/// <summary>
/// Handles the <see cref="ButtonBase.Click"/> event for the "Circumscribe" <see
/// cref="Button"/> on the <see cref="StructureTab"/> page.</summary>
/// <param name="sender">
/// The <see cref="Object"/> where the event handler is attached.</param>
/// <param name="args">
/// A <see cref="RoutedEventArgs"/> object containing event data.</param>
/// <remarks><para>
/// <b>OnCircumscribe</b> sets the "Side Length" control to a value that circumscribes <see
/// cref="PolygonGrid.Element"/> of the <see cref="MapGrid"/> around the selected item, if
/// any, in the "Image Frame Sizes" combo box.
/// </para><para>
/// Changing the "Side Length" control triggers <see cref="OnLengthChanged"/> which resizes
/// the <see cref="PolygonGrid.Element"/> accordingly and sets the <see cref="DataChanged"/>
/// flag.</para></remarks>
private void OnCircumscribe(object sender, RoutedEventArgs args)
{
args.Handled = true;
if (this._ignoreEvents)
{
return;
}
// get selected image size, if any
ImageSizeItem item = ImageSizeCombo.SelectedItem as ImageSizeItem;
if (item == null)
{
return;
}
// circumscribe polygon around image size
RegularPolygon element = MapGrid.Element;
var circumscribed = element.Circumscribe(item.Value.Width, item.Value.Height);
// restrict side length to legal range
double length = circumscribed.Length;
if (length < AreaSection.MinPolygonLength)
{
length = AreaSection.MinPolygonLength;
}
if (length > AreaSection.MaxPolygonLength)
{
length = AreaSection.MaxPolygonLength;
}
// show new side length if changed (triggers OnLengthChanged)
if (length != element.Length)
{
LengthUpDown.Value = (decimal)length;
}
}
