/// <summary>
/// Handles the <see cref="ButtonBase.Click"/> event for the "Add Entity" <see
/// cref="Button"/>.</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>OnEntityAdd</b> shows an error message if the <see cref="ImageSection"/> does not
/// currently define any images. Otherwise, <b>OnEntityAdd</b> displays a <see
/// cref="Dialog.ChangeIdentifier"/> dialog, followed by a <see cref="Dialog.ChangeEntity"/>
/// dialog, allowing the user to define a new entity. The new entity copies the properties
/// of the first selected item in the "Entity" list view, if any; otherwise, it is created
/// with default properties.
/// </para><para>
/// If the user confirmed both dialogs, <b>OnEntityAdd</b> adds the new entity to the
/// "Entity" list view and to the <see cref="CurrentEntities"/> collection, and sets the
/// <see cref="SectionTabItem.DataChanged"/> flag.</para></remarks>
private void OnEntityAdd(object sender, RoutedEventArgs args)
{
args.Handled = true;
// abort if there are no images
if (MasterSection.Instance.Images.Collection.Count == 0)
{
MessageBox.Show(MainWindow.Instance,
Global.Strings.DialogImageNone, Global.Strings.TitleImageNone,
MessageBoxButton.OK, MessageBoxImage.Information);
return;
}
// ask user for new entity ID
var entities = CurrentEntities;
var dialog = new Dialog.ChangeIdentifier(CurrentDefaultId,
Global.Strings.TitleEntityIdEnter, entities.ContainsKey, false);
dialog.Owner = MainWindow.Instance;
if (dialog.ShowDialog() != true)
{
return;
}
// retrieve new entity ID
string id = String.Intern(dialog.Identifier);
// create new entity based on selected entity, if any
EntityClass entity, selection = EntityList.SelectedItem as EntityClass;
if (selection == null)
{
entity = EntityClass.Create(id, CurrentCategory);
}
else
{
entity = (EntityClass)selection.Clone();
entity.Id = id;
}
// let user make changes to new entity
var entityDialog = new Dialog.ChangeEntity(entity)
{
Owner = MainWindow.Instance
};
if (entityDialog.ShowDialog() != true)
{
return;
}
// add entity to section table
entities.Add(id, entity);
// update list view and select new item
EntityList.Items.Refresh();
EntityList.SelectAndShow(entity);
// broadcast data changes
EnableListButtons();
SectionTab.DataChanged = true;
}
