Forum:

Applets

linking between applet pages

Greenhorn

Posts: 22

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

hi guys,
i have an applet with many buttons. i wanna be able to press a button and directs it to another page.
it is kinda like clicking a link in a webpage. i am not sure how to do this. can you please tell me how?

this is what i did in the button's actionPerformed:

thanks in advance!

Ulf Dittmer

Rancher

Posts: 43081

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Assuming that by "page" you mean another web page, that's what the Applet class's showDocument method does.

nasha shaharan

Greenhorn

Posts: 22

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

no..not a webpage. it's an applet also.

Ulf Dittmer

Rancher

Posts: 43081

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Is the applet on the same web page? Then it should be visible already. If It's on a different web page, then showDocument is the way to go.

nasha shaharan

Greenhorn

Posts: 22

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

same web page..how can it be visible? i need to click a button, say: View Profile. then it will take me to another applet called Profile.
just like a website. can you tell me more?

Andrew Thompson

Ranch Hand

Posts: 77

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

I suspect the best approach to this is to convert Hello class to a JPanel and add it and the other GUI elements to a CardLayout. Here is a short example.

// <applet code='SwitchApplet' width='400' height='300'></applet>
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.URL;

public class SwitchApplet extends JApplet {

public void init() {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                initGui();
            }
        });
    }

private void initGui() {
        JPanel gui = new JPanel(new BorderLayout());
        JPanel buttons = new JPanel(new FlowLayout(FlowLayout.CENTER));
        gui.add(buttons, BorderLayout.NORTH);

final JButton tree = new JButton("Tree");
        buttons.add(tree);
        JButton text = new JButton("Text");
        buttons.add(text);

final CardLayout cardLayout = new CardLayout();
        final JPanel content = new JPanel(cardLayout);
        gui.add(content, BorderLayout.CENTER);
        content.add(new JScrollPane(new JTree()), "tree");

JEditorPane textContent = new JEditorPane();
        content.add(new JScrollPane(textContent), "text");
        try {
            URL url = new URL(getDocumentBase(), "SwitchApplet.java");
            textContent.setPage(url);
        } catch(Exception weTried) {
        }

ActionListener al = new ActionListener(){
            public void actionPerformed(ActionEvent ae) {
                if (ae.getSource().equals(tree)) {
                    cardLayout.show(content, "tree");
                } else {
                    cardLayout.show(content, "text");
                }
            }
        };
        tree.addActionListener(al);
        text.addActionListener(al);

setContentPane(gui);
    }
}

Andrew Thompson
http://pscode.org/

nasha shaharan

Greenhorn

Posts: 22

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

thanks for the example, Andrew! i will look into it and study more about cardlayout.
i'm wondering why i can't link to other applet in the same page, when my login page can do that whenever i hit the login button. when i log in successfully, the page changes to the content page.

this is my login page code:

//username : nasya , password : nasya

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;

public class Login extends JApplet {
	public static final String text = "<html><center>Central Manager</center> </html>";

JPanel jPanel1 = new JPanel();
	BorderLayout borderLayout1 = new BorderLayout();
	JLabel jLabel1 = new JLabel();
	JPanel jPanel2 = new JPanel();
	GridBagLayout gridBagLayout1 = new GridBagLayout();
	JLabel jLabel2 = new JLabel();
	JLabel jLabel3 = new JLabel();
	JTextField loginTextField = new JTextField(20);
	JPasswordField passwordTextField = new JPasswordField(20);
	JPanel jPanel3 = new JPanel();
	JButton exitButton = new JButton();
	JButton enterButton = new JButton();
	FlowLayout flowLayout1 = new FlowLayout();
	
	private static String tableName = "users";
	private static Connection conn = null;
	private static Statement stmt = null;
	
	/*public Login() {
		try {
			jbInit();
		}
		catch(Exception e) {
			e.printStackTrace();
		}
	}*/

private void login(ActionEvent e) {
		try
		{
			Class.forName("org.postgresql.Driver"); 
			//gets a connection
			conn = DriverManager.getConnection("jdbc:postgresql://localhost:5432/test","postgres","870127");
			stmt = conn.createStatement();
			String login = loginTextField.getText();
			String pass = new String(passwordTextField.getPassword());
			ResultSet results = stmt.executeQuery("select username, password from " + tableName +" where username ='"+login+"'");
			String username = "";
			String password = "";
			
			while(results.next())
			{
				username = results.getString("username");
				password = results.getString("password");
			}
				//validate login and password here. validity will be done by sending login/password to the server
				if (login.equals(username) && pass.equals(password)) {
					System.out.println("login successful");
					showButtonsView();
				} 	
				else {
					JOptionPane.showMessageDialog(this,"Incorrect login or password","Error",JOptionPane.ERROR_MESSAGE);
					loginTextField.setText("");
					passwordTextField.setText("");
					loginTextField.requestFocusInWindow();
				}
				
			
			results.close();
			stmt.close();
		}
		catch (Exception ex)
		{
			ex.printStackTrace();
		}
	}

private void showButtonsView() {
		getContentPane().removeAll();
		ButtonView button = new ButtonView();
		button.init();
		getContentPane().add(button);
		getContentPane().validate();
	}
	
	private void exit(ActionEvent e) {
		setVisible(false);
	}

/*public static void main(String[] args) {
		Login f = new Login();
		f.setLocation(200,200);
		f.pack();
		f.show();
	}*/

public void init()
	{
		resize(500,200);
		//getContentPane().setLocation(400,400);
		//getContentPane().setSize(500, 500);
		jPanel1.setLayout(borderLayout1);
		jLabel1.setHorizontalAlignment(SwingConstants.CENTER);
		jLabel1.setText(text);
		jPanel2.setLayout(gridBagLayout1);
		jLabel2.setText("Password:");
		jLabel3.setText("Login:");
		exitButton.setText("Exit");
		exitButton.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(ActionEvent e) {
				exit(e);
			}
		});
		
		enterButton.setText("Enter");
		enterButton.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(ActionEvent e) {
				login(e);
			}
		});
		
		jPanel3.setLayout(flowLayout1);
		flowLayout1.setAlignment(FlowLayout.RIGHT);
		this.getContentPane().add(jPanel1, BorderLayout.CENTER);
		jPanel1.add(jLabel1, BorderLayout.NORTH);
		jPanel1.add(jPanel2, BorderLayout.CENTER);
		jPanel2.add(loginTextField, new GridBagConstraints(2, 1, 1, 1, 0.0, 0.0
				,GridBagConstraints.CENTER, GridBagConstraints.NONE, new Insets(0, 11, 0, 0), 0, 0));
		jPanel2.add(jLabel2, new GridBagConstraints(1, 2, 1, 1, 0.0, 0.0
				,GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(11, 0, 0, 0), 0, 0));
		jPanel2.add(passwordTextField, new GridBagConstraints(2, 2, 1, 1, 0.0, 0.0
				,GridBagConstraints.CENTER, GridBagConstraints.NONE, new Insets(11, 11, 0, 0), 0, 0));
		jPanel2.add(jLabel3, new GridBagConstraints(1, 1, 1, 1, 0.0, 0.0
				,GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0));
		jPanel1.add(jPanel3, BorderLayout.SOUTH);
		jPanel3.add(enterButton, null);
		jPanel3.add(exitButton, null);
	}
}

and this is the code for the other applet when 'enter' button is pressed:

import java.awt.*;
import java.awt.event.ActionEvent;

import javax.swing.BoxLayout;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class ButtonView extends JApplet
	{
	//GridLayout gridLayout1 = new GridLayout(2,2);
	BorderLayout borderLayout1 = new BorderLayout();
	//JScrollPane jScrollPane1 = new JScrollPane();

JPanel jPanel1 = new JPanel();
	JButton jButton1 = new JButton();
	JButton jButton2 = new JButton();
	JButton jButton3 = new JButton();
	JButton jButton4 = new JButton();

/*public ButtonView() {
		try {
			jbInit();
		}
		catch(Exception ex) {
			ex.printStackTrace();
		}
	}*/

public void init()
	{
		getContentPane().add(jPanel1);
		this.setLayout(borderLayout1);
		jButton1.setText("View FileSystem");
		jButton1.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(ActionEvent e) {
				new FileExplorer();
				setVisible(true);
				//showFile();
			}
		});
		jButton2.setText("Employee Profile");
		jButton1.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(ActionEvent e) {
				employeeView();
				setVisible(true);
			}
		});
		jButton3.setText("Hello,Hi!");
		jButton1.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(ActionEvent e) {
				helloWorld();
				setVisible(true);
			}
		});
		jButton4.setText("Example");
		this.add(jPanel1, BorderLayout.CENTER);
		jPanel1.setLayout(new BoxLayout(jPanel1, BoxLayout.PAGE_AXIS));

jPanel1.add(jButton1, null);
		jButton1.setAlignmentX(CENTER_ALIGNMENT);
		jPanel1.add(jButton2, null);
		jButton2.setAlignmentX(CENTER_ALIGNMENT);
		jPanel1.add(jButton3, null);
		jButton3.setAlignmentX(CENTER_ALIGNMENT);
		jPanel1.add(jButton4, null);
		jButton4.setAlignmentX(CENTER_ALIGNMENT);
}
	private void showFile() {
		getContentPane().removeAll();
		FileExplorer file = new FileExplorer();
		
		//getContentPane().add(file);
		//getContentPane().validate();
	}
	
	private void employeeView()
	{
		getContentPane().removeAll();
		Employee emp = new Employee();
		emp.init();
		//getContentPane().add(emp);
		//getContentPane().validate();
	}
	
	private void helloWorld()
	{
		getContentPane().removeAll();
		Hello h = new Hello();
		h.init();
		getContentPane().add(h);
		getContentPane().validate();
	}
}

please help because i'm confused...

Andrew Thompson

Ranch Hand

Posts: 77

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

nasha shaharan wrote:..i'm wondering why i can't link to other applet in the same page, ...

Probably because that makes about as much sense as "Why can't I banana card hat manifesto?".

Or to put that another way, I don't have the 1st idea about what your 'requirement' is supposed to mean. Links are either to other pages, other resources like images or ZIP archives, or anchors in the same page. There is no such thing as a 'link to an applet'.

Can you give us the URL of a web page that behaves as your applets are supposed to work?

Andrew Thompson
http://pscode.org/

nasha shaharan

Greenhorn

Posts: 22

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

It's like a website with a login page. after login, press the enter button and the applet called ButtonView takes the place of the login applet.
then in the ButtonView applet will have 3 buttons which do different things and they will open other applets as well.

the login to buttonView successfully linked, but the buttons in buttonView cannot open their respective applets.

just take a look at my code...

i don't want to use showDocuments because it will use different web pages. i only want one webpage, but the applets in one place, responding to whatever button being pressed.
or is this not possible? an applet contents cannot be changed? but in login page it was successful...maybe the panel from buttonView that was called?

sorry because i don't know a lot about applets..thanks for your help

Ulf Dittmer

Rancher

Posts: 43081

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

CardLayout is definitely the way to go.

nasha shaharan

Greenhorn

Posts: 22

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

oh CardLayout..can cardlayout contain applets in various sizes?

Ulf Dittmer

Rancher

Posts: 43081

posted 13 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Being a layout, CardLayout does not contain applets but Panels or JPanels. You'll have to rewrite your code so that it is a single applet. And no, all panels in a CardLayout are of the same size. But that shouldn't be a problem.

nasha shaharan

Greenhorn

Posts: 22

posted 13 years ago