Build Your Own DataGrid for Silverlight: Step 3

// Copyright 2008-2009 NETiKA TECH.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Windows;

namespace Open.Windows.Controls
{
    /// <summary>
    /// Item to use inside a HandyContainer control. 
    /// </summary>
    public partial class ContainerItem : HandyListItem
    {
        public static readonly DependencyProperty HandyStyleProperty;
        public static readonly DependencyProperty HandyOverflowedStyleProperty;

        static ContainerItem()
        {
            HandyStyleProperty = DependencyProperty.Register("HandyStyle", typeof(HandyContainerItemStyle), typeof(ContainerItem), new PropertyMetadata(new PropertyChangedCallback(OnHandyStyleChanged)));
            HandyOverflowedStyleProperty = DependencyProperty.Register("HandyOverflowedStyle", typeof(HandyContainerItemStyle), typeof(ContainerItem), new PropertyMetadata(new PropertyChangedCallback(OnHandyOverflowedStyleChanged)));
        }

        public ContainerItem()
        {
            this.DefaultStyleKey = typeof(ContainerItem);
        }

        /// <summary>
        /// The Style to apply to the item  
        /// </summary>
        public HandyContainerItemStyle HandyStyle
        {
            get
            {
                return (HandyContainerItemStyle)this.GetValue(HandyStyleProperty);
            }
            set
            {
                base.SetValue(HandyStyleProperty, value);
            }
        }

        private static void OnHandyStyleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ContainerItem item = (ContainerItem)d;

            item.ApplyHandyStyle();
        }

        private void ApplyHandyStyle()
        {
            if (HandyStyle == HandyContainerItemStyle.None)
            {
                HasInternalStyle = false;
                return;
            }

            HandyContainer container = ManagedItemsControl as HandyContainer;
            if (container != null)
            {
                Style style = container.GetItemStyle(HandyStyle);
                if (style != null)
                {
                    if (this.Style == null)
                    {
                        this.Style = style;
                        OnHandyStyleApplied(EventArgs.Empty);
                    }
                }
            }

            HasInternalStyle = true;            
        }

        /// <summary>
        /// The Style to apply to the item if it is displayed in an OverflowControl.  
        /// </summary>
        public HandyContainerItemStyle HandyOverflowedStyle
        {
            get
            {
                return (HandyContainerItemStyle)this.GetValue(HandyOverflowedStyleProperty);
            }
            set
            {
                base.SetValue(HandyOverflowedStyleProperty, value);
            }
        }

        private static void OnHandyOverflowedStyleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ContainerItem item = (ContainerItem)d;

            item.ApplyHandyOverflowedStyle();
        }

        private void ApplyHandyOverflowedStyle()
        {
            if (HandyOverflowedStyle == HandyContainerItemStyle.None)
                return;

            HandyContainer container = ManagedItemsControl as HandyContainer;
            if (container != null)
            {
                Style style = container.GetItemStyle(HandyOverflowedStyle);

                if (style != null)
                {
                    if (this.OverflowedItemStyle == null)
                        this.OverflowedItemStyle = style;
                }
            }
        }

        private void _OnApplyTemplate()
        {
            if ((this.Style == null) && (!System.ComponentModel.DesignerProperties.GetIsInDesignMode(this)))
                throw new NotSupportedException("ContainerItem style is null. Please apply a style to the item either using the DefaultItemStyle or the HandyDefaultItemStyle of its container. A frequent mistake is to use a ContainerItem inside a HandyNavigator or a HandyCommand.");

        }

        protected override void OnManagedItemsControlChanged(EventArgs e)
        {
            base.OnManagedItemsControlChanged(e);

            ApplyHandyStyle();
            ApplyHandyOverflowedStyle();
        }
    }
}