Hello All,
I have developed a WPF application that permits the user to draw shapes like Rectangle, Ellipse, Line, and Polyline objects over DrawingSurface (canvas), also the user can zoom-in and zoom-out the DrawingSurface , which means zooming-in/out these shapes too. These shapes can be resized. For resizing I used adorners.
I iherited the Adorner class and made custom ResizeAdorner class. This class contains 8 thumbs (topLeft, top, topRight, left, right, bottomLeft, bottom ,bottomRight) who are placed at corners and sides of adorned item (selected shape).
Because, I didn`t want my thumbs to be scaled with shape that is currently editing, if the shape was scaled-up or down, therefore I overrided the GetDesiredTransform method in my adorner class (ResizeAdorner) to scale down the thumb by setting the Thumb.RenderTransform property to 1/zoomFactor.
This is the point where my problems starts.
If I try to resize the shape, the thub starts to behave strange. It`s drag delta gets strange values who are not desired and who affect on shape`s shape(size). If I let thumbs to scale with shape (I have big, scaled thumbs) everything works fine.
I noticed that Canvas.SetTop(), CanvasSetLeft() method in MoveXXX mehtods in EllipseResizeAdorner class affect on this problem. Everything works fine on zoom level 1. (1:1) but when I increase/decrease zoom level problems starts.
What might be a problem ?
Thanks in advance.
Here is code of ResizeAdorner class:
public abstract class ResizeAdorner : Adorner
{
#region Fields
public static readonly RoutedEvent MoveResizeAdornerThumbEvent = EventManager.RegisterRoutedEvent("MoveResizeAdornerThumb", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(ResizeAdorner));
// Represent Flag that indicates that mirrored axis is corssed during ellipse resizing process.
private bool mirrorAxisYCrossed = false;
private bool mirrorAxisXCrossed = false;
// Represent thumbs which surrounds DrawingItem and we use them for resizing the drawing item.
private ResizeAdornerThumb resizeTopLeftThumb;
private ResizeAdornerThumb resizeTopThumb;
private ResizeAdornerThumb resizeTopRightThumb;
private ResizeAdornerThumb resizeLeftThumb;
private ResizeAdornerThumb resizeRightThumb;
private ResizeAdornerThumb resizeBottomLeftThumb;
private ResizeAdornerThumb resizeBottomThumb;
private ResizeAdornerThumb resizeBottomRightThumb;
// Represent Horisontal and Vertical start points of ResizeAdorner Thumbs during moving.
private double thumbHorizontalStartPoint;
private double thumbVerticalStartPoint;
#endregion
private VisualCollection visualChildren;
protected DrawingItem DrawingItem { get; set; }
protected FrameworkElement ItemCanvas { get; set; }
// Constructors
public ResizeAdorner(FrameworkElement itemCanvas, DrawingItem drawingItem)
: base(drawingItem)
{
this.DrawingItem = drawingItem;
this.visualChildren = new VisualCollection(this);
this.ItemCanvas = itemCanvas;
InitializeResizeTopLeftThumb();
InitializeResizeTopThumb();
InitializeResizeTopRightThumb();
InitializeResizeLeftThumb();
InitializeResizeRightThumb();
InitializeResizeBottomLeftThumb();
InitializeResizeBottomThumb();
InitializeResizeBottomRightThumb();
}
public event RoutedEventHandler MoveResizeAdornerThumbHandler
{
add { AddHandler(MoveResizeAdornerThumbEvent, value); }
remove { RemoveHandler(MoveResizeAdornerThumbEvent, value); }
}
#region Properties
protected bool MirrorAxisYCrossed
{
get { return mirrorAxisYCrossed; }
set { mirrorAxisYCrossed = value; }
}
protected bool MirrorAxisXCrossed
{
get { return mirrorAxisXCrossed; }
set { mirrorAxisXCrossed = value; }
}
protected ResizeAdornerThumb ResizeTopLeftThumb
{
get { return resizeTopLeftThumb; }
set { resizeTopLeftThumb = value; }
}
protected ResizeAdornerThumb ResizeTopThumb
{
get { return resizeTopThumb; }
set { resizeTopThumb = value; }
}
protected ResizeAdornerThumb ResizeTopRightThumb
{
get { return resizeTopRightThumb; }
set { resizeTopRightThumb = value; }
}
protected ResizeAdornerThumb ResizeLeftThumb
{
get { return resizeLeftThumb; }
set { resizeLeftThumb = value; }
}
protected ResizeAdornerThumb ResizeRightThumb
{
get { return resizeRightThumb; }
set { resizeRightThumb = value; }
}
protected ResizeAdornerThumb ResizeBottomLeftThumb
{
get { return resizeBottomLeftThumb; }
set { resizeBottomLeftThumb = value; }
}
protected ResizeAdornerThumb ResizeBottomThumb
{
get { return resizeBottomThumb; }
set { resizeBottomThumb = value; }
}
protected ResizeAdornerThumb ResizeBottomRightThumb
{
get { return resizeBottomRightThumb; }
set { resizeBottomRightThumb = value; }
}
#endregion
public void ShowAdorner()
{
resizeTopLeftThumb.Visibility = Visibility.Visible;
resizeTopThumb.Visibility = Visibility.Visible;
resizeTopRightThumb.Visibility = Visibility.Visible;
resizeLeftThumb.Visibility = Visibility.Visible;
resizeRightThumb.Visibility = Visibility.Visible;
resizeBottomLeftThumb.Visibility = Visibility.Visible;
resizeBottomThumb.Visibility = Visibility.Visible;
resizeBottomRightThumb.Visibility = Visibility.Visible;
}
public void HideAdorner()
{
resizeTopLeftThumb.Visibility = Visibility.Hidden;
