[Command] Added tv example and pattern notes

README.md

@@ -33,6 +33,7 @@ Composición de clases u objetos.
 
 Forma en que clases las u objetos interaccionan y distribuyen funcionalidades.
 
+* [Command](#command)
 * [Observer](#observer)
 * [Strategy](#strategy)
 
@@ -215,3 +216,25 @@ Extender la funcionalidad de los objetos se puede hacer de forma estática en nu
 **Ejemplos:**
 * [Banco](https://github.com/LuisBurgos/design-patterns/tree/master/src/facade/examples/bank)
 * [Computadora](https://github.com/LuisBurgos/design-patterns/tree/master/src/facade/examples/computer)
+
+## <a name="command">Command</a> [&#8593;](#lista-de-patrones)
+
+ El patrón *Command* encapsula comandos( llamados a métodos) en objetos, permitiéndonos realizar peticiones sin conocer exactamente la petición que se realiza o el objeto al cuál se le hace la petición. Este patrón nos provee las opciones para hacer listas de comandos, hacer/deshacer acciones y otras manipulaciones.
+
+ Este patrón desacopla al *objeto que invoca* la operación del *objeto que sabe cómo* llevar a cabo la misma. Un objeto llamado *Invoker* transfiere el *comando* a otro objeto llamado *Receiver* el cual ejecuta el código correcto para el *comando* recibido.
+
+**Propósito:** Encapsular una petición en forma de objeto, permitiendo de ese modo que parametrizar clientes con diferentes peticiones, "colas" o registros de solicitudes, y apoyar las operaciones de deshacer.
+
+**Aplicación:** Usamos el patrón [Command...](https://github.com/LuisBurgos/design-patterns/tree/master/src/command/pattern)
+* Cuando queremos realizar peticiones en diferentes tiempos. Se puede hacer a través de la especificación de una "cola".
+* Para implementar la función de deshacer (*undo*), ya que se puede almacenar el estado de la ejecución del comando para revertir sus efectos.
+* Cuando necesitemos mantener un registro (*log*) de los cambios y acciones.
+
+**Usos típicos:**
+* Mantener un historial de peticiones. (*requests*)
+* Implementar la funcionalidad de *callbacks*.
+* Implementar la funcionalidad de *undo*.
+
+**Ejemplos:**
+* [Televisión](https://github.com/LuisBurgos/design-patterns/tree/master/src/command/examples/tv)
+* [Hechizos](https://github.com/LuisBurgos/design-patterns/tree/master/src/command/examples/spells) (No implementado aún)

src/command/examples/tv/Client.java

@@ -0,0 +1,57 @@
+package command.examples.tv;
+
+import command.examples.tv.commands.TurnOffAllDevices;
+import command.examples.tv.commands.TurnOffTelevision;
+import command.examples.tv.commands.TurnOnTelevision;
+import command.examples.tv.commands.VolumeUpTelevision;
+import command.examples.tv.devices.ElectronicDevice;
+import command.examples.tv.devices.Radio;
+import command.examples.tv.devices.Television;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class Client {
+
+    public static void main(String[] args){
+
+        ElectronicDevice televisionOne = new Television("SAMSUMG");
+
+        TurnOnTelevision onCommand = new TurnOnTelevision(televisionOne);
+
+        DeviceButton onPressed;
+        onPressed = new DeviceButton(onCommand);
+        onPressed.press();
+
+
+        TurnOffTelevision offCommand = new TurnOffTelevision(televisionOne);
+        onPressed = new DeviceButton(offCommand);
+        onPressed.press();
+
+        VolumeUpTelevision volUpCommand = new VolumeUpTelevision(televisionOne);
+        onPressed = new DeviceButton(volUpCommand);
+        onPressed.press();
+        onPressed.press();
+        onPressed.press();
+
+        Television televisionTwo = new Television("SONY");
+        Radio radioOne = new Radio("PIONEER");
+
+        List<ElectronicDevice> allDevices = new ArrayList<>();
+
+        allDevices.add(televisionTwo);
+        allDevices.add(radioOne);
+
+        TurnOffAllDevices turnOffDevices = new TurnOffAllDevices(allDevices);
+
+        DeviceButton turnThemOff = new DeviceButton(turnOffDevices);
+
+        turnThemOff.press();
+        turnThemOff.pressUndo();
+
+    }
+
+}

src/command/examples/tv/DeviceButton.java

@@ -0,0 +1,24 @@
+package command.examples.tv;
+
+import command.examples.tv.commands.Command;
+
+/**
+ * The INVOKER
+ * Created by luisburgos on 13/08/15.
+ */
+public class DeviceButton {
+
+    private Command command;
+
+    public DeviceButton(Command command){
+        this.command = command;
+    }
+
+    public void press(){
+        command.execute();
+    }
+
+    public void pressUndo(){
+        command.undo();
+    }
+}

