
The one component that does not support the size variants property is
JLabel. However, you can change the size of a label
by changing the size of its font.
You can set the size of a component with one line of code, before the component is displayed. The following snippet shows how to use each size:
// mini
myButton.putClientProperty("JComponent.sizeVariant", "mini");
// small
mySlider.putClientProperty("JComponent.sizeVariant", "small");
// large
myTextField.putClientProperty("JComponent.sizeVariant", "large");
SwingUtilities.updateComponentTreeUI(Component) method before the window is displayed.  The following code
snippet updates the window and all the components it contains:
JFrame frame = ...; SwingUtilities.updateComponentTreeUI(frame); frame.pack(); frame.setVisible(true);