Netbeans/C2/Adding-a-File-Chooser/English-timed

From Script | Spoken-Tutorial
Jump to: navigation, search
Time Narration
00:00 Hello.Welcome to the tutorial on Adding a File Chooser to a Java Application.
00:07 In this tutorial, we will:
00:09 Create an application, Create the application form.
00:12 Add the File Chooser,
00:14 Configure the File Chooser and
00:17 run the application.
00:19 For this demonstration, I am using the Linux Operating System, Ubuntu version 12.04
00:26 and Netbeans IDE version 7.1.1.
00:31 In this tutorial, we will learn to add a File chooser to a Java Application using the javax.swing.JFileChooser component.
00:42 As a part of this exercise, we will learn to create a small Java application that loads a '.txt' file into a Text Area.
00:52 Let us first create the Java Application:
00:55 Launch the IDE.
00:57 From the main menu, choose File and New Project.
01:03 Choose the "Java" Category and the "Java Application" Projects type.
01:08 And click Next.
01:10 In the Project Name field, let's type: "JFileChooserDemo".
01:20 Clear the Create Main Class check-box.
01:23 Make sure that the Set as Main Project check-box is selected.
01:27 Click Finish.
01:31 Here, we will create the JFrame container and add a few components to it.
01:37 Right-click on the Source Packages node.
01:41 Choose New > Other.
01:45 Choose the Swing GUI Forms categories and the JFrameForm type.
01:51 Click Next.
01:54 For Class Name, type: "JFileChooserDemo".
02:02 In the Package field, type: "jfilechooserdemo.resources".
02:12 Click Finish.
02:17 In the Properties window, select the Title property
02:22 and type: "Demo Application".
02:30 Press Enter to confirm.
02:32 In the Palette, open the Swing Menus category.
02:40 Select the Menu Bar component and drag it to the top left corner of the Jframe.
02:50 Right-click the Edit item of the Menu Bar component.
02:55 Select Delete in the context menu.
02:59 Next, let us add a menu item that allows to open the FileChooser from the running application.
03:07 Make sure that the Menu Bar' is selected before you drag another Menu Item here.
03:14 In the Swing Menus category in the Palette, select a new Menu Item.
03:22 Drag it to the Menu Bar and drop it onto the File item of the Menu Bar.
03:30 Right-click jMenuItem1 in the Design view.
03:35 And choose Change Variable Name from the context menu.
03:41 Rename the item to Open and click OK.
03:48 Make sure that the jMenuItem1 is still selected in the Design view.
03:53 Press the Space bar to edit the text of the component.
03:58 Change the text to Open and press Enter to confirm.
04:04 Specify the action handler for the Open menu item.
04:08 Right-click the menu item Open and choose Events, Action, Action Performed from the context menu.
04:20 The GUI builder automatically switches to the source view.
04:25 A new event handler method OpenActionPerformed() is generated.
04:31 Let us switch back to the Design view.
04:35 Let's add a menu item to exit the File Chooser.
04:39 In the Palette , choose the Swing Menus category.
04:45 Select Menu Item.
04:48 Drag it to the Menu Bar below the Open menu item on the form.
04:53 Notice the orange highlighting that indicates where the jmenuItem1 is going to be placed.
05:03 Right-click jMenuItem1 in the Design view.
05:07 Choose Change Variable Name from the context menu.
05:12 Rename the item to Exit and click on OK.
05:20 Make sure that the jMenuItem1 is still selected in the Design view.
05:25 Press the Space bar to edit the text of the component.
05:30 Change the text to Exit and press Enter to confirm.
05:36 Specify the action handler for the Exit menu item.
05:41 Right-click the menu-item Exit.
05:44 Choose Events, Action, Action Performed from the context menu.
05:51 The GUI Builder automatically switches to the Source view.
05:56 A new event handler method named ExitActionPerformed() is generated.
06:02 The ExitActionPerformed node appears in the Navigator window above the OpenActionPerformed() node.
06:12 If you cannot view your Navigator,
06:14 go to the Window menu in the menu bar,
06:18 choose Navigating and click on Navigator.
06:25 Here, you can see the ExitActionPerformed node appearing above the OpenActionPerformed node.
