SWT: A Developer's Notebook

Creating a Complete Toolbar Example

Toolbars and menus go hand in hand, and often there is a correspondence between MenuItem and ToolItem objects that you create. To create a functional toolbar, begin by examining your menu code to determine which functions to expose as toolbar buttons. If you look at the MenuShell example from Chapter 3, you find that several common toolbar functions are included. The best candidates for a toolbar from the example are Open and Save (from the File menu), and Cut, Copy, and Paste (from the Edit menu).

Once you have planned your toolbar, you are ready to develop the code necessary to create it.

How do I do that?

Example 4-1 demonstrates how to create a window, complete with both toolbar and menu.

Example 4-1. Creating a Toolbar example

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.*;

public class ToolbarShellExample {    
        Display d;
        Shell s;
        ToolbarShellExample( )    {
            d = new Display( );
            s = new Shell(d);
            s.setSize(300,300);
            s.setImage(new Image(d, "c:\\icons\\JavaCup.ico"));
            s.setText("A Shell Toolbar Example");
            
            final ToolBar bar = new ToolBar(s,SWT.HORIZONTAL);
            bar.setSize(300,70);
            bar.setLocation(0,0);

            // create images for toolbar buttons
            final Image saveIcon = new Image(d, "c:\\icons\\save.jpg");
            final Image openIcon = new Image(d, "c:\\icons\\open.jpg");
            final Image cutIcon = new Image(d, "c:\\icons\\cut.jpg");
            final Image copyIcon = new Image(d, "c:\\icons\\copy.jpg");
            final Image pasteIcon = new Image(d, "c:\\icons\\paste.jpg");

            // create and add the button for performing an open operation
            final ToolItem openToolItem = new ToolItem(bar, SWT.PUSH);
            openToolItem.setImage(openIcon);
            openToolItem.setText("Open");
            openToolItem.setToolTipText("Open File");
            
            //create and add the button for performing a save operation
            final ToolItem saveToolItem = new ToolItem(bar, SWT.PUSH);
            saveToolItem.setImage(saveIcon);
            saveToolItem.setText("Save");
            saveToolItem.setToolTipText("Save File");
            
           //create and add the button for performing a cut operation
            final ToolItem cutToolItem = new ToolItem(bar, SWT.PUSH);
            cutToolItem.setImage(cutIcon);
            cutToolItem.setText("Cut");
            cutToolItem.setToolTipText("Cut");
            
            // create and add the button for performing a copy operation
            final ToolItem copyToolItem = new ToolItem(bar, SWT.PUSH);
            copyToolItem.setImage(copyIcon);
            copyToolItem.setText("Copy");
            copyToolItem.setToolTipText("Copy");
            
            // create and add the button for performing a paste operation
            final ToolItem pasteToolItem = new ToolItem(bar, SWT.PUSH);
            pasteToolItem.setImage(pasteIcon);
            pasteToolItem.setText("Paste");
            pasteToolItem.setToolTipText("Paste");
            
            // create the menu
            Menu m = new Menu(s,SWT.BAR);

            // create a File menu and add an Exit item
            final MenuItem file = new MenuItem(m, SWT.CASCADE);
            file.setText("&File");
            final Menu filemenu = new Menu(s, SWT.DROP_DOWN);
            file.setMenu(filemenu);
            final MenuItem openMenuItem = new MenuItem(filemenu, SWT.PUSH);
            openMenuItem.setText("&Open\tCTRL+O");
            openMenuItem.setAccelerator(SWT.CTRL+'O');
            final MenuItem saveMenuItem = new MenuItem(filemenu, SWT.PUSH);
            saveMenuItem.setText("&Save\tCTRL+S");
            saveMenuItem.setAccelerator(SWT.CTRL+'S');
            final MenuItem separator = new MenuItem(filemenu, SWT.SEPARATOR);
            final MenuItem exitMenuItem = new MenuItem(filemenu, SWT.PUSH);
            exitMenuItem.setText("E&xit");
            
            // create an Edit menu and add Cut, Copy, and Paste items
            final MenuItem edit = new MenuItem(m, SWT.CASCADE);
            edit.setText("&Edit");
            final Menu editmenu = new Menu(s, SWT.DROP_DOWN);
            edit.setMenu(editmenu);
            final MenuItem cutMenuItem = new MenuItem(editmenu, SWT.PUSH);
            cutMenuItem.setText("&Cut");
            final MenuItem copyMenuItem = new MenuItem(editmenu, SWT.PUSH);
            copyMenuItem.setText("Co&py");
            final MenuItem pasteMenuItem = new MenuItem(editmenu, SWT.PUSH);
            pasteMenuItem.setText("&Paste");            
          
            //create a Window menu and add Child items
            final MenuItem window = new MenuItem(m, SWT.CASCADE);
            window.setText("&Window");
            final Menu windowmenu = new Menu(s, SWT.DROP_DOWN);
            window.setMenu(windowmenu);
            final MenuItem maxMenuItem = new MenuItem(windowmenu, SWT.PUSH);
            maxMenuItem.setText("Ma&ximize");
            final MenuItem minMenuItem = new MenuItem(windowmenu, SWT.PUSH);
            minMenuItem.setText("Mi&nimize");
            
            // create a Help menu and add an About item
            final MenuItem help = new MenuItem(m, SWT.CASCADE);
            help.setText("&Help");
            final Menu helpmenu = new Menu(s, SWT.DROP_DOWN);
            help.setMenu(helpmenu);
            final MenuItem abouMenutItem = new MenuItem(helpmenu, SWT.PUSH);
            aboutMenuItem.setText("&About");    
            
            // add action listeners for the menu items
            
            openMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    System.out.println("Open");
                }
                public void widgetDefaultSelected(SelectionEvent e) {                
               }
               });

         
           saveMenuItem.addSelectionListener(new SelectionListener( ) {
                 public void widgetSelected(SelectionEvent e) {
                     System.out.println("Save");
                }
                 public void widgetDefaultSelected(SelectionEvent e) {                
                }
                });

           exitMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    System.exit(0);
                }
                public void widgetDefaultSelected(SelectionEvent e) {                
                }
                });
        
           cutMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    System.out.println("Cut");
                }
                public void widgetDefaultSelected(SelectionEvent e) {                
                }
                });
        
           copyMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    System.out.println("Copy");
                }
                public void widgetDefaultSelected(SelectionEvent e) {               
                }
                });
        
           pasteMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    System.out.println("Paste");
                }
                public void widgetDefaultSelected(SelectionEvent e) {                
                }
                });
        
           maxMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    Shell parent = (Shell)maxItem.getParent( ).getParent( );
                    parent.setMaximized(true);
                }
                public void widgetDefaultSelected(SelectionEvent e) {                
                }
                });
        
           minMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    Shell parent = (Shell)minItem.getParent( ).getParent( );
                    parent.setMaximized(false);
                }
                public void widgetDefaultSelected(SelectionEvent e) {                
                }
                });

           aboutMenuItem.addSelectionListener(new SelectionListener( ) {
                public void widgetSelected(SelectionEvent e) {
                    System.out.println("Help Invoked");
              }
                public void widgetDefaultSelected(SelectionEvent e) {                
                }
                });            
            
            s.setMenuBar(m);
        
            s.open( );
            while(!s.isDisposed( )){
                if(!d.readAndDispatch( ))
                    d.sleep( );
            }
            d.dispose( );
        }        
}

Creating an instance of ToolbarShellExample displays Figure 4-1.

Figure 4-1. Window with toolbar

Note

As with menus, creating toolbars takes a lot of code, though fewer objects. Toolbars are expensive, but much less so than menus.