March 2014 update

Task/GUI-component-interaction/Kotlin/gui-component-interaction.kotlin

@@ -0,0 +1,58 @@
+import java.awt.GridLayout
+import java.awt.event.ActionEvent
+import java.awt.event.ActionListener
+import java.awt.event.KeyEvent
+import java.awt.event.KeyListener
+
+import java.lang.Long // jet.Long doesn't suit our needs here
+import javax.swing.JButton
+import javax.swing.JFrame
+import javax.swing.JOptionPane
+import javax.swing.JPanel
+import javax.swing.JTextField
+
+class Interact : JFrame() {
+    val numberField = JTextField()
+    val incButton = JButton("Increment")
+    val randButton = JButton("Random")
+    val buttonPanel = JPanel();
+
+    {
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)
+        numberField setText "0"
+
+        numberField addKeyListener(object : KeyListener {
+            public override fun keyTyped(e : KeyEvent) : Unit =
+                if(!Character.isDigit(e.getKeyChar())) e.consume()
+            public override fun keyReleased(e : KeyEvent?) {}
+            public override fun keyPressed(e : KeyEvent) {}
+        });
+
+        incButton addActionListener(object : ActionListener {
+            public override fun actionPerformed(e : ActionEvent) {
+                val num = Long.parseLong(numberField.getText() ?: "")
+                numberField setText (num + 1).toString()
+            }
+        });
+
+        randButton addActionListener(object : ActionListener {
+            fun proceedOrNot() = JOptionPane.showConfirmDialog(randButton, "Are you sure?")
+            public override fun actionPerformed(e : ActionEvent) {
+                if(proceedOrNot() == JOptionPane.YES_OPTION)
+                    numberField setText Long.toString((Math.random() * Long.MAX_VALUE).toLong())
+            }
+        });
+
+        setLayout(GridLayout(2, 1))
+        buttonPanel setLayout GridLayout(1, 2)
+        buttonPanel add incButton
+        buttonPanel add randButton
+        add(numberField)
+        add(buttonPanel)
+        pack()
+    }
+}
+
+fun main(args : Array<String>) {
+    Interact() setVisible(true)
+}