using System;
using System.Collections.Generic;
using System.Text;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace MyCustomControls
{
    [ValidationPropertyAttribute("Text")]
    public class RestrictedTextArea : CompositeControl
    {
        TextBox textbox = new TextBox();
        CustomValidator validator = new CustomValidator();

        public RestrictedTextArea()
        {
            // Configure the textbox
            this.textbox.TextMode = TextBoxMode.MultiLine;
            this.Controls.Add(textbox);

            // Configure the validator
            this.validator.Text = "X";
            this.validator.Style.Add("font-weight", "bold");
            // The event handler will be created when we get to the MaxLength property
            this.validator.ServerValidate +=
                new ServerValidateEventHandler(validator_ServerValidate);
            this.Controls.Add(validator);

            // Conifgure some CompositeControl properties
            this.Width = new Unit(155);
            this.Height = new Unit(30);
        }

        bool customErrorMessage = false;
        public string ErrorMessage
        {
            set
            {
                this.validator.ErrorMessage = value;
                this.customErrorMessage = true;
            }
        }

        private string fieldName = "";
        public string PrettyFieldName
        {
            get { return this.fieldName; }
            set { this.fieldName = value; }
        }


        public int MaxLength
        {
            get { return this.textbox.MaxLength; }
            set
            {
                this.textbox.MaxLength = value;
                this.textbox.Attributes.Add(
                    "OnKeyUp",
                    "if (this.value.length > " + value +
                    ") { alert('Sorry! The max number of allowed characters is " +
                    value + ".'); this.value = this.value.substring(0," +
                    value + "); }");
            }
        }
        void validator_ServerValidate(object source, ServerValidateEventArgs args)
        {
            if (this.textbox.Text.Length != 0 &&
                this.textbox.Text.Length > this.textbox.MaxLength)
            {
                if (!this.customErrorMessage)
                    this.validator.ErrorMessage = "Sorry! You're only allowed a max of " +
                        this.textbox.MaxLength + " characters for the '" +
                        this.fieldName + "' field. Your text has a size of " +
                        this.textbox.Text.Length + " characters.";

                args.IsValid = false;
            }
        }

        public override Unit Height
        {
            get
            {
                return base.Height;
            }
            set
            {
                this.textbox.Height = base.Height = value;
            }
        }
        public override Unit Width
        {
            get
            {
                return base.Width;
            }
            set
            {
                double validatorWidth = 30;
                if (value.Value > validatorWidth)
                {
                    base.Width = value;
                    this.textbox.Width = new Unit(value.Value - validatorWidth);
                }
            }
        }
        public string Text
        {
            set { this.textbox.Text = value; }
            get { return this.textbox.Text; }
        }

    }
}