Shopping - A .NET shopping application for Pocket PC

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Xml;

using Shopping.Engine;

namespace Shopping
{
	/// <summary>
	/// Summary description for frmCategories.
	/// </summary>
	public class frmCategories : System.Windows.Forms.Form
	{
		private const string UPDATE = "Update";
		private const string NEW = "New";
		private const string ADD = "Add";
		private const string READY = "Ready";				

		private System.Windows.Forms.Label lblMessage;
		private System.Windows.Forms.TextBox txtItem;
		private System.Windows.Forms.ColumnHeader Name;
		private System.Windows.Forms.Button btnUpdate;
		private Microsoft.WindowsCE.Forms.InputPanel inputPanel1;
		private System.Windows.Forms.MainMenu mainMenu1;
		private System.Windows.Forms.ListView lvCategories;
		private System.Windows.Forms.Button btnDelete;
		private System.Windows.Forms.Button btnNew;

		private string mLastAddedCategory = string.Empty;
	
		public frmCategories()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			// Load Categories
			LoadCategories();
			
			// Initialize GUI
			lvCategories.SelectedIndexChanged += new EventHandler(lvCategories_SelectedIndexChanged);
			lblMessage.Text = READY;
		}

		public string LastAddedCategory
		{
			get{return mLastAddedCategory;}
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			base.Dispose( disposing );
		}


		/// <summary>
		/// Save elements when window close
		/// </summary>
		/// <param name="e"></param>
		protected override void OnClosing(CancelEventArgs e)
		{
			base.OnClosing (e);

			inputPanel1.Enabled = false;
			SaveCategories();
		}


		private void lvCategories_SelectedIndexChanged(object sender, EventArgs e)
		{
			if(lvCategories.SelectedIndices.Count == 0) return;

			txtItem.Text = lvCategories.Items[lvCategories.SelectedIndices[0]].Text;	
			txtItem.Enabled = true;							
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.lblMessage = new System.Windows.Forms.Label();
			this.btnUpdate = new System.Windows.Forms.Button();
			this.txtItem = new System.Windows.Forms.TextBox();
			this.lvCategories = new System.Windows.Forms.ListView();
			this.Name = new System.Windows.Forms.ColumnHeader();
			this.btnDelete = new System.Windows.Forms.Button();
			this.btnNew = new System.Windows.Forms.Button();
			this.inputPanel1 = new Microsoft.WindowsCE.Forms.InputPanel();
			this.mainMenu1 = new System.Windows.Forms.MainMenu();
			// 
			// lblMessage
			// 
			this.lblMessage.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Italic);
			this.lblMessage.Location = new System.Drawing.Point(2, 247);
			this.lblMessage.Size = new System.Drawing.Size(176, 16);
			this.lblMessage.Text = "Ready";
			// 
			// btnUpdate
			// 
			this.btnUpdate.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular);
			this.btnUpdate.Location = new System.Drawing.Point(58, 8);
			this.btnUpdate.Size = new System.Drawing.Size(78, 24);
			this.btnUpdate.Text = "Update";
			this.btnUpdate.Click += new System.EventHandler(this.btnUpdate_Click);
			// 
			// txtItem
			// 
			this.txtItem.Enabled = false;
			this.txtItem.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular);
			this.txtItem.Location = new System.Drawing.Point(2, 35);
			this.txtItem.Size = new System.Drawing.Size(235, 20);
			this.txtItem.Text = "";
			this.txtItem.LostFocus += new System.EventHandler(this.txtItem_LostFocus);
			this.txtItem.GotFocus += new System.EventHandler(this.txtItem_GotFocus);
			// 
			// lvCategories
			// 
			this.lvCategories.Columns.Add(this.Name);
			this.lvCategories.FullRowSelect = true;
			this.lvCategories.Location = new System.Drawing.Point(2, 63);
			this.lvCategories.Size = new System.Drawing.Size(235, 176);
			this.lvCategories.View = System.Windows.Forms.View.Details;
			this.lvCategories.GotFocus += new System.EventHandler(this.lvCategories_GotFocus);
			// 
			// Name
			// 
			this.Name.Text = "Name";
			this.Name.Width = 215;
			// 
			// btnDelete
			// 
			this.btnDelete.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular);
			this.btnDelete.Location = new System.Drawing.Point(179, 8);
			this.btnDelete.Size = new System.Drawing.Size(58, 24);
			this.btnDelete.Text = "Delete";
			this.btnDelete.Click += new System.EventHandler(this.btnDelete_Click);
			// 
			// btnNew
			// 
			this.btnNew.Font = new System.Drawing.Font("Tahoma", 8F, System.Drawing.FontStyle.Regular);
			this.btnNew.Location = new System.Drawing.Point(2, 8);
			this.btnNew.Size = new System.Drawing.Size(48, 24);
			this.btnNew.Text = "New";
			this.btnNew.Click += new System.EventHandler(this.btnNew_Click);
			// 
			// inputPanel1
			// 
			this.inputPanel1.EnabledChanged += new System.EventHandler(this.inputPanel1_EnabledChanged);
			// 
			// frmCategories
			// 
			this.Controls.Add(this.lblMessage);
			this.Controls.Add(this.btnUpdate);
			this.Controls.Add(this.txtItem);
			this.Controls.Add(this.lvCategories);
			this.Controls.Add(this.btnDelete);
			this.Controls.Add(this.btnNew);
			this.Menu = this.mainMenu1;
			this.Text = "Category Manager";

