C:/Users/Andreas Schiffler/Desktop/SVN/NewGamePhysics/GravityChooser/Screens/GravityChooserMainMenuScreen.cs

//-----------------------------------------------------------------------------
// GravityChooserMainMenuScreen.cs
// (A. Schiffler, 2009-2011)
//-----------------------------------------------------------------------------

namespace GravityChooser
{
    using Microsoft.Xna.Framework;
    using Microsoft.Xna.Framework.Graphics;
    using NewGamePhysics.StateManager;
    using NewGamePhysics.Physics;
    using NewGamePhysics.GraphicalElements;
    using System;
    using System.IO;
    using System.Text;

    class GravityChooserMainMenuScreen : MenuScreen
    {
        private ScrollingText scrollingInfoText;

        private MenuEntry chooseValueMenuEntry;

        public GravityChooserMainMenuScreen()
            : base("Gravity Chooser")
        {
            // Create our menu entries.
            this.chooseValueMenuEntry = new MenuEntry("*"); // text will be set later
            MenuEntry optionsMenuEntry = new MenuEntry("Change Celestial Body");
            MenuEntry helpMenuEntry = new MenuEntry("Module Controls Help");
            MenuEntry infoMenuEntry = new MenuEntry("Module Information");
            MenuEntry doneMenuEntry = new MenuEntry("Done");

            // Hook up menu event handlers.
            chooseValueMenuEntry.Selected += ChooseValueMenuEntrySelected;
            optionsMenuEntry.Selected += OptionsMenuEntrySelected;
            infoMenuEntry.Selected += InfoMenuEntrySelected;
            helpMenuEntry.Selected += HelpMenuEntrySelected; 
            doneMenuEntry.Selected += OnCancel;

            // Add entries to the menu.
            MenuEntries.Add(chooseValueMenuEntry);
            MenuEntries.Add(optionsMenuEntry);
            MenuEntries.Add(infoMenuEntry);
            MenuEntries.Add(helpMenuEntry);
            MenuEntries.Add(doneMenuEntry);
        }

        public override void LoadContent()
        {
            // Create scrollers
            SpriteFont font = ScreenManager.Fonts["menu"];
            GravityChooser game = (GravityChooser)ScreenManager.Game;
            int width = game.GraphicsDevice.Viewport.Width;
            scrollingInfoText = new ScrollingText("-", font, width, 400); // text will be set later           

            base.LoadContent();
        }


        public override void Update(GameTime gameTime, bool otherScreenHasFocus, bool coveredByOtherScreen)
        {
            if (WaitForUncover)
            {
                if ((!coveredByOtherScreen) || (!otherScreenHasFocus))
                {
                    // Update the texts
                    UpdateAllTexts();

                    // Update menu text
                    WaitForUncover = false;
                }
            }

            // Update scrollers
            scrollingInfoText.Update(gameTime);

            base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen);
        }

        public override void Draw(GameTime gameTime)
        {
            base.Draw(gameTime);

            // Draw scroller
            SpriteBatch spriteBatch = ScreenManager.SpriteBatch;
            scrollingInfoText.Draw(gameTime, spriteBatch);
        }

        #region Handle Input

        void ChooseValueMenuEntrySelected(object sender, PlayerIndexEventArgs e)
        {
            GravityChooserLoadingScreen.Load(ScreenManager, true, e.PlayerIndex,
                               new GravityChooserGameplayScreen());

            // Set flag to update text when we return
            WaitForUncover = true;
        }

        void OptionsMenuEntrySelected(object sender, PlayerIndexEventArgs e)
        {
            ScreenManager.AddScreen(new GravityChooserOptionsMenuScreen(), null);
            
            // Reset to play entry
            this.SelectedEntry = 0;

            // Set flag to update text when we return
            WaitForUncover = true;
        }

        protected override void OnCancel(PlayerIndex playerIndex)
        {
            // Set environment batch code
            string batchCode = "set GRAVITY=" + GravityChooser.state.CurrentGravity.ToString();
            File.WriteAllText("gravity.bat", batchCode);
            
            ScreenManager.Game.Exit();
        }

        #endregion

        void InfoMenuEntrySelected(object sender, PlayerIndexEventArgs e)
        {
            // Text to display
            string[] messages = { 
            "Information on The Gravity Chooser", 
            "",
            "The Gravity Chooser is an implementation of a hypothetical game",
            "component which allows players to select gravity (hence the name).",
            "",
            "The gravity is not a constant value, but specific to the location",
            "due to the non-uniform shape and density of any celestial body.",
            "",
            "Geodesy research has generated very high quality models of the",            
            "gravity of earth, some of which are available through the chooser.",
            "Other celestial bodies have significant different gravitatation",
            "which can be explored with the gravity chooser.",
            "",
            "The chooser returns the selected gravity for use by another game.",
            };

            ScreenManager.AddScreen(new GravityChooserHelpScreen(messages), null);

            // Reset back to play entry
            this.SelectedEntry = 0;

            // Set flag to update text when we return
            WaitForUncover = true;
        }

        void HelpMenuEntrySelected(object sender, PlayerIndexEventArgs e)
        {
            // Text to display
            string[] messages = { 
            "Controls for The Gravity Chooser", 
            "",
            " [Up]/[Down] cursor/pad",
            " [Left]/[Right] cursor/pad",
            "            rotate the celestial body",
            " [Space] or (A)",
            "            continue or select in menu, game or help screens",
            " [Escape] or (Back)",
            "            pause game or quit to main menu",
            };

            ScreenManager.AddScreen(new GravityChooserHelpScreen(messages), null);

            // Reset back to play entry
            this.SelectedEntry = 0;

            // Set flag to update text when we return
            WaitForUncover = true;
        }

        private void UpdateAllTexts()
        {
            // Menu text
            chooseValueMenuEntry.Text =
                "Choose Your Gravity on " + GravityChooser.state.CurrentCelestialObject.ToString();

            // Scroller text
            if (null != scrollingInfoText)
            {
                scrollingInfoText.Text =
                        "Your selected gravity on " + GravityChooser.state.CurrentCelestialObject.ToString() + ": ";
                if (GravityChooser.state.CurrentGravity > 0.0)
                {
                    scrollingInfoText.Text = scrollingInfoText.Text +
                        "g = " + GravityChooser.state.CurrentGravity.ToString() + " m/s^-2";
                }
                else
                {
                    scrollingInfoText.Text = scrollingInfoText.Text +
                        "not set yet.";
                }
            }
        }
    }
}

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