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![BUILD A WINDOW
Import javax.swing.*;
public class Trigo extends JFrame{}
The first line simply import the package where the class is defined JFrame. A JFrame is
the class that represents the type "Window". In other words a "JFrame" is a Windows
operating system. As our class inherits (extends) the class JFrame, Wheat will therefore
also a JFrame is a window.
To check this add to our class a "main" method, now being as follows:
import javax.swing.*;
public class Trigo extends JFrame{
public static void main(String[] arg){
Trigo miAplicacion = new Trigo();
miAplicacion.setBounds(10,10,200,200);
miAplicacion.pack();
miAplicacion.setVisible(true);
}
}
All messages sent to the object "myapp" are methods inherited from "JFrame". The first
method "setBounds" sets the initial position of the window on the screen and its
dimensions. The second, "pack", at this time it was not really necessary because the
window is empty, but we wanted to include it to avoid having to modify the main later.
This method optimizes the arrangement of the elements within the window. And the last
message is simply to order the sale is made visible. After compiling and running the
code you see something like the screen shown in Figure 1.](https://image.slidesharecdn.com/ingles2doparcial-130121224412-phpapp02/75/Ingles-2do-parcial-6-2048.jpg)
Uploaded byHarry Ostaiza
Ingles 2do parcial
1) The document is a technical project for a partial second English project submitted by Harry Ostaiza to his teacher Dany Jarre from September 2012 to February 2013 about Swing and Java GUI components. 2) It introduces Swing as an improvement over AWT, describing some key Swing components like JPanel, JFrame, layout managers, and dialog boxes using JOptionPane. 3) It provides instructions on how to build basic windows with Swing using JFrames and setting layout managers like BorderLayout, FlowLayout, and GridLayout to position components.
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Ingles 2do parcial
- 1. TECHNICAL UNIVERSITY OFMANABI FACULTY OF COMPUTER ENGLISH PROJECT TOPIC: PARTIAL 2ND PROJECT ENGLISH NAME: HARRY OSTAIZA 3”C” TEACHER: DANY JARRE PERIOD: SEPTEMBER 2012-FEBRUAARY 2013
- 2. INTRODUCTION TO SWING Swingis one of the major improvements that have experienced the JDK in version 1.2 with respect to version 1.1, and represents the new generation of AWT. It is also one of the API of Basics Classes Java (JFC), which is the result of a collaborative effort between Sun large, Netscape, IBM and other companies. Swing what gives power its importance is offered to develop graphical user interfaces (GUI) for applets And applications. The quantity and quality of checks Swing GUI offering is unrivaled in any other toolkit controls GUI .the source Swing GUI that presents can find on Internet Basics Classes Netscape (IFC). Swing components beyond the IFC, to the extent that there is no significant similarity between the components of IFC Swing. Swing also offers the possibility of quickly and easily changes the look and feel (L & F) of a single component or component group. This possibility, known with aspect and feel Pluggable (PL & F), is a hallmark of Swing. Abstract Windows Toolkit (AWT) is the original toolkit Java. Its main advantages are that comes with each version of Java technology, including Java applications in old browsers, and is very stable. AWT is a very simple set of tools with few components with layout managers, and events. This is because Sun Microsystems decided to use the lowest common denominator (LCD) for AWT approach. The content of AWT: Object CheckboxGroup Component Button Canvas CheckBox Choice Container Panel Applet ScrollPane Window Dialog Frame Label List TextComponent TextArea
- 3.
- 4. SWING Java Swing, alsoknown as part of the Java Foundation Classes (JFC), was an attempt to solve most of the shortcomings of AWT. In Swing, Sun created a beautifully designed, flexible and powerful set of tools .Unfortunately, this means that Swing takes time to learn, and is sometimes too complex for common situations.Swing is built on AWT parts. All parts are also part of Swing AWT. Swing uses the AWT event model and support classes, such as colors, images and graphics. Swing components, layout managers, and events are summarized below. Object Component Container JComponent AbstractButton JButton JMenuItem JCheckBonMenuItem JMenu JRadioButonMenuItem JToggleButton JCheckBox JRadioButton Box Filler JColorChooser JComboBox JDesktopIcon JFileChooser JInternalFrame JLabel JLayeredPane JDesktopPane JList JMenuBar JOptionPane JPanel JPopupMenu JProgressBar JRootPane JScrollBar JScrollPane
- 5.
