/// <summary>
/// Combines two drawing objects into single canvas object.
/// If both drawing objects are canvas, first canvas will get all second canvas drawing objects and second canvas will be cleared.
/// If only one of the objects is canvas, second object will be added to the canvas.
/// If none of the objects is canvas, new canvas will be created with both drawings.
/// </summary>
/// <param name="graphics"><see cref="IGraphics"/> object.</param>
/// <param name="drawing1">First drawing object.</param>
/// <param name="drawing2">Second drawing object.</param>
/// <returns>Canvas object containing both drawing objects.</returns>
public static ICanvas Combine(this IGraphics graphics, IDrawing drawing1, IDrawing drawing2)
{
ICanvas canvas1 = drawing1 as ICanvas;
ICanvas canvas2 = drawing2 as ICanvas;
if (canvas1 != null && canvas2 != null)
{
IDrawing[] drawings = canvas2.Drawings.ToArray();
canvas2.Clear();
foreach (IDrawing drawing in drawings)
{
canvas1.AddDrawing(drawing);
}
return(canvas1);
}
else if (canvas1 != null)
{
canvas1.AddDrawing(drawing2);
return(canvas1);
}
else if (canvas2 != null)
{
canvas2.AddDrawing(drawing1);
return(canvas2);
}
else
{
return(graphics.CreateCanvas(drawing1, drawing2));
}
}
/// <summary>
/// Adds drawing objects to the list of drawing objects.
/// </summary>
/// <param name="canvas"><see cref="ICanvas"/> object.</param>
/// <param name="drawings">Drawing objects.</param>
public static void Add(this ICanvas canvas, params IDrawing[] drawings)
{
foreach (IDrawing drawing in drawings)
{
canvas.AddDrawing(drawing);
}
}