/// <summary>
/// Implement the single-click behavior for this handle, to toggle the
/// expansion state of the <see cref="T:Northwoods.Go.IGoCollapsible" /> that this handle is in.
/// </summary>
/// <param name="evt"></param>
/// <param name="view"></param>
/// <returns>true if the parent <see cref="P:Northwoods.Go.IGoCollapsible.Collapsible" /> property is true</returns>
/// <remarks>
/// If <see cref="P:Northwoods.Go.IGoCollapsible.IsExpanded" /> is true, this calls <see cref="M:Northwoods.Go.IGoCollapsible.Collapse" />;
/// otherwise this calls <see cref="M:Northwoods.Go.IGoCollapsible.Expand" />.
/// If the view is non-null, this method calls <see cref="M:Northwoods.Go.GoView.StartTransaction" />
/// and <see cref="M:Northwoods.Go.GoView.FinishTransaction(System.String)" />, with a transaction name specified by
/// the value of <see cref="F:Northwoods.Go.GoUndoManager.CollapsedName" /> or <see cref="F:Northwoods.Go.GoUndoManager.ExpandedName" />.
/// </remarks>
public override bool OnSingleClick(GoInputEventArgs evt, GoView view)
{
IGoCollapsible goCollapsible = FindCollapsible();
if (goCollapsible == null)
{
return(false);
}
string tname = null;
try
{
view?.StartTransaction();
if (goCollapsible.IsExpanded)
{
goCollapsible.Collapse();
tname = "Collapsed";
}
else
{
goCollapsible.Expand();
tname = "Expanded";
}
}
finally
{
view?.FinishTransaction(tname);
}
return(true);
}
