Add sample applet sources.

2014-01-13 00:25:09 +00:00
parent e98f349e9c
commit 1b6be3c99f
2 changed files with 208 additions and 0 deletions
--- a/examples/jse/SampleApplet.java
+++ b/examples/jse/SampleApplet.java
@@ -0,0 +1,97 @@
+import java.applet.Applet;
+import java.awt.Graphics;
+
+import org.luaj.vm2.Globals;
+import org.luaj.vm2.LuaValue;
+import org.luaj.vm2.lib.jse.CoerceJavaToLua;
+import org.luaj.vm2.lib.jse.JsePlatform;
+
+/**
+ * Simple Applet that forwards Applet lifecycle events to a lua script.
+ * 
+ * <p>
+ * On Applet.init() a script is loaded and executed, with the Applet instance as
+ * the first argument. Initialization of the Applet UI can be done here.
+ * 
+ * <p>
+ * Other Applet lifecycle events are invoked when they are recieved, and
+ * forwarded to methods in the global environment, if they exist. These are:
+ * <ul>
+ * <li>start() called when {@link Applet#start} is called.
+ * <li>stop() called when {@link Applet#stop} is called.
+ * <li>paint(graphics) called when {@link Applet#paint(Graphics)} is called. If
+ * this is not defined as a function the superclass method will be called.
+ * <li>update(graphics) called when {@link Applet#update(Graphics)} is called.
+ * If this is not defined as a function the superclass method will be called. By
+ * calling <code>applet:paint(graphics)</code> in the implementation the applet
+ * content will not be cleared before painting.
+ * </ul>
+ * 
+ * <p>
+ * Note that these lookups are done at runtime, so the paint method or any other
+ * method can be changed based on application logic, if desired.
+ * 
+ * @see Globals
+ * @see LuaValue
+ * @see Applet
+ */
+public class SampleApplet extends Applet {
+	private static final long serialVersionUID = 1L;
+
+	Globals globals;
+	LuaValue pcall;
+	LuaValue graphics;
+	Graphics coerced;
+
+	// This applet property is searched for the name of script to load.
+	static String script_parameter = "script";
+
+	// This must be located relative to the document base to be loaded.
+	static String default_script = "swingapplet.lua";
+
+	public void init() {
+		// Find the script to load from the applet parameters.
+		String script = getParameter(script_parameter);
+		if (script == null)
+			script = default_script;
+		System.out.println("Loading " + script);
+
+		// Construct globals to use.
+		globals = JsePlatform.debugGlobals();
+		pcall = globals.get("pcall");
+
+		// Load and execute the script, supplying this Applet as the only
+		// argument.
+		globals.loadfile(script).call(CoerceJavaToLua.coerce(this));
+	}
+
+	public void start() {
+		pcall.call(globals.get("start"));
+	}
+
+	public void stop() {
+		pcall.call(globals.get("stop"));
+	}
+
+	public void update(Graphics g) {
+		LuaValue u = globals.get("update");
+		if (!u.isfunction())
+			super.update(g);
+		else
+			pcall.call(
+					u,
+					coerced == g ? graphics : (graphics = CoerceJavaToLua
+							.coerce(coerced = g)));
+	}
+
+	public void paint(Graphics g) {
+		LuaValue p = globals.get("paint");
+		if (!p.isfunction())
+			super.paint(g);
+		else
+			pcall.call(
+					p,
+					coerced == g ? graphics : (graphics = CoerceJavaToLua
+							.coerce(coerced = g)));
+	}
+}