Implements state template

Author: LBeghini

README.md

@@ -1,90 +1,39 @@
 # ☕ Java Design Patterns
 
-## About
+## State
 
-This application is a simple Java Console Application that aims to implement design pattern examples to a Programmin Language Class. A set of design patterns will be developed
-each week, and they are divided in different [branches](https://github.com/LBeghini/Java-Design-Patterns/branches).  
+State pattern is used when you need to control the state of an object.
 
-The main branch is just a template for every other branch.
+For example, if we want to create a keep track of the state of a music, that follows the diagram:
 
-Also, to make it easier to download the source code, [releases](https://github.com/LBeghini/Java-Design-Patterns/releases) are created related to the task of the week, giving a snapshot of the code for that specific implementation.
+<img src="./resources/StateDiagram.png" width="300px" />
 
-## Implemented design patterns
+we would implement a class like below:
 
-### Behavioural patterns
+```java
+public class Music {
+    private String title;
+    private String artist;
+    private MusicState state;
 
-- [ ] Chain of responsability
-- [ ] Command
-- [ ] Iterator
-- [ ] Memento
-- [ ] Observer
-- [ ] State
-- [ ] Strategy
-- [ ] Template method
-
-### Creational patterns
-
-- [ ] Abstract factory
-- [x] [Builder](https://github.com/LBeghini/Java-Design-Patterns/tree/1-builder)
-- [x] [Factory method](https://github.com/LBeghini/Java-Design-Patterns/tree/2-factory-method)
-- [x] [Prototype](https://github.com/LBeghini/Java-Design-Patterns/tree/2-prototype)
-- [x] [Singleton](https://github.com/LBeghini/Java-Design-Patterns/tree/1-singleton)
-
-### Structural patterns
-
-- [ ] Adapter
-- [ ] Bridge
-- [ ] Composite
-- [ ] Decorator
-- [ ] Facade
-- [ ] Flyweight
-- [ ] Mediator
-- [ ] Proxy
-
-## Technologies
-
-- Java
-- JUnit
-- Maven
-
-## Requirements 
-
-To run and edit the project, be sure to have installed in your computer the following softwares:
-- A code editor
-
-After that, you'll need to clone this repo:
-
-```bash
-git clone https://github.com/LBeghini/Java-Design-Patterns.git
-```
-
-## Change branch
-
-To change to a different branch, run the command:
-
-```bash
-git checkout name-of-the-branch
+    // constructor, getters and setters were ommited for simplification
+}
 ```
 
-The branch names have the pattern:
-
-```bash
-{number-of-the-week}-{pattern-name}
-```
+and create a MusicState interface:
 
-> `number-of-the-week` corresponds to the week asked to be implemented certain pattern 
+```java
+public interface MusicState {
 
-## Testing
+    String getState();
 
-This project has no aim to run any of the implemented classes, as the goal is the code itself. However, the classes will be tested to visualize the behaviour and implementation 
-of the patterns.  
+    String play(Music music);
 
-You can run the tests using the maven wrapper:
+    String pause(Music music);
 
-```bash
-./mvnw test 
-```
+    String skip(Music music);
 
-## :balance_scale: License
+    String stop(Music music);
+}
 
-[MIT License](https://github.com/LBeghini/Java-Design-Patterns/blob/main/LICENSE)
+```

resources/StateDiagram.png

@@ -0,0 +1,40 @@
+package com.language.programming.model;
+
+import com.language.programming.model.states.Play;
+
+public class Music {
+    private String title;
+    private String artist;
+    private MusicState state;
+
+    public Music(String title, String artist) {
+        this.title = title;
+        this.artist = artist;
+        this.state = Play.getInstance();
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getArtist() {
+        return artist;
+    }
+
+    public void setArtist(String artist) {
+        this.artist = artist;
+    }
+
+    public MusicState getState() {
+        return state;
+    }
+
+    public void setArtist(MusicState state) {
+        this.state = state;
+    }
+
+}

src/main/java/com/language/programming/model/Music.java

@@ -0,0 +1,14 @@
+package com.language.programming.model;
+
+public interface MusicState {
+
+    String getState();
+
+    String play(Music music);
+
+    String pause(Music music);
+
+    String skip(Music music);
+
+    String stop(Music music);
+}

src/main/java/com/language/programming/model/MusicState.java

@@ -0,0 +1,43 @@
+package com.language.programming.model.states;
+
+import com.language.programming.model.Music;
+import com.language.programming.model.MusicState;
+
+public class Pause implements MusicState {
+
+    private static Pause instance = new Pause();
+
+    public static Pause getInstance() {
+        return instance;
+    }
+
+    @Override
+    public String getState() {
+        return "⏸";
+    }
+
+    @Override
+    public String play(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String pause(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String skip(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String stop(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}

src/main/java/com/language/programming/model/states/Pause.java

@@ -0,0 +1,43 @@
+package com.language.programming.model.states;
+
+import com.language.programming.model.Music;
+import com.language.programming.model.MusicState;
+
+public class Play implements MusicState {
+
+    private static Play instance = new Play();
+
+    public static Play getInstance() {
+        return instance;
+    }
+
+    @Override
+    public String getState() {
+        return "▶️";
+    }
+
+    @Override
+    public String play(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String pause(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String skip(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String stop(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}

src/main/java/com/language/programming/model/states/Play.java

@@ -0,0 +1,43 @@
+package com.language.programming.model.states;
+
+import com.language.programming.model.Music;
+import com.language.programming.model.MusicState;
+
+public class Skip implements MusicState {
+
+    private static Skip instance = new Skip();
+
+    public static Skip getInstance() {
+        return instance;
+    }
+
+    @Override
+    public String getState() {
+        return "⏭️";
+    }
+
+    @Override
+    public String play(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String pause(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String skip(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String stop(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}

src/main/java/com/language/programming/model/states/Skip.java

@@ -0,0 +1,43 @@
+package com.language.programming.model.states;
+
+import com.language.programming.model.Music;
+import com.language.programming.model.MusicState;
+
+public class Stop implements MusicState {
+
+    private static Stop instance = new Stop();
+
+    public static Stop getInstance() {
+        return instance;
+    }
+
+    @Override
+    public String getState() {
+        return "⏹️";
+    }
+
+    @Override
+    public String play(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String pause(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String skip(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public String stop(Music music) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}