qt5base-lts/examples/embedded/flickable/main.cpp

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/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the demonstration applications of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this
** file. Please review the following information to ensure the GNU Lesser
** General Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtCore>
2011-05-08 07:13:40 +00:00
#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 = qrand() % 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 = 0)
: 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) {
QString c = colors[i];
QString str;
str.sprintf("%4d", i + 1);
m_colorNames << (str + " " + c);
QStringList duet = c.split(' ');
m_firstColor << duet[0];
m_secondColor << 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->pos().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();
}