How to get other window's text input cursor position ?

[Soul]

I want to make an input tool with QT, but I don't know how to get other application's text input cursor posion.
Any idea ? Please help ~

[jsulm]

@Soul Can you please explain better what you want to do?
Do you want to implement a virtual keyboard?
There is already one implemented with Qt.

[Soul]

Hi @jsulm
For example: Window A has an textEdit control . When my mouse clicked on the textEdit , there where be a cursor indicate I can input text. My Qt-aplication job is to show a window fllow the cursor. Just like the IME .

[jsulm]

@Soul Would this Window A be a window of your application or another application (another process)?

[Soul]

@jsulm The window A is another process.

[jsulm]

@Soul I don't think you can do this with Qt. You will need to use OS native APIs.

[Soul]

@jsulm Do you have any suggestions ? The application only runs on windows.

[jsulm]

@Soul Windows API, but I'm not expert in this area.

[SamurayH]

Hi @Soul,
To get the textCursorPos or the caretPos you'll have to use native OS apis as @jsulm had already mentioned. I can help you to achieve that on Windows only, let have a look at this sample :

• First open a new Qt Application project, choose a title, and then let everything as default.
• Then go to the .pro file and add this line : QT += concurrent widgets,
  this line doesn't have any relation with our goal, it's just needed for the sample that I will describe above. If you're not familiar with QtConcurrent or Qt&Multithreading, I recommend you to learn about that, especially QtConcurrent.
• And finally make the main.cpp look like that, and hit RUN:

#include "mainwindow.h"
#include <QApplication>
#include <QDebug>
#include <QtConcurrent>

#include <windows.h>

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

    QtConcurrent::run([=]()
    {
      forever
      {
         AttachThreadInput(GetCurrentThreadId(),GetWindowThreadProcessId(GetForegroundWindow(),0), true);

         POINT caretPos, cCaretPos;
         GetCaretPos(&caretPos);
         GetCaretPos(&cCaretPos);
         ClientToScreen(GetFocus(),&cCaretPos);
         qDebug() << caretPos.x << "," << caretPos.y << " - " << cCaretPos.x << "," << cCaretPos.y;
      }
    });
    
    return a.exec();
}

If you want a further explanation of all of that, replay YES.