xenadmin/XenAdmin/Commands/Controls/CommandButton.cs

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 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
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using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.ComponentModel;
using System.Drawing.Design;

namespace XenAdmin.Commands
{
    /// <summary>
    /// A <see cref="Button"/> that can be bound to a Command.
    /// </summary>
    internal class CommandButton : Button, ICommandControl
    {
        private Command _command;
        private SelectionBroadcaster _selectionBroadcaster;

        /// <summary>
        /// Initializes a new instance of the <see cref="CommandButton"/> class.
        /// </summary>
        public CommandButton()
        {
        }

        /// <summary>
        /// Gets or sets the command which is being used by the Command control.
        /// </summary>
        [DefaultValue(null)]
        [Editor(typeof(CommandEditor<Command>), typeof(UITypeEditor))]
        public Command Command
        {
            get
            {
                return _command;
            }
            set
            {
                if (value != _command)
                {
                    _command = value;
                    Update();
                }
            }
        }

        private void SelectionChanged(object sender, EventArgs e)
        {
            if (_command != null && _selectionBroadcaster != null)
            {
                ((ICommand)_command).SetSelection(_selectionBroadcaster.Selection);
                Update();
            }
        }

        private new void Update()
        {
            base.Enabled = DesignMode || Enabled;

            if (_command != null)
            {
                if (_command.ButtonText != null)
                {
                    Text = _command.ButtonText;
                }
            }
        }

        protected override void OnClick(EventArgs e)
        {
            if (Enabled)
            {
                _command.Execute();
            }
            base.OnClick(e);
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                SelectionBroadcaster = null;
            }

            base.Dispose(disposing);
        }

        [Browsable(false)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public new bool Enabled
        {
            get
            {
                return _command != null && _command.CanExecute();
            }
        }

        /// <summary>
        /// Sets the <see cref="SelectionBroadcaster"/> that should be listened to for selection changes.
        /// </summary>
        /// <value></value>
        [Browsable(false)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public SelectionBroadcaster SelectionBroadcaster
        {
            set
            {
                if (value != _selectionBroadcaster)
                {
                    if (_selectionBroadcaster != null)
                    {
                        _selectionBroadcaster.SelectionChanged -= SelectionChanged;
                    }

                    _selectionBroadcaster = value;

                    if (_selectionBroadcaster != null)
                    {
                        _selectionBroadcaster.SelectionChanged += SelectionChanged;
                    }

                    SelectionChanged(null, null);
                }
            }
        }
    }
}