[Qt-interest] A new (?) const-correct way to create a Ui object and do setupUi

[Thiago Macieira]

Em terça-feira, 8 de fevereiro de 2011, às 11:50:03, Robert Hairgrove 
escreveu:
> If "ui" is const, you cannot call any of the non-const functions on any
> of the GUI objects it contains ... such as setText() on an edit control,
> for example. I think this would be severely limiting.

Hello Robert

That is not correct. If the "ui" object is const, its members are const. That 
means if you a QTextEdit* as a member, the *pointer* becomes const, not the 
pointed object.

So you can do this:
	ui->textEdit->setText("foo");

But you can't do this:
	ui->textEdit = new QTextEdit(this);

> As to deletion, normally the parent of an object which inherits QObject
> will delete its children automatically. I would think that creating ui
> as a member object variable would lead to a double deletion, but I might
> be mistaken.

No, there's no double deletion. The Ui_* classes have no constructor or 
destructors. So they don't delete the form elements that setupUi creates. They 
contain only pointers, so these classes are effectively POD.

However, the Ui class itself must be deleted if it was newed.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
  Senior Product Manager - Nokia, Qt Development Frameworks
      PGP/GPG: 0x6EF45358; fingerprint:
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