factored out options screen GUI elements using the new GUI subsystem

backButton.cpp

@@ -0,0 +1,26 @@
+#include "backButton.h"
+#include "gameManager.h"
+#include "concreteGuiManager.h"
+
+namespace battleship{
+	using namespace std;
+	using namespace vb01;
+	using namespace vb01Gui;
+
+    BackButton::BackButton(Vector2 pos, Vector2 size, string name, string screen) : Button(pos, size, name, GameManager::getSingleton()->getPath() + "Fonts/batang.ttf", -1, true) {
+		this->screen = screen;
+	}
+
+    void BackButton::onClick() {
+		ConcreteGuiManager *guiManager = ConcreteGuiManager::getSingleton();
+		guiManager->removeAllButtons(vector<Button*>{this});
+		guiManager->removeAllListboxes();
+		guiManager->removeAllCheckboxes();
+		guiManager->removeAllSliders();
+		guiManager->removeAllTextboxes();
+
+		guiManager->readLuaScreenScript(screen);
+
+		guiManager->removeButton(this);
+	}
+}