Refactored gesture api

Rewritten the api almost from scratch, making it simplier and more
flexible at the same time.

The current implementation will not have complex gseturemanager class
inside Qt, but the QGesture base class, which represents both a
gesture recognizer and a gesture itself with a set of properties. A
set of common gestures that can use used in third-party applications
(and in Qt itself internally) is supposed to be found in
qstandardgestures.h, and a base class for user-defined gestures is in
qgesture.h

Gesture implementation for Pan on Windows7 has also been added as a
reference implementation for platform gestures.

1 files changed, 254 insertions, 0 deletions

diff --git a/src/gui/kernel/qstandardgestures.cpp b/src/gui/kernel/qstandardgestures.cpp
new file mode 100644
index 0000000..c8b11c5
--- /dev/null
+++ b/src/gui/kernel/qstandardgestures.cpp
@@ -0,0 +1,254 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtGui module 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://www.qtsoftware.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qstandardgestures.h"
+#include "qstandardgestures_p.h"
+
+#include <qabstractscrollarea.h>
+#include <qscrollbar.h>
+#include <private/qapplication_p.h>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QPanGesture
+    \since 4.6
+
+    \brief The QPanGesture class represents a Pan gesture,
+    providing additional information related to panning.
+*/
+
+/*!
+    Creates a new Pan gesture handler object and marks it as a child of \a
+    parent.
+
+    On some platform like Windows it's necessary to provide a non-null widget
+    as \a parent to get native gesture support.
+*/
+QPanGesture::QPanGesture(QWidget *parent)
+    : QGesture(*new QPanGesturePrivate, parent)
+{
+#ifdef Q_WS_WIN
+    if (parent) {
+        QApplicationPrivate* getQApplicationPrivateInternal();
+        QApplicationPrivate *qAppPriv = getQApplicationPrivateInternal();
+        qAppPriv->widgetGestures[parent].pan = this;
+    }
+#endif
+}
+
+/*! \internal */
+bool QPanGesture::event(QEvent *event)
+{
+#ifdef Q_WS_WIN
+    QApplicationPrivate* getQApplicationPrivateInternal();
+    switch (event->type()) {
+    case QEvent::ParentAboutToChange:
+        if (QWidget *w = qobject_cast<QWidget*>(parent()))
+            getQApplicationPrivateInternal()->widgetGestures[w].pan = 0;
+        break;
+    case QEvent::ParentChange:
+        if (QWidget *w = qobject_cast<QWidget*>(parent()))
+            getQApplicationPrivateInternal()->widgetGestures[w].pan = this;
+        break;
+    default:
+        break;
+    }
+#endif
+    return QObject::event(event);
+}
+
+/*! \internal */
+bool QPanGesture::filterEvent(QEvent *event)
+{
+    Q_D(QPanGesture);
+    if (!event->spontaneous())
+        return false;
+    const QTouchEvent *ev = static_cast<const QTouchEvent*>(event);
+    if (event->type() == QEvent::TouchBegin) {
+        d->touchPoints = ev->touchPoints();
+        const QPoint p = ev->touchPoints().at(0).pos().toPoint();
+        setStartPos(p);
+        setLastPos(p);
+        setPos(p);
+        return false;
+    } else if (event->type() == QEvent::TouchEnd) {
+        if (state() != Qt::NoGesture) {
+            setState(Qt::GestureFinished);
+            setLastPos(pos());
+            setPos(ev->touchPoints().at(0).pos().toPoint());
+            emit triggered();
+            emit finished();
+        }
+        setState(Qt::NoGesture);
+        reset();
+    } else if (event->type() == QEvent::TouchUpdate) {
+        d->touchPoints = ev->touchPoints();
+        QPointF pt = d->touchPoints.at(0).pos() - d->touchPoints.at(0).startPos();
+        setLastPos(pos());
+        setPos(ev->touchPoints().at(0).pos().toPoint());
+        if (pt.x() > 10 || pt.y() > 10 || pt.x() < -10 || pt.y() < -10) {
+            if (state() == Qt::NoGesture)
+                setState(Qt::GestureStarted);
+            else
+                setState(Qt::GestureUpdated);
+            emit triggered();
+        }
+    }
+    return false;
+}
+
+/*! \internal */
+void QPanGesture::reset()
+{
+    Q_D(QPanGesture);
+    d->touchPoints.clear();
+}
+
+/*!
+    \property QPanGesture::totalOffset
+
+    Specifies a total pan offset since the start of the gesture.
+*/
+QSize QPanGesture::totalOffset() const
+{
+    QPoint pt = pos() - startPos();
+    return QSize(pt.x(), pt.y());
+}
+
+/*!
+    \property QPanGesture::lastOffset
+
+    Specifies a pan offset since the last time the gesture was
+    triggered.
+*/
+QSize QPanGesture::lastOffset() const
+{
+    QPoint pt = pos() - lastPos();
+    return QSize(pt.x(), pt.y());
+}
+
+/*!
+    \class QTapAndHoldGesture
+    \since 4.6
+
+    \brief The QTapAndHoldGesture class represents a Tap-and-Hold gesture,
+    providing additional information.
+*/
+
+const int QTapAndHoldGesturePrivate::iterationCount = 40;
+const int QTapAndHoldGesturePrivate::iterationTimeout = 50;
+
+/*!
+    Creates a new Tap and Hold gesture handler object and marks it as a child
+    of \a parent.
+
+    On some platforms like Windows there is a system-wide tap and hold gesture
+    that cannot be overriden, hence the gesture might never trigger and default
+    context menu will be shown instead.
+*/
+QTapAndHoldGesture::QTapAndHoldGesture(QWidget *parent)
+    : QGesture(*new QTapAndHoldGesturePrivate, parent)
+{
+}
+
+/*! \internal */
+bool QTapAndHoldGesture::filterEvent(QEvent *event)
+{
+    Q_D(QTapAndHoldGesture);
+    if (!event->spontaneous())
+        return false;
+    const QTouchEvent *ev = static_cast<const QTouchEvent*>(event);
+    switch (event->type()) {
+    case QEvent::TouchBegin: {
+        if (d->timer.isActive())
+            d->timer.stop();
+        d->timer.start(QTapAndHoldGesturePrivate::iterationTimeout, this);
+        const QPoint p = ev->touchPoints().at(0).pos().toPoint();
+        setStartPos(p);
+        setLastPos(p);
+        setPos(p);
+        break;
+    }
+    case QEvent::TouchUpdate:
+        if (ev->touchPoints().size() != 1)
+            reset();
+        else if ((startPos() - ev->touchPoints().at(0).pos().toPoint()).manhattanLength() > 15)
+            reset();
+        break;
+    case QEvent::TouchEnd:
+        reset();
+        break;
+    default:
+        break;
+    }
+    return false;
+}
+
+/*! \internal */
+void QTapAndHoldGesture::timerEvent(QTimerEvent *event)
+{
+    Q_D(QTapAndHoldGesture);
+    if (event->timerId() != d->timer.timerId())
+        return;
+    if (d->iteration == QTapAndHoldGesturePrivate::iterationCount) {
+        d->timer.stop();
+        setState(Qt::GestureFinished);
+        emit triggered();
+    } else {
+        setState(Qt::GestureStarted);
+        emit triggered();
+    }
+    ++d->iteration;
+}
+
+/*! \internal */
+void QTapAndHoldGesture::reset()
+{
+    Q_D(QTapAndHoldGesture);
+    if (state() != Qt::NoGesture)
+        emit cancelled();
+    setState(Qt::NoGesture);
+    d->timer.stop();
+    d->iteration = 0;
+}
+
+QT_END_NAMESPACE