resizeTopThumb.Visibility = Visibility.Hidden;
resizeTopRightThumb.Visibility = Visibility.Hidden;
resizeLeftThumb.Visibility = Visibility.Hidden;
resizeRightThumb.Visibility = Visibility.Hidden;
resizeBottomLeftThumb.Visibility = Visibility.Hidden;
resizeBottomThumb.Visibility = Visibility.Hidden;
resizeBottomRightThumb.Visibility = Visibility.Hidden;
}
public void RaiseMoveResizeAdornerThumbEvent(ResizeAdornerThumb thumb, double horizontalChange, double verticalChange, bool mirrorAxisXCrossed, bool mirrorAxisYCrossed)
{
MovedResizeAdornerThumbRoutedEventArgs newEventArgs = new MovedResizeAdornerThumbRoutedEventArgs(MoveResizeAdornerThumbEvent,
this,
thumb,
horizontalChange,
verticalChange,
mirrorAxisXCrossed,
mirrorAxisYCrossed);
RaiseEvent(newEventArgs);
}
public void MoveResizeAdornerThumb(ResizeAdornerThumb thumb, double horizontalMove, double verticalMove, bool resetMirrorFlags)
{
ResizeAdornerThumb.ThumbType thumbType = thumb.Type;
//CheckHelper.CheckCanvasBoundaries(this.ItemCanvas, thumb, ref horizontalMove, ref verticalMove);
switch (thumbType)
{
case ResizeAdornerThumb.ThumbType.TopLeft:
MoveTop(verticalMove);
MoveLeft(horizontalMove);
break;
case ResizeAdornerThumb.ThumbType.Top:
MoveTop(verticalMove);
break;
case ResizeAdornerThumb.ThumbType.TopRight:
MoveTop(verticalMove);
MoveRight(horizontalMove);
break;
case ResizeAdornerThumb.ThumbType.Left:
MoveLeft(horizontalMove);
break;
case ResizeAdornerThumb.ThumbType.Right:
MoveRight(horizontalMove);
break;
case ResizeAdornerThumb.ThumbType.BottomLeft:
MoveBottom(verticalMove);
MoveLeft(horizontalMove);
break;
case ResizeAdornerThumb.ThumbType.Bottom:
MoveBottom(verticalMove);
break;
case ResizeAdornerThumb.ThumbType.BottomRight:
MoveBottom(verticalMove);
MoveRight(horizontalMove);
break;
default:
break;
}
if (resetMirrorFlags)
{
// Reset mirror flags
this.mirrorAxisXCrossed = false;
this.mirrorAxisYCrossed = false;
}
}
protected abstract void MoveTop(double verticalChange);
protected abstract void MoveBottom(double verticalChange);
protected abstract void MoveLeft(double horizontalChange);
protected abstract void MoveRight(double horizontalChange);
#region ResizeAdornerThumbs
private void InitializeResizeTopLeftThumb()
{
resizeTopLeftThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.TopLeft, Cursors.SizeNWSE);
resizeTopLeftThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeTopLeftThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeTopLeftThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeTopLeftThumb);
}
private void InitializeResizeTopThumb()
{
resizeTopThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.Top, Cursors.SizeNS);
resizeTopThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeTopThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeTopThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeTopThumb);
}
private void InitializeResizeTopRightThumb()
{
this.resizeTopRightThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.TopRight, Cursors.SizeNESW);
resizeTopRightThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeTopRightThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeTopRightThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeTopRightThumb);
}
private void InitializeResizeLeftThumb()
{
resizeLeftThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.Left, Cursors.SizeWE);
resizeLeftThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeLeftThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeLeftThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeLeftThumb);
}
private void InitializeResizeRightThumb()
{
resizeRightThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.Right, Cursors.SizeWE);
resizeRightThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeRightThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeRightThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeRightThumb);
}
private void InitializeResizeBottomLeftThumb()
{
resizeBottomLeftThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.BottomLeft, Cursors.SizeNESW);
resizeBottomLeftThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeBottomLeftThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeBottomLeftThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeBottomLeftThumb);
}
private void InitializeResizeBottomThumb()
{
resizeBottomThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.Bottom, Cursors.SizeNS);
resizeBottomThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeBottomThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeBottomThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeBottomThumb);
}
private void InitializeResizeBottomRightThumb()
{
resizeBottomRightThumb = new ResizeAdornerThumb(ResizeAdornerThumb.ThumbType.BottomRight, Cursors.SizeNWSE);
resizeBottomRightThumb.DragStarted += new DragStartedEventHandler(ResizeAdornerThumb_DragStarted);
resizeBottomRightThumb.DragCompleted += new DragCompletedEventHandler(ResizeAdornerThumb_DragCompleted);
resizeBottomRightThumb.DragDelta += new DragDeltaEventHandler(ResizeAdornerThumb_DragDelta);
this.visualChