Differences

This shows you the differences between two versions of the page.

--- swing:jcheckbox [2018/03/23 11:29] – created gthanos
+++ swing:jcheckbox [Unknown date] (current) – external edit (Unknown date) 127.0.0.1
@@ Line 14: / Line 14: @@
  * geek-cg--.gif, ..., geek-cght.gif.
  */
-public class CheckBoxDemo extends JPanel
+public class CheckBoxDemo extends JPanel {
-              implements ItemListener {
   JCheckBox chinButton;
   JCheckBox glassesButton;
@@ Line 45: / Line 45: @@
     //Register a listener for the check boxes.
-    chinButton.addItemListener(this);
+    chinButton.addItemListener(itemListener);
-    glassesButton.addItemListener(this);
+    glassesButton.addItemListener(itemListener);
-    hairButton.addItemListener(this);
+    hairButton.addItemListener(itemListener);
-    teethButton.addItemListener(this);
+    teethButton.addItemListener(itemListener);
     //Indicates what's on the geek.
@@ Line 59: / Line 59: @@
     //Put the check boxes in a column in a panel
-    JPanel checkPanel = new JPanel(new GridLayout(0, 1));
+    JPanel checkBoxPanel = new JPanel(new GridLayout(0, 1));
-    checkPanel.add(chinButton);
+    checkBoxPanel.add(chinButton);
-    checkPanel.add(glassesButton);
+    checkBoxPanel.add(glassesButton);
-    checkPanel.add(hairButton);
+    checkBoxPanel.add(hairButton);
-    checkPanel.add(teethButton);
+    checkBoxPanel.add(teethButton);
-    add(checkPanel, BorderLayout.LINE_START);
+    add(checkBoxPanel, BorderLayout.LINE_START);
     add(pictureLabel, BorderLayout.CENTER);
     setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
   }
+  ItemListener itemListener = new ItemListener() {
-  /** Listens to the check boxes. */
+    /* Listens to the check boxes. */
-  public void itemStateChanged(ItemEvent e) {
+    public void itemStateChanged(ItemEvent e) {
-    int index = 0;
+      int index = 0;
-    char c = '-';
+      char c = '-';
-    Object source = e.getItemSelectable();
+      Object source = e.getItemSelectable();
-    if (source == chinButton) {
+      if (source == chinButton) {
-      index = 0;
+        index = 0;
-      c = 'c';
+        c = 'c';
-    } else if (source == glassesButton) {
+      } else if (source == glassesButton) {
-      index = 1;
+        index = 1;
-      c = 'g';
+        c = 'g';
-    } else if (source == hairButton) {
+      } else if (source == hairButton) {
-      index = 2;
+        index = 2;
-      c = 'h';
+        c = 'h';
-    } else if (source == teethButton) {
+      } else if (source == teethButton) {
-      index = 3;
+        index = 3;
-      c = 't';
+        c = 't';
-    }
+      }
-    //Now that we know which button was pushed, find out
+      //Now that we know which button was pushed, find out
-    //whether it was selected or deselected.
+      //whether it was selected or deselected.
-    if (e.getStateChange() == ItemEvent.DESELECTED) {
+      if (e.getStateChange() == ItemEvent.DESELECTED) {
-      c = '-';
+        c = '-';
-    }
+      }
-    //Apply the change to the string.
+      //Apply the change to the string.
-    choices.setCharAt(index, c);
+      choices.setCharAt(index, c);
-    updatePicture();
+      updatePicture();
-  }
+    }
+  };
   protected void updatePicture() {