/*
 * GUIPanel.cs
 * Authors: Bradley Blankenship, Mike DeMauro
 * Copyright (c) 2007-2008 Cornell University

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

using Microsoft.Xna.Framework.Graphics;

namespace tAC_Engine.GUI
{
    /// <summary>
    /// Results of a closing panel.
    /// </summary>
    public enum PanelResult
    {
        NONE,
        YES,
        NO,
        OKAY,
        CANCEL
    }

    /// <summary>
    /// Handler for a panel result event
    /// </summary>
    /// <param name="source">The object sending the event</param>
    /// <param name="result">The result data</param>
    public delegate void PanelResultHandler(object source, PanelResult result);

    /// <summary>
    /// Represents a panel for the GUI.
    /// </summary>
    public class GUIPanel : GUIContainer
    {
        #region Fields

        /// <summary>
        /// The background texture for the panel
        /// </summary>
        Texture2D mBackground;

        #endregion

        #region Properties

        /// <summary>
        /// Allows access to the background of the panel.
        /// </summary>
        public Texture2D Background
        {
            get { return mBackground; }
            set { mBackground = value; }
        }

        #endregion

        #region Initialization

        /// <summary>
        /// Get the basic texture if we do not have one for our background.
        /// </summary>
        public override void LoadContent()
        {
            // If our texture is null
            if (Background == null && ParentScreen != null)
            {
                // Load the basic background texture
                Background = ParentScreen.Content.Load<Texture2D>(@"Textures\BasicGUIBackground");
            }
            base.LoadContent();
        }

        #endregion

        #region Draw

        /// <summary>
        /// Draw us then the rest of our components.
        /// </summary>
        /// <param name="gameTime">The current game time.</param>
        public override void Draw(Microsoft.Xna.Framework.GameTime gameTime)
        {
            // If we're visible
            if (Visible)
            {
                // If we have a background
                if (Background != null)
                {
                    // Draw it!
                    Batch.Draw(Background, Bounds, mAddColor);
                }

                // The rest are drawn
                base.Draw(gameTime);
            }
        }

        #endregion

        /// <summary>
        /// Attempts to remove the panel from its parent screen
        /// </summary>
        /// <param name="result">The result state.</param>
        public void Remove(PanelResult result)
        {
            if (PanelRemoving != null) PanelRemoving(this, result);
            if (ParentScreen != null) ParentScreen.Remove(this);
            else throw new System.Exception("Attempted to remove a GUIPanel that has no parent.");
            if (PanelRemoved != null) PanelRemoved(this, result);
        }

        /// <summary>
        /// Occurs just before a panel closes
        /// </summary>
        public event PanelResultHandler PanelRemoving;

        /// <summary>
        /// Occurs just after a panel closes
        /// </summary>
        public event PanelResultHandler PanelRemoved;
    }
}