Netbeans/C2/Handling-Images-in-a-Java-GUI-Application/English-timed
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Revision as of 12:20, 10 July 2014 by Pratik kamble (Talk | contribs)
| Time | Narration |
| 00:01 | Hii everyone. |
| 00:02 | Welcome to this tutorial on Handling Images in a Java GUI Application using Netbeans IDE. |
| 00:10 | We assume that you have the basic working knowledge of Netbeans. |
| 00:15 | We also assume that you know to place text fields, buttons, menus, etc. on a JFrame form. |
| 00:22 | If not, then please visit the Spoken Tutorial website for relevant tutorials on Netbeans. |
| 00:29 | In this tutorial, we will learn in detail about handling images |
| 00:34 | And perform actions on them, in a sample GUI application.
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| 00:39 | For this demonstration, I am using the Linux Operating System Ubuntu v11.04 and Netbeans IDE v7.1.1 |
| 00:52 | The standard way to handle and access images in a Java Application is by using the getResource() method. |
| 00:59 | We will learn how to use the IDE's GUI Builder to generate the code to include images in your application, |
| 01:07 | and create a simple Jframe with one Jlabel displaying an image.
|
| 01:13 | In this tutorial, we will - |
| 01:15 | Create the application form
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| 01:18 | Add a package for the image
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| 01:20 | Display the image on the Label
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| 01:22 | Create mouse-events and pop-ups |
| 01:25 | Build and run the application |
| 01:28 | Now let us switch to the IDE to create our sample application.
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| 01:33 | From the File menu, choose New Project.
|
| 01:37 | Under Categories , select Java, under Projects select Java Application and click Next. |
| 01:46 | In the Project Name field, type ImageDisplayApp.
|
| 01:54 | Clear the Create Main Class checkbox.
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| 01:58 | Make sure that the Set as Main Project checkbox is selected. |
| 02:03 | Click Finish. The project is created in your IDE. |
| 02:08 | In this section, we will create the Jframe form and add a Jlabel to the form.
|
| 02:14 | Let us first create the Jframe form. |
| 02:17 | In the Projects window, expand the ImageDisplayApp node. |
| 02:23 | Right-click on the Source Packages node and choose New, Jframe form. |
| 02:30 | In the Class Name field, type ImageDisplay. |
| 02:37 | In the Package field, type org.me.myimageapp. |
| 02:45 | And Click Finish. |
| 02:48 | Now let us add the Jlabel. |
| 02:52 | In the Palette, on the right hand side of the IDE, select the Label component and drag it to the Jframe. |
| 03:01 | For now, your form should look something like this.
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| 03:06 | When you use images or other resources in an application, typically you create a separate Java package for the resource.
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| 03:15 | On your local file system, a package corresponds with a folder.
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| 03:19 | In the Projects window, right-click the org.me.myimageapp node and choose New > Java Package.
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| 03:30 | In the New Package Wizard, add .resources to org.me.myimageapp.
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| 03:40 | So the new package is now called org.me.myimageapp.resources.
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| 03:47 | Click Finish.
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| 03:49 | In the Projects window, you should see the image appear within the org.me.myimageapp.resources package, when you add the image.
|
| 03:59 | In this application, the image will be embedded within a Jlabel component.
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| 04:04 | Let us now add the image to the label. |
| 04:08 | In the GUI designer, select the label that you have added to your form.
|
| 04:14 | In the Properties window, below the palette, on the right hand side of the window, scroll to the Icon property.
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| 04:23 | Click the ellipsis (...) or the three dots on the right side.
|
| 04:30 | In the Icon Property dialog box, click Import to Project. |
| 04:34 | In the file chooser, navigate to the folder that contains your image that you want to use. |
| 04:42 | Click Next. |
| 04:45 | In the Select Target Folder page of the wizard, select the Resources folder. |
| 04:49 | And click Finish. |
| 04:52 | After you click Finish, the IDE copies the image to your project. |
| 04:57 | Therefore, when you build and run the application, the image is included in the distributable JAR file.
|
| 05:07 | Click OK here. |
| 05:11 | And right click on your project node and select Clean and Build option. |
| 05:18 | You can now go to the Files menu, and under the build folder, |
| 05:29 | under dist folder, you can see the jar file. |
| 05:33 | It generates the code in the imagedisplay class to access the image. |
| 05:38 | It also displays your image on the label in the Design view of your form. |
| 05:43 | At this point, you can do some simple things to improve the appearance of the form.
|
| 05:48 | In the Properties window, select the Text property |
| 05:56 | and delete jLabel1.
|
| 06:04 | That value was generated by the GUI Builder as display text for the label. |
| 06:10 | However, you are using the label to display an image rather than text.
|
| 06:15 | So this text is not needed.
|
| 06:18 | Now let us drag the label to center it on the form. |
| 06:26 | In the GUI Designer, click the Source tab.
|
| 06:30 | Scroll down to the line that says Generated Code. |
| 06:33 | And click the plus sign (+) to the left of the Generated Code line to display the code that the GUI Designer has generated. |
| 06:42 | Here, the keyline is this.
