Intercepting mouse events and getting element information ? ERROR in Qt

[learnist]

I am able to intercept mouse events, but the desired effect i want , is that when i click on an element(button/listitem/combobox) using mouse cursor, i should get its information(Name/AutomationID) in my UI ?

How can i achieve this ?

To achieve this, i have tried some code but it gives me errors, here is my files , i guess i need a bit of change in my mainwindow.cpp mouseproc function, i hope i am clear, have provided comments in all parts where needed, Thanks.

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
using namespace std;

 IUIAutomation* automation = NULL;  //Here are the global variables, which i am gonna use if my Wparam == "WM_RBUTTONDOWN"
 IUIAutomationElement* elem = NULL;   
 POINT mousePt;
 BSTR elemName = NULL;
 //BOOL stat = InitializeUIAutomation(&automation);


 BOOL InitializeUIAutomation(IUIAutomation** automation)
 {
     CoInitialize(NULL);
     HRESULT hr = CoCreateInstance(__uuidof(CUIAutomation), NULL,
         CLSCTX_INPROC_SERVER, __uuidof(IUIAutomation),
         (void**)automation);
     return (SUCCEEDED(hr));
 }
 
 MainWindow& MainWindow::instance() //instance 
 {
     static MainWindow _instance;
     return _instance;
 }

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

    //added here
     HINSTANCE hInstance = GetModuleHandle(NULL);

    // Set hook
    mouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, 0);
    // Check hook is correctly
    if (mouseHook == NULL)
    {
        qWarning() << "Mouse Hook failed";
    }
}

void MainWindow::closeEvent(QCloseEvent* event)  // function executed when window is closed.
{
    // Code for destroy
    exContext.destroy();
    //automation->Release();
    CoUninitialize();

    mouseThread->Stop = true;
    mouseThread->quit();

    exContext.pUIAutomation = NULL;
}

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

LRESULT CALLBACK MainWindow::mouseProc(int Code, WPARAM wParam, LPARAM lParam)
{
    Q_UNUSED(Code)
        auto& ms = *(const MOUSEHOOKSTRUCT*)lParam;
        MOUSEHOOKSTRUCT* pMouseStruct = (MOUSEHOOKSTRUCT*)lParam;
    if (pMouseStruct != nullptr) 
    {  
        if (wParam == WM_RBUTTONDOWN)
        {
            IUIAutomation* automation = NULL;

                    GetCursorPos(&mousePt);
                     HRESULT hr = automation->ElementFromPoint(mousePt, &elem);  //Getting error here 
                    if (SUCCEEDED(hr) && elem != NULL)
                    {
                        elem->get_CurrentName(&elemName);
                        std::wstring ws(elemName, SysStringLen(elemName));
                        std::wcout << ws << std::endl;
                        QString testing = QString::fromStdWString(ws);
                        qDebug() << testing;
                    }
                    SysFreeString(elemName);
                    elem->Release();
        }
    
        emit instance().mouseEvent();
    }
    // After that you need to return back to the chain hook event handlers
    return CallNextHookEx(NULL, Code, wParam, lParam);
}

mainwindow.h

#pragma once
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QThread>
#include <QtWidgets/QMainWindow>
#include <QtWidgets/qlistwidget.h>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE


class MainWindow : public QMainWindow
{
    Q_OBJECT                      
    Q_DISABLE_COPY(MainWindow) //added

public:
    MainWindow(QWidget* parent = 0);
    ~MainWindow();                   

    static MainWindow &instance //Here is the instance
    // Static method that will act as a callback-function
   static LRESULT CALLBACK mouseProc(int Code, WPARAM wParam, LPARAM lParam);

private slots:

public:
    BOOL InitializeUIAutomation(IUIAutomation** automation); //function

    Ui::MainWindow* ui; // pointing to UI class

signals:
    // The signal, which will report the occurrence of an event
   void mouseEvent();
   
private:  
    HHOOK mouseHook;    // hook handler
};
#endif // MAINWINDOW_H

main.cpp

#include "mainwindow.h"
#include <qdebug.h>
#include <UIAutomation.h>
#include <QtWidgets/qapplication.h>  

int main(int argc, char** argv)
{
    QApplication a(argc, argv);
    MainWindow w;
  
    QObject::connect(&MainWindow::instance(), &MainWindow::mouseEvent, //Connecting instance with mouseEvent
        []() {
            qDebug() << "Mouse Event";
        });
        
    w.show();  
    return a.exec();

}

[SGaist]

Hi,

QObject based classes cannot be copied.
Static QObject is also wrong. QApplication should be the first QObject created as it setups the internal state to make things work.

[learnist]

@SGaist im sorry for my noob question, but i don't understand , where did i go wrong? can u tell me file name and probably line please ?

[SGaist]

Your singleton instance of MainWindow, that is one of the issue.

[JonB]

@learnist
Further to @SGaist: why do you try to have MainWindow::instance() returning a static MainWindow while you have a local MainWindow w;?