1 files changed, 309 insertions, 0 deletions
diff --git a/demos/embedded/anomaly/src/flickcharm.cpp b/demos/embedded/anomaly/src/flickcharm.cpp
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+++ b/demos/embedded/anomaly/src/flickcharm.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the Graphics Dojo project on Qt Labs.
+**
+** This file may be used under the terms of the GNU General Public
+** License version 2.0 or 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 GNU
+** General Public Licensing requirements will be met:
+** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+**
+** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+**
+****************************************************************************/
+
+#include "flickcharm.h"
+
+#include <QAbstractScrollArea>
+#include <QApplication>
+#include <QBasicTimer>
+#include <QEvent>
+#include <QHash>
+#include <QList>
+#include <QMouseEvent>
+#include <QScrollBar>
+#include <QWebFrame>
+#include <QWebView>
+
+#include <QDebug>
+
+struct FlickData {
+    typedef enum { Steady, Pressed, ManualScroll, AutoScroll, Stop } State;
+    State state;
+    QWidget *widget;
+    QPoint pressPos;
+    QPoint offset;
+    QPoint dragPos;
+    QPoint speed;
+    QList<QEvent*> ignored;
+};
+
+class FlickCharmPrivate
+{
+public:
+    QHash<QWidget*, FlickData*> flickData;
+    QBasicTimer ticker;
+};
+
+FlickCharm::FlickCharm(QObject *parent): QObject(parent)
+{
+    d = new FlickCharmPrivate;
+}
+
+FlickCharm::~FlickCharm()
+{
+    delete d;
+}
+
+void FlickCharm::activateOn(QWidget *widget)
+{
+    QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
+    if (scrollArea) {
+        scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+        scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+
+        QWidget *viewport = scrollArea->viewport();
+
+        viewport->installEventFilter(this);
+        scrollArea->installEventFilter(this);
+
+        d->flickData.remove(viewport);
+        d->flickData[viewport] = new FlickData;
+        d->flickData[viewport]->widget = widget;
+        d->flickData[viewport]->state = FlickData::Steady;
+
+        return;
+    }
+
+    QWebView *webView = dynamic_cast<QWebView*>(widget);
+    if (webView) {
+        QWebFrame *frame = webView->page()->mainFrame();
+        frame->setScrollBarPolicy(Qt::Vertical, Qt::ScrollBarAlwaysOff);
+        frame->setScrollBarPolicy(Qt::Horizontal, Qt::ScrollBarAlwaysOff);
+
+        webView->installEventFilter(this);
+
+        d->flickData.remove(webView);
+        d->flickData[webView] = new FlickData;
+        d->flickData[webView]->widget = webView;
+        d->flickData[webView]->state = FlickData::Steady;
+
+        return;
+    }
+
+    qWarning() << "FlickCharm only works on QAbstractScrollArea (and derived classes)";
+    qWarning() << "or QWebView (and derived classes)";
+}
+
+void FlickCharm::deactivateFrom(QWidget *widget)
+{
+    QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
+    if (scrollArea) {
+        QWidget *viewport = scrollArea->viewport();
+
+        viewport->removeEventFilter(this);
+        scrollArea->removeEventFilter(this);
+
+        delete d->flickData[viewport];
+        d->flickData.remove(viewport);
+
+        return;
+    }
+
+    QWebView *webView = dynamic_cast<QWebView*>(widget);
+    if (webView) {
+        webView->removeEventFilter(this);
+
+        delete d->flickData[webView];
+        d->flickData.remove(webView);
+
+        return;
+    }
+}
+
+static QPoint scrollOffset(QWidget *widget)
+{
+    int x = 0, y = 0;
+
+    QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
+    if (scrollArea) {
+        x = scrollArea->horizontalScrollBar()->value();
+        y = scrollArea->verticalScrollBar()->value();
+    }
+
+    QWebView *webView = dynamic_cast<QWebView*>(widget);
+    if (webView) {
+        QWebFrame *frame = webView->page()->mainFrame();
+        x = frame->evaluateJavaScript("window.scrollX").toInt();
+        y = frame->evaluateJavaScript("window.scrollY").toInt();
+    }
+
+    return QPoint(x, y);
+}
+
+static void setScrollOffset(QWidget *widget, const QPoint &p)
+{
+    QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
+    if (scrollArea) {
+        scrollArea->horizontalScrollBar()->setValue(p.x());
+        scrollArea->verticalScrollBar()->setValue(p.y());
+    }
+
+    QWebView *webView = dynamic_cast<QWebView*>(widget);
+    QWebFrame *frame = webView ? webView->page()->mainFrame() : 0;
+    if (frame)
+        frame->evaluateJavaScript(QString("window.scrollTo(%1,%2);").arg(p.x()).arg(p.y()));
