QDialog margin and spacing

[TheRonin]

I'm using solaris 5.8, Qt 4.2.2 and gcc 3.3 and have been trying to create a dialog with no margin or spacing for its child widgets. Unfortunately, things aren't going too well. It turns out that i only get the desired effect if i use a QWidget or QMainWindow instead of a QDialog. Could this be a bug in Qt?

Below is some code that produces two windows, one being a QDialog and the other a QWidget. The QDialog behaves incorrectly, insisting on drawing a margin and spacing for the child widgets, while the QWidget has the desired behavior.

#include <QApplication>
#include <QDialog>
#include <QVBoxLayout>
#include <QPushButton>
 
int main(int argc, char** argv)
{
  QApplication app(argc, argv);
 
  //////////////////////////////////////////////////////////////////////
  // create a dialog with two buttons
 
  QDialog diag;
  diag.setWindowFlags(Qt::Widget);
  diag.setWindowTitle("dialog");
  QVBoxLayout* layout = new QVBoxLayout();
  diag.setLayout(layout);
 
  QSizePolicy policy(QSizePolicy::Minimum, QSizePolicy::Minimum);
  QPushButton* button1 = new QPushButton("button1");
  button1->setSizePolicy(policy);
  layout->addWidget(button1);
 
  QPushButton* button2 = new QPushButton("button2");
  button2->setSizePolicy(policy);
  layout->addWidget(button2);
 
  layout->setMargin(0);
  layout->setSpacing(0);
 
  diag.show();
 
  //////////////////////////////////////////////////////////////////////
  // create a widget with two buttons
 
  QWidget widg;
  widg.setWindowTitle("widget");
  layout = new QVBoxLayout();
  widg.setLayout(layout);
 
  button1 = new QPushButton("buttonA");
  button1->setSizePolicy(policy);
  layout->addWidget(button1);
 
  button2 = new QPushButton("buttonB");
  button2->setSizePolicy(policy);
  layout->addWidget(button2);
 
  layout->setMargin(0);
  layout->setSpacing(0);
 
  widg.show();
 
  return app.exec();
}

#include <QApplication>
#include <QDialog>
#include <QVBoxLayout>
#include <QPushButton>

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

  //////////////////////////////////////////////////////////////////////
  // create a dialog with two buttons

  QDialog diag;
  diag.setWindowFlags(Qt::Widget);
  diag.setWindowTitle("dialog");
  QVBoxLayout* layout = new QVBoxLayout();
  diag.setLayout(layout);

  QSizePolicy policy(QSizePolicy::Minimum, QSizePolicy::Minimum);
  QPushButton* button1 = new QPushButton("button1");
  button1->setSizePolicy(policy);
  layout->addWidget(button1);

  QPushButton* button2 = new QPushButton("button2");
  button2->setSizePolicy(policy);
  layout->addWidget(button2);

  layout->setMargin(0);
  layout->setSpacing(0);

  diag.show();

  //////////////////////////////////////////////////////////////////////
  // create a widget with two buttons
  
  QWidget widg;
  widg.setWindowTitle("widget");
  layout = new QVBoxLayout();
  widg.setLayout(layout);

  button1 = new QPushButton("buttonA");
  button1->setSizePolicy(policy);
  layout->addWidget(button1);

  button2 = new QPushButton("buttonB");
  button2->setSizePolicy(policy);
  layout->addWidget(button2);

  layout->setMargin(0);
  layout->setSpacing(0);
  
  widg.show();
    
  return app.exec();
}

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Please, can any of you confirm the incorrect behavior? Or maybe i'm alone out here on Solaris island?

Thanks in advance!

[jpn]

Could you provide a screenshot? Which style are you using? Does it happen with other styles, for example:

./app -style plastique

[TheRonin]

screenshot.jpg

As you can see in the attached screenshot, the cde, motif and windows styles force the dialog to have a margin and spacing. It's most apparent in cde and motif. Cleanlooks, plastique and WindowsXp do not produce a noticable margin and spacing.

[jpn]

Looks weird, indeed. I'd suggest opening a new task at the task-tracker.

[TheRonin]

Apparently, the discrepancy is due to the autodefault property:

http://doc.trolltech.com/4.2/qpushbu...toDefault-prop

And hats off to trolltech for their speedy reply to my query.