옵저버 패턴 연습

design_pattern/src/main/java/honggi/Clipboard.java

@@ -0,0 +1,13 @@
+package honggi;
+
+public class Clipboard {
+    private String text = "";
+
+    public String getText() {
+        return text;
+    }
+
+    public void setText(String text) {
+        this.text = text;
+    }
+}

design_pattern/src/main/java/honggi/CopySubscriber.java

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+package honggi;
+
+public class CopySubscriber implements KeyboardSubscriber {
+
+    private final Clipboard clipboard;
+
+    public CopySubscriber(Clipboard clipboard) {
+        this.clipboard = clipboard;
+    }
+
+    @Override
+    public void onKeyClick(String keyCode, boolean isCtrlDown, String selected) {
+        if (isCtrlDown && keyCode.equals("c")) {
+            clipboard.setText(selected);
+            System.out.println("클립보드에 내용이 복사되었습니다.");
+        }
+    }
+}

design_pattern/src/main/java/honggi/KeyboardPublisher.java

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+package honggi;
+
+import java.util.ArrayList;
+
+/**
+ * 키보드 입력을 관리합니다.
+ */
+public class KeyboardPublisher {
+
+    private ArrayList<KeyboardSubscriber> subscribers = new ArrayList<>();
+    public void addSubscriber(KeyboardSubscriber subscriber) {
+        // 구독되어 있지 않다면 구독 추가
+        if (!subscribers.contains(subscriber)) subscribers.add(subscriber);
+    }
+    public void removeSubscriber(KeyboardSubscriber subscriber) {
+        subscribers.remove(subscriber);
+    }
+
+    // 클릭 발생
+    public void click(String keyCode, boolean isCtrlDown, String selected) {
+        for (KeyboardSubscriber subscriber : subscribers) {
+            subscriber.onKeyClick(keyCode, isCtrlDown, selected);
+        }
+    }
+}

design_pattern/src/main/java/honggi/KeyboardSubscriber.java

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+package honggi;
+
+public interface KeyboardSubscriber {
+    void onKeyClick(String keyCode, boolean isCtrlDown, String selected);
+}

design_pattern/src/main/java/honggi/MuteSubscriber.java

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+package honggi;
+
+/**
+ * 동영상을 음소거하거나 음소거를 해제합니다.
+ */
+public class MuteSubscriber implements KeyboardSubscriber {
+
+    private boolean isMuted = false;
+
+    @Override
+    public void onKeyClick(String keyCode, boolean isCtrlDown, String selected) {
+        if (!isCtrlDown && keyCode.equals("m")) {
+            if (isMuted)
+                System.out.println("동영상 음소거가 해제되었습니다.");
+            else
+                System.out.println("동영상이 음소거되었습니다.");
+
+            isMuted = !isMuted;
+        }
+    }
+}

design_pattern/src/main/java/honggi/PasteSubscriber.java

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+package honggi;
+
+public class PasteSubscriber implements KeyboardSubscriber {
+
+    private final Clipboard clipboard;
+
+    public PasteSubscriber(Clipboard clipboard) {
+        this.clipboard = clipboard;
+    }
+
+    @Override
+    public void onKeyClick(String keyCode, boolean isCtrlDown, String selected) {
+        if (isCtrlDown && keyCode.equals("v")) {
+            System.out.println("클립보드 내용(" + clipboard.getText() + ")을 붙여넣었습니다.");
+        }
+    }
+}