+}
+
+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);
+}
+
+bool FlickCharm::eventFilter(QObject *object, QEvent *event)
+{
+    if (!object->isWidgetType())
+        return false;
+
+    QEvent::Type type = event->type();
+    if (type != QEvent::MouseButtonPress &&
+            type != QEvent::MouseButtonRelease &&
+            type != QEvent::MouseMove)
+        return false;
+
+    QMouseEvent *mouseEvent = dynamic_cast<QMouseEvent*>(event);
+    if (!mouseEvent || mouseEvent->modifiers() != Qt::NoModifier)
+        return false;
+
+    QWidget *viewport = dynamic_cast<QWidget*>(object);
+    FlickData *data = d->flickData.value(viewport);
+    if (!viewport || !data || data->ignored.removeAll(event))
+        return false;
+
+    bool consumed = false;
+    switch (data->state) {
+
+    case FlickData::Steady:
+        if (mouseEvent->type() == QEvent::MouseButtonPress)
+            if (mouseEvent->buttons() == Qt::LeftButton) {
+                consumed = true;
+                data->state = FlickData::Pressed;
+                data->pressPos = mouseEvent->pos();
+                data->offset = scrollOffset(data->widget);
+            }
+        break;
+
+    case FlickData::Pressed:
+        if (mouseEvent->type() == QEvent::MouseButtonRelease) {
+            consumed = true;
+            data->state = FlickData::Steady;
+
+            QMouseEvent *event1 = new QMouseEvent(QEvent::MouseButtonPress,
+                                                  data->pressPos, Qt::LeftButton,
+                                                  Qt::LeftButton, Qt::NoModifier);
+            QMouseEvent *event2 = new QMouseEvent(*mouseEvent);
+
+            data->ignored << event1;
+            data->ignored << event2;
+            QApplication::postEvent(object, event1);
+            QApplication::postEvent(object, event2);
+        }
+        if (mouseEvent->type() == QEvent::MouseMove) {
+            consumed = true;
+            data->state = FlickData::ManualScroll;
+            data->dragPos = QCursor::pos();
+            if (!d->ticker.isActive())
+                d->ticker.start(20, this);
+        }
+        break;
+
+    case FlickData::ManualScroll:
+        if (mouseEvent->type() == QEvent::MouseMove) {
+            consumed = true;
+            QPoint delta = mouseEvent->pos() - data->pressPos;
+            setScrollOffset(data->widget, data->offset - delta);
+        }
+        if (mouseEvent->type() == QEvent::MouseButtonRelease) {
+            consumed = true;
+            data->state = FlickData::AutoScroll;
+        }
+        break;
+
+    case FlickData::AutoScroll:
+        if (mouseEvent->type() == QEvent::MouseButtonPress) {
+            consumed = true;
+            data->state = FlickData::Stop;
+            data->speed = QPoint(0, 0);
+            data->pressPos = mouseEvent->pos();
+            data->offset = scrollOffset(data->widget);
+        }
+        if (mouseEvent->type() == QEvent::MouseButtonRelease) {
+            consumed = true;
+            data->state = FlickData::Steady;
+            data->speed = QPoint(0, 0);
+        }
+        break;
+
+    case FlickData::Stop:
+        if (mouseEvent->type() == QEvent::MouseButtonRelease) {
+            consumed = true;
+            data->state = FlickData::Steady;
+        }
+        if (mouseEvent->type() == QEvent::MouseMove) {
+            consumed = true;
+            data->state = FlickData::ManualScroll;
+            data->dragPos = QCursor::pos();
+            if (!d->ticker.isActive())
+                d->ticker.start(20, this);
+        }
+        break;
+
+    default:
+        break;
+    }
+
+    return consumed;
+}
+
+void FlickCharm::timerEvent(QTimerEvent *event)
+{
+    int count = 0;
+    QHashIterator<QWidget*, FlickData*> item(d->flickData);
+    while (item.hasNext()) {
+        item.next();
+        FlickData *data = item.value();
+
+        if (data->state == FlickData::ManualScroll) {
+            count++;
+            data->speed = QCursor::pos() - data->dragPos;
+            data->dragPos = QCursor::pos();
+        }
+
+        if (data->state == FlickData::AutoScroll) {
+            count++;
+            data->speed = deaccelerate(data->speed);
+            QPoint p = scrollOffset(data->widget);
+            setScrollOffset(data->widget, p - data->speed);
+            if (data->speed == QPoint(0, 0))
+                data->state = FlickData::Steady;
+        }
+    }
+
+    if (!count)
+        d->ticker.stop();
+
+    QObject::timerEvent(event);
+}