QTouchEvent Error touch position
-
Hi,
After read and try this example http://doc.qt.nokia.com/qt-maemo/touch-knobs.html I'm trying to do a similar thing where i move a ellipse.My code is:
@#ifndef JOYSTICK_H
#define JOYSTICK_H#include <QGraphicsItem>
class joystick : public QGraphicsEllipseItem
{
public:
joystick();bool sceneEvent(QEvent *event);};
#endif // JOYSTICK_H
@@#include "joystick.h"
#include <QBrush>
#include <QTouchEvent>#include <QDebug>
joystick::joystick()
: QGraphicsEllipseItem(0, 0, 90, 90)
{
setAcceptTouchEvents(true);
setBrush(Qt::lightGray);
}bool joystick::sceneEvent(QEvent *event)
{
switch (event->type()) {
case QEvent::TouchBegin:
event->accept();
break;
case QEvent::TouchUpdate:
case QEvent::TouchEnd:
{
QTouchEvent *touchEvent = static_cast<QTouchEvent *>(event);
if (touchEvent->touchPoints().count() == 1) {
QTouchEvent::TouchPoint touchPoint1 = touchEvent->touchPoints().first();
qDebug()<<touchPoint1.pos();
setPos(touchPoint1.pos());
}touchEvent->accept(); break; } default: return QGraphicsItem::sceneEvent(event); } return true;}@
and main.cpp
@#include <QApplication>
#include <QGraphicsView>#include "joystick.h"
int main(int argc, char **argv)
{
QApplication app(argc, argv);QGraphicsScene scene; QGraphicsView view(&scene); view.viewport()->setAttribute(Qt::WA_AcceptTouchEvents); joystick *joy1 = new joystick; joy1->setPos(-150,0); scene.addItem(joy1); view.showFullScreen(); view.fitInView(scene.sceneRect(), Qt::KeepAspectRatio); return app.exec();}@
while the knobs works great my code give me bad touch position. This is the log of a line moving the touchpoint:
QPointF(55.1084, 32.283)
QPointF(133.696, -52.8265)
QPointF(54.1301, 32.283)
QPointF(132.718, -52.8265)
QPointF(53.1519, 32.283)
QPointF(131.739, -52.8265)
QPointF(51.1954, 32.283)
QPointF(130.761, -52.8265)
QPointF(49.2388, 32.283)
QPointF(129.783, -52.8265)
QPointF(48.2606, 32.283)
QPointF(128.805, -52.8265)
QPointF(46.3041, 35.2178)
QPointF(122.935, -51.8482)
QPointF(45.3258, 35.2178)
QPointF(120.979, -50.87)
QPointF(43.3693, 35.2178)
QPointF(119.022, -50.87)
QPointF(41.4128, 35.2178)
QPointF(117.065, -50.87)
QPointF(39.4562, 35.2178)
QPointF(115.109, -49.8917)
QPointF(37.4997, 35.2178)
QPointF(113.152, -49.8917)
QPointF(35.5432, 35.2178)
QPointF(112.174, -49.8917)
QPointF(33.5867, 35.2178)
QPointF(110.218, -49.8917)
QPointF(32.6084, 35.2178)
QPointF(108.261, -48.9134)
QPointF(31.6302, 35.2178)
QPointF(107.283, -48.9134)
QPointF(30.6519, 35.2178)
QPointF(104.348, -48.9134)
QPointF(28.6954, 35.2178)
QPointF(101.413, -48.9134)
QPointF(26.7389, 36.1961)
QPointF(99.4568, -48.9134)
QPointF(24.7823, 36.196)
QPointF(98.4785, -48.9134)
QPointF(22.8258, 36.196)
QPointF(96.522, -48.9134)
QPointF(21.8475, 36.196)
QPointF(94.5655, -48.9134)