- 6. BUILD A WINDOW Importjavax.swing.*; public class Trigo extends JFrame{} The first line simply import the package where the class is defined JFrame. A JFrame is the class that represents the type "Window". In other words a "JFrame" is a Windows operating system. As our class inherits (extends) the class JFrame, Wheat will therefore also a JFrame is a window. To check this add to our class a "main" method, now being as follows: import javax.swing.*; public class Trigo extends JFrame{ public static void main(String[] arg){ Trigo miAplicacion = new Trigo(); miAplicacion.setBounds(10,10,200,200); miAplicacion.pack(); miAplicacion.setVisible(true); } } All messages sent to the object "myapp" are methods inherited from "JFrame". The first method "setBounds" sets the initial position of the window on the screen and its dimensions. The second, "pack", at this time it was not really necessary because the window is empty, but we wanted to include it to avoid having to modify the main later. This method optimizes the arrangement of the elements within the window. And the last message is simply to order the sale is made visible. After compiling and running the code you see something like the screen shown in Figure 1.
- 7. THE BORDERLAYOUT MANAGER Thesteps to set the BorderLayout manager are different from those used for the FlowLayout manager. 1. Create buttons (Button class objects) and the layout manager (BorderLayout class object) Button btnOeste = new Button(); BorderLayout borderLayout1 = new BorderLayout(); 2. Set its properties in init btnOeste.setFont(new Font("Dialog", 1, 16)); btn1.setLabel("Oeste"); Add the controls to the applet (or panel) using add, in the second argument indicating the position you occupy each panel control by static BorderLayout class. this.add (btnOeste, BorderLayout.WEST); FLOWLAYOUT MANAGER Controls are objects of the Button class, and the layout manager is an object of the class FlowLayout. Once initialized data members in member function init set their properties and add the applet using the add function, once established by the layout manager setLayout. The steps are as follows 1. Create buttons (Button class objects) and design manager (class object FlowLayout) Button btn1 = new Button (); FlowLayout1 = new FlowLayout FlowLayout (); 2. Set its properties in init
- 8. btn1.setFont (new Font("Dialog", 1, 16)); btn1.setLabel ("1"); flowLayout1.setHgap (20); 3. Set the applet's layout manager (or Blank) by setLayout this.setLayout (flowLayout1); 4. Add the controls to the applet (or panel) by add this.add (btn1, null); What has been said for a voucher for any panel applet as an applet is simply a specialized panel. GRIDLAYOUT The steps to set the GridLayout manager are identical to those we have used for determining lel FlowLayout manager. This manager controls available in a matrix form as shown in Fig. We have eight buttons arranged in two rows and four columns. JPANEL a JPanel object is a so-called "containers". This is because they serve to contain other objects. In this way, they act as "boxes" where are you getting them to handle things and so as a group. For example, if you group a series of buttons inside a JPanel and want to disable them all at once, you can disable the JPanel that contains all the contents and so is disabled. Or if you want to move them all at once, etc..
- 9. The containers arevery useful as they help to simplify things and structure them. Dialogs (JOptionPane) are "tools" very useful when entering data and display information; say useful because these do not need to create objects of type BufferedReader and "pull" more code to use correct data entered as I explained briefly in elanterior post. Among the JOptionPane entontraremos: showConfirmDialog, showInputDialog, showMessageDialog and showOptionDialog. The most used are the first three. SHOWMESSAGEDIALOG This dialog box is ideal for displaying information of any kind, this replaces the System.out.print () The syntax is: 1 JOptionPane.showMessageDialog (null, "Hello world!"); - As noted in the previous line, which goes inside the "..." is the message we want to show, for these messages can also be used to display messages concatenation and variables at once. - What you see when you run the application is: SHOWINPUTDIALOG This dialog box is ideal for data entry, you have to keep in mind that all that is received is taken as a string, but this is no problem to work with other data types, in which case you need to convert the string receives the type of data you need (int, float, double, etc.). The syntax is the following:
- 10. String x =JOptionPane.showInputDialog ("Enter a number:"); JOptionPane.showMessageDialog (null, "The number entered is:" + x); - In line 1 create a variable of type String which call "ax" in this variable I store the data that is entered with showInputDialog, like the showMessageDialog what goes into the "..." is the message that showed the user. - On line 2 show the data I got right through the variable x. - When running the application will see the following: SHOWCONFIRMDIALOG This dialog box is of type integer, so you have to create a variable of type int to handle this options dialog offers the above are yes, no, and cancel, the syntax is: int x = JOptionPane.showConfirmDialog (null, "You are in java?"); if (x == JOptionPane.YES_OPTION) JOptionPane.showMessageDialog (null, "You have chosen SI."); else if (x == JOptionPane.NO_OPTION) JOptionPane.showMessageDialog (null, "You have chosen NOT.");
- 11. - On line1 shows that create an integer variable, the null that comes before the message is necessary, as this is taken when the user presses the Esc key or press Cancel, the message to display is used as in the previous dialog boxes. - On lines 2 and 4 are used to make conditional respective shares according to the option that the user has given. - In lines 3 and 5 are shown for the respective message option that the user has given. If we select if we will see the following dialog box: If instead you select will not see the following dialog box: