Proxy mouse/touch events

[zing0000]

There has been some prior discussion, e.g.

"fake events":http://stackoverflow.com/questions/18849663/generating-simulating-fake-mouse-events-in-qt

but I am trying to get this working correctly with Qt5.4 and QQuickView. The simple project below demonstrates. A remote or proxy cursor moves within the main window and if it coincides with an UI element such as a button, a MouseEvent is generated that fakes a users action. The position of the proxy click can be anywhere but the event generated uses the position of the proxy cursor. So the button gets pressed.

The ClickSimulator class creates an event and sends it to an UI element. This appears to work but the event is never received by the QML id realbutton.

I am using prebuilt Qt5.4 and I am targeting multiple platforms. This is a genrally useful utility so I hope someone has done this and can spot some problem in my code.

main.cpp
@#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQuickView>
#include "clicksimulator.h"

int main(int argc, char *argv[])
{
QApplication app(argc, argv);

QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

QObject *topLevel = engine.rootObjects().value(0);
QQuickWindow *window = qobject_cast<QQuickWindow *>(topLevel);

QQuickView *view = new QQuickView;
view->setParent(window);

// Setup the finger click handler
ClickSimulator sim(window);
sim.connect(window, SIGNAL(newfingerpos(int, int)),  SLOT(proxyClick(int, int)));
QObject::connect(view->engine(), SIGNAL(quit()), view, SLOT(close()));

return app.exec();

}
@

main.qml
@import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Window 2.2
import QtQuick.Dialogs 1.2

ApplicationWindow {
title: qsTr("Hello World")
width: 640
height: 480
visible: true

signal newfingerpos(int x, int y)

// This is the overlay that catches the finger clicks
Button {
    objectName: "overlaybutton"
    anchors.fill: parent
    opacity: 0.3
    z: 2

    MouseArea {
        anchors.fill: parent
        propagateComposedEvents: false
        onClicked: {
            mouse.accepted = true
            console.log("overlay tapped")
            newfingerpos(50, 50)
        }
    }
}

// This is the 'real' button but it will only be pressed from the newfingerpos signal
Button {
    id: button
    objectName: "realbutton"
    width: 100; height: 100
    x:25; y:25
    text: qsTr("Press Me")
    z: 1

    MouseArea {
        anchors.fill: parent
        onClicked: {
            console.log("button pressed by proxy event")
            console.log("Mouse x: ", mouseX, "Mouse y: ", mouseY)
        }
    }
}

}
@

clicksimulator.h
@#pragma once

#include <QObject>
#include <QQuickView>

class ClickSimulator : public QObject
{
Q_OBJECT

public:
explicit ClickSimulator(QQuickWindow* viewer, QObject *parent = 0);

public slots:
void proxyClick(int, int);

private:
QQuickWindow* _viewport;

};
@

clicksimulator.cpp
@#include "clicksimulator.h"

#include <QMouseEvent>
#include <QQuickItem>

ClickSimulator::ClickSimulator(QQuickWindow* viewport, QObject *parent) :
QObject(parent),
_viewport(viewport)
{
}

void ClickSimulator::proxyClick(int x, int y)
{
if (_viewport != NULL) {
QMouseEvent pressEvent(QEvent::MouseButtonPress, QPoint(x, y), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
QQuickItem* controlarea = _viewport->findChild<QQuickItem*>("realbutton");
const bool isSent = _viewport->sendEvent(controlarea, &pressEvent);
qDebug() << "'Press' at (" << x << "," << y << ") successful? " << isSent;

    QMouseEvent releaseEvent(QEvent::MouseButtonRelease, QPoint(x, y), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
    const bool isRlseSent = _viewport->sendEvent(controlarea, &releaseEvent);
    qDebug() << "'Release' at (" << x << "," << y << ") successful? " << isRlseSent;

    _viewport->update();
}

}
@

mousetest.pro
@TEMPLATE = app

QT += qml quick widgets

SOURCES += main.cpp
clicksimulator.cpp

RESOURCES += qml.qrc

Additional import path used to resolve QML modules in Qt Creator's code model

QML_IMPORT_PATH =

Default rules for deployment.

include(deployment.pri)

HEADERS +=
clicksimulator.h
@