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This script creates a button, with the text "Hello world!" inside a window. When you click this button a information window will pop up, saying "Hello World!" and displaying a OK button.

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set w [qwidget ]

A window in QTcl is an instance of a QWidget object, hence the command name. It may be followed by a list of flags. Although rarely used, the flags can be used to modify the widgets look and behaviour. The next statement tells QTcl to delete the widget from memory when it is closed:

qsetattribute deleteonclose

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qsetwindowtitle "Hello"

The qsetwindowtitle command sets the window title. While there may be several windows available, QTcl will simply apply the command to the most recently created widget, which in this case is the QWidget window. The most recently created widget is also the so-called current widget. It does not matter whether the widget is visible or not. This is in fact how most Qt commands work.

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qvboxlayout {
	
}

The qvboxlayout command creates a layout manager for the window. A layout manager is also known as a geometry manager. The task of the layout manager is to arrange the widgets in a particular order. For instance, the QVBoxLayout layout manager stacks widgets vertically in their order of creation. There are two other layout managers in QTcl:

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qpushbutton "Hello world!"

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qinformation Information "Hello world!"

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qshow $w

QTcl will then draw the most recently created widget, or current widget, on to the screen. In this case the current widget is the window, which is then displayed along with its contents.

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