sw_concepts: replace command example

topics/sw_concepts/images/command/command-bad-case.puml

@@ -0,0 +1,33 @@
+@startuml
+
+skinparam defaultFontSize 25
+
+together {
+    abstract class DarkThemeButton
+
+    class DarkDarkThemeButton
+
+    class LightDarkThemeButton
+
+    abstract class LightThemeButton
+
+    class DarkLightThemeButton
+
+    class LightLightThemeButton
+
+    DarkThemeButton <|.. DarkDarkThemeButton
+    DarkThemeButton <|.. LightDarkThemeButton
+
+    LightThemeButton <|.. DarkLightThemeButton
+    LightThemeButton <|.. LightLightThemeButton
+}
+
+class ThemeObservable {
+}
+
+DarkDarkThemeButton ---> ThemeObservable
+LightDarkThemeButton ---> ThemeObservable
+DarkLightThemeButton ---> ThemeObservable
+LightLightThemeButton ---> ThemeObservable
+
+@enduml

topics/sw_concepts/images/command/command-good-case.puml

@@ -0,0 +1,34 @@
+@startuml
+
+skinparam defaultFontSize 25
+
+together {
+    class DarkButton {
+        void setCommand(Command command)
+    }
+
+    class LightButton {
+        void setCommand(Command command)
+    }
+}
+
+together {
+    interface Command
+
+    class SetDarkThemeCommand
+
+    class SetLightThemeCommand
+
+    Command <|.. SetDarkThemeCommand
+    Command <|.. SetLightThemeCommand
+}
+
+class ThemeObservable
+
+DarkButton --> Command
+LightButton --> Command
+
+SetDarkThemeCommand ---> ThemeObservable
+SetLightThemeCommand ---> ThemeObservable
+
+@enduml

topics/sw_concepts/sw_concept_slides.md

@@ -546,7 +546,19 @@ Observer Beispiel: nachher
 Command
 -------
 
-<https://github.com/iluwatar/java-design-patterns/blob/master/command/README.md>
+* Use Case:
+  * Man möchte von einer Funktionalität das Wie vom Wann trennen.
+  * Man möchte die Klasse, die ein Kommando auslöst, von der Klasse, an der das Kommando ausgeführt wird, trennen.
+
+Command Beispiel: vorher
+-------
+
+![Observer bad case](images/command/command-bad-case.png)
+
+Command Beispiel: nachher
+-------
+
+![Observer good case](images/command/command-good-case.png){height=90%}
 
 Zusammenfassung Abstraktion
 ------