private DiagramContext getContext()
{
if (_context == null)
{
var testCanvas = new DiagramCanvas();
var diagramDef = new DiagramDefinition(null);
foreach (var item in _items.Values)
{
diagramDef.DrawItem(item);
}
var provider = new DrawingProvider(testCanvas, new TestDrawingFactory());
_context = provider.Display(diagramDef);
testCanvas.Measure(new Size(Double.PositiveInfinity, Double.PositiveInfinity));
testCanvas.Arrange(new Rect(new Point(), testCanvas.DesiredSize));
}
return(_context);
}
/// <summary>
/// Draws the specified item for given instance.
/// </summary>
/// <param name="instance">Instance which is represented by given drawing item</param>
/// <param name="item">Item drawing.</param>
internal void DrawItem(DrawedInstance instance, DiagramItemDefinition item)
{
Context.DrawItem(item);
_displayedInstances.Add(instance.WrappedInstance);
}