Data commit

Task/Animation/Java/animation.java

@@ -0,0 +1,61 @@
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+import java.util.Timer;
+import java.util.TimerTask;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.WindowConstants;
+
+public class Rotate {
+
+    private static class State {
+        private final String text = "Hello World! ";
+        private int startIndex = 0;
+        private boolean rotateRight = true;
+    }
+
+    public static void main(String[] args) {
+        State state = new State();
+
+        JLabel label = new JLabel(state.text);
+        label.addMouseListener(new MouseAdapter() {
+            @Override
+            public void mouseClicked(MouseEvent event) {
+                state.rotateRight = !state.rotateRight;
+            }
+        });
+
+        TimerTask task = new TimerTask() {
+            public void run() {
+                int delta = state.rotateRight ? 1 : -1;
+                state.startIndex = (state.startIndex + state.text.length() + delta) % state.text.length();
+                label.setText(rotate(state.text, state.startIndex));
+            }
+        };
+        Timer timer = new Timer(false);
+        timer.schedule(task, 0, 500);
+
+        JFrame rot = new JFrame();
+        rot.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
+        rot.add(label);
+        rot.pack();
+        rot.setLocationRelativeTo(null);
+        rot.addWindowListener(new WindowAdapter() {
+            @Override
+            public void windowClosed(WindowEvent e) {
+                timer.cancel();
+            }
+        });
+        rot.setVisible(true);
+    }
+
+    private static String rotate(String text, int startIdx) {
+        char[] rotated = new char[text.length()];
+        for (int i = 0; i < text.length(); i++) {
+            rotated[i] = text.charAt((i + startIdx) % text.length());
+        }
+        return String.valueOf(rotated);
+    }
+}