Touchscreen in WebAssembly application

Renio

Good morning everyone!
I'm develop an webassembly application that must use touchscreen.
I studied the examples:
dials
fingerpaint
knobs
pinchzoom
(see https://doc.qt.io/qt-6/touchinputexamples.html)

I tryed to run the tablet example (see https://doc.qt.io/qt-6/qtwidgets-widgets-tablet-example.html) compiled in webassembly but don't work.
I have this problem:
If I compile my application with MinGW kit (Desktop application), I'm able to move a dialog grabbed with mouse
If I compile my application with WebAssembly kit (WebAssembly application), I'm NOT able to move a dialog tapped on title.
But if I tap on the canvas or on any button of the dialog the touch event is catched.

My question is: how can I perform the same behaviour in all configuration
I posted a minimal application affected for same issue
The example is composed by a MainWindow that show a non modal dialog, across the menu file, open.
The dialog is a simple default QDialog with two button (ok and cancel)
My configuration:

Qt Creator 7.0.0
Based on Qt 6.2.3 (MSVC 2019, 64 bit)
From revision 638b93591b

Qt 6.3.0 WebAssembly with Emscripten 3.1.6 for C++

Google Chrome Ver. 101.0.4951.54

thank's for your help

here WasmDialog code:

#include "WasmDialog.h"
#include "ui_wasmdialog.h"

#include <QDebug>
#include <QMoveEvent>

WasmDialog::WasmDialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::WasmDialog)
{
    ui->setupUi(this);
    setAttribute(Qt::WA_AcceptTouchEvents);

} // ctr

WasmDialog::~WasmDialog()
{
    delete ui;
} // dtr

void WasmDialog::mousePressEvent(QMouseEvent *event)
{
    qDebug() << " e->type " <<  event->type() << " e->flags " <<  event->flags();
    QDialog::mousePressEvent(event);
}

bool WasmDialog::event(QEvent *event)
{
    switch (event->type())
    {
        case QEvent::TouchBegin:
        case QEvent::TouchUpdate:
        case QEvent::TouchEnd:
        {
            qDebug() << " e->type " <<  event->type();
            break;
        }
        default:
        {
            break;
        }
    }
    return QDialog::event(event);
}

void WasmDialog::tabletEvent(QTabletEvent *event)
{
    switch (event->type())
    {
        case QEvent::TabletPress:
        case QEvent::TabletMove:
        {
            qDebug() << " e->type " <<  event->type();
            break;
        }
        case QEvent::TabletRelease:
        {
            qDebug() << " e->type " <<  event->type();
            update();
            break;
        }
        default:
        {
            break;
        }
    }
    QDialog::tabletEvent(event);
}

here MainWindow code:

#include "MainWindow.h"
#include "ui_mainwindow.h"


MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    setAttribute(Qt::WA_AcceptTouchEvents);

    connect(ui->actionOpen, &QAction::triggered, &moWD, &WasmDialog::show);
} // ctr

MainWindow::~MainWindow()
{
    delete ui;
} // dtr

here main.cpp code:

#include "MainWindow.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

lorn.potter

@Renio said in Touchscreen in WebAssembly application:

ly application), I'm NOT able to move a dialog tapped on title.

What tablet are you using? Android, iOS, Windows or some Linux version?

lorn.potter

Qt 6.4.0 will have better mobile touch support. I just tested this on 6.4.0 and I cannot move the dialog, so that is a bug.

lorn.potter

I started a bug report, thanks!
https://bugreports.qt.io/browse/QTBUG-103498

Renio

@lorn-potter My Boss, want to use a laptop with a touchscreen display and this device have windows installed.

Renio

This post is deleted!