Valentino Vranić - Objektovo-orientovane programovanie 2014/15

Prednáška 4: Model-View-Controller a používateľské rozhranie

19. marec 2015

Kód zo slajdov



Príklad: jednoduché okno

import javax.swing.*;

class C {
	public static void main(String[] args) {
		JFrame w = new JFrame("Moje okno");
		w.setSize(300, 300);
		w.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		w.setVisible(true);
	}
}



Príklad: okno dedením od JFrame

import javax.swing.*;

class MyWindow extends JFrame {
	public MyWindow() {
		setTitle("Moje okno");
		setSize(300, 300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
}
class C {
	public static void main(String[] args) {
		JFrame w = new MyWindow();
		w.setVisible(true);
	}
}



Príklad: okno s tlačidlom

import javax.swing.*;

class C {
	public static void main(String[] args) {
		JFrame w = new JFrame("Moje okno");
		w.setSize(300, 300);
		JButton b1 = new JButton("Tlacidlo1");
		w.add(b1);
		w.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		w.setVisible(true);
	}
}



Príklad: rozloženie prvkov v okne (1)

import javax.swing.*;
import java.awt.*;

class C {
	public static void main(String[] args) {
		JFrame w = new JFrame("Moje okno");
		w.setSize(300, 300);
		JButton b1 = new JButton("Tlacidlo1");
		JButton b2 = new JButton("Tlacidlo2");
//	 prednastavené rozloženie:
//	 w.setLayout(new BorderLayout());
		w.add(b1, BorderLayout.WEST);
		w.add(b2, BorderLayout.EAST);
		w.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		w.setVisible(true);
	}
}



Príklad: kliknutie na tlačidlo

import javax.swing.*;
import java.awt.*;
import java.awt.event.*; // niekedy aj javax.swing.event.*

class MyWindow extends JFrame {
	private JButton t = new JButton("Tlacidlo1");
	public MyWindow() {
		setSize(300, 300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLayout(new FlowLayout());
		add(t);
		t.addActionListener(new MyListener());
	}

	// trieda vhniezdená v MyWindow
	private class MyListener implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			if (t.getText() != "Jeden")
				t.setText("Jeden");
			else
				t.setText("Dva");
		}
	}
} // class MyWindow

class C {  
	public static void main(String[] args) {
		JFrame w = new MyWindow();
		w.setVisible(true);
	}
}



Príklad: prijímač pomocou anonymnej triedy

class MyWindow extends JFrame {
	private JButton t = new JButton("Jeden");
	public MyWindow() {
		setSize(300, 300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLayout(new FlowLayout());
		add(t);
		t.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if (t.getText() != "Jeden")
					t.setText("Jeden");
				else
					t.setText("Dva");
			}
		});
	}
}



Príklad: sledovanie pohybu myši

		t.addMouseListener(new MouseListener() {
			public void mouseEntered(MouseEvent e) {
				if (t.getText() != "Jeden")
					t.setText("Jeden");
				else
					t.setText("Dva");
			}
			public void mouseReleased(MouseEvent e) {				  	
			}
			public void mousePressed(MouseEvent e) {				  	
			}
			public void mouseExited(MouseEvent e) {				  	
			}
			public void mouseClicked(MouseEvent e) {				  	
			}
		});




Príklad: použitie adaptéra

		t.addMouseListener(new MouseAdapter() {
			public void mouseEntered(MouseEvent e) {
				if (t.getText() != "Jeden")
					t.setText("Jeden");
				else
					t.setText("Dva");
			}
		});



Príklad: korektná zmena GUI po realizácii

class MyWindow extends JFrame {
	private JLabel l;
  
	public MyWindow() {
		setTitle("Moje okno");
		setSize(300, 300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		l = new JLabel("Text");
		add(l);
	}
	public void changeText(String s) {
		l.setText(s);
	}
}

class C {
	public static void main(String[] args) throws Exception {
		final MyWindow w = new MyWindow();
		w.setVisible(true);

		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				w.changeText("Novy text");
			}
		});
	}
}



Príklad: spustenie náročného výpočtu z GUI

public class NastyComputation {
	private MyWindow w;

	public void setWindow(MyWindow w) {
		this.w = w;
	}
	public void compute() {
		w.setBusy();	  
		for (int i = 0; i < 100000; i++)
			System.out.println("c");
		w.setFree();
	}
}


import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class MyWindow extends JFrame {
	private NastyComputation c;
	private JButton PressButton = new JButton("Press");
	private JButton CompButton = new JButton("Comp");
	private JLabel l = new JLabel("Free");
	public JPanel p = new JPanel();
	public MyWindow(NastyComputation c) {
		super("MyWindow");
		this.c = c;
		setSize(200, 75);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLayout(new FlowLayout());
		add(PressButton);
		add(CompButton);
		add(l);
		PressButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if (PressButton.getText() != "Press") {
					PressButton.setText("Press");
				}
				else {
					PressButton.setText("Again");
				}
			}
		});
		CompButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				MyWindow.this.c.compute();
			}
		});
	} // MyWindow(NastyComputation c)

	public void setBusy() {
		l.setText("Busy");
	}
	public void setFree() {
		l.setText("Free");
	}

	public static void main(String[] args) {
		NastyComputation c = new NastyComputation();
		MyWindow w = new MyWindow(c);
		c.setWindow(w);
		w.setVisible(true);
	}
} // MyWindow




public class NastyComputation {
	private MyWindow w;

	public void setWindow(MyWindow w) {
		this.w = w;
	}
	public void compute() {
		w.setBusy();	  
		new Thread() {
			public void run() {
				for (int i = 0; i < 100000; i++)
					System.out.println("c");
				SwingUtilities.invokeLater(new Runnable() {
					public void run() {
						w.setFree();
					}
				});
			}
		}.start();
	}
}



public class NastyComputation {
	public void compute() {
		for (int i = 0; i < 10000; i++)
			System.out.println("c");
	}
}



		CompButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				setBusy();
				new SwingWorker<Object, Object>() {
					public Object doInBackground() {
						c.compute();
						return null;
					}
					protected void done() {
						setFree();
					}
				}.execute();
			}
		});