Event Handling for QComboBox

psbhardwaj09gmail.com

Hi All,

I have an application in which i want to handle mousePress event for QComboBox.
My Combo box is edittable. & I wants that when i click on combo box its default text is clear.
my code is as following:-

.h file
@
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtGui/QMainWindow>
#include <QTextEdit>
#include <QComboBox>

class MainWindow : public QMainWindow
{
Q_OBJECT

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

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

public:
QTextEdit textEdit;
QComboBox mpgroupCombo;
};

#endif // MAINWINDOW_H
@

& .cpp file is
@
#include "mainwindow.h"
#include <QDebug>
#include <QEvent>
#include <QKeyEvent>
#include <QMouseEvent>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{

//textEdit = new QTextEdit;

mpgroupCombo = new QComboBox();
mpgroupCombo->setEditable(true);
mpgroupCombo->setEditText(tr("Type or Select Contact"));
setCentralWidget(mpgroupCombo);

mpgroupCombo->installEventFilter(this);

}

MainWindow::~MainWindow()
{

}

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

@

here problem is that when i clicked on the text part of QCombobox, nothing is print whereas when i click on the dropdown button then text is printed.
So how can i print text when i click on text?

Can any one suggest me for that.

b1gsnak3

You are trying to do something that QComboBox already has... I think... You are trying to add a placeholder text to the comboBox... Try using:

@
mygroupCombo->lineEdit()->setPlaceHolderText("Some text");
@

Sorry first time I wrote it wrong..

psbhardwaj09gmail.com

Hi b1gsnak3,
when i try
@mygroupCombo->lineEdit()->setPlaceHolderText("Some text");@

the following errors occurs

bq. error: C2027: use of undefined type 'QLineEdit'

bq. error: C2227: left of '->setPlaceHolderText' must point to class/struct/union/generic type

Sam

Try to include QLineEdit.h

psbhardwaj09gmail.com

Hi Sam,

Thank you for your reply. But After include @qlineedit.h@ there is again another error

bq. error: C2039: 'setPlaceHolderText' : is not a member of 'QLineEdit'

psbhardwaj09gmail.com

But after including @QLineEdit@

its coplied with no error but place holder is not displaying?

Sam

It wont be displayed as your comboBox->lineEdit already has the focus.

Try to add the following for test

@MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
//textEdit = new QTextEdit;

mpgroupCombo = new QComboBox();
mpgroupCombo->setEditable(true);

QPushButton *mButton = new QPushButton("Press Me");
mpgroupCombo->lineEdit()->setPlaceholderText("Hellooo");

QHBoxLayout *layout = new QHBoxLayout;
layout->addWidget(mpgroupCombo);
layout->addWidget(mButton);

QWidget *widget = new QWidget(this);
widget->setLayout(layout);

setCentralWidget(widget);

mpgroupCombo->installEventFilter(this);

}@

Click on the button to change to focus.