QListWidget width

[colin207]

Hi

What, precisely, controls the default width of a QListWidget. I want a list widget that makes itself exactly wide enough to display the width of its widest item but no more.

E.g. I would have expected the following simple code to produce a dialog with a list box exactly wide enough to hold the items "fred" and "bloggs" but no more. Yet the dialog that gets shown has a list widget some 5 times wider than necessary. Why?

QDialog dlg(this);
	QListWidget* pListWidget = new QListWidget();
	new QListWidgetItem("Fred", pListWidget);
	new QListWidgetItem("Bloggs", pListWidget);
	QVBoxLayout* pLayout = new QVBoxLayout();
	pLayout->addWidget(pListWidget);
	dlg.setLayout(pLayout);
	dlg.exec();

QDialog dlg(this);
	QListWidget* pListWidget = new QListWidget();
	new QListWidgetItem("Fred", pListWidget);
	new QListWidgetItem("Bloggs", pListWidget);
	QVBoxLayout* pLayout = new QVBoxLayout();
	pLayout->addWidget(pListWidget);
	dlg.setLayout(pLayout);
	dlg.exec();

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What is the simplest, clean and reliable way to control the list width width without relying on pixel width constants. Code needs to be properly portable. Thanks

[aamer4yu]

Try setting different size policies and see if it works for you...
(QSizePolicy::Minimum)

[colin207]

Thanks. But I had already tried setting horz size policy on the QListWidget to Minimum. Makes no difference. Specifically I used:

QSizePolicy sp = pListWidget->sizePolicy();
sp.setHorizontalPolicy(QSizePolicy::Minimum);
pListWidget->setSizePolicy(sp);

QSizePolicy sp = pListWidget->sizePolicy();
sp.setHorizontalPolicy(QSizePolicy::Minimum);
pListWidget->setSizePolicy(sp);

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Any other ideas?

[SneakyPeterson]

Have you tried setMinimumWidth() and setMaximumWidth? I just made this up on the fly, so it might not compile, but it should look something like this.

QDialog dlg(this);
	QListWidget* pListWidget = new QListWidget();
	QListWidgetItem fred = new QListWidgetItem("Fred", pListWidget);
	QListWidgetItem bloggs = new QListWidgetItem("Bloggs", pListWidget);
	QVBoxLayout* pLayout = new QVBoxLayout();
	pLayout->addWidget(pListWidget);
	dlg.setLayout(pLayout);
        dlg->setMinimumWidth(fred->sizeHint().width()+bloggs->sizeHint().width());
        dlg->setMaximumWidth(fred->sizeHint().width()+bloggs->sizeHint().width());
	dlg.exec();

QDialog dlg(this);
	QListWidget* pListWidget = new QListWidget();
	QListWidgetItem fred = new QListWidgetItem("Fred", pListWidget);
	QListWidgetItem bloggs = new QListWidgetItem("Bloggs", pListWidget);
	QVBoxLayout* pLayout = new QVBoxLayout();
	pLayout->addWidget(pListWidget);
	dlg.setLayout(pLayout);
        dlg->setMinimumWidth(fred->sizeHint().width()+bloggs->sizeHint().width());
        dlg->setMaximumWidth(fred->sizeHint().width()+bloggs->sizeHint().width());
	dlg.exec();

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[colin207]

Thanks for the suggestion. But calling sizeHint().width() on the list widget items returns -1 which doesnt seem to help!

[SneakyPeterson]

Hehe, moment of stupidity. Fred and Bloggs are being handled by your pListWidget, so that's the size you care about.
These things always happen to me on Monday mornings...

QDialog dlg(this);
	QListWidget* pListWidget = new QListWidget();
	new QListWidgetItem("Fred", pListWidget);
	new QListWidgetItem("Bloggs", pListWidget);
	QVBoxLayout* pLayout = new QVBoxLayout();
	pLayout->addWidget(pListWidget);
	dlg.setLayout(pLayout);
        dlg->setMinimumWidth(pListWidget->size());
        dlg->setMaximumWidth(pListWidget->size());
	dlg.exec();

QDialog dlg(this);
	QListWidget* pListWidget = new QListWidget();
	new QListWidgetItem("Fred", pListWidget);
	new QListWidgetItem("Bloggs", pListWidget);
	QVBoxLayout* pLayout = new QVBoxLayout();
	pLayout->addWidget(pListWidget);
	dlg.setLayout(pLayout);
        dlg->setMinimumWidth(pListWidget->size());
        dlg->setMaximumWidth(pListWidget->size());
	dlg.exec();

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