setFixedWidth(200); QVBoxLayout *mainGroupLayout = new QVBoxLayout(mainGroup); mainGroupLayout->addWidget(editorGroup); mainGroupLayout->addWidget(typeGroup); mainGroupLayout->addWidget(spreadGroup); mainGroupLayout->addWidget(presetsGroup); mainGroupLayout->addWidget(defaultsGroup); mainGroupLayout->addStretch(1); mainGroupLayout->addWidget(showSourceButton); #if QT_CONFIG(opengl) mainGroupLayout->addWidget(enableOpenGLButton); #endif mainGroupLayout->addWidget(whatsThisButton); QVBoxLayout *editorGroupLayout = new QVBoxLayout(editorGroup); editorGroupLayout->addWidget(m_editor); QVBoxLayout *typeGroupLayout = new QVBoxLayout(typeGroup); typeGroupLayout->addWidget(m_linearButton); typeGroupLayout->addWidget(m_radialButton); typeGroupLayout->addWidget(m_conicalButton); QVBoxLayout *spreadGroupLayout = new QVBoxLayout(spreadGroup); spreadGroupLayout->addWidget(m_padSpreadButton); spreadGroupLayout->addWidget(m_repeatSpreadButton); spreadGroupLayout->addWidget(m_reflectSpreadButton); QHBoxLayout *presetsGroupLayout = new QHBoxLayout(presetsGroup); presetsGroupLayout->addWidget(prevPresetButton); presetsGroupLayout->addWidget(m_presetButton, 1); presetsGroupLayout->addWidget(nextPresetButton); QHBoxLayout *defaultsGroupLayout = new QHBoxLayout(defaultsGroup); defaultsGroupLayout->addWidget(default1Button); defaultsGroupLayout->addWidget(default2Button); defaultsGroupLayout->addWidget(default3Button); editorGroupLayout->addWidget(default4Button); connect(m_editor, &GradientEditor::gradientStopsChanged, m_renderer, &GradientRenderer::setGradientStops); connect(m_linearButton, &QRadioButton::clicked, m_renderer, &GradientRenderer::setLinearGradient); connect(m_radialButton, &QRadioButton::clicked, m_renderer, &GradientRenderer::setRadialGradient); connect(m_conicalButton,&QRadioButton::clicked, m_renderer, &GradientRenderer::setConicalGradient); connect(m_padSpreadButton, &QRadioButton::clicked, m_renderer, &GradientRenderer::setPadSpread); connect(m_reflectSpreadButton, &QRadioButton::clicked, m_renderer, &GradientRenderer::setReflectSpread); connect(m_repeatSpreadButton, &QRadioButton::clicked, m_renderer, &GradientRenderer::setRepeatSpread); connect(prevPresetButton, &QPushButton::clicked, this, &GradientWidget::setPrevPreset); connect(m_presetButton, &QPushButton::clicked, this, &GradientWidget::setPreset); connect(nextPresetButton, &QPushButton::clicked, this, &GradientWidget::setNextPreset); connect(default1Button, &QPushButton::clicked, this, &GradientWidget::setDefault1); connect(default2Button, &QPushButton::clicked, this, &GradientWidget::setDefault2); connect(default3Button, &QPushButton::clicked, this, &GradientWidget::setDefault3); connect(default4Button, &QPushButton::clicked, this, &GradientWidget::setDefault4); connect(showSourceButton, &QPushButton::clicked, m_renderer, &GradientRenderer::showSource); #if QT_CONFIG(opengl) connect(enableOpenGLButton, QOverload<bool>::of(&QPushButton::clicked), m_renderer, &ArthurFrame::enableOpenGL); #endif connect(whatsThisButton, QOverload<bool>::of(&QPushButton::clicked), m_renderer, &ArthurFrame::setDescriptionEnabled); connect(whatsThisButton, QOverload<bool>::of(&QPushButton::clicked), m_renderer->hoverPoints(), &HoverPoints::setDisabled); connect(m_renderer, QOverload<bool>::of(&ArthurFrame::descriptionEnabledChanged), whatsThisButton, &QPushButton::setChecked); connect(m_renderer, QOverload<bool>::of(&ArthurFrame::descriptionEnabledChanged), m_renderer->hoverPoints(), &HoverPoints::setDisabled); m_renderer->loadSourceFile(":res/gradients/gradients.cpp"); m_renderer->loadDescription(":res/gradients/gradients.html"); QTimer::singleShot(50, this, SLOT(setDefault1())); } void GradientWidget::setDefault(int config) { QGradientStops stops; QPolygonF points; switch (config) { case 1: stops << QGradientStop(0.00, QColor::fromRgba(0)); stops << QGradientStop(0.04, QColor::fromRgba(0xff131360)); stops << QGradientStop(0.08, QColor::fromRgba(0xff202ccc)); stops << QGradientStop(0.42, QColor::fromRgba(0xff93d3f9)); stops << QGradientStop(0.51, QColor::fromRgba(0xffb3e6ff)); stops << QGradientStop(0.73, QColor::fromRgba(0xffffffec)); stops << QGradientStop(0.92, QColor::fromRgba(0xff5353d9)); stops << QGradientStop(0.96, QColor::fromRgba(0xff262666)); stops << QGradientStop(1.00, QColor::fromRgba(0)); m_linearButton->animateClick(); m_repeatSpreadButton->animateClick(); break; case 2: stops << QGradientStop(0.00, QColor::fromRgba(0xffffffff)); stops << QGradientStop(0.11, QColor::fromRgba(0xfff9ffa0)); stops << QGradientStop(0.13, QColor::fromRgba(0xfff9ff99)); stops << QGradientStop(0.14, QColor::fromRgba(0xfff3ff86)); stops << QGradientStop(0.49, QColor::fromRgba(0xff93b353)); stops << QGradientStop(0.87, QColor::fromRgba(0xff264619)); stops << QGradientStop(0.96, QColor::fromRgba(0xff0c1306)); stops << QGradientStop(1.00, QColor::fromRgba(0)); m_radialButton->animateClick(); m_padSpreadButton->animateClick(); break; case 3: stops << QGradientStop(0.00, QColor::fromRgba(0)); stops << QGradientStop(0.10, QColor::fromRgba(0xffe0cc73)); stops << QGradientStop(0.17, QColor::fromRgba(0xffc6a006)); stops << QGradientStop(0.46, QColor::fromRgba(0xff600659)); stops << QGradientStop(0.72, QColor::fromRgba(0xff0680ac)); stops << QGradientStop(0.92, QColor::fromRgba(0xffb9d9e6)); stops << QGradientStop(1.00, QColor::fromRgba(0)); m_conicalButton->animateClick(); m_padSpreadButton->animateClick(); break; case 4: stops << QGradientStop(0.00, QColor::fromRgba(0xff000000)); stops << QGradientStop(1.00, QColor::fromRgba(0xffffffff)); break; default: qWarning("bad default: %d\n", config); break; } QPolygonF pts; int h_off = m_renderer->width() / 10; int v_off = m_renderer->height() / 8; pts << QPointF(m_renderer->width() / 2, m_renderer->height() / 2) << QPointF(m_renderer->width() / 2 - h_off, m_renderer->height() / 2 - v_off); m_editor->setGradientStops(stops); m_renderer->hoverPoints()->setPoints(pts); m_renderer->setGradientStops(stops); } void GradientWidget::updatePresetName() { QMetaEnum presetEnum = QMetaEnum::fromType<QGradient::Preset>(); m_presetButton->setText(QLatin1String(presetEnum.key(m_presetIndex))); } void GradientWidget::changePresetBy(int indexOffset) { QMetaEnum presetEnum = QMetaEnum::fromType<QGradient::Preset>(); m_presetIndex = qBound(0, m_presetIndex + indexOffset, presetEnum.keyCount() - 1); QGradient::Preset preset = static_cast<QGradient::Preset>(presetEnum.value(m_presetIndex)); QGradient gradient(preset); if (gradient.type() != QGradient::LinearGradient) return; QLinearGradient *linearGradientPointer = static_cast<QLinearGradient *>(&gradient); QLineF objectStopsLine(linearGradientPointer->start(), linearGradientPointer->finalStop()); qreal scaleX = qFuzzyIsNull(objectStopsLine.dx()) ? 1.0 : (0.8 * m_renderer->width() / qAbs(objectStopsLine.dx())); qreal scaleY = qFuzzyIsNull(objectStopsLine.dy()) ? 1.0 : (0.8 * m_renderer->height() / qAbs(objectStopsLine.dy())); QLineF logicalStopsLine = QTransform::fromScale(scaleX, scaleY).map(objectStopsLine); logicalStopsLine.translate(m_renderer->rect().center() - logicalStopsLine.center()); QPolygonF logicalStops; logicalStops << logicalStopsLine.p1() << logicalStopsLine.p2(); m_linearButton->animateClick(); m_padSpreadButton->animateClick(); m_editor->setGradientStops(gradient.stops()); m_renderer->hoverPoints()->setPoints(logicalStops); m_renderer->setGradientStops(gradient.stops()); updatePresetName(); } GradientRenderer::GradientRenderer(QWidget *parent) : ArthurFrame(parent) { m_hoverPoints = new HoverPoints(this, HoverPoints::CircleShape); m_hoverPoints->setPointSize(QSize(20, 20)); m_hoverPoints->setConnectionType(HoverPoints::NoConnection); m_hoverPoints->setEditable(false); QVector<QPointF> points; points << QPointF(100, 100) << QPointF(200, 200); m_hoverPoints->setPoints(points); m_spread = QGradient::PadSpread; m_gradientType = Qt::LinearGradientPattern; } void GradientRenderer::setGradientStops(const QGradientStops &stops) { m_stops = stops; update(); } void GradientRenderer::mousePressEvent(QMouseEvent *) { setDescriptionEnabled(false); } void GradientRenderer::paint(QPainter *p) { QPolygonF pts = m_hoverPoints->points(); QGradient g; if (m_gradientType == Qt::LinearGradientPattern) { g = QLinearGradient(pts.at(0), pts.at(1)); } else if (m_gradientType == Qt::RadialGradientPattern) { g = QRadialGradient(pts.at(0), qMin(width(), height()) / 3.0, pts.at(1)); } else { QLineF l(pts.at(0), pts.at(1)); qreal angle = l.angle(QLineF(0, 0, 1, 0)); if (l.dy() > 0) angle = 360 - angle; g = QConicalGradient(pts.at(0), angle); } for (int i = 0; i < m_stops.size(); ++i) g.setColorAt(m_stops.at(i).first, m_stops.at(i).second); g.setSpread(m_spread); p->setBrush(g); p->setPen(Qt::NoPen); p->drawRect(rect()); }

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