clean up VarChangeSample and move out of sandbox

fxgl-samples/src/main/java/sandbox/VarChangeSample.java → fxgl-samples/src/main/java/intermediate/VarChangeSample.java

@@ -4,35 +4,26 @@
  * See LICENSE for details.
  */
 
-package sandbox;
+package intermediate;
 
 import com.almasb.fxgl.app.GameApplication;
 import com.almasb.fxgl.app.GameSettings;
-import javafx.scene.input.KeyCode;
 import javafx.util.Duration;
 
 import java.util.Map;
 
 import static com.almasb.fxgl.dsl.FXGL.*;
 
 /**
- * @author Almas Baimagambetov (AlmasB) ([email protected])
+ * Shows how to listen for changes in variables and react.
+ *
+ * @author Almas Baim (https://github.com/AlmasB)
  */
 public class VarChangeSample extends GameApplication {
 
     @Override
     protected void initSettings(GameSettings settings) { }
 
-    @Override
-    protected void initInput() {
-        onKeyDown(KeyCode.F, "update", () -> {
-            inc("time", +1.0);
-
-            var name = gets("name");
-            set("name", name + "H");
-        });
-    }
-
     @Override
     protected void initGameVars(Map<String, Object> vars) {
         vars.put("hp", 0);
@@ -42,29 +33,44 @@ protected void initGameVars(Map<String, Object> vars) {
 
     @Override
     protected void initGame() {
-        // the event builder way
-        eventBuilder()
-                .when(() -> geti("hp") == 7)
-                .limit(4)
-                .thenRun(() -> System.out.println("hello"))
-                .buildAndStart();
-
-        // the DSL way
+        // the DSL way, if you need something set up quickly
         onDoubleChange("time", value -> {
-            System.out.println(value);
+            System.out.println("The var <time> is now: " + value);
         });
 
         onStringChange("name", value -> {
-            System.out.println(value);
+            System.out.println("The var <name> is now: " + value);
         });
 
         onStringChangeTo("name", "HelloHH", () -> {
-            System.out.println("bye");
+            System.out.println("The var <name> reached HelloHH");
         });
 
-        onIntChangeTo("hp", 5, () -> System.out.println("Hello"));
+        onIntChangeTo("hp", 5, () -> {
+            System.out.println("The var <hp> reached 5");
+        });
+
+        // the event builder way, if you need more control over execution
+        eventBuilder()
+                .when(() -> geti("hp") == 7)
+                .limit(4)
+                .thenRun(() -> System.out.println("The <hp> var reached 7. You will see this message 4 times"))
+                .buildAndStart();
+
+        // the listener way, if you want to control lifecycle / clean-up process
+        getip("hp").subscribe((oldValue, newValue) -> {
+            if (newValue.intValue() == 4) {
+                System.out.println("The var <hp> reached 4");
+            }
+        });
+
+        run(() -> {
+            inc("hp", +1);
+            inc("time", +1.0);
+
+            set("name", gets("name") + "H");
 
-        run(() -> inc("hp", +1), Duration.seconds(1));
+        }, Duration.seconds(1));
     }
 
     public static void main(String[] args) {