JSeparator wont show with GridBagLayout
I want to add a vertical JSeparator between two components using a GridBagLayout. The code I have is as follows:
public MainWindowBody(){
setLayout(new GridBagLayout()开发者_开发知识库);
JPanel leftPanel = new InformationPanel();
JPanel rightPanel = new GameSelectionPanel();
JSeparator sep = new JSeparator(JSeparator.VERTICAL);
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.anchor = GridBagConstraints.NORTH;
add(leftPanel,gbc);
gbc.gridx = 1;
gbc.gridy = 0;
gbc.fill = GridBagConstraints.VERTICAL;
add(sep,gbc);
gbc.gridx = 2;
gbc.gridy = 0;
gbc.fill = GridBagConstraints.NONE;
add(rightPanel,gbc);
}
But the JSeperator doesn't show, any ideas?
Thanks
You could try to set the preferred width for the separator:
sep.setPreferredSize(new Dimension(5,1));
Then, make GridBagLayout use up all available height for the separator:
gbc.fill = GridBagConstraints.VERTICAL;
gbc.weighty = 1;
Taken from Sun's guide for JSeparator
:
In most implementations, a vertical separator has a preferred height of 0, and a horizontal separator has a preferred width of 0. This means a separator is not visible unless you either set its preferred size or put it in under the control of a layout manager such as BorderLayout or BoxLayout that stretches it to fill its available display area.
The vertical separator does have a bit of width (and the horizontal a bit of height), so you should see some space where the separator is. However, the actual dividing line isn't drawn unless the width and height are both non-zero.
Maybe you should set right constraints?
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