package examples;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.*;
import javax.swing.border.LineBorder;

import static java.awt.BorderLayout.*;

public class GUILayoutExample extends JPanel {
	static final GridBagConstraints gbc = new GridBagConstraints();
	static final SpringLayout.Constraints sc = new SpringLayout.Constraints();
	static enum LayoutChoice {border, flow, grid, gridbag, cascade};

	ButtonGroup selection = new ButtonGroup();
	ChoiceButton[] choices = new ChoiceButton[LayoutChoice.values().length];
	JPanel choicesPanel = new JPanel();
	
	public GUILayoutExample() {
		setLayout(new BorderLayout());
		AbstractButton no, yes;

		add(yes = new JButton(), WEST);
		yes.setIcon(new ImageIcon("smile.jpg"));
		yes.setToolTipText("yes");
		add(no = new JButton("no"), EAST);
		no.setIcon(new ImageIcon("frown.jpg"));
		
		JPanel nestedPanel = new JPanel(new BorderLayout());
		add(nestedPanel, BorderLayout.SOUTH);
		nestedPanel.add(new JSlider(), EAST);
		nestedPanel.add(new JTextField("Enter text here"), WEST);

		add(new JLabel("What's your favorite LayoutManager?"), NORTH);
		add(choicesPanel, CENTER);
		choicesPanel.setBorder(new LineBorder(Color.BLUE, 2));
		
		for (LayoutChoice choice : LayoutChoice.values())
			choices[choice.ordinal()] = new ChoiceButton(choice);
		choices[0].doClick();
	}
	
	void changeLayout(LayoutChoice lc) {
		choicesPanel.removeAll();
		switch (lc) {
		case flow: addComponentsFlow(); break;
		case border: addComponentsBorder(); break;
		case grid: addComponentsGrid(); break;
		case gridbag: addComponentsGridBag(); break;
		case cascade: addComponentsCascade(); break;
		}
		choicesPanel.revalidate();
	}
	
	void addComponentsFlow() {
		choicesPanel.setLayout(new FlowLayout());
		for (JComponent c : choices)
			choicesPanel.add(c);
	}
	
	void addComponentsGrid() {
		choicesPanel.setLayout(new GridLayout(2,0));
		for (JComponent c : choices)
			choicesPanel.add(c);
	}
	
	void addComponentsBorder() {
		choicesPanel.setLayout(new BorderLayout());
		choicesPanel.add(choices[0], NORTH);
		choicesPanel.add(choices[1], WEST);
		choicesPanel.add(choices[2], CENTER);
		choicesPanel.add(choices[3], EAST);
		choicesPanel.add(choices[4], SOUTH);
	}
	
	void addComponentsGridBag() {
		choicesPanel.setLayout(new GridBagLayout());
		addToGridBag(choices[0],0,0,1,2);
		addToGridBag(choices[1],2,0,2,1);
		addToGridBag(choices[2],0,2,10,1);
		addToGridBag(choices[3],0,5,2,2);
		addToGridBag(choices[4],2,7,2,2);
	}
	
	void addToGridBag(JComponent c, int x, int y, int width, int height) {
		gbc.gridx = x;
		gbc.gridy = y;
		gbc.gridwidth = width;
		gbc.gridheight = height;
		gbc.fill = GridBagConstraints.BOTH;
		gbc.anchor = GridBagConstraints.EAST;
		choicesPanel.add(c, gbc);
	}
	
	void addComponentsCascade() {
		choicesPanel.setLayout(new CascadingLayout());
		for (JComponent c : choices) {
			choicesPanel.add(c);
		}
	}
	
	
	class ChoiceButton extends JToggleButton implements ActionListener {
		LayoutChoice choice;
		
		ChoiceButton(LayoutChoice choice) {
			super(choice + " layout");
			this.choice = choice;
			selection.add(this);
			addActionListener(this);
		}
		public void actionPerformed(ActionEvent e) {
			changeLayout(choice);
		}
	}
	
	public static void main(String[] args) {
		GUILayoutExample g = new GUILayoutExample();
		JFrame f = new JFrame("My GUI");
		f.add(g);
		f.pack();
		f.setVisible(true);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
}