Development/Tutorials/Qt4 Ruby Tutorial/Chapter 06

Building Blocks Galore!

Tutorial Series	Qt4 Ruby Tutorial
Previous	Tutorial 5 - Building Blocks
What's Next	Tutorial 7 - One Thing Leads to Another
Further Reading	n/a

Building Blocks

Files:

t6.rb

Overview

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.

require 'Qt4'

class LCDRange < Qt::Widget

 def initialize(parent = nil)
   super()
   lcd = Qt::LCDNumber.new(2)

   slider = Qt::Slider.new(Qt::Horizontal)
   slider.setRange(0, 99)
   slider.setValue(0)

   connect(slider, SIGNAL('valueChanged(int)'), lcd, SLOT('display(int)'))

   layout = Qt::VBoxLayout.new()
   layout.addWidget(lcd)
   layout.addWidget(slider)
   setLayout(layout)
 end

end
class MyWidget < Qt::Widget

 def initialize(parent = nil)
   super()
   quit = Qt::PushButton.new(tr('Quit'))
   quit.setFont(Qt::Font.new('Times', 18, Qt::Font::Bold))
   connect(quit, SIGNAL('clicked()'), $qApp, SLOT('quit()'))

   grid = Qt::GridLayout.new()
   
   for row in 0..2
     for column in 0..2
       grid.addWidget(LCDRange.new(), row, column)
     end
   end

   layout = Qt::VBoxLayout.new()
   layout.addWidget(quit)
   layout.addLayout(grid)
   setLayout(layout)
 end

end    
app = Qt::Application.new(ARGV)

widget = MyWidget.new() widget.show()

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