[SOLVED] Why Q*Window Events are eaten by QML Item??

[madoodia]

Hello All

I have a very simple application here, that create a QQuickWindow Under a QQuickItem everything seems ok but why mousePressEvent function does not call by the QQuickWindow ?
Just we can see QML related messages

Thanks for any idea

---------------

main.cpp

#include "view.h"

#include <QtQml/QQmlApplicationEngine>
#include <QtWidgets/QApplication>

int main(int argc, char **argv)
{
  QApplication app(argc, argv);
  QQmlApplicationEngine engine;

  qmlRegisterType<MyItem>("Sample", 1, 0, "MyItem");

  engine.load(QUrl("qrc:/main.qml"));
  if (engine.rootObjects().isEmpty())
    return -1;

  return app.exec();
}

---------------

main.qml

import QtQuick 2.12
import QtQuick.Controls 2.13
import QtQuick.Window 2.12
import Sample 1.0

Window {
    id: main
    width: 600
    height: 600
    visible: true
    
    SplitView {
        id: splitView
        anchors.fill: parent
        orientation: Qt.Horizontal

        handle: Rectangle {
            implicitWidth: 4
            implicitHeight: 4
            color: SplitHandle.pressed ? "#81e889"
                : (SplitHandle.hovered ? Qt.lighter("#c2f4c6", 1.1) : "#c2f4c6")
        }

        MyItem {
            id: lefty
            implicitWidth: 300
            implicitHeight: 300
            MouseArea
            {
                anchors.fill: parent;
                onClicked:
                {
                    console.log("Lefty");
                }
            }
        }

        Item {
            id: righty
            implicitWidth: 300
            implicitHeight: 300
            Rectangle {
                anchors.fill: parent
                color: "gray"
                MouseArea
                {
                    anchors.fill: parent;
                    onClicked:
                    {
                        console.log("Righty");
                    }
                }                  
            }
        }   
    }
}

---------------

view.h

#ifndef VIEW_H
#define VIEW_H

#include <QtQuick/QQuickItem>
#include <QtQuick/QQuickWindow>

class MyWindow;

// ----------------------------------
class MyItem : public QQuickItem
{
  Q_OBJECT

public:
  explicit MyItem();
  ~MyItem();

private:
  MyWindow *win;
};

// ----------------------------------
class MyWindow : public QQuickWindow
{
  Q_OBJECT

public:
  explicit MyWindow();
  ~MyWindow();

protected:
  void mousePressEvent(QMouseEvent *event) override;
};

#endif // VIEW_H

---------------

view.cpp

#include "view.h"

MyItem::MyItem()
    : win(nullptr)
{
  if (!win)
  {
    win = new MyWindow();
  }
}

MyItem::~MyItem()
{
  delete win;
  win = nullptr;
}

// ----------------------------------------
MyWindow::MyWindow()
{
}

MyWindow::~MyWindow()
{
}

void MyWindow::mousePressEvent(QMouseEvent *event)
{
  qDebug() << "mousePressEvent";
  QQuickWindow::mousePressEvent(event);
}

[KroMignon]

@madoodia Hello, like written in documentation, you have to enable mouse before ==> QQuickItem::acceptedMouseButtons()

The default value is Qt::NoButton; that is, no mouse buttons are accepted.
If an item does not accept the mouse button for a particular mouse event, the mouse event will not be delivered to the item and will be delivered to the next item in the item hierarchy instead.

For example add setCursor(Qt::AllButtons) in your constructor.

[madoodia]

thanks @KroMignon

there are a few things here

• setCursor is for the shape of the cursor so don't think is solve the problem
• I used setAcceptedMouseButtons(Qt::LeftButton); in constructor of MyItem type, and it allow me to have mousePressEvent function inside MyItem class not MyWindow class (however it behaves weird)
• if we have MouseArea in MyItem type in qml file it doesn't let the mousePressEvent works, I think it eats the event.
• btw, I want to have mousePressEvent in MyWindow class not MyItem

I think there are three layers here (top to bottom):

1. qml MouseArea events (like onClicked)
2. MyItem's mousePressEvent
3. MyWindow's mousePressEvent

I want to have first and third simultaneously, and don't know which one override or eat the others, and totally this is possible or not!!

I hope it makes sense.
btw, I'm still testing

[KroMignon]

@madoodia I apologize, I have not take care about all you have written and read your post too fast... Sorry about that.

For the MouseArea, you have to say to it to not consume the mouse events:

MouseArea {
   anchors.fill: parent
    propagateComposedEvents: true
    onClicked: {
        console.log("clicked!!")
        mouse.accepted = false // ==> to propagate this event to lower level
    }
}

This should solve your issue, take a look at propagateComposedEvents for more details.

[madoodia]

thank @KroMignon
related to propagateComposedEvents, yes I did this, but does not work properly on composedEvents like onClicked
but for onPressed and onReleased implementation in QML code it works fine

but about my problem I had to call MyWindow events from the MyItem events.
solved it a little bit.

If I get the result I am looking for will update the post

[madoodia]

[SOLVED]

My problem is solve by these steps

• instead of having QQuickWindow I used QObject inside QQuickItem
• in MyItem Constructor used setAcceptedMouseButtons(Qt::AllButtons);
• calling fake mouse***Event function of QObject Subclass (here MyWindow from MyItem's real mouse***Event function)

Thanks

[jsulm]

@madoodia Please mark as solved (see "Topic Tools" at right bottom side).