Data commit

Task/Window-management/Java/window-management.java

@@ -0,0 +1,191 @@
+import java.awt.BorderLayout;
+import java.awt.EventQueue;
+import java.awt.Frame;
+import java.awt.GridLayout;
+import java.awt.event.ActionEvent;
+import java.lang.reflect.InvocationTargetException;
+import javax.swing.AbstractAction;
+import javax.swing.JButton;
+import javax.swing.JComboBox;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.JOptionPane;
+import javax.swing.JPanel;
+import javax.swing.border.EmptyBorder;
+
+public class WindowController extends JFrame {
+   // Create UI on correct thread
+   public static void main( final String[] args ) {
+      EventQueue.invokeLater( () -> new WindowController() );
+   }
+
+   private JComboBox<ControlledWindow> list;
+
+   // Button class to call the right method
+   private class ControlButton extends JButton {
+      private ControlButton( final String name ) {
+         super(
+            new AbstractAction( name ) {
+               public void actionPerformed( final ActionEvent e ) {
+                  try {
+                     WindowController.class.getMethod( "do" + name )
+                        .invoke ( WindowController.this );
+                  } catch ( final Exception x ) { // poor practice
+                     x.printStackTrace();        // also poor practice
+                  }
+               }
+            }
+         );
+      }
+   }
+
+   // UI for controlling windows
+   public WindowController() {
+      super( "Controller" );
+
+      final JPanel main = new JPanel();
+      final JPanel controls = new JPanel();
+
+      setLocationByPlatform( true );
+      setResizable( false );
+      setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
+      setLayout( new BorderLayout( 3, 3 ) );
+      getRootPane().setBorder( new EmptyBorder( 3, 3, 3, 3 ) );
+      add( new JLabel( "Add windows and control them." ), BorderLayout.NORTH );
+      main.add( list = new JComboBox<>() );
+      add( main, BorderLayout.CENTER );
+      controls.setLayout( new GridLayout( 0, 1, 3, 3 ) );
+      controls.add( new ControlButton( "Add"      ) );
+      controls.add( new ControlButton( "Hide"     ) );
+      controls.add( new ControlButton( "Show"     ) );
+      controls.add( new ControlButton( "Close"    ) );
+      controls.add( new ControlButton( "Maximise" ) );
+      controls.add( new ControlButton( "Minimise" ) );
+      controls.add( new ControlButton( "Move"     ) );
+      controls.add( new ControlButton( "Resize"   ) );
+      add( controls, BorderLayout.EAST );
+      pack();
+      setVisible( true );
+   }
+
+   // These are the windows we're controlling, but any JFrame would do
+   private static class ControlledWindow extends JFrame {
+      private int num;
+
+      public ControlledWindow( final int num ) {
+         super( Integer.toString( num ) );
+         this.num = num;
+         setLocationByPlatform( true );
+         getRootPane().setBorder( new EmptyBorder( 3, 3, 3, 3 ) );
+         setDefaultCloseOperation( JFrame.DISPOSE_ON_CLOSE );
+         add( new JLabel( "I am window " + num + ". Use the controller to control me." ) );
+         pack();
+         setVisible( true );
+      }
+
+      public String toString() {
+         return "Window " + num;
+      }
+   }
+
+   // Here comes the useful bit - window control code
+   // Everything else was just to allow us to do this!
+
+   public void doAdd() {
+      list.addItem( new ControlledWindow( list.getItemCount () + 1 ) );
+      pack();
+   }
+
+   public void doHide() {
+      final JFrame window = getWindow();
+      if ( null == window ) {
+         return;
+      }
+      window.setVisible( false );
+   }
+
+   public void doShow() {
+      final JFrame window = getWindow();
+      if ( null == window ) {
+         return;
+      }
+      window.setVisible( true );
+   }
+
+   public void doClose() {
+      final JFrame window = getWindow();
+      if ( null == window ) {
+         return;
+      }
+      window.dispose();
+   }
+
+   public void doMinimise() {
+      final JFrame window = getWindow();
+      if ( null == window ) {
+         return;
+      }
+      window.setState( Frame.ICONIFIED );
+   }
+
+   public void doMaximise() {
+      final JFrame window = getWindow();
+      if ( null == window ) {
+         return;
+      }
+      window.setExtendedState( Frame.MAXIMIZED_BOTH );
+   }
+
+   public void doMove() {
+      final JFrame window = getWindow();
+      if ( null == window ) {
+         return;
+      }
+      final int hPos = getInt( "Horizontal position?" );
+      if ( -1 == hPos ) {
+         return;
+      }
+      final int vPos = getInt( "Vertical position?" );
+      if ( -1 == vPos ) {
+         return;
+      }
+      window.setLocation ( hPos, vPos );
+   }
+
+   public void doResize() {
+      final JFrame window = getWindow();
+      if ( null == window ) {
+         return;
+      }
+      final int width = getInt( "Width?" );
+      if ( -1 == width ) {
+         return;
+      }
+      final int height = getInt( "Height?" );
+      if ( -1 == height ) {
+         return;
+      }
+      window.setBounds ( window.getX(), window.getY(), width, height );
+   }
+
+   private JFrame getWindow() {
+      final JFrame window = ( JFrame ) list.getSelectedItem();
+      if ( null == window ) {
+         JOptionPane.showMessageDialog( this, "Add a window first" );
+      }
+      return window;
+   }
+
+   private int getInt(final String prompt) {
+      final String s = JOptionPane.showInputDialog( prompt );
+      if ( null == s ) {
+         return -1;
+      }
+      try {
+         return Integer.parseInt( s );
+      } catch ( final NumberFormatException x ) {
+         JOptionPane.showMessageDialog( this, "Not a number" );
+         return -1;
+      }
+   }
+}