/// <summary>
/// Updates selected elements according to rubberband adorner position
/// </summary>
private void UpdateSelection()
{
this.Rectangle = new Rect(this.startPoint.Value, this.endPoint.Value);
// update selection only when in appropriate mode
if (!this.toSelect)
{
return;
}
this.canvas.ClearSelection();
foreach (ContentPresenter presenter in this.canvas.Children)
{
// get item bounds
Rect itemRect = VisualTreeHelper.GetDescendantBounds(presenter);
Rect itemBounds = presenter.TransformToAncestor(this.canvas).TransformBounds(itemRect);
// check if item contains in rubberband rectangle
if (this.Rectangle.IntersectsWith(itemBounds))
{
// select item
BaseOmrElement question = (BaseOmrElement)VisualTreeHelper.GetChild(presenter, 0);
question.IsSelected = true;
}
}
}
/// <summary>
/// Finds all selected base omr elements inside canvas
/// </summary>
/// <param name="canvas">Canvas containing searched items</param>
/// <returns>List of content presenters with selected items</returns>
public static List <ContentPresenter> GetSelectedChildPresenters(CustomCanvas canvas)
{
List <ContentPresenter> presenters = new List <ContentPresenter>();
int childsCount = VisualTreeHelper.GetChildrenCount(canvas);
for (int i = 0; i < childsCount; i++)
{
ContentPresenter childPresenter = (ContentPresenter)VisualTreeHelper.GetChild(canvas, i);
BaseOmrElement childOmrItem = (BaseOmrElement)VisualTreeHelper.GetChild(childPresenter, 0);
if (childOmrItem.IsSelected)
{
presenters.Add(childPresenter);
}
}
return(presenters);
}
/// <summary>
/// Clears elements selection
/// </summary>
public void ClearSelection()
{
// find all content presenters wrapping child items (questions or bubbles)
List <ContentPresenter> presenters = ControlHelper.GetChildPresenters(this);
foreach (ContentPresenter presenter in presenters)
{
// find actual omr element that wrapped inside presenter
BaseOmrElement omrElement = VisualTreeHelper.GetChild(presenter, 0) as BaseOmrElement;
if (omrElement != null)
{
if (omrElement.IsSelected)
{
omrElement.IsSelected = false;
}
}
}
}
/// <summary>
/// Fires on IsSelected property changed
/// </summary>
/// <param name="sender">The sender</param>
/// <param name="e">The event args</param>
private static void IsSelectedPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
BaseOmrElement question = (BaseOmrElement)sender;
question.UpdateAdorners((bool)e.NewValue);
}
