Import the flick list (kinetic scrolling) example.

Originally it was published in Qt Labs:
http://labs.trolltech.com/blogs/2009/07/19/kinetic-scrolling-on-any-widgets/

Reviewed-by: Jason Barron

7 files changed, 601 insertions, 1 deletions

diff --git a/demos/embedded/embedded.pro b/demos/embedded/embedded.pro
index e425eb5..7fcae45 100644
--- a/demos/embedded/embedded.pro
+++ b/demos/embedded/embedded.pro
@@ -1,5 +1,5 @@
 TEMPLATE  = subdirs
-SUBDIRS   = styledemo raycasting
+SUBDIRS   = styledemo raycasting flickable
 
 contains(QT_CONFIG, svg) {
     SUBDIRS += embeddedsvgviewer \
diff --git a/demos/embedded/flickable/flickable.cpp b/demos/embedded/flickable/flickable.cpp
new file mode 100644
index 0000000..8fbefe6
--- /dev/null
+++ b/demos/embedded/flickable/flickable.cpp
@@ -0,0 +1,284 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the demonstration applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at http://qt.nokia.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "flickable.h"
+
+#include <QtCore>
+#include <QtGui>
+
+class FlickableTicker: QObject
+{
+public:
+    FlickableTicker(Flickable *scroller) {
+        m_scroller = scroller;
+    }
+
+    void start(int interval) {
+        if (!m_timer.isActive())
+            m_timer.start(interval, this);
+    }
+
+    void stop() {
+        m_timer.stop();
+    }
+
+protected:
+    void timerEvent(QTimerEvent *event) {
+        Q_UNUSED(event);
+        m_scroller->tick();
+    }
+
+private:
+    Flickable *m_scroller;
+    QBasicTimer m_timer;
+};
+
+class FlickablePrivate
+{
+public:
+    typedef enum {
+        Steady,
+        Pressed,
+        ManualScroll,
+        AutoScroll,
+        Stop
+    } State;
+
+    State state;
+    int threshold;
+    QPoint pressPos;
+    QPoint offset;
+    QPoint delta;
+    QPoint speed;
+    FlickableTicker *ticker;
+    QTime timeStamp;
+    QWidget *target;
+    QList<QEvent*> ignoreList;
+};
+
+Flickable::Flickable()
+{
+    d = new FlickablePrivate;
+    d->state = FlickablePrivate::Steady;
+    d->threshold = 10;
+    d->ticker = new FlickableTicker(this);
+    d->timeStamp = QTime::currentTime();
+    d->target = 0;
+}
+
+Flickable::~Flickable()
+{
+    delete d;
+}
+
+void Flickable::setThreshold(int th)
+{
+    if (th >= 0)
+        d->threshold = th;
+}
+
+int Flickable::threshold() const
+{
+    return d->threshold;
+}
+
+void Flickable::setAcceptMouseClick(QWidget *target)
+{
+    d->target = target;
+}
+
+static QPoint deaccelerate(const QPoint &speed, int a = 1, int max = 64)
+{
+    int x = qBound(-max, speed.x(), max);
+    int y = qBound(-max, speed.y(), max);
+    x = (x == 0) ? x : (x > 0) ? qMax(0, x - a) : qMin(0, x + a);
+    y = (y == 0) ? y : (y > 0) ? qMax(0, y - a) : qMin(0, y + a);
+    return QPoint(x, y);
+}
+
+void Flickable::handleMousePress(QMouseEvent *event)
+{
+    event->ignore();
+
+    if (event->button() != Qt::LeftButton)
+        return;
+
+    if (d->ignoreList.removeAll(event))
+        return;
+
+    switch (d->state) {
+
+    case FlickablePrivate::Steady:
+        event->accept();
+        d->state = FlickablePrivate::Pressed;
+        d->pressPos = event->pos();
+        break;
+
+    case FlickablePrivate::AutoScroll:
+        event->accept();
+        d->state = FlickablePrivate::Stop;
+        d->speed = QPoint(0, 0);
+        d->pressPos = event->pos();
+        d->offset = scrollOffset();
+        d->ticker->stop();
+        break;
+
+    default:
+        break;
+    }
+}
+
+void Flickable::handleMouseRelease(QMouseEvent *event)
+{
+    event->ignore();
+
+    if (event->button() != Qt::LeftButton)
+        return;
+
+    if (d->ignoreList.removeAll(event))
+        return;
+
+    QPoint delta;
+
+    switch (d->state) {
+
+    case FlickablePrivate::Pressed:
+        event->accept();
+        d->state = FlickablePrivate::Steady;
+        if (d->target) {
+            QMouseEvent *event1 = new QMouseEvent(QEvent::MouseButtonPress,
+                                                  d->pressPos, Qt::LeftButton,
+                                                  Qt::LeftButton, Qt::NoModifier);
+            QMouseEvent *event2 = new QMouseEvent(*event);
+            d->ignoreList << event1;
+            d->ignoreList << event2;
+            QApplication::postEvent(d->target, event1);
+            QApplication::postEvent(d->target, event2);
+        }
+        break;
+
+    case FlickablePrivate::ManualScroll:
+        event->accept();
+        delta = event->pos() - d->pressPos;
+        if (d->timeStamp.elapsed() > 100) {
+            d->timeStamp = QTime::currentTime();
+            d->speed = delta - d->delta;
+            d->delta = delta;
+        }
+        d->offset = scrollOffset();
+        d->pressPos = event->pos();
+        if (d->speed == QPoint(0, 0)) {
+            d->state = FlickablePrivate::Steady;
+        } else {
+            d->speed /= 4;
