QT I want to increase the size of comboBox Down list not the drop- Down icon ?

amarism

I have a combo box and i want to change (increase) the size of the down list. That contain all description index value visible.
Initially I am getting this one output.

But i want output like this

Also I want to remove the icon index that is showing inside the down list. Here is my code.

QIcon icon = QIcon::fromTheme("C:/Users/DragDrop/black-play-button.jpg");
 QString label = "";
   ui->comboBox->addItem( icon,label );
ui->comboBox->setMinimumWidth(100);
ui->comboBox->setIconSize(QSize(40, 40));
ui->comboBox->setDisabled(false);
ui->comboBox->addItem("Fill viewport  ctrl+0");
ui->comboBox->addItem("100%   ctrl+1");
ui->comboBox->addItem("200%   ctrl+2");
ui->comboBox->addItem("400%   ctrl+3");
ui->comboBox->addItem("800%   ctrl+4");

mrjj

Hi
You can set size via the model. (pr item)

#include <QtGui>
#include <QApplication>
#include <QComboBox>

int main(int argc, char **argv)
{
QApplication app(argc, argv);
QComboBox cb;
cb.addItems(QStringList() << "a" << "b" << "c" << "d");
cb.model()->setData(cb.model()->index(0, 0), QSize(100, 100), Qt::SizeHintRole);
cb.show();
return app.exec();
}

You can also use a stylesheet.

amarism

@mrjj when i use one code :-

ui->comboBox->model()->setData(ui->comboBox->model()->index(0, 0), QSize(100, 100), Qt::SizeHintRole);

this one just increase the size icon index size not the down list width.
Also I dont want to show the icon inside the drop list.

mrjj

@amarism
Hi
It sets the Items Height.
Just make all items bigger and dropdown also be bigger.
Sample just sets item 0,0. you need set on all items.

amarism

@mrjj said in QT I want to increase the size of comboBox Down list not the drop- Down icon ?:

Just make all items bigger and dropdown also be bigger.

Sorry i am not getting this thing. item bigger and dropdown bigger. But I want only item width bigger

mrjj

@amarism
Just adjust to what u want
QSize(100, 100) is the size. 100 width, 100 height

But the width of the drop-down is the width of the combo itself
alt text

amarism

@mrjj I don't want to increase the size of header combo box . Becaue i am using combobox as a button in my ui viewer. So, I can't set button size this much. I want the combo Box like this

mrjj

@amarism
ok.
you need to subclass for that i think.
https://forum.qt.io/topic/30405/how-to-change-qcombobox-popup-width

Alternatively, you canuse toolbutton and QMenu.

amarism

@mrjj So i need to create QTableWidget inside the comboBox or any other method to do this

mrjj

@amarism
I dont know what u mean.
Link talks about overriding showPopup to alter size.
That should do it.

amarism

@mrjj Still i am not getting any proper solution for this question

jsulm

@amarism Did you try what @mrjj suggested?

amarism

@jsulm yup but still this one not working

mrjj

@amarism
In what way did it not work for you ?
Seems to work as expected.
alt text

class WideComboBox : public QComboBox
{
    Q_OBJECT
public:
    explicit WideComboBox(QWidget *parent = nullptr) : QComboBox(parent) {};
    ~WideComboBox() {}
public:
    void showPopup() {
        this->view()->setMinimumWidth(this->view()->sizeHintForColumn(0));
        QComboBox::showPopup();
    }
};

setting it to 400 ;)

alt text

J.Hilk

Additionally to what @mrjj wrote, you should also be able to set the size of the view via a StyleSheet, a viable option if you don't plan to vary the size all to often

ui->comboBox->setStyleSheet("QComboBox QAbstractItemView {min-width: 400px;}"),

amarism

can i add the vertical spacing between the rows

amarism

@J.Hilk Thanku @J-Hilk . Now its working for me

amarism

@J.Hilk One more problem comes here, I am added a icon for combo box . And it will showing inside the dropdown popup. can i hide from icom from dropdown button

J.Hilk

@amarism I don't think you can do that via the StyleSheet. My guess would be to subclass QComboBox and override the paintEvent and ignore the Qt::DecorationRole !?