/// <summary>
/// Sets scroll and zoom to center the given rectangle in the client area with a given scale</summary>
/// <param name="adapter">Adapter managing transform</param>
/// <param name="scale">Scale</param>
/// <param name="itemBounds">Rectangle to frame, in client coordinates</param>
/// <param name="clientBounds">Client area</param>
public static void ZoomAboutCenter(this ITransformAdapter adapter, Point scale, Rect itemBounds, Rect clientBounds)
{
if (adapter == null || !adapter.Transform.HasInverse)
{
return;
}
Rect worldBounds = MathUtil.InverseTransform(adapter.Transform, itemBounds);
if (adapter.UniformScale)
{
scale.X = scale.Y = Math.Min(scale.X, scale.Y);
}
scale = TransformAdapters.ConstrainScale(adapter, scale);
// calculate translation needed to put bounds center at center of view
Point worldBoundsCenter = new Point(
worldBounds.X + worldBounds.Width / 2,
worldBounds.Y + worldBounds.Height / 2);
Point translation = new Point(
clientBounds.Width / 2 - worldBoundsCenter.X * scale.X,
clientBounds.Height / 2 - worldBoundsCenter.Y * scale.Y);
adapter.SetTransform(scale.X, scale.Y, translation.X, translation.Y);
}
/// <summary>
/// Sets scroll and zoom so that the largest axis of the given rectangle almost
/// fills the client area</summary>
/// <param name="adapter">Adapter managing transform</param>
/// <param name="itemBounds">Rectangle to frame, in client coordinates</param>
/// <param name="clientBounds">Client area</param>
public static void Frame(this ITransformAdapter adapter, Rect itemBounds, Rect clientBounds)
{
if (adapter == null || itemBounds.IsEmpty || !adapter.Transform.HasInverse)
{
return;
}
Rect worldBounds = MathUtil.InverseTransform(adapter.Transform, itemBounds);
// calculate scale so bounding rectangle (in world coordinates) fills client
// rectangle with some margin around the edges
const double MarginScale = 0.86;
Point scale = new Point(
Math.Abs(clientBounds.Width / worldBounds.Width) * MarginScale,
Math.Abs(clientBounds.Height / worldBounds.Height) * MarginScale);
if (adapter.UniformScale)
{
scale.X = scale.Y = Math.Min(scale.X, scale.Y);
}
scale = TransformAdapters.ConstrainScale(adapter, scale);
// calculate translation needed to put bounds center at center of view
Point worldBoundsCenter = new Point(
worldBounds.X + worldBounds.Width / 2,
worldBounds.Y + worldBounds.Height / 2);
Point translation = new Point(
clientBounds.Width / 2 - worldBoundsCenter.X * scale.X,
clientBounds.Height / 2 - worldBoundsCenter.Y * scale.Y);
adapter.SetTransform(scale.X, scale.Y, translation.X, translation.Y);
}
/// <summary>
/// If the given rectangle isn't visible, sets scroll and scale so that the largest axis
/// of the rectangle almost fills the client area</summary>
/// <param name="adapter">Adapter managing transform</param>
/// <param name="itemBounds">Rectangle to ensure visible</param>
/// <param name="clientBounds">Client area</param>
public static void EnsureVisible(this ITransformAdapter adapter, Rect itemBounds, Rect clientBounds)
{
// check rectangle is already in the visible rect
if (clientBounds.Contains(itemBounds))
{
// already visible
return;
}
TransformAdapters.Frame(adapter, itemBounds, clientBounds);
}
