/// <summary>
/// Occurs as the mouse changes position when a Thumb control has logical focus and mouse capture
/// </summary>
/// <param name="sender">The sender</param>
/// <param name="e">The event args</param>
private void ResizeDragDelta(object sender, DragDeltaEventArgs e)
{
// get to resized element
Grid thumbsGrid = (Grid)VisualTreeHelper.GetParent(this);
Thumb parentThumb = (Thumb)VisualTreeHelper.GetParent(thumbsGrid);
Adorner adorner = (Adorner)VisualTreeHelper.GetParent(parentThumb);
// presenter that holds dragged item
ContentPresenter presenter = (ContentPresenter) VisualTreeHelper.GetParent(adorner.AdornedElement);
// parent canvas
CustomCanvas canvas = (CustomCanvas) VisualTreeHelper.GetParent(presenter);
// prepare items for resize depending on item level (question or bubble)
List<ContentPresenter> presenters;
if (canvas.Name.Equals(Properties.Resources.RootCanvasName))
{
// here we resize questions (e.g. choicebox), so take selected items
presenters = ControlHelper.GetSelectedChildPresenters(canvas);
}
else
{
// here we resize bubbles, so get neighbor bubbles inside question (always resize bubbles equally)
presenters = ControlHelper.GetChildPresenters(canvas);
}
double minLeft, minTop, minDeltaHorizontal, minDeltaVertical;
double maxDeltaVertical, maxDeltaHorizontal;
double maxHorizontalDeltaToChild = double.MaxValue;
double maxVerticalDeltaToChild = double.MaxValue;
this.CalculateLimits(canvas, presenters, out minLeft, out minTop, out minDeltaHorizontal, out minDeltaVertical,
out maxDeltaHorizontal, out maxDeltaVertical);
minDeltaVertical = Math.Min(minDeltaVertical, maxVerticalDeltaToChild);
minDeltaHorizontal = Math.Min(minDeltaHorizontal, maxHorizontalDeltaToChild);
foreach (ContentPresenter element in presenters)
{
double newHeight = element.ActualHeight;
double newWidth = element.ActualWidth;
double newTop = Canvas.GetTop(element);
double newLeft = Canvas.GetLeft(element);
double scale, dragDeltaVertical;
switch (this.VerticalAlignment)
{
case VerticalAlignment.Bottom:
dragDeltaVertical = Math.Max(Math.Min(-e.VerticalChange, minDeltaVertical), -maxDeltaVertical);
newHeight = element.ActualHeight - dragDeltaVertical;
break;
case VerticalAlignment.Top:
dragDeltaVertical = Math.Min(Math.Max(-minTop, e.VerticalChange), minDeltaVertical);
scale = (element.ActualHeight - dragDeltaVertical) / element.ActualHeight;
newTop = newTop - element.Height * (scale - 1);
newHeight = element.ActualHeight - dragDeltaVertical;
break;
}
double dragDeltaHorizontal;
switch (this.HorizontalAlignment)
{
case HorizontalAlignment.Left:
dragDeltaHorizontal = Math.Min(Math.Max(-minLeft, e.HorizontalChange), minDeltaHorizontal);
scale = (element.ActualWidth - dragDeltaHorizontal) / element.ActualWidth;
newLeft = Canvas.GetLeft(element) - element.Width * (scale - 1);
newWidth = element.ActualWidth * scale;
break;
case HorizontalAlignment.Right:
dragDeltaHorizontal = Math.Max(Math.Min(-e.HorizontalChange, minDeltaHorizontal), -maxDeltaHorizontal);
newWidth = element.ActualWidth - dragDeltaHorizontal;
break;
}
var childs = this.GetChildElements(element);
if (childs == null)
{
element.Width = newWidth;
element.Height = newHeight;
Canvas.SetTop(element, newTop);
Canvas.SetLeft(element, newLeft);
}
else
{
double scaleH = newHeight / element.ActualHeight;
double scaleW = newWidth / element.ActualWidth;
if (this.CanTransformChildsRecursive(childs, scaleH, scaleW))
{
this.TransformChildsRecursive(childs, scaleH, scaleW);
element.Width = newWidth;
element.Height = newHeight;
Canvas.SetTop(element, newTop);
Canvas.SetLeft(element, newLeft);
}
}
}
e.Handled = true;
}