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1.å ã®Componentã¯ã©ã¹ãDecoratorã¯ã©ã¹ã«ãµãã¯ã©ã¹åããïŒUMLãã€ã¢ã°ã©ã ãåç §ïŒïŒ
2.Decorator ã¯ã©ã¹ã«ããã£ãŒã«ããšã㊠Component ãã€ã³ã¿ãŒãè¿œå ããŸãïŒ
3.Decoratorã¯ã©ã¹ã§ãDecoratorã³ã³ã¹ãã©ã¯ã¿ã«Componentãæž¡ããŠComponentãã€ã³ã¿ãåæåããïŒ
4.Decoratorã¯ã©ã¹ã§ããã¹ãŠã®Componentã¡ãœãããComponentãã€ã³ã¿ã«è»¢éããã
5.ConcreteDecoratorã¯ã©ã¹ã§ãåäœãå€æŽããå¿ èŠãããComponentã¡ãœããããªãŒããŒã©ã€ãããã
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Javaãš.NET Frameworkã®I/O Streamså®è£ ã¯ããã³ã¬ãŒã¿ãŒã»ãã¿ãŒã³ãåãå ¥ããŠããã
Adapterã¯ã€ã³ã¿ãŒãã§ãŒã¹ã®äºææ§ããDecoratorã¯åçãªè²¬åè¿œå ããStrategyã¯ã¢ã«ãŽãªãºã ã®æè»ãªåãæ¿ãããããããµããŒãããŸãã
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function run() {
var user = new User("Kelly");
user.say();
var decorated = new DecoratedUser(user, "Broadway", "New York");
decorated.say();
log.show();
}
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A decorator lets you change the skin of an object; a strategy lets you change the guts. These are two alternative ways ofãchanging an object.ãã³ã¬ãŒã¿ãŒã¯ãªããžã§ã¯ãã®è¡šå±€ãå€ãããã¹ãã©ããžã¯å èããããã
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Decorator ãã¿ãŒã³ã¯ãæ¢åã®ãªããžã§ã¯ãã«åçã«æ°ãã責任ãæ©èœãè¿œå ããããã®ãã¶ã€ã³ãã¿ãŒã³ã§ãã
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ååž°çãªçµåãšã¯ãDecorator ãã¿ãŒã³ã®ç¹åŸŽçãªæ§é ã§ããããã³ã¬ãŒã¿ãå¥ã®ãã³ã¬ãŒã¿ãåºæ¬ã®ã³ã³ããŒãã³ããã©ããã§ããããšãæå³ããŸããããã«ãããè€æ°ã®ãã³ã¬ãŒã¿ãé£éçã«çµã¿åãããããšã§ãåçã«ãªããžã§ã¯ãã®æ¯ãèãã責任ãã«ã¹ã¿ãã€ãºããããšãã§ããŸãã
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AdDecorator: ãããªã®åã«åºåãè¿œå ããŸãã
SubtitleDecorator: ãããªã«åå¹ãè¿œå ããŸãã
WatermarkDecorator: ãããªã«éãããè¿œå ããŸãã
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![](https://assets.st-note.com/img/1694825378944-igF0zNmO9T.png?width=1200)
Dot
digraph DecoratorPattern {
node [shape=record]
Component [label="{Component|+operation(): void}"]
ConcreteComponent [label="{ConcreteComponent|+operation(): void}"]
Decorator [label="{Decorator|+operation(): void\n+addedBehavior(): void}"]
ConcreteDecoratorA [label="{ConcreteDecoratorA|+operation(): void\n+addedBehavior(): void}"]
ConcreteDecoratorB [label="{ConcreteDecoratorB|+operation(): void\n+addedBehavior(): void}"]
Component -> ConcreteComponent [arrowhead="none"]
Component -> Decorator [arrowhead="none"]
Decorator -> ConcreteDecoratorA [arrowhead="none"]
Decorator -> ConcreteDecoratorB [arrowhead="none"]
Decorator -> Component [label="decorates" dir="back"]
{rank=same; ConcreteDecoratorA ConcreteDecoratorB}
}
![](https://assets.st-note.com/img/1715345161881-FQQs4NZKzX.png?width=1200)
![](https://assets.st-note.com/img/1717751205470-wtLHYzW8he.png?width=1200)
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