feat: added DSL API for world variable changes

AlmasB · AlmasB · commit 44c7690b4b80 · 2022-03-07T18:28:59.000Z
diff --git a/fxgl-samples/src/main/java/sandbox/VarChangeSample.java b/fxgl-samples/src/main/java/sandbox/VarChangeSample.java
@@ -0,0 +1,73 @@
+/*
+ * FXGL - JavaFX Game Library. The MIT License (MIT).
+ * Copyright (c) AlmasB (almaslvl@gmail.com).
+ * See LICENSE for details.
+ */
+
+package sandbox;
+
+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) (almaslvl@gmail.com)
+ */
+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);
+        vars.put("time", 0.0);
+        vars.put("name", "Hello");
+    }
+
+    @Override
+    protected void initGame() {
+        // the event builder way
+        eventBuilder()
+                .when(() -> geti("hp") == 7)
+                .limit(4)
+                .thenRun(() -> System.out.println("hello"))
+                .buildAndStart();
+
+        // the DSL way
+        onDoubleChange("time", value -> {
+            System.out.println(value);
+        });
+
+        onStringChange("name", value -> {
+            System.out.println(value);
+        });
+
+        onStringChangeTo("name", "HelloHH", () -> {
+            System.out.println("bye");
+        });
+
+        onIntChangeTo("hp", 5, () -> System.out.println("Hello"));
+
+        run(() -> inc("hp", +1), Duration.seconds(1));
+    }
+
+    public static void main(String[] args) {
+        launch(args);
+    }
+}
diff --git a/fxgl/src/main/kotlin/com/almasb/fxgl/dsl/FXGL.kt b/fxgl/src/main/kotlin/com/almasb/fxgl/dsl/FXGL.kt
@@ -16,6 +16,7 @@ import com.almasb.fxgl.app.services.SystemBundleService
 import com.almasb.fxgl.audio.AudioPlayer
 import com.almasb.fxgl.audio.Music
 import com.almasb.fxgl.core.EngineService
+import com.almasb.fxgl.core.collection.PropertyChangeListener
 import com.almasb.fxgl.core.concurrent.Async
 import com.almasb.fxgl.core.concurrent.Executor
 import com.almasb.fxgl.core.math.FXGLMath
@@ -326,6 +327,67 @@ class FXGL private constructor() { companion object {
 
     @JvmStatic fun inc(varName: String, value: Double) = getWorldProperties().increment(varName, value)
 
+    @JvmStatic fun onIntChangeTo(varName: String, value: Int, action: Runnable): PropertyChangeListener<Int> {
+        return onIntChange(varName) {
+            if (it == value)
+                action.run()
+        }
+    }
+
+    @JvmStatic fun onIntChange(varName: String, action: Consumer<Int>): PropertyChangeListener<Int> {
+        val listener = PropertyChangeListener<Int> { _, newValue -> action.accept(newValue) }
+
+        getWorldProperties().addListener(varName, listener)
+
+        return listener
+    }
+
+    @JvmStatic fun onDoubleChange(varName: String, action: Consumer<Double>): PropertyChangeListener<Double> {
+        val listener = PropertyChangeListener<Double> { _, newValue -> action.accept(newValue) }
+
+        getWorldProperties().addListener(varName, listener)
+
+        return listener
+    }
+
+    @JvmStatic fun onBooleanChangeTo(varName: String, value: Boolean, action: Runnable): PropertyChangeListener<Boolean> {
+        return onBooleanChange(varName) {
+            if (it == value)
+                action.run()
+        }
+    }
+
+    @JvmStatic fun onBooleanChange(varName: String, action: Consumer<Boolean>): PropertyChangeListener<Boolean> {
+        val listener = PropertyChangeListener<Boolean> { _, newValue -> action.accept(newValue) }
+
+        getWorldProperties().addListener(varName, listener)
+
+        return listener
+    }
+
+    @JvmStatic fun onStringChangeTo(varName: String, value: String, action: Runnable): PropertyChangeListener<String> {
+        return onStringChange(varName) {
+            if (it == value)
+                action.run()
+        }
+    }
+
+    @JvmStatic fun onStringChange(varName: String, action: Consumer<String>): PropertyChangeListener<String> {
+        val listener = PropertyChangeListener<String> { _, newValue -> action.accept(newValue) }
+
+        getWorldProperties().addListener(varName, listener)
+
+        return listener
+    }
+
+    @JvmStatic fun <T> onObjectChange(varName: String, action: Consumer<T>): PropertyChangeListener<T> {
+        val listener = PropertyChangeListener<T> { _, newValue -> action.accept(newValue) }
+
+        getWorldProperties().addListener(varName, listener)
+
+        return listener
+    }
+
 /* ASSET LOADING */
 
     @JvmStatic fun image(assetName: String): Image = getAssetLoader().loadImage(assetName)
