TextEdit and eventFilter: characters not appearing on ui element

Tamfub

Hi everyone.

I have a textEdit widget on my mainwindow.ui, and I would like to catch the key pressed by the user when the focus is on the textEdit.
I gave a read here and adapted the example to this:

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;

protected:
    bool eventFilter(QObject *obj, QEvent *ev) override;
};

#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

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

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

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
//    if (obj == textEdit) {
        if (event->type() == QEvent::KeyPress) {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            qDebug() << "Ate key press " << keyEvent->text();
            return true;
        } else {
            return false;
        }
//    } else {
//        // pass the event on to the parent class
//        return QMainWindow::eventFilter(obj, event);
//    }
}

mainwindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QTextEdit" name="textEdit">
    <property name="geometry">
     <rect>
      <x>100</x>
      <y>50</y>
      <width>221</width>
      <height>141</height>
     </rect>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>400</width>
     <height>25</height>
    </rect>
   </property>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>

The keys pressed are shown correctly on the output, but they do not appear on my textEdit.

How can I solve this?

SGaist

Hi,

Because you are stoping the event processing there by returning true exactly how it is explained in the documentation you are linking.

Tamfub

@SGaist
Hi. Ok, I changed eventFilter() a little bit:

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == ui->textEdit) {
        if (event->type() == QEvent::KeyPress) {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            qDebug() << "Ate key press " << keyEvent->text();
        }
    }
    return QMainWindow::eventFilter(obj, event);
}

and now it works. Thanks!