qt6windows7/examples/widgets/painting/gradients/gradients.cpp
2023-10-29 23:33:08 +01:00

548 lines
20 KiB
C++

// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#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_OpaquePaintEvent);
}
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));
if (qIsNull(l.dx()))
continue;
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 (const auto &stop : stops) {
QColor c = stop.second;
m_alpha_gradient.setColorAt(stop.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->setContentsMargins(1, 1, 1, 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) {
const int x = int(points.at(i).x());
if (i + 1 < points.size() && x == int(points.at(i + 1).x()))
continue;
QColor color((0x00ff0000 & m_red_shade->colorAt(x)) >> 16,
(0x0000ff00 & m_green_shade->colorAt(x)) >> 8,
(0x000000ff & m_blue_shade->colorAt(x)),
(0xff000000 & m_alpha_shade->colorAt(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);
QWidget *mainContentWidget = new QWidget();
QGroupBox *mainGroup = new QGroupBox(mainContentWidget);
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);
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);
mainGroup->setLayout(mainGroupLayout);
QVBoxLayout *mainContentLayout = new QVBoxLayout();
mainContentLayout->addWidget(mainGroup);
mainContentWidget->setLayout(mainContentLayout);
QScrollArea *mainScrollArea = new QScrollArea();
mainScrollArea->setWidget(mainContentWidget);
mainScrollArea->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Preferred);
// Layouts
QHBoxLayout *mainLayout = new QHBoxLayout(this);
mainLayout->addWidget(m_renderer);
mainLayout->addWidget(mainScrollArea);
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, &GradientWidget::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);
QList<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 = QLineF(0, 0, 1, 0).angleTo(l);
g = QConicalGradient(pts.at(0), angle);
}
for (const auto &stop : std::as_const(m_stops))
g.setColorAt(stop.first, stop.second);
g.setSpread(m_spread);
p->setBrush(g);
p->setPen(Qt::NoPen);
p->drawRect(rect());
}