corejava第10版

corejava第10版/v1ch12/comboBox/ComboBoxFrame.java

@@ -0,0 +1,51 @@
+package comboBox;
+
+import java.awt.BorderLayout;
+import java.awt.Font;
+
+import javax.swing.JComboBox;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.JPanel;
+
+/**
+ * A frame with a sample text label and a combo box for selecting font faces.
+ */
+public class ComboBoxFrame extends JFrame
+{
+   private JComboBox<String> faceCombo;
+   private JLabel label;
+   private static final int DEFAULT_SIZE = 24;
+
+   public ComboBoxFrame()
+   {
+      // add the sample text label
+
+      label = new JLabel("The quick brown fox jumps over the lazy dog.");
+      label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE));
+      add(label, BorderLayout.CENTER);
+
+      // make a combo box and add face names
+
+      faceCombo = new JComboBox<>();
+      faceCombo.addItem("Serif");
+      faceCombo.addItem("SansSerif");
+      faceCombo.addItem("Monospaced");
+      faceCombo.addItem("Dialog");
+      faceCombo.addItem("DialogInput");
+
+      // the combo box listener changes the label font to the selected face name
+
+      faceCombo.addActionListener(event ->
+         label.setFont(
+            new Font(faceCombo.getItemAt(faceCombo.getSelectedIndex()), 
+               Font.PLAIN, DEFAULT_SIZE)));
+
+      // add combo box to a panel at the frame's southern border
+
+      JPanel comboPanel = new JPanel();
+      comboPanel.add(faceCombo);
+      add(comboPanel, BorderLayout.SOUTH);
+      pack();
+   }
+}