Qt 5.5 - touchscreen-events only working in initial (first) window - c++

Question

I've set up a basic Qt-Widgets-Application (Qt 5.5 community) with a simple QWidget "MainWindow" and an additinal QWidget "SettingsScreen".
Within the "MainWindow", touchscreen-events (handled by OS) are working as expected, but after opening the "SettingsScreen" all touch-events are executed on the desktop until I close the "SettingsScreen" using mouse or keyboard.
Environment:
Ubuntu Studio 14.04.03
Qt 5.5 Open Source Edition
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QWidget>
#include <settingsscreen.h>
namespace Ui {
class MainWindow;
}
class MainWindow : public QWidget
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
void on_btnExit_clicked();
void on_btnSettings_clicked();
private:
Ui::MainWindow *ui;
SettingsScreen *wSettingsScreen;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "settingsscreen.h"
#include "ui_settingsscreen.h"
MainWindow::MainWindow(QWidget *parent) : QWidget(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_btnExit_clicked()
{
this->close();
}
void MainWindow::on_btnSettings_clicked()
{
wSettingsScreen = new SettingsScreen(parentWidget());
wSettingsScreen->show();
}
settingsscreen.h
#ifndef SETTINGSSCREEN_H
#define SETTINGSSCREEN_H
#include <QWidget>
namespace Ui {
class SettingsScreen;
}
class SettingsScreen : public QWidget
{
Q_OBJECT
public:
explicit SettingsScreen(QWidget *parent = 0);
~SettingsScreen();
private slots:
void on_pushButton_clicked();
void on_btnBack_clicked();
private:
Ui::SettingsScreen *ui;
};
#endif // SETTINGSSCREEN_H
settingsscreen.cpp
#include "settingsscreen.h"
#include "ui_settingsscreen.h"
SettingsScreen::SettingsScreen(QWidget *parent) :
QWidget(parent),
ui(new Ui::SettingsScreen)
{
ui->setupUi(this);
}
SettingsScreen::~SettingsScreen()
{
delete ui;
}
void SettingsScreen::on_btnBack_clicked()
{
this->close();
}
I've just started developing with Qt, so please forgive me if I'm missing something essential :)
Any help would by highly appreciated!!
Thank you in advance!

Answer 1

Actually the thing is QMainwindow or any base Widget of your application is able to properly synthesize the Unhandled touch screen events to Mouse events. So whenever you are creating a dialog/widget, make sure to set Mainwindow as there parent and in the constructor of the child widget use setParent(parent). Even I was facing this kind of Issue and this worked for me.