QDateTimeEdit : Dumb Mistake or bug?

[ChrisW67]

This code:

#include <QApplication>
#include <QDateTimeEdit>
 
int main(int argc, char **argv)
{
    QApplication app(argc, argv);
 
    QDateTimeEdit edit;
    edit.setDateTime(QDateTime::currentDateTimeUtc());
    edit.setDisplayFormat("yyyy-MM-dd hh:mm");
    edit.setSelectedSection(QDateTimeEdit::DaySection);
    // also tried these:
    // edit.setCurrentSection(QDateTimeEdit::DaySection);
    // edit.setCurrentSectionIndex(2);
    edit.show();
 
    return app.exec();
}

#include <QApplication>
#include <QDateTimeEdit>

int main(int argc, char **argv)
{
    QApplication app(argc, argv);

    QDateTimeEdit edit;
    edit.setDateTime(QDateTime::currentDateTimeUtc());
    edit.setDisplayFormat("yyyy-MM-dd hh:mm");
    edit.setSelectedSection(QDateTimeEdit::DaySection);
    // also tried these:
    // edit.setCurrentSection(QDateTimeEdit::DaySection);
    // edit.setCurrentSectionIndex(2);
    edit.show();

    return app.exec();
}

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I would have expected to show the current time with the "dd" day field already selected. What I get with 4.8.5/5.1.0 on 64-bit Linux, and 4.8.4 on 32-bit Windows is the year (first, presumably default) section selected. I have also tried deferring the setSelectedSection() call until after the show() with a zero timer. Meanwhile the currentSection() property returns 0x100, i.e. the DaySection.

Am I missing the absolutely obvious?

[anda_skoa]

Looks like a bug to me.

I tried not setting the datetime format and then it looked like it worked correctly (because my locale format has day as the first section), but then I change the code to select year (third section) and it didn't work either.

Cheers,
_

[stampede]

Same here (64 bit linux, Qt 5.1.1).
Looks like some events are clearing the initial selection to default, because this works ok after the edit widget is shown:

#ifndef WIDGET_H
#define WIDGET_H
 
#include <QWidget>
#include <QDateTimeEdit>
#include <QPushButton>
 
class Widget : public QWidget{
	Q_OBJECT
public:
	Widget(QWidget * parent = NULL)
	:QWidget(parent)
	{
		_btn = new QPushButton("next section",this);
		connect(_btn, SIGNAL(clicked()), this, SLOT(nextSection()));
		_edit.show();
		_edit.setDateTime(QDateTime::currentDateTimeUtc());
		_edit.setDisplayFormat("yyyy-MM-dd hh:mm");
	}
public slots:
	void nextSection(){
		static int s = 0;
		s = (s+1)%3;
		_edit.setCurrentSectionIndex(s);
		_edit.setSelectedSection(_edit.currentSection());
	}
private:
	QDateTimeEdit _edit;
	QPushButton * _btn;
};
 
#endif

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QDateTimeEdit>
#include <QPushButton>

class Widget : public QWidget{
	Q_OBJECT
public:
	Widget(QWidget * parent = NULL)
	:QWidget(parent)
	{
		_btn = new QPushButton("next section",this);
		connect(_btn, SIGNAL(clicked()), this, SLOT(nextSection()));
		_edit.show();
		_edit.setDateTime(QDateTime::currentDateTimeUtc());
		_edit.setDisplayFormat("yyyy-MM-dd hh:mm");
	}
public slots:
	void nextSection(){
		static int s = 0;
		s = (s+1)%3;
		_edit.setCurrentSectionIndex(s);
		_edit.setSelectedSection(_edit.currentSection());
	}
private:
	QDateTimeEdit _edit;
	QPushButton * _btn;
};

#endif

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When pressing the button, section is changed as expected.

[ChrisW67]

I refined it and lodged a bug
https://bugreports.qt-project.org/browse/QTBUG-34759

It appears that the focusInEvent() is resetting the currentSection() so I am working around this by subclassing QDateTimeEdit, which is OK for my purposes:

class Edit: public QDateTimeEdit {
public:
    Edit(QWidget *p): QDateTimeEdit(p) { }
protected:
    void focusInEvent(QFocusEvent *event) {
        Section section = currentSection();
        QDateTimeEdit::focusInEvent(event);
        setSelectedSection(section);
    }
};

class Edit: public QDateTimeEdit {
public:
    Edit(QWidget *p): QDateTimeEdit(p) { }
protected:
    void focusInEvent(QFocusEvent *event) {
        Section section = currentSection();
        QDateTimeEdit::focusInEvent(event);
        setSelectedSection(section);
    }
};

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