make template a little more featureful, add a button to menulayer

src/main.cpp

@@ -2,35 +2,88 @@
  * Include the Geode headers.
  */
 #include <Geode/Geode.hpp>
-/**
- * Required to modify the MenuLayer class
- */
-#include <Geode/modify/MenuLayer.hpp>
 
 /**
- * Brings cocos2d and all Geode namespaces 
- * to the current scope.
+ * Brings cocos2d and all Geode namespaces to the current scope.
  */
 using namespace geode::prelude;
 
 /**
- * `$modify` lets you extend and modify GD's 
- * classes; to hook a function in Geode, 
- * simply $modify the class and write a new 
- * function definition with the signature of 
- * the one you want to hook.
+ * `$modify` lets you extend and modify GD's classes.
+ * To hook a function in Geode, simply $modify the class
+ * and write a new function definition with the signature of
+ * the function you want to hook.
+ *
+ * Here we use the overloaded `$modify` macro to set our own class name,
+ * so that we can use it for button callbacks.
+ *
+ * Notice the header being included, you *must* include the header for
+ * the class you are modifying, or you will get a compile error.
  */
-class $modify(MenuLayer) {
+#include <Geode/modify/MenuLayer.hpp>
+class $modify(MyMenuLayer, MenuLayer) {
 	/**
-	 * MenuLayer::onMoreGames is a GD function, 
-	 * so we hook it by simply writing its name 
-	 * inside a $modified MenuLayer class.
-	 * 
-	 * Note that for all hooks, your signature 
-	 * has to match exactly - `bool onMoreGames` 
-	 * would not place a hook!
-	 */
-	void onMoreGames(CCObject*) {
-		FLAlertLayer::create("Geode", "Hello from my custom mod!", "OK")->show(); 
-	} 
+	 * Typically classes in GD are initialized using the `init` function, (though not always!),
+	 * so here we use it to add our own button to the bottom menu.
+	 *
+	 * Note that for all hooks, your signature has to *match exactly*,
+	 * `void init()` would not place a hook!
+	*/
+	bool init() {
+		/**
+		 * We call the original init function so that the
+		 * original class is properly initialized.
+		 */
+		if (!MenuLayer::init()) {
+			return false;
+		}
+
+		/**
+		 * See this page for more info about buttons
+		 * https://docs.geode-sdk.org/tutorials/buttons
+		*/
+		auto myButton = CCMenuItemSpriteExtra::create(
+			CCSprite::createWithSpriteFrameName("GJ_likeBtn_001.png"),
+			this,
+			/**
+			 * Here we use the name we set earlier for our modify class.
+			*/
+			menu_selector(MyMenuLayer::onMyButton)
+		);
+
+		/**
+		 * Here we access the `bottom-menu` node by its ID, and add our button to it.
+		 * Node IDs are a Geode feature, see this page for more info about it:
+		 * https://docs.geode-sdk.org/tutorials/nodetree
+		*/
+		auto menu = this->getChildByID("bottom-menu");
+		menu->addChild(myButton);
+
+		/**
+		 * The `_spr` string literal operator just prefixes the string with
+		 * your mod id followed by a slash. This is good practice for setting your own node ids.
+		*/
+		myButton->setID("my-button"_spr);
+
+		/**
+		 * We update the layout of the menu to ensure that our button is properly placed.
+		 * This is yet another Geode feature, see this page for more info about it:
+		 * https://docs.geode-sdk.org/tutorials/layouts
+		*/
+		menu->updateLayout();
+
+		/**
+		 * We return `true` to indicate that the class was properly initialized.
+		 */
+		return true;
+	}
+
+	/**
+	 * This is the callback function for the button we created earlier.
+	 * The signature for button callbacks must always be the same,
+	 * return type `void` and taking a `CCObject*`.
+	*/
+	void onMyButton(CCObject*) {
+		FLAlertLayer::create("Geode", "Hello from my custom mod!", "OK")->show();
+	}
 };