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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:expandtab:shiftwidth=4:tabstop=4:
*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozSwipeGesture.h"
#include <QTouchEvent>
#include <QGraphicsWidget>
#include <prtypes.h>
#include <nsIDOMSimpleGestureEvent.h>
#include <math.h>
// Percent of screen size
static const float TRIGGER_DISTANCE = 0.3;
// It would be nice to get platform defines for these values
// Maximum finger distance in pixels
const int MAX_FINGER_DISTANCE = 250;
// We could define it as 2*QT_GUI_DOUBLE_CLICK_RADIUS, but it's not available
// due to QTBUG-9630
const int FINGER_DISTANCE_MISTAKE = 50;
QGesture*
MozSwipeGestureRecognizer::create(QObject* target)
{
return new MozSwipeGesture();
}
QGestureRecognizer::Result
MozSwipeGestureRecognizer::recognize(QGesture* aState,
QObject* aWatched,
QEvent* aEvent)
{
const QTouchEvent* ev = static_cast<const QTouchEvent *>(aEvent);
MozSwipeGesture* swipe = static_cast<MozSwipeGesture *>(aState);
QGestureRecognizer::Result result = QGestureRecognizer::Ignore;
QGraphicsWidget* widget = qobject_cast<QGraphicsWidget*>(aWatched);
if (!widget) {
return result;
}
switch (aEvent->type()) {
case QEvent::TouchBegin:
swipe->mSwipeState = MozSwipeGesture::NOT_STARTED;
result = QGestureRecognizer::MayBeGesture;
break;
case QEvent::TouchEnd:
if (swipe->state() != Qt::NoGesture &&
swipe->mSwipeState == MozSwipeGesture::TRIGGERED) {
result = QGestureRecognizer::FinishGesture;
}
else {
result = QGestureRecognizer::CancelGesture;
}
break;
case QEvent::TouchUpdate:
// We have already handled this swipe
if (swipe->mSwipeState > MozSwipeGesture::STARTED) {
break;
}
if (ev->touchPoints().count() > 2) {
swipe->mSwipeState = MozSwipeGesture::CANCELLED;
result = QGestureRecognizer::CancelGesture;
break;
}
if (ev->touchPoints().count() == 2) {
swipe->mSwipeState = MozSwipeGesture::STARTED;
QList <QTouchEvent::TouchPoint> touchPoints = ev->touchPoints();
if (!swipe->Update(touchPoints[0], touchPoints[1], widget->size())) {
result = QGestureRecognizer::CancelGesture;
swipe->mSwipeState = MozSwipeGesture::CANCELLED;
}
if (swipe->mSwipeState == MozSwipeGesture::TRIGGERED) {
result = QGestureRecognizer::TriggerGesture;
}
else {
result = QGestureRecognizer::MayBeGesture;
}
}
break;
default:
result = QGestureRecognizer::Ignore;
}
return result;
}
void
MozSwipeGestureRecognizer::reset(QGesture* aState)
{
MozSwipeGesture* swipe = static_cast<MozSwipeGesture *>(aState);
swipe->mHorizontalDirection = 0;
swipe->mVerticalDirection = 0;
QGestureRecognizer::reset(aState);
}
MozSwipeGesture::MozSwipeGesture()
: mHorizontalDirection(0)
, mVerticalDirection(0)
, mSwipeState(MozSwipeGesture::NOT_STARTED)
{
}
int MozSwipeGesture::Direction()
{
return mHorizontalDirection | mVerticalDirection;
}
bool
MozSwipeGesture::Update(const QTouchEvent::TouchPoint& aFirstPoint,
const QTouchEvent::TouchPoint& aSecondPoint,
const QSizeF& aSize)
{
// Check that fingers are not too far away
QPointF fingerDistance = aFirstPoint.pos() - aSecondPoint.pos();
if (fingerDistance.manhattanLength() > MAX_FINGER_DISTANCE) {
return false;
}
// Check that fingers doesn't move too much from the original distance
QPointF startFingerDistance = aFirstPoint.startPos() - aSecondPoint.startPos();
if ((startFingerDistance - fingerDistance).manhattanLength()
> FINGER_DISTANCE_MISTAKE) {
return false;
}
QPointF startPosition = aFirstPoint.startNormalizedPos();
QPointF currentPosition = aFirstPoint.normalizedPos();
float xDistance = fabs(currentPosition.x() - startPosition.x());
float yDistance = fabs(currentPosition.y() - startPosition.y());
startPosition = aFirstPoint.startPos();
currentPosition = aFirstPoint.pos();
if (!aSize.isEmpty()) {
xDistance = fabs(currentPosition.x() - startPosition.x())
/ aSize.width();
yDistance = fabs(currentPosition.y() - startPosition.y())
/ aSize.height();
}
mVerticalDirection = nsIDOMSimpleGestureEvent::DIRECTION_UP;
if (currentPosition.y() > startPosition.y()) {
mVerticalDirection = nsIDOMSimpleGestureEvent::DIRECTION_DOWN;
}
mHorizontalDirection = nsIDOMSimpleGestureEvent::DIRECTION_LEFT;
if (currentPosition.x() > startPosition.x()) {
mHorizontalDirection = nsIDOMSimpleGestureEvent::DIRECTION_RIGHT;
}
if (xDistance > TRIGGER_DISTANCE) {
if (yDistance < TRIGGER_DISTANCE/2) {
mVerticalDirection = 0;
}
mSwipeState = TRIGGERED;
}
if (yDistance > TRIGGER_DISTANCE) {
if (xDistance < TRIGGER_DISTANCE/2) {
mHorizontalDirection = 0;
}
mSwipeState = TRIGGERED;
}
// Use center of touchpoints as hotspot
QPointF hotspot = aFirstPoint.pos() + aSecondPoint.pos();
hotspot /= 2;
setHotSpot(hotspot);
return true;
}
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