		}
		#endregion

		private void btnUpdate_Click(object sender, System.EventArgs e)
		{
			UpdateCategories();
			txtItem.Enabled = false;		
		}

		private void btnDelete_Click(object sender, System.EventArgs e)
		{
			if(lvCategories.SelectedIndices.Count == 0)
			{				
				MessageBox.Show("You must select an item to delete.", "Deleting ...", 
					MessageBoxButtons.OK, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button1);			
			}
			else
			{
				if(MessageBox.Show("Remove selected category ?", "Deleting", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.Yes)
				{
					lvCategories.Items.RemoveAt(lvCategories.SelectedIndices[0]);
					txtItem.Text = string.Empty;
				}
			}
		}

		private void btnNew_Click(object sender, System.EventArgs e)
		{
			if(btnNew.Text == NEW)
			{
				txtItem.Enabled = true;
				txtItem.Text = string.Empty;
				btnNew.Text = ADD;
				txtItem.Focus();
			}
			else
			{
				AddCategory();
				txtItem.Focus();
			}	
		}

		/// <summary>
		/// Update categories
		/// </summary>
		private void UpdateCategories()
		{
			if(lvCategories.SelectedIndices.Count == 0) return;

			if(txtItem.Text == string.Empty)
				lvCategories.Items.RemoveAt(lvCategories.SelectedIndices[0]);
			else
				lvCategories.Items[lvCategories.SelectedIndices[0]].Text = txtItem.Text;
		}

		/// <summary>
		/// Add a new Category to the list
		/// </summary>
		private void AddCategory()
		{
			try
			{
				if(txtItem.Text != string.Empty)
				{					
					if(!IsCategoryExists(txtItem.Text))
					{
						lvCategories.Items.Add(new ListViewItem(txtItem.Text));

						//Select the added item 
						lvCategories.Items[lvCategories.Items.Count -1].Selected = true;
						lvCategories.EnsureVisible(lvCategories.Items.Count -1);

						lblMessage.ForeColor = Color.Black;
						lblMessage.Text = "Category Added";
					}
					else
					{
						lblMessage.ForeColor = Color.Red;
						lblMessage.Text = "Category already exists.";
					}
				}

				mLastAddedCategory = txtItem.Text;
			}
			finally
			{
				txtItem.Text = string.Empty;				
			}
		}

		/// <summary>
		/// Load Categories into listview
		/// </summary>
		/// <param name="file"></param>
		private void LoadCategories()
		{													
			ArrayList elems = ShoppingApp.GetCategories();						
			
			lvCategories.Items.Clear();			

			foreach(string elem in elems)
			{
				lvCategories.Items.Add(new ListViewItem(elem));
			}					
		}

		/// <summary>
		/// Saves Categories to permanent memory
		/// </summary>
		private void SaveCategories()
		{			
			try
			{
				//Saving list
				XmlDocument doc = new XmlDocument();
				XmlElement root = doc.CreateElement("Categories");
				doc.AppendChild(root);

				XmlElement elem;

				foreach(ListViewItem itm in lvCategories.Items)
				{
					elem = doc.CreateElement("Item");
					elem.SetAttribute("Name", itm.Text);
					doc.DocumentElement.AppendChild(elem);
				}
												
				doc.Save(CST.XMLCATEGORIES);
			}
			catch
			{				
				MessageBox.Show("An error occured during save operation.", "Saving ...", 
					MessageBoxButtons.OK, MessageBoxIcon.Hand, MessageBoxDefaultButton.Button1);				
			}
		}

		/// <summary>
		/// Determine if the specified category already exists
		/// </summary>
		/// <param name="name"></param>
		/// <returns></returns>
		private bool IsCategoryExists(string name)
		{
			foreach(ListViewItem lvi in lvCategories.Items)
			{
				if(lvi.Text == name) return true;
			}

			return false;
		}

		private void txtItem_GotFocus(object sender, System.EventArgs e)
		{
			inputPanel1.Enabled = true;
		}

		private void txtItem_LostFocus(object sender, System.EventArgs e)		
		{
			try
			{
				inputPanel1.Enabled = false;
			}
			catch
			{				
			}
		}

		private void inputPanel1_EnabledChanged(object sender, System.EventArgs e)
		{
			if (inputPanel1.Enabled == false)
			{				
				lvCategories.Height = 176;
			}
			else
			{			
				lvCategories.Height = 120;
			}	
		}

		private void lvCategories_GotFocus(object sender, System.EventArgs e)
		{
			btnNew.Text = "New";
		}		
	}
}