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| 06:49 | Since you have used the Property editor for jLabel1s icon property, the IDE has generated the setIcon method. |
| 06:57 | The parameter of that method contains a call to the getResource() method on an anonymous inner class of ImageIcon. |
| 07:10 | Once your image has been added, in the Design view right-click on the image.
|
| 07:19 | Click on Events > Mouse > mouseClicked. |
| 07:24 | The view is switched to the Source mode. |
| 07:28 | Here you can add the code to customize your action on a mouse click. |
| 07:33 | Let me add a few lines of code to generate a pop-up when the image is clicked in the GUI.
|
| 08:00 | I have now entered a few lines of code to generate the pop-up.
|
| 08:05 | First I have created a new Jframe for the pop-up.
|
| 08:12 | And I have set the default close operation.
|
| 08:15 | And finally provided the text for the pop-up. |
| 08:24 | After adding these lines of code, let us import the necessary packages by adding two statements at the beginning of the file. |
| 08:36 | Include: import javax.swing.*;
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| 08:45 | and import java.awt.*;
|
| 08:53 | This will import the necessary packages required for this program. |
| 08:59 | Let us now build and run the application. |
| 09:02 | We have generated the code for accessing and displaying the image.
|
| 09:07 | Let us build and run the application to ensure that the image is accessed.
|
| 09:12 | First, we need to set the project's Main class. |
| 09:16 | When you set the Main class, the IDE knows which class to run when you run the project. |
| 09:21 | In addition, this ensures that the Main class element in the application's JAR file is generated when you build the application. |
| 09:33 | Here right-click on the ImageDisplayApp project's Node in the Projects window, and choose Properties. |
| 09:41 | In the Project Properties dialog box, select the Run category on the left side. |
| 09:47 | Click the Browse button, that is next to the Main Class field. |
| 09:51 | Select org.me.myimageapp.ImageDisplay and click on Select Main Class |
| 10:01 | Say OK here. |
| 10:05 | Now right-click on the Project node, and select Clean & Build. |
| 10:11 | You can view the Build properties of the application in the Files window. |
| 10:20 | The Build folder contains the compiled class. |
| 10:23 | The dist folder contains an executable JAR file that contains the compiled class and the image. |
| 10:32 | Now choose Run from the tool bar. |
| 10:34 | Our output window opens with the image. |
| 10:39 | I will click on this image now. |
| 10:42 | And you can see the pop-up at the top, which shows the description of the image. |
| 10:50 | Now, time for the assignment! |
| 10:54 | Create another GUI with four images, similar to the demonstration shown in this tutorial, |
| 11:01 | For each of the image, specify different events such as keyboard event, mouse-motion event, mouse-click event, mouse-wheel event . |
| 11:12 | I have already created the assignment. |
| 11:17 | Let us run the assignment project. |
| 11:20 | Your assignment should look similar to this.
|
| 11:26 | I have created keyboard-events and mouse events for my assignment here. |
| 11:34 | So, to summarize, |
| 11:36 | we have, created a Jframe form |
| 11:39 | added a package for the image |
| 11:41 | displayed the image on the label |
| 11:44 | and also created mouse events and pop-ups
|
| 11:49 | Watch the video available at the link shown on the screen. |
| 11:53 | It summarizes the Spoken Tutorial project. |
| 11:56 | If you do not have good bandwidth, you can download and watch it. |
| 12:02 | The Spoken Tutorial project team conduct workshops using Spoken Tutorials.
|
| 12:07 | Gives certificates to those who pass an online test.
|
| 12:11 | For more details please write to contact@spoken-tutorial.org
|
| 12:19 | Spoken Tutorial Project is a part of the Talk to a Teacher Project |
| 12:23 | It is Supported by the National Mission on education through ICT, MHRD, Government of India |
| 12:30 | More information on this mission is available at spoken-tutorial.org/NMEICT-Intro |
| 12:42 | This tutorial has been contributed by IT for Change
|
| 12:46 | Thank you for joining us. |