Controale Java - slidere

  • Elemente de tip "Slider"

        Pentru aplicatii in care trebuie modificat liniar un parametru, se folosesc elemente de tip "Slider". Urmatoarea aplicatie plaseaza un slider care are rolul e a modifica valoarea afisata intr-o eticheta.

        In cazul ca nu se lanseaza aplicatia de sus, pe calculatorul d-voastra trebuie instalat pachetul JDC versiunea JDK6 sau mai recenta.

        Cum se plaseaza elementele de tip button intr-un applet ? 
    package Controale;

import java.awt.BorderLayout;
import java.awt.Rectangle;
import java.awt.GridBagLayout;
import javax.swing.JPanel;
import javax.swing.JApplet;
import javax.swing.JLabel;
import javax.swing.JSlider;

public class utiliz_slider_v2 extends JApplet {

	private static final long serialVersionUID = 1L;
	private JLabel etich_1 = null; 		// eticheta 1 
	private JSlider slider_1 = null; 	// slider-ul 1
	private JPanel panel_1 = null; 		// panoul 1
	private JPanel c_panel_1 = null; 	// paneloul 1 cu controale plasate
	
	/**
	 * Constructorul implicit pentru "utiliz_slider_v2"
	 */
	
	public utiliz_slider_v2() {
		super();
	}
	
	/**
	 * Aceasta metoda initializeaza: this
	 * 
	 * @returneaza  void
	 */
	
	public void init() {
		this.setSize(300,200);
		this.setContentPane(init_panel_1());
	}

	/**
	 * Aceasta metoda initializeaza controlul de tip slider: slider_1
	 * @returneaza slider_1 de tipul: javax.swing.JSlider	
	 */
	
	private JSlider creaza_slider_1() {
		if (slider_1 == null) {
			slider_1 = new JSlider();
			slider_1.setBounds(new Rectangle(10, 150, 270, 25));
			slider_1.addChangeListener(new javax.swing.event.ChangeListener() {
				public void stateChanged(javax.swing.event.ChangeEvent e) {
					etich_1.setText(Integer.toString(slider_1.getValue()));
				}
			});
		}
		return slider_1;
	}
	
	/**
	 * Aceasta metoda creaza panelul: "panel_1"	
	 * Returneaza panel_1 de tipul:	javax.swing.JPanel
	 */
	
	private JPanel creaza_panel_1() {
		if (panel_1 == null) {
			panel_1 = new JPanel();
			panel_1.setLayout(new GridBagLayout());
			panel_1.setBounds(new Rectangle(0, 20, 450, 200));
		}
		return panel_1;
	}

	/**
	 * Aceasta metoda initializeaza panel_1 plasand controalele dorite 
	 * Returneaza c_panel_1 de tipul: javax.swing.JPanel 
	 */
	
	private JPanel init_panel_1() {
		if (c_panel_1 == null) {		
			etich_1 = new JLabel();
			etich_1.setBounds(new Rectangle(75, 10, 100, 10));
			etich_1.setText("Utilizare slider");
			c_panel_1 = new JPanel();
			c_panel_1.setLayout(null);
			c_panel_1.add(etich_1, null);
			c_panel_1.add(creaza_slider_1(), null);
			c_panel_1.add(creaza_panel_1(), null);
			c_panel_1.setLayout(new BorderLayout());
		}
		return c_panel_1;
	}	
}


        Elementele de tip "slider" dispune de o serie de proprietati, cum ar fi pozitia, diviziunile, valoarea afisata, etc.
        Vom seta aceste aplicatii in aplicatia urmatoare 


    package Controale;

import java.awt.BorderLayout;
import java.awt.Rectangle;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JApplet;
import javax.swing.JLabel;
import javax.swing.JSlider;

public class utiliz_slider_v3 extends JApplet {

	private static final long serialVersionUID = 1L;
	private JLabel etich_1 = null; 		// eticheta 1 
	private JSlider slider_1 = null; 	// slider-ul 1
	private JButton but_1 = null; 		// butonul 1
	private JPanel panel_1 = null; 		// panoul 1
	private JPanel c_panel_1 = null; 	// panoul 1 cu controale plasate

	/**
	 * Constructorul implicit pentru "utiliz_slider_v3"
	 */
	public utiliz_slider_v3() {
		super();
	}
	
	/**
	 * Aceasta metoda initializeaza: this
	 * 
	 * @returneaza  void
	 */
	
	public void init() {
		this.setSize(400,300);
		this.setContentPane(init_panel_1());
	}

	/**
	 * Aceasta metoda initializeaza controlul de tip slider: slider_1
	 * @returneaza slider_1 de tipul: javax.swing.JSlider	
	 */
	private JSlider creaza_slider_1() {
		if (slider_1 == null) {
			//(amplasare, minim, maxim, val_initiala)
			slider_1 = new JSlider(JSlider.VERTICAL,0,50,25); 
			slider_1.setMajorTickSpacing(10);
			slider_1.setMinorTickSpacing(1);
			slider_1.setPaintTicks(true);
			slider_1.setPaintLabels(true); 
			//slider_1.setBounds(new Rectangle(10, 140, 270, 60));
			slider_1.setBounds(new Rectangle(10, 10, 80, 270));
			slider_1.addChangeListener(new javax.swing.event.ChangeListener() {
				public void stateChanged(javax.swing.event.ChangeEvent e) {
					etich_1.setText(Integer.toString(slider_1.getValue()));
				}
			});
		}
		return slider_1;
	}
	
	 	/**
		 * Aceasta metoda creaza panelul: "but_1"	
		 * Returneaza but_1 de tipul:	javax.swing.JButton
		 */
		private JButton creaza_but_1() {
			if (but_1 == null) {
				but_1 = new JButton();
				but_1.setBounds(new Rectangle(100, 40, 180, 30));
				but_1.setText("Setare la valoarea 33");
				but_1.addActionListener(new java.awt.event.ActionListener() {
					public void actionPerformed(java.awt.event.ActionEvent e) {
						etich_1.setText("Ati setat valoarea 33");
						slider_1.setValue(33);
					}
				});
			}
			return but_1;
		}
	 
	/**
	 * Aceasta metoda creaza panelul: "panel_1"	
	 * Returneaza panel_1 de tipul:	javax.swing.JPanel
	 */
	private JPanel creaza_panel_1() {
		if (panel_1 == null) {
			panel_1 = new JPanel();
			panel_1.setLayout(new GridBagLayout());
			panel_1.setBounds(new Rectangle(0, 20, 450, 200));
		}
		return panel_1;
	}

	/**
	 * Aceasta metoda initializeaza panel_1 plasand controalele dorite 
	 * Returneaza c_panel_1 de tipul: javax.swing.JPanel 
	 */
	private JPanel init_panel_1() {
		if (c_panel_1 == null) {		
			etich_1 = new JLabel();
			etich_1.setBounds(new Rectangle(100, 10, 150, 10));
			etich_1.setText("Utilizare slider");
			c_panel_1 = new JPanel();
			c_panel_1.setLayout(null);
			c_panel_1.add(etich_1, null);
			c_panel_1.add(creaza_slider_1(), null);
			c_panel_1.add(creaza_but_1(), null);
			c_panel_1.add(creaza_panel_1(), null);
			c_panel_1.setLayout(new BorderLayout());
		}
		return c_panel_1;
	}	
}