Java GridBag Layout

When you create GUI application using Java , layout method is complicated. I used GridBag Layout, which is very flexible to use. However, it's confusing at the same time
http://docs.oracle.com/javase/tutorial/uiswing/layout/gridbag.html

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public WasteWeightWindow(CollectionWindow cw)
{
         this.collectionWindow=cw;
         frame.setSize(350,400);
         panel.setLayout(layout);
         GridBagConstraints gbc = new GridBagConstraints();
         gbc.gridx = 1;
         gbc.gridy = 0;
         gbc.gridwidth = 20;
         gbc.gridheight = 1;
         gbc.ipadx=150;
         gbc.fill = GridBagConstraints.HORIZONTAL;
         gbc.insets = new Insets(10, 10, 0, 0);
         weightBox=new JTextField();
         layout.setConstraints(weightBox, gbc);
         panel.add(weightBox);
}

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