QT Layout problem

[bod]

I want to add a textedit widget to my window. It has a "QHBoxLayout" layout.
I'm tryin to add this textedit but I cannot. I think, it places the textedit under the treewidget.
I don't understand why.
Can u help me pls?
Here is my code:

glWidget = new GLWidget;
	tree = new QTreeWidget;
	tree->setHeaderLabel("Items");
	qtItem = new QTreeWidgetItem(tree);
	qtItem->setText(0, tr("QtLogo"));
                QWidget *tmpw = new QWidget();
	QTextEdit *cmd = new QTextEdit(tmpw);
                QHBoxLayout *mainLayout = new QHBoxLayout;
                mainLayout->addWidget(glWidget);
	mainLayout->addWidget(tree);
	mainLayout->addWidget(tmpw);

glWidget = new GLWidget;
	tree = new QTreeWidget;
	tree->setHeaderLabel("Items");
	qtItem = new QTreeWidgetItem(tree);
	qtItem->setText(0, tr("QtLogo"));
                QWidget *tmpw = new QWidget();
	QTextEdit *cmd = new QTextEdit(tmpw);
                QHBoxLayout *mainLayout = new QHBoxLayout;
                mainLayout->addWidget(glWidget);
	mainLayout->addWidget(tree);
	mainLayout->addWidget(tmpw);

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Edit: I'm sorry I posted it twice mistakely.

[aamer4yu]

did u set the layout to the main widget ?
like this->setLayout(mainLayout); ??

[bod]

yes i did...

[lyuts]

What are you doing this for?:

QWidget *tmpw = new QWidget();
QTextEdit *cmd = new QTextEdit(tmpw);
...
mainLayout->addWidget(tmpw);

QWidget *tmpw = new QWidget();
QTextEdit *cmd = new QTextEdit(tmpw);
...
mainLayout->addWidget(tmpw);

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why not like this:

mainLayout->addWidget(cmd);

mainLayout->addWidget(cmd);

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[jpn]

You add 'tmpw' to 'mainLayout' but 'tmpw' itself doesn't have any layout installed even if it has one child, namely 'cmd'. But what's the point of 'tmpw' anyway if it only contains that QTextEdit?

[bod]

What are you doing this for?:

QWidget *tmpw = new QWidget();
QTextEdit *cmd = new QTextEdit(tmpw);
...
mainLayout->addWidget(tmpw);

QWidget *tmpw = new QWidget();
QTextEdit *cmd = new QTextEdit(tmpw);
...
mainLayout->addWidget(tmpw);

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why not like this:

mainLayout->addWidget(cmd);

mainLayout->addWidget(cmd);

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cuz QTextEdit is not a qWidgetItem

[bod]

You add 'tmpw' to 'mainLayout' but 'tmpw' itself doesn't have any layout installed even if it has one child, namely 'cmd'. But what's the point of 'tmpw' anyway if it only contains that QTextEdit?

cuz I couldn't add tmpw without putting it into a widget

[lyuts]

cuz QTextEdit is not a qWidgetItem

1) QHBoxLayout's method addWidget accepts QWidget...
2)
QTextEdit inherits QAbstractScrollArea
QAbstractScrollArea inherits QFrame
QFrame inherits QWidget

=> QTextEdit inherits QWidget

I have the same question again. Why not just

mainLayout->addWidget(cmd);

mainLayout->addWidget(cmd);

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???

[bod]

It worked just now. I don't know why it did not compile when i first tried it.