QPointF(19.891, 36.196)
QPointF(91.6307, -47.9352)
QPointF(17.9345, 36.196)
QPointF(90.6525, -47.9352)
QPointF(16.9562, 36.196)
QPointF(89.6742, -47.9352)
QPointF(15.978, 36.196)
QPointF(88.696, -47.9352)
QPointF(14.9997, 37.1743)
QPointF(86.7394, -47.9352)
QPointF(14.0214, 37.1743)
QPointF(84.7829, -47.9352)
QPointF(13.0432, 37.1743)
QPointF(82.8264, -47.9352)
QPointF(11.0866, 37.1743)
QPointF(81.8481, -47.9352)
QPointF(10.1084, 38.1526)
QPointF(80.8699, -47.9352)
QPointF(8.15185, 38.1526)
QPointF(78.9134, -47.9352)
QPointF(7.17359, 38.1526)
QPointF(76.9568, -47.9352)
QPointF(5.21707, 38.1526)
QPointF(75.0003, -47.9352)
QPointF(4.23881, 38.1526)
QPointF(73.0438, -46.9569)
QPointF(3.26054, 38.1526)
QPointF(72.0655, -46.9569)
QPointF(2.28229, 38.1526)
QPointF(71.0873, -46.9569)
QPointF(-1.63075, 38.1526)
QPointF(68.1525, -46.957)
QPointF(-3.58727, 38.1526)
QPointF(66.196, -45.9787)
QPointF(-4.56554, 38.1526)
QPointF(64.2394, -45.9787)
QPointF(-6.52206, 38.1526)
QPointF(63.2612, -45.9787)
QPointF(-7.50032, 38.1526)
QPointF(62.2829, -45.9787)
QPointF(-8.47858, 38.1526)
QPointF(59.3481, -45.0004)
QPointF(-10.4351, 38.1526)
QPointF(58.3699, -45.0004)
QPointF(-12.3916, 38.1526)
QPointF(57.3916, -45.0004)
QPointF(-16.3047, 38.1526)
QPointF(56.4134, -44.0222)
QPointF(-18.2612, 38.1526)
QPointF(55.4351, -44.0222)
QPointF(-19.2395, 38.1526)
QPointF(54.4569, -44.0222)
QPointF(-20.2177, 38.1526)
QPointF(52.5003, -44.0222)
QPointF(-22.1742, 38.1526)
QPointF(50.5438, -43.0439)
QPointF(-26.0873, 38.1526)
QPointF(49.5656, -43.0439)
QPointF(-28.0438, 38.1526)
QPointF(47.609, -43.0439)
QPointF(-30.0003, 38.1526)
QPointF(46.6308, -43.0439)
QPointF(-30.9786, 38.1526)
QPointF(45.6525, -42.0657)
QPointF(-31.9569, 38.1526)
QPointF(44.6743, -42.0657)
QPointF(-33.9134, 38.1527)
QPointF(42.7177, -42.0657)
QPointF(-36.8482, 38.1527)
QPointF(40.7612, -42.0657)
QPointF(-39.783, 38.1527)
QPointF(38.8047, -42.0657)
QPointF(-41.7395, 39.1309)
QPointF(35.8699, -42.0657)
QPointF(-44.6743, 39.1309)
QPointF(33.9134, -42.0657)
QPointF(-46.6308, 39.1309)
QPointF(31.9569, -42.0657)
QPointF(-47.6091, 39.1309)
QPointF(30.9786, -42.0657)
QPointF(-48.5873, 39.1309)
QPointF(29.0221, -42.0657)
QPointF(-49.5656, 39.1309)
QPointF(28.0439, -42.0657)
QPointF(-50.5439, 40.1092)
QPointF(26.0873, -42.0657)
QPointF(-51.5221, 40.1092)
QPointF(24.1308, -42.0657)
QPointF(-52.5004, 40.1092)
QPointF(23.1526, -42.0657)
QPointF(-53.4786, 40.1092)
QPointF(22.1743, -42.0657)
QPointF(-53.4786, 40.1092)
QPointF(22.1743, -42.0657)As you can see the value change a lot but with knobs example it simple work. Another thing is if i just click it moves for another position :s
I recorded a simple movie to ilustrate the problem: http://www.youtube.com/watch?v=tDK2Ta2IoCY