Sudoku/app/src/main/java/gui/menu/StateMachine.java

package gui.menu;

import java.util.Stack;

import gui.Images;
import imgui.ImGui;
import imgui.ImVec2;
import imgui.flag.ImGuiKey;
import imgui.flag.ImGuiWindowFlags;

public class StateMachine {

	private final Stack<BaseView> menus;

	public StateMachine() {
		this.menus = new Stack<>();
	}

	public void clear() {
		for (BaseView view : menus) {
			view.cleanResources();
		}
		menus.clear();
	}

	public void pushState(BaseView menu) {
		menus.add(menu);
	}

	public void popState() {
		menus.getLast().cleanResources();
		menus.pop();
	}

	private void checkEscape() {
		if (ImGui.isKeyPressed(ImGuiKey.Escape) && menus.size() > 1) {
			menus.getLast().closeMenu();
		}
	}

	public void render() {
		var displaySize = ImGui.getIO().getDisplaySize();
		ImGui.setNextWindowPos(new ImVec2(0.0f, 0.0f));
		ImGui.setNextWindowSize(displaySize);
		ImGui.begin("Background", null, ImGuiWindowFlags.NoDecoration | ImGuiWindowFlags.NoMove
		| ImGuiWindowFlags.NoSavedSettings | ImGuiWindowFlags.NoBackground  | ImGuiWindowFlags.NoBringToFrontOnFocus | ImGuiWindowFlags.NoInputs);
		ImGui.image(Images.BACKGROUND, displaySize, new ImVec2(displaySize.x / 100, displaySize.y / 100));
		ImGui.end();
		ImGui.setNextWindowPos(new ImVec2(0.0f, 0.0f));
		ImGui.setNextWindowSize(displaySize);
		ImGui.begin("##Main Window", null, ImGuiWindowFlags.NoDecoration | ImGuiWindowFlags.NoMove
				| ImGuiWindowFlags.NoSavedSettings | ImGuiWindowFlags.NoBackground);
		menus.get(menus.size() - 1).render();
		ImGui.end();
		// ImGui.showDemoWindow();
		checkEscape();
	}

}