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This example shows how to encapsulate two widgets into a new component and how easy it is to use many widgets. For the first time, we use a custom widget as a child widget.‎

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=== Line by Line Walkthrough ===‎

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The '''<tt>LCDRange</tt>''' widget is a widget without any API. It just has a constructor. This sort of widget is not very useful, so we'll add some API later.‎

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This is lifted straight from the '''<tt>MyWidget</tt>''' constructor in [[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_05|Chapter 5]]. The only differences are that the <strong>Quit</strong> button is left out and the class is renamed.‎

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'''<tt>MyWidget</tt>''', too, contains no API except a constructor.‎

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The push button that used to be in what is now '''<tt>LCDRange</tt>''' has been separated so that we can have one <strong>Quit</strong> button and many '''<tt>LCDRange</tt>''' objects.‎

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We create a [http://doc.qt.nokia.com/latest/qwidget.html Qt::Widget] with a [http://doc.qt.nokia.com/latest/qgridlayout.html Qt::GridLayout] that will contain three columns. The [http://doc.qt.nokia.com/latest/qgridlayout.html Qt::GridLayout] automatically arranges its widgets in rows and columns; you can specify the row and column numbers when adding widgets to the layout, and [http://doc.qt.nokia.com/latest/qgridlayout.html Qt::GridLayout] will fit them into the grid.‎

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We create nine '''<tt>LCDRange</tt>''' widgets, all of which are children of the grid object, and we arrange them in three rows and three columns.‎

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=== Running the Application ===‎

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This program shows how easy it is to use many widgets at a time. Each one behaves like the slider and LCD number in the previous chapter. Again, the difference lies in the implementation.‎

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=== Exercises ===‎

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Initialize each slider with a different/random value on startup.‎

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[[Category:Ruby]]‎

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