Netbeans/C2/Adding-a-File-Chooser/English-timed
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Revision as of 18:36, 7 June 2016 by Sandhya.np14 (Talk | contribs)
Time | Narration |
00:00 | Hello. |
00:01 | Welcome to the tutorial on Adding a File Chooser to a Java Application. |
00:07 | In this tutorial, we will: |
00:09 | * Create the application |
00:10 | * 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. |
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13:59 | This tutorial has been contributed by IT for Change. |
14:04 | Thank you for joining us. |