More UI

Text directionality

• Swing components such as JLabel, JTextField and JTextArea are able to handle bi-directional text and display it correctly

• 
  
  import javax.swing.*;
  import java.awt.*;
  
  public class BiDi extends JFrame {
      
      public final static char RIGHT_TO_LEFT_EMBEDDING = '\u202B';
      public final static char RIGHT_TO_LEFT_OVERRIDE = '\u202E';
      public final static char POP_DIRECTIONAL_FORMATTING = '\u202C';
  
      /** This string is logically "abcDEFghi". But by overriding the
       * direction, it will appear as "abcFEDghi"
       */
      public static String bidiStr = "abc" + RIGHT_TO_LEFT_OVERRIDE + "DEF" +
  	POP_DIRECTIONAL_FORMATTING + "ghi";
  
      public static void main(String[] args) {
  	BiDi app = new BiDi();
  	app.pack();
  	app.setVisible(true);
      }
      
      public BiDi() {
  	Font font = new Font("Monospaced,", Font.PLAIN, 24);
  	Container content = getContentPane();
          content.setLayout(new GridLayout(3,1));
  
  	JLabel label = new JLabel(bidiStr);
  	label.setFont(font);
  	content.add(label);
  
  	JTextField textField = new JTextField(bidiStr);
  	textField.setFont(font);
  	content.add(textField);
  
  	JTextArea textArea = new JTextArea(bidiStr + '\n' + bidiStr + '\n' + bidiStr);
  	textArea.setFont(font);
  	content.add(textArea);
      }
  }
  

Component orientation

• Layouts such as menus and layout managers such as GridLayout use left-to-right by default
• These can be controlled by the ComponentOrientation class

• 
  
  import javax.swing.*;
  import java.awt.*;
  import java.util.Locale;
  
  public class Orientation extends JFrame {
      
      public final static char RIGHT_TO_LEFT_EMBEDDING = '\u202B';
      public final static char RIGHT_TO_LEFT_OVERRIDE = '\u202E';
      public final static char POP_DIRECTIONAL_FORMATTING = '\u202C';
  
      /** This string is logically "abcDEFghi". But by overriding the
       * direction, it will appear as "abcFEDghi"
       */
      public static String bidiStr = "abc" + RIGHT_TO_LEFT_OVERRIDE + "DEF" +
  	POP_DIRECTIONAL_FORMATTING + "ghi";
  
      public static void main(String[] args) {
  	Orientation app = new Orientation();
  	app.pack();
  	app.setVisible(true);
      }
      
      public Orientation() {
  	Font font = new Font("Monospaced,", Font.PLAIN, 24);
  
  	ComponentOrientation orientation = 
  	    ComponentOrientation.getOrientation(Locale.getDefault());
  
  	GridLayout layout = new GridLayout(1, 2);
  
  	Container content = getContentPane();
  	// GridLayout uses the orientation of its container
  	content.setComponentOrientation(orientation);
          content.setLayout(layout);
  
  	JLabel label = new JLabel(bidiStr);
  	label.setFont(font);
  	content.add(label);
  
  	JTextField textField = new JTextField(bidiStr);
  	textField.setFont(font);
  	content.add(textField);
      }
  }
  

• Run by e.g.

  java -Duser.language=ar -Duser.country=EG Orientation