06:33 To make the Exit menu-item work,
06:36 let us include the statement System.exit(0); into the ExitActionPerformed() method body.
06:47 Switch back to the Design mode.
06:50 From the Swing Controls category of the Palette, drag a Text Area onto the form.
07:06 Resize the added component to make room for the text, displayed by the File Chooser later.
07:18 Rename the variable as "textarea".
07:26 Let us next add the actual File Chooser.
07:31 If your Navigator window is not open, choose Window, Navigating, a Navigator to open it.
07:38 And in the Navigator, right-click the Jframe node.
07:44 Choose Add From Palette, Swing Windows and File Chooser from the context menu.
07:54 You can notice in the Navigator that a JFileChooser was added to the form.
08:01 Right-click the JFileChooser node and rename the variable to fileChooser.
08:16 Click OK.
08:19 We have now added the File Chooser.
08:21 The next step is to configure the File Chooser to display the title that you want.
08:27 We will also add a custom file filter and integrate the File Chooser into your application.
08:34 Click to select the JfileChooser in the Navigator window.
08:38 Now, let's edit its properties in the Properties dialog-box.
08:43 In the Properties window, below the Palette,
08:47 change the dialogTitle to "This is my open dialog".
09:00 Press Enter to confirm.
09:03 Now, switch to the Source mode.
09:07 Now, to integrate the FileChooser into your application,
09:12 I have an existing code snippet which I will copy and paste into the existing OpenActionPerformed() method.
09:20 This example reads the file contents and displays them in the Text Area.
09:27 We will now call the FileChooser's getSelectedFile() method to determine which file the user has clicked.
09:36 I will copy this code onto my clipboard and in the Source view of the IDE, paste it inside the OpenActionPerformed() method.
09:51 If the editor reports errors in your code, right-click anywhere in the code and select Fix Imports.
10:00 Now, let us add a custom file filter that makes the File Chooser display only '.txt' files.
10:09 Switch to the Design mode and select the fileChooser in the Navigator window.
10:16 In the Properties window, click the ellipsis button, next to the fileFilter property.
10:25 In the fileFilter dialog-box, select Custom Code from the combo-box.
10:31 Type new MyCustomFilter() in the text field
10:41 and click OK.
10:44 To make the custom code work, we will write the MyCustomFilter class.
10:52 This inner or outer class will extend the fileFilter class.
10:57 I will copy and paste this code snippet
11:04 into the source of our class, below the import statements.
11:11 This inner or outer class will extend the fileFilter class.
11:20 Right-click the JFileChooserDemo project in the Project window and select Run to start the sample project.
11:31 In the Run Project dialog-box, select the jfilechooserdemo.resources.JFileChooserDemo main class.
11:41 Click OK.
11:47 In the running Demo Application, choose Open in the File menu to trigger the action.
11:55 Open any text file to display its contents in the text area.
12:00 Let me select the Sample.txt file and choose Open.
12:06 The fileChooser displays the contents of the text file.
12:10 To close the application, select Exit in the File Menu.
12:17 In this tutorial, you learnt to:
12:19 Add a File chooser to a Java application and
12:23 Configure the File chooser.
12:27 As an assignment- use the same demo project we have created and add the following features:
12:35 Add a Save menu item under the menu bar.
12:38 Add keyboard short-cuts for all the menu items.
12:42 Add a code snippet to the Save action, to save the file.
12:51 I have already created a similar assignment where the file chooser displays the Save option under the File menu
13:01 and gives you the option to save the text file which you open.
13:09 About the Spoken tutorial project:
13:12 Watch the video available at the link shown on the screen.
13:15 It summarizes the Spoken Tutorial project.
13:19 If you do not have good bandwidth, you can download and watch it.
13:24 The Spoken Tutorial project team: * conducts workshops using Spoken Tutorials.
13:30 Gives certificates to those who pass an online test.
13:33 For more details, please write to:contact@spoken-tutorial.org
13:41 Spoken Tutorial project is a part of the Talk to a Teacher project.
13:46 It is supported by the National Mission on education through ICT, MHRD, Government of India.
13:53 More information on this mission is available at the link provided here.
13:59 This tutorial has been contributed by IT for Change.
14:04 Thank you for joining us.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Sandhya.np14