How to create Combo Box in SWT

This section illustrates you how to create a combo box.

In this example, we have created two different combo boxes where one is performing an action on the second combo box. The items tea , coffee and cold drink are added to the first combo box by using the method add() of Combo class. To perform an action on the second combo box, the class SelectionEvent is called. If you select the cold drink from the first combo box, the array of drinks is added to the second combo box by using the method combo2.setItems(drinks).The method getText().equals("Cold drink") returns the text Cold drink. If you select Tea or Coffee, the second combo box shows the text 'not Applicable'.

Here is the code of ComboBox.java


import java.util.Arrays;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.*;

import org.eclipse.swt.widgets.*;

import org.eclipse.swt.layout.GridLayout;

      

public class ComboBox {

  Display display = new Display();

  Shell shell = new Shell(display);

      

  public ComboBox() {

    shell.setText("Combo box");

    shell.setLayout(new GridLayout(4, false));

      

    Label label=new Label(shell, SWT.NULL);

    label.setText("What do you like to drink?");

    final Combo combo1 = new Combo(shell, SWT.VERTICAL |

             SWT.DROP_DOWN | SWT.BORDER | SWT.READ_ONLY);

    final Combo combo2 = new Combo(shell, SWT.VERTICAL| 

             SWT.BORDER  |SWT.READ_ONLY);

    

     combo1.add("Tea");

     combo1.add("Coffee");

     combo1.add("Cold drink");

   combo1.addSelectionListener(new SelectionAdapter() {

     public void widgetSelected(SelectionEvent e) {

        if (combo1.getText().equals("Cold drink")) {

          String[] drinks = new String[]{"Pepsi", "CocaCola", 

                 "Miranda","Sprite","ThumbsUp"};

          combo2.setItems(drinks);

          combo2.setEnabled(true);

      combo2.add("-Select-");

      combo2.setText("-Select-");

        } else if (combo1.getText().equals("Tea")) {

          combo2.add("Not Applicable");

          combo2.setText("Not Applicable");

        } else {

          combo2.add("Not Applicable");

          combo2.setText("Not Applicable");

        }

      }

    });

    shell.pack();

    shell.open();

    while (!shell.isDisposed()) {

      if (!display.readAndDispatch()) {

        

        display.sleep();

      }

    }

  display.dispose();

  }

  public static void main(String[] args) {

    new ComboBox();

  }

}

Output will be displayed as:

As no value is added for the item tea and coffee, therefore if you select the tea, it will show you Not Applicable on the second combo box.

If you select the cold drink, it will show you select.

After selecting the cold drink, output will be displayed as:

Download source Code: