GridLayout with weightx

Hi guys, in my application that I'm working on, I need to use GridLayout but required the GridBagLayout/GridBagConstraints weightx feature. Reason to use is GridLayout automatically wrap components to the next line when user resize the GUI where GridBagLayout does not provides.

Any idea for this issue? Please advise, thanks!

You are mistaken. GridLayout never wraps things on to the next line, and it does not use constraints like weightx. You have probably got a component which uses FlowLayout by mistake.

Campbell Ritchie wrote:You are mistaken. GridLayout never wraps things on to the next line, and it does not use constraints like weightx. You have probably got a component which uses FlowLayout by mistake.

Sorry missed out this info. Wrapping works as I've a nested panel with FlowLayout on the panel using GridLayout(1, 2). If I change the panel to GridBagLayout that allow extra horizontal space distribution with weightx, the wrapping on nested panel with FlowLayout does not work.

It's not at all helpful when you miss out such information: read this.

Afraid I don't understand the problem any more.

You might be interested in the Wrap Layout.

Rob Camick wrote:You might be interested in the Wrap Layout.

Thanks Rob, this is what I needed! Together with this, now I'm able to use GridBagLayout.

In my usage, I need to have the component which is a JToolBar using your WrapLayout to be a on JPanel which is using the GridBagLayout (as above). When I drag my right JToolBar out to a frame and then close it, the following error will be generated:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: cannot add to layout: constraints must be a GridBagConstraint
	at java.awt.GridBagLayout.addLayoutComponent(Unknown Source)
	at java.awt.Container.addImpl(Unknown Source)
	at java.awt.Container.add(Unknown Source)
	at javax.swing.plaf.basic.BasicToolBarUI$FrameListener.windowClosing(Unknown Source)
	at java.awt.Window.processWindowEvent(Unknown Source)
	at javax.swing.JFrame.processWindowEvent(Unknown Source)
	at java.awt.Window.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)

I can remove this exception by adding the JToolBar to a JPanel. Problem is by doing this the wrapping does not work anymore. Any idea?

Please find my test program codes where uncommenting lines 84 to 87 and commenting lines 89 to 90 to fixed the exception when closed the left dragged JToolBar but no wrapping or vice-versa for wrapping to works but generate exception when closed the left dragged JToolBar.

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Toolkit;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToolBar;

import framework.gui.ResizableToolBarUI;
import framework.gui.WrapLayout;

public class Test {

/**
	 * @param args
	 */
	public static void main(String[] args) {
		JFrame frame = getFrame();
		frame.add(getNorthComponent(), BorderLayout.NORTH);
		frame.add(new JPanel(), BorderLayout.CENTER);
		frame.add(new JPanel(), BorderLayout.SOUTH);

Toolkit toolkit = Toolkit.getDefaultToolkit();
		Dimension dimension = toolkit.getScreenSize();
		frame.setLocation(dimension.width / 4, dimension.height / 4);

frame.pack();
		frame.setVisible(true);
	}

private static JComponent getNorthComponent() {
//		 JPanel panel = new JPanel(new GridLayout(1, 2));
//		 panel.add(getLeftComponent());
//		 panel.add(getRightComponent());

JPanel panel = new JPanel(new GridBagLayout());
		GridBagConstraints c = new GridBagConstraints();

c.fill = GridBagConstraints.HORIZONTAL;
		c.weightx = 0.9;
		c.gridx = 0;
		c.gridy = 0;
		panel.add(getLeftComponent(), c);

c.weightx = 0.1;
		c.gridx = 1;
		panel.add(getRightComponent(), c);

return panel;
	}

private static JComponent getRightComponent() {
		JToolBar toolbar = new JToolBar(Test.class.getName());
		toolbar.add(new JButton("right button"));
		
		JPanel panel = new JPanel(new FlowLayout(FlowLayout.RIGHT));
		panel.add(toolbar);
		
		increaseWindowMinimumWidth(panel.getPreferredSize().width);
		
		return panel;
	}

private static JComponent getLeftComponent() {
		JToolBar toolbar = new JToolBar(Test.class.getName());
		toolbar.setLayout(new WrapLayout(FlowLayout.LEADING));
//		toolbar(new FlowLayout(FlowLayout.LEADING));
		toolbar.setUI(new ResizableToolBarUI());

int numberOfComponent = 5;
		
		for (int i = 0; i < numberOfComponent; i++) {
			JButton button = new JButton("left button " + i);
			toolbar.add(button);
		}
		
//		JPanel panel = new JPanel(new FlowLayout(FlowLayout.LEFT));
//		panel.add(toolbar);
//		increaseWindowMinimumWidth(panel.getPreferredSize().width / numberOfComponent + 40);
//		return panel;
		
		increaseWindowMinimumWidth(toolbar.getPreferredSize().width / numberOfComponent + 40);
		return toolbar;
	}
	
	private static void increaseWindowMinimumWidth(int width) {
		Dimension dimension = frame.getMinimumSize();
		dimension.width += width;
		frame.setMinimumSize(dimension);
	}

private static JFrame frame = new JFrame(Test.class.getName());
	
	private static JFrame getFrame() {		
		frame.setPreferredSize(new Dimension(640, 480));
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setLayout(new BorderLayout());

return frame;
	}
}

JToolBar is designed to be housed in a BorderLayout, not a GridBagLayout. I would suggest enclosing both the toolbar and your panel that has a GridBagLayout in a parent container that has a BorderLayout.

db

I need to use FlowLayout If I want components to wrap to the next line when the user perform a resize. If I need this panel to be nested onto another a parent panel, the parent panel need to be a GridLayout in order for the wrapping to work. Any idea why?