c++ - QT: Scrolling 2 QPlainTextEdits at the same time -

i want create internal tool usage 2 qplaintextedits. want make functionality when scroll 1 text edit other scrolled also. tried figure out http://doc.qt.io/qt-4.8/qt-widgets-codeeditor-example.html not work expected

here code:

customedit.h

#ifndef customedit_h #define customedit_h  #include <qplaintextedit>  class customedit : public qplaintextedit {     q_object public:     customedit(qwidget *parent = 0);  public slots:     void updateposition(const qrect &, int); };  #endif // customedit_h 

customedit.cpp

#include "customedit.h"  customedit::customedit(qwidget *parent) : qplaintextedit(parent) {  }  void customedit::updateposition(const qrect &rect, int position) {      if (position) {         this->scroll(0, position);         this->update(0, rect.y(), this->width(), rect.height());     }     else {         this->update(0, rect.y(), this->width(), rect.height());     }  } 

mainwindow constructor

mainwindow::mainwindow(qwidget *parent) :     qmainwindow(parent),     ui(new ui::mainwindow) {     ui->setupui(this);      printoutanalyzer = new printoutanalyzer();      ui->log->setreadonly(true);     ui->progress->reset();      resultedit = new customedit(this);     printoutedit = new customedit(this);      resultedit->setreadonly(true);     printoutedit->setreadonly(true);      ui->horizontallayout->addwidget(printoutedit);     ui->horizontallayout->addwidget(resultedit);       connect(printoutanalyzer, signal(writetolog(qstring)), this, slot(putlogtext(qstring)));     connect(printoutanalyzer, signal(writetoresult(qstring)), this, slot(putresulttext(qstring)));     connect(printoutanalyzer, signal(setprogress(int)), this, slot(setprogress(int)));     connect(ui->loadprintout, signal(triggered()), this, slot(chooseprintoutfile()));      connect(printoutedit, signal(updaterequest(qrect, int)), resultedit, slot(updateposition(qrect, int)));     connect(resultedit, signal(updaterequest(qrect, int)), printoutedit, slot(updateposition(qrect, int))); } 

when execute code , scroll 1 text edit second 1 looks (text edits have same content):

the simple keep vertical scrollbars of qplaintextedit in sync of ''sliderposition property''.