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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include <QtCore>
#include <QtWidgets>
#include "flickable.h"
// Returns a list of two-word color names
static QStringList colorPairs(int max)
{
// capitalize the first letter
QStringList colors = QColor::colorNames();
colors.removeAll("transparent");
int num = colors.count();
for (int c = 0; c < num; ++c)
colors[c] = colors[c][0].toUpper() + colors[c].mid(1);
// combine two colors, e.g. "lime skyblue"
QStringList combinedColors;
for (int i = 0; i < num; ++i)
for (int j = 0; j < num; ++j)
combinedColors << QString("%1 %2").arg(colors[i]).arg(colors[j]);
// randomize it
colors.clear();
while (combinedColors.count()) {
int i = QRandomGenerator::global()->bounded(combinedColors.count());
colors << combinedColors[i];
combinedColors.removeAt(i);
if (colors.count() == max)
break;
}
return colors;
}
class ColorList : public QWidget, public Flickable
{
Q_OBJECT
public:
ColorList(QWidget *parent = nullptr)
: QWidget(parent) {
m_offset = 0;
m_height = QFontMetrics(font()).height() + 5;
m_highlight = -1;
m_selected = -1;
QStringList colors = colorPairs(999);
for (int i = 0; i < colors.count(); ++i) {
const QString c = colors[i];
const QString str = QString::asprintf("%4d", i + 1);
m_colorNames << (str + " " + c);
QStringList duet = c.split(' ');
m_firstColor << QColor::fromString(duet[0]);
m_secondColor << QColor::fromString(duet[1]);
}
setAttribute(Qt::WA_OpaquePaintEvent, true);
setAttribute(Qt::WA_NoSystemBackground, true);
setMouseTracking(true);
Flickable::setAcceptMouseClick(this);
}
protected:
// reimplement from Flickable
virtual QPoint scrollOffset() const {
return QPoint(0, m_offset);
}
// reimplement from Flickable
virtual void setScrollOffset(const QPoint &offset) {
int yy = offset.y();
if (yy != m_offset) {
m_offset = qBound(0, yy, m_height * m_colorNames.count() - height());
update();
}
}
protected:
void paintEvent(QPaintEvent *event) {
QPainter p(this);
p.fillRect(event->rect(), Qt::white);
int start = m_offset / m_height;
int y = start * m_height - m_offset;
if (m_offset <= 0) {
start = 0;
y = -m_offset;
}
int end = start + height() / m_height + 1;
if (end > m_colorNames.count() - 1)
end = m_colorNames.count() - 1;
for (int i = start; i <= end; ++i, y += m_height) {
p.setBrush(Qt::NoBrush);
p.setPen(Qt::black);
if (i == m_highlight) {
p.fillRect(0, y, width(), m_height, QColor(0, 64, 128));
p.setPen(Qt::white);
}
if (i == m_selected) {
p.fillRect(0, y, width(), m_height, QColor(0, 128, 240));
p.setPen(Qt::white);
}
p.drawText(m_height + 2, y, width(), m_height, Qt::AlignVCenter, m_colorNames[i]);
p.setPen(Qt::NoPen);
p.setBrush(m_firstColor[i]);
p.drawRect(1, y + 1, m_height - 2, m_height - 2);
p.setBrush(m_secondColor[i]);
p.drawRect(5, y + 5, m_height - 11, m_height - 11);
}
p.end();
}
void keyReleaseEvent(QKeyEvent *event) {
if (event->key() == Qt::Key_Down) {
m_offset += 20;
event->accept();
update();
return;
}
if (event->key() == Qt::Key_Up) {
m_offset -= 20;
event->accept();
update();
return;
}
}
void mousePressEvent(QMouseEvent *event) {
Flickable::handleMousePress(event);
if (event->isAccepted())
return;
if (event->button() == Qt::LeftButton) {
int y = event->position().toPoint().y() + m_offset;
int i = y / m_height;
if (i != m_highlight) {
m_highlight = i;
m_selected = -1;
update();
}
event->accept();
}
}
void mouseMoveEvent(QMouseEvent *event) {
Flickable::handleMouseMove(event);
}
void mouseReleaseEvent(QMouseEvent *event) {
Flickable::handleMouseRelease(event);
if (event->isAccepted())
return;
if (event->button() == Qt::LeftButton) {
m_selected = m_highlight;
event->accept();
update();
}
}
private:
int m_offset;
int m_height;
int m_highlight;
int m_selected;
QStringList m_colorNames;
QList<QColor> m_firstColor;
QList<QColor> m_secondColor;
};
#include "main.moc"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
ColorList list;
list.setWindowTitle("Kinetic Scrolling");
list.resize(320, 320);
list.show();
return app.exec();
}
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