Java by API/java.awt/Container

Container: addPropertyChangeListener(PropertyChangeListener listener)

   <source lang="java">
 

import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; import java.io.File; import javax.swing.JFileChooser; public class Main {

 public static void main(String[] argv) throws Exception {
   JFileChooser chooser = new JFileChooser();
   chooser.addPropertyChangeListener(new PropertyChangeListener() {
     public void propertyChange(PropertyChangeEvent evt) {
       if (JFileChooser.SELECTED_FILE_CHANGED_PROPERTY.equals(evt.getPropertyName())) {
         JFileChooser chooser = (JFileChooser) evt.getSource();
         File oldFile = (File) evt.getOldValue();
         File newFile = (File) evt.getNewValue();
         
         File curFile = chooser.getSelectedFile();
       }       
     }
   });
 }

}

 </source>
   
  
 
  

Container: getComponentCount()

   <source lang="java">
 

import java.awt.ruponent; import java.awt.ruponentOrientation; import java.awt.Container; import java.awt.FlowLayout; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JMenu; public class MainClass extends JFrame {

 public MainClass() {
   super("MainClass");
   Container contentPane = getContentPane();
   contentPane.setLayout(new FlowLayout());
   contentPane.add(new JButton("OK"));
   contentPane.add(new JButton("Cancel"));
   applyOrientation(this, ComponentOrientation.RIGHT_TO_LEFT);
 }
 public static void main(String[] argv) {
   JFrame frame = new MainClass();
   frame.addWindowListener(new WindowAdapter() {
     public void windowClosing(WindowEvent e) {
       System.exit(0);
     }
   });
   frame.pack();
   frame.setVisible(true);
 }
 private void applyOrientation(Component c, ComponentOrientation o) {
   c.setComponentOrientation(o);
   if (c instanceof JMenu) {
     JMenu menu = (JMenu) c;
     int ncomponents = menu.getMenuComponentCount();
     for (int i = 0; i < ncomponents; ++i) {
       applyOrientation(menu.getMenuComponent(i), o);
     }
   } else if (c instanceof Container) {
     Container container = (Container) c;
     int ncomponents = container.getComponentCount();
     for (int i = 0; i < ncomponents; ++i) {
       applyOrientation(container.getComponent(i), o);
     }
   }
 }

}

 </source>
   
  
 
  

Container: getFocusTraversalPolicy()

   <source lang="java">
 

import java.awt.ruponent; import java.awt.Container; import java.awt.FlowLayout; import java.awt.FocusTraversalPolicy; import java.awt.KeyboardFocusManager; import javax.swing.JButton; import javax.swing.JFrame; public class Main {

 public static void main(String[] argv) {
   JFrame frame = new JFrame();
   JButton component1 = new JButton("1");
   JButton component2 = new JButton("2");
   JButton component3 = new JButton("3");
   frame.setLayout(new FlowLayout());
   frame.add(component1);
   frame.add(component2);
   frame.add(component3);
   frame.pack();
   frame.setVisible(true);
   System.out.println(findNextFocus().getName());
 }
 public static Component findNextFocus() {
   Component c = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
   Container root = c.getFocusCycleRootAncestor();
   FocusTraversalPolicy policy = root.getFocusTraversalPolicy();
   Component nextFocus = policy.getComponentAfter(root, c);
   if (nextFocus == null) {
     nextFocus = policy.getDefaultComponent(root);
   }
   return nextFocus;
 }

}

 </source>
   
  
 
  

Container: setFocusTraversalPolicy(FocusTraversalPolicy policy)

   <source lang="java">
 

import java.awt.ruponent; import java.awt.Container; import java.awt.FocusTraversalPolicy; import java.awt.GridLayout; import java.util.Arrays; import java.util.ruparator; import java.util.List; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.SortingFocusTraversalPolicy; public class Main {

 public static void main(String args[]) {
   JFrame frame = new JFrame("Reverse Sample");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.setLayout(new GridLayout(3, 3));
   for (int i = 0; i < 9; i++) {
     JButton button = new JButton(Integer.toString(i));
     frame.add(button);
   }
   final Container contentPane = frame.getContentPane();
   Comparator<Component> comp = new Comparator<Component>() {
     public int compare(Component c1, Component c2) {
       Component comps[] = contentPane.getComponents();
       List list = Arrays.asList(comps);
       int first = list.indexOf(c1);
       int second = list.indexOf(c2);
       return second - first;
     }
   };
   FocusTraversalPolicy policy = new SortingFocusTraversalPolicy(comp);
   frame.setFocusTraversalPolicy(policy);
   frame.setSize(300, 200);
   frame.setVisible(true);
 }

}

 </source>