src/command/examples/tv/commands/Command.java

@@ -0,0 +1,9 @@
+package command.examples.tv.commands;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public interface Command {
+    public void execute();
+    public void undo();
+}

src/command/examples/tv/commands/TurnOffAllDevices.java

@@ -0,0 +1,29 @@
+package command.examples.tv.commands;
+
+import command.examples.tv.devices.ElectronicDevice;
+
+import java.util.List;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class TurnOffAllDevices implements Command {
+
+    List<ElectronicDevice> allDevices;
+
+    public TurnOffAllDevices(List<ElectronicDevice> newDevices) {
+        allDevices = newDevices;
+    }
+
+    public void execute() {
+        for (ElectronicDevice device : allDevices) {
+            device.off();
+        }
+    }
+
+    public void undo() {
+        for (ElectronicDevice device : allDevices) {
+            device.on();
+        }
+    }
+}

src/command/examples/tv/commands/TurnOffTelevision.java

@@ -0,0 +1,25 @@
+package command.examples.tv.commands;
+
+import command.examples.tv.devices.ElectronicDevice;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class TurnOffTelevision implements Command {
+
+    private ElectronicDevice device;
+
+    public TurnOffTelevision(ElectronicDevice device){
+        this.device = device;
+    }
+
+    @Override
+    public void execute() {
+        device.off();
+    }
+
+    @Override
+    public void undo() {
+        device.on();
+    }
+}

src/command/examples/tv/commands/TurnOnTelevision.java

@@ -0,0 +1,25 @@
+package command.examples.tv.commands;
+
+import command.examples.tv.devices.ElectronicDevice;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class TurnOnTelevision implements Command {
+
+    private ElectronicDevice device;
+
+    public TurnOnTelevision(ElectronicDevice device){
+        this.device = device;
+    }
+
+    @Override
+    public void execute() {
+        device.on();
+    }
+
+    @Override
+    public void undo() {
+        device.off();
+    }
+}

src/command/examples/tv/commands/VolumeDownTelevision.java

@@ -0,0 +1,27 @@
+package command.examples.tv.commands;
+
+import command.examples.tv.devices.ElectronicDevice;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class VolumeDownTelevision implements Command {
+
+    private ElectronicDevice device;
+
+    public VolumeDownTelevision(ElectronicDevice device){
+        this.device = device;
+    }
+
+    @Override
+    public void execute() {
+        device.volumenDown();
+    }
+
+    @Override
+    public void undo() {
+        device.volumeUp();
+    }
+
+
+}

src/command/examples/tv/commands/VolumeUpTelevision.java

@@ -0,0 +1,27 @@
+package command.examples.tv.commands;
+
+import command.examples.tv.devices.ElectronicDevice;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class VolumeUpTelevision implements Command {
+
+    private ElectronicDevice device;
+
+    public VolumeUpTelevision(ElectronicDevice device){
+        this.device = device;
+    }
+
+    @Override
+    public void execute() {
+        device.volumeUp();
+    }
+
+    @Override
+    public void undo() {
+        device.volumenDown();
+    }
+
+
+}

src/command/examples/tv/devices/ElectronicDevice.java

@@ -0,0 +1,11 @@
+package command.examples.tv.devices;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public interface ElectronicDevice {
+    public void on();
+    public void off();
+    public void volumeUp();
+    public void volumenDown();
+}

src/command/examples/tv/devices/Radio.java

@@ -0,0 +1,36 @@
+package command.examples.tv.devices;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class Radio  implements ElectronicDevice {
+
+    private int volume = 0;
+    private String name;
+
+    public Radio(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public void on() {
+        System.out.println(name + "RADIO is on");
+    }
+
+    @Override
+    public void off() {
+        System.out.println(name + "RADIO is off");
+    }
+
+    @Override
+    public void volumeUp() {
+        volume++;
+        System.out.println(name + "RADIO Volume at: " + volume);
+    }
+
+    @Override
+    public void volumenDown() {
+        volume--;
+        System.out.println(name + "RADIO Volume at: " + volume);
+    }
+}

src/command/examples/tv/devices/Television.java

@@ -0,0 +1,36 @@
+package command.examples.tv.devices;
+
+/**
+ * Created by luisburgos on 13/08/15.
+ */
+public class Television implements ElectronicDevice {
+
+    private int volume = 0;
+    private String name;
+
+    public Television(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public void on() {
+        System.out.println(name + "TV is on");
+    }
+
+    @Override
+    public void off() {
+        System.out.println(name + "TV is off");
+    }
+
+    @Override
+    public void volumeUp() {
+        volume++;
+        System.out.println(name + "TV Volume at: " + volume);
+    }
+
+    @Override
+    public void volumenDown() {
+        volume--;
+        System.out.println(name + "TV Volume at: " + volume);
+    }
+}