/// <summary>
/// Handles the event which occurs when the selected item has changed
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void CollectionViewCurrentChanged(object sender, EventArgs e)
{
CollectionView collectionView = (CollectionView)sender;
if (collectionView != null && collectionView.CurrentPosition >= 0 && collectionView.CurrentPosition <= piePieces.Count)
{
PiePiece piece = piePieces[collectionView.CurrentPosition];
DoubleAnimation a = new DoubleAnimation();
a.To = 10;
a.Duration = new Duration(TimeSpan.FromMilliseconds(200));
piece.BeginAnimation(PiePiece.PushOutProperty, a);
}
}
/// <summary>
/// Handles the event which occurs just before a pie piece tooltip opens
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void PiePieceToolTipOpening(object sender, ToolTipEventArgs e)
{
PiePiece piece = (PiePiece)sender;
CollectionView collectionView = (CollectionView)CollectionViewSource.GetDefaultView(this.DataContext);
if (collectionView == null)
{
return;
}
// select the item which this pie piece represents
int index = (int)piece.Tag;
if (piece.ToolTip != null)
{
ToolTip tip = (ToolTip)piece.ToolTip;
tip.DataContext = collectionView.GetItemAt(index);
}
}
/// <summary>
/// Handles the MouseUp event from the individual Pie Pieces
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void PiePieceMouseUp(object sender, MouseButtonEventArgs e)
{
CollectionView collectionView = (CollectionView)CollectionViewSource.GetDefaultView(this.DataContext);
if (collectionView == null)
{
return;
}
PiePiece piece = sender as PiePiece;
if (piece == null)
{
return;
}
// select the item which this pie piece represents
int index = (int)piece.Tag;
collectionView.MoveCurrentToPosition(index);
}
/// <summary>
/// Constructs pie pieces and adds them to the visual tree for this control's canvas
/// </summary>
private void ConstructPiePieces()
{
CollectionView myCollectionView = (CollectionView)CollectionViewSource.GetDefaultView(this.DataContext);
if (myCollectionView == null)
return;
double halfWidth = this.Width / 2;
double innerRadius = halfWidth * HoleSize;
// compute the total for the property which is being plotted
double total = 0;
foreach (Object item in myCollectionView)
{
total += GetPlottedPropertyValue(item);
}
// add the pie pieces
canvas.Children.Clear();
piePieces.Clear();
double accumulativeAngle = 0;
foreach (Object item in myCollectionView)
{
bool selectedItem = item == myCollectionView.CurrentItem;
double wedgeAngle = GetPlottedPropertyValue(item) * 360 / total;
PiePiece piece = new PiePiece()
{
Radius = halfWidth,
InnerRadius = innerRadius,
CentreX = halfWidth,
CentreY = halfWidth,
PushOut = (selectedItem ? 10.0 : 0),
WedgeAngle = wedgeAngle,
PieceValue = GetPlottedPropertyValue(item),
RotationAngle = accumulativeAngle,
Fill = ColorSelector != null ? ColorSelector.SelectBrush(item, myCollectionView.IndexOf(item)) : Brushes.Black,
// record the index of the item which this pie slice represents
Tag = myCollectionView.IndexOf(item),
ToolTip = new ToolTip()
};
piece.ToolTipOpening += new ToolTipEventHandler(PiePieceToolTipOpening);
piece.MouseUp += new MouseButtonEventHandler(PiePieceMouseUp);
piePieces.Add(piece);
canvas.Children.Insert(0, piece);
accumulativeAngle += wedgeAngle;
}
}