More Javascript interaction examples

Author: Janrupf

example/lwjgl3-opengl/src/main/java/com/labymedia/ultralight/lwjgl3/opengl/js/JSInteraction.java

@@ -0,0 +1,38 @@
+package com.labymedia.ultralight.lwjgl3.opengl.js;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Example class containing methods which Javascript can interact with.
+ */
+public class JSInteraction {
+    private final String[] messages;
+
+    /**
+     * Javascript can call varargs method as if they would be native.
+     *
+     * @param messages The message to store
+     */
+    public JSInteraction(String... messages) {
+        this.messages = messages;
+    }
+
+    /**
+     * Javascript can work on interface types without any issues.
+     *
+     * @return The stored messages as a list
+     */
+    public List<String> getMessageList() {
+        return Arrays.asList(messages);
+    }
+
+    /**
+     * Java arrays are translated to Javascript arrays automatically.
+     *
+     * @return The stored messages
+     */
+    public String[] getMessageArray() {
+        return messages;
+    }
+}

example/lwjgl3-opengl/src/main/resources/example.js

@@ -38,6 +38,9 @@ if(!counterFile.exists()) {
     }
 }
 
+/**
+ * Saves the counter to the counter.txt file.
+ */
 function saveCounter() {
     console.log(`Saving counter value ${counter}`);
 
@@ -50,6 +53,28 @@ function saveCounter() {
 setInterval(() => {
     console.log(`Counter now at ${++counter}`);
     if(counter % 10 === 0) {
+        // Save the counter every 10 seconds.
+        // (Good enough for demo purposes)
         saveCounter();
     }
-}, 1000);
+}, 1000);
+
+// Import the interaction class
+const JSInteraction = java.importClass("com.labymedia.ultralight.lwjgl3.opengl.js.JSInteraction");
+
+// Instantiate using the varargs constructor
+const interaction = new JSInteraction("Hello, World!", "How are you doing?", "I hope you are fine.");
+
+// Call the demo methods
+const messageList = interaction.getMessageList();
+const messageArray = interaction.getMessageArray();
+
+// Since the list is not a Javascript own type, we have to use an indexed for loop
+for(let i = 0; i < messageList.size(); i++) {
+    console.log(`messageList[${i}] = ${messageList.get(i)}`);
+}
+
+// The array however has been fully translated
+for(const message of messageArray) {
+    console.log(`messageArray[@] = ${message}`)
+}