/CBR/CBR/Components/Designer/ResizeThumb.cs

using System;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Controls.Primitives;

using System.Windows.Media;



namespace CBR.Components.Designer

{

    public class ResizeThumb : Thumb

    {

        private DesignerItem designerItem;

        private DesignerCanvas designerCanvas;



        public ResizeThumb()

        {

            DragStarted += new DragStartedEventHandler(this.ResizeThumb_DragStarted);

            DragDelta += new DragDeltaEventHandler(this.ResizeThumb_DragDelta);

        }



        private void ResizeThumb_DragStarted(object sender, DragStartedEventArgs e)

        {

            this.designerItem = DataContext as DesignerItem;



            if (this.designerItem != null)

            {

                this.designerCanvas = VisualTreeHelper.GetParent(this.designerItem) as DesignerCanvas;

            }

        }



        private void ResizeThumb_DragDelta(object sender, DragDeltaEventArgs e)

        {

            if (this.designerItem != null && this.designerCanvas != null && this.designerItem.IsSelected)

            {

                double minLeft = double.MaxValue;

                double minTop = double.MaxValue;

                double minDeltaHorizontal = double.MaxValue;

                double minDeltaVertical = double.MaxValue;

                double dragDeltaVertical, dragDeltaHorizontal;



                foreach (DesignerItem item in this.designerCanvas.SelectedItems)

                {

                    minLeft = Math.Min(Canvas.GetLeft(item), minLeft);

                    minTop = Math.Min(Canvas.GetTop(item), minTop);



                    minDeltaVertical = Math.Min(minDeltaVertical, item.ActualHeight - item.MinHeight);

                    minDeltaHorizontal = Math.Min(minDeltaHorizontal, item.ActualWidth - item.MinWidth);

                }



                foreach (DesignerItem item in this.designerCanvas.SelectedItems)

                {

                    switch (VerticalAlignment)

                    {

                        case VerticalAlignment.Bottom:

                            dragDeltaVertical = Math.Min(-e.VerticalChange, minDeltaVertical);

                            item.Height = item.ActualHeight - dragDeltaVertical;

                            break;

                        case VerticalAlignment.Top:

                            dragDeltaVertical = Math.Min(Math.Max(-minTop, e.VerticalChange), minDeltaVertical);

                            Canvas.SetTop(item, Canvas.GetTop(item) + dragDeltaVertical);

                            item.Height = item.ActualHeight - dragDeltaVertical;

                            break;

                    }



                    switch (HorizontalAlignment)

                    {

                        case HorizontalAlignment.Left:

                            dragDeltaHorizontal = Math.Min(Math.Max(-minLeft, e.HorizontalChange), minDeltaHorizontal);

                            Canvas.SetLeft(item, Canvas.GetLeft(item) + dragDeltaHorizontal);

                            item.Width = item.ActualWidth - dragDeltaHorizontal;

                            break;

                        case HorizontalAlignment.Right:

                            dragDeltaHorizontal = Math.Min(-e.HorizontalChange, minDeltaHorizontal);

                            item.Width = item.ActualWidth - dragDeltaHorizontal;

                            break;

                    }

                }



                e.Handled = true;

            }

        }

    }

}