+            d->state = FlickablePrivate::AutoScroll;
+            d->ticker->start(20);
+        }
+        break;
+
+    case FlickablePrivate::Stop:
+        event->accept();
+        d->state = FlickablePrivate::Steady;
+        d->offset = scrollOffset();
+        break;
+
+    default:
+        break;
+    }
+}
+
+void Flickable::handleMouseMove(QMouseEvent *event)
+{
+    event->ignore();
+
+    if (!(event->buttons() & Qt::LeftButton))
+        return;
+
+    if (d->ignoreList.removeAll(event))
+        return;
+
+    QPoint delta;
+
+    switch (d->state) {
+
+    case FlickablePrivate::Pressed:
+    case FlickablePrivate::Stop:
+        delta = event->pos() - d->pressPos;
+        if (delta.x() > d->threshold || delta.x() < -d->threshold ||
+                delta.y() > d->threshold || delta.y() < -d->threshold) {
+            d->timeStamp = QTime::currentTime();
+            d->state = FlickablePrivate::ManualScroll;
+            d->delta = QPoint(0, 0);
+            d->pressPos = event->pos();
+            event->accept();
+        }
+        break;
+
+    case FlickablePrivate::ManualScroll:
+        event->accept();
+        delta = event->pos() - d->pressPos;
+        setScrollOffset(d->offset - delta);
+        if (d->timeStamp.elapsed() > 100) {
+            d->timeStamp = QTime::currentTime();
+            d->speed = delta - d->delta;
+            d->delta = delta;
+        }
+        break;
+
+    default:
+        break;
+    }
+}
+
+void Flickable::tick()
+{
+    if (d->state == FlickablePrivate:: AutoScroll) {
+        d->speed = deaccelerate(d->speed);
+        setScrollOffset(d->offset - d->speed);
+        d->offset = scrollOffset();
+        if (d->speed == QPoint(0, 0)) {
+            d->state = FlickablePrivate::Steady;
+            d->ticker->stop();
+        }
+    } else {
+        d->ticker->stop();
+    }
+}
diff --git a/demos/embedded/flickable/flickable.h b/demos/embedded/flickable/flickable.h
new file mode 100644
index 0000000..26497db
--- /dev/null
+++ b/demos/embedded/flickable/flickable.h
@@ -0,0 +1,80 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the demonstration applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at http://qt.nokia.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef FLICKABLE_H
+#define FLICKABLE_H
+
+class QMouseEvent;
+class QPoint;
+class QWidget;
+
+class FlickableTicker;
+class FlickablePrivate;
+
+class Flickable
+{
+public:
+
+    Flickable();
+    virtual ~Flickable();
+
+    void setThreshold(int threshold);
+    int threshold() const;
+
+    void setAcceptMouseClick(QWidget *target);
+
+    void handleMousePress(QMouseEvent *event);
+    void handleMouseMove(QMouseEvent *event);
+    void handleMouseRelease(QMouseEvent *event);
+
+protected:
+    virtual QPoint scrollOffset() const = 0;
+    virtual void setScrollOffset(const QPoint &offset) = 0;
+
+private:
+    void tick();
+
+private:
+    FlickablePrivate *d;
+    friend class FlickableTicker;
+};
+
+#endif // FLICKABLE_H
diff --git a/demos/embedded/flickable/flickable.pro b/demos/embedded/flickable/flickable.pro
new file mode 100644
index 0000000..3c021dd
--- /dev/null
+++ b/demos/embedded/flickable/flickable.pro
@@ -0,0 +1,2 @@
+SOURCES = flickable.cpp main.cpp
+HEADERS = flickable.h
diff --git a/demos/embedded/flickable/main.cpp b/demos/embedded/flickable/main.cpp
new file mode 100644
index 0000000..cc024d9
--- /dev/null
+++ b/demos/embedded/flickable/main.cpp
@@ -0,0 +1,233 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the demonstration applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at http://qt.nokia.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore>
+#include <QtGui>
+
+#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");
+#ifdef Q_OS_SYMBIAN
+    list.showMaximized();
+#else
+    list.resize(320, 320);
+    list.show();
+#endif
+
+    return app.exec();
+}
diff --git a/demos/embedded/fluidlauncher/config_s60/config.xml b/demos/embedded/fluidlauncher/config_s60/config.xml
index 08cdb90..dfa8da7 100644
--- a/demos/embedded/fluidlauncher/config_s60/config.xml
+++ b/demos/embedded/fluidlauncher/config_s60/config.xml
@@ -18,6 +18,7 @@
     <example filename="lightmaps" name="OpenStreetMap" image="screenshots/lightmaps.png"/>
     <example filename="flightinfo" name="Flight Info" image="screenshots/flightinfo_s60.png"/>
     <example filename="weatherinfo" name="Weather Info" image="screenshots/weatherinfo.png"/>
+    <example filename="flickable" name="Kinetic Scrolling" image="screenshots/flickable.png"/>
   </demos>
   <slideshow timeout="60000" interval="10000">
     <imagedir dir="slides"/>
diff --git a/demos/embedded/fluidlauncher/screenshots/flickable.png b/demos/embedded/fluidlauncher/screenshots/flickable.png
new file mode 100644
index 0000000..7080fc1
--- /dev/null
+++ b/demos/embedded/fluidlauncher/screenshots/flickable.png