chapter 2 finished

helloGUIWorld.vala

@@ -0,0 +1,22 @@
+// helloGUIWorld.vala
+int main (string[] args) {
+    Gtk.init (ref args);
+
+    var window = new Gtk.Window ();
+    window.title = "Hello UI World";
+    window.border_width = 10;
+    window.window_position = Gtk.WindowPosition.CENTER;
+    window.set_default_size (400, 150);
+    window.destroy.connect (Gtk.main_quit);
+
+    var button = new Gtk.Button.with_label ("Click me!");
+    button.clicked.connect ( () => {
+        button.label = "Thank you!";
+    });
+
+    window.add (button);
+    window.show_all ();
+
+    Gtk.main ();
+    return 0;
+}

helloObjectWorld.vala

@@ -1,9 +1,9 @@
 // helloObjectWorld.vala
 
 class HelloWorld {
-    private string? name;
+    private string name;
 
-    public HelloWorld (string name) {
+    public HelloWorld (string? name) {
         this.name = name;
     }
 

helloObjectWorld.vala~

@@ -0,0 +1,24 @@
+// helloObjectWorld.vala
+
+class HelloWorld {
+    private string name;
+
+    public HelloWorld (string? name) {
+        this.name = name;
+    }
+
+    public void greet () {
+        var fullGreeting = "Hello " + this.name + "!\n";
+        stdout.printf (fullGreeting);
+    }
+}
+
+int main (string[] args) {
+    if ( args.length < 2 ) {
+        stderr.printf ("Usage: %s <name>\n", args[0]);
+        return -1;
+    }
+    HelloWorld helloWorldObject = new HelloWorld (args [1]);
+    helloWorldObject.greet();
+    return 0;
+}

helloObjectWorld2.vala

@@ -0,0 +1,24 @@
+// helloObjectWorld.vala
+
+class HelloWorld {
+    private string name;
+
+    public HelloWorld (string? name) {
+        this.name = name;
+    }
+
+    public void greet () {
+        var fullGreeting = "Hello " + this.name + "!\n";
+        stdout.printf (fullGreeting);
+    }
+}
+
+int main (string[] args) {
+    if ( args.length < 2 ) {
+        stderr.printf ("Usage: %s <name>\n", args[0]);
+        return -1;
+    }
+    HelloWorld helloWorldObject = new HelloWorld (args [1]);
+    helloWorldObject.greet();
+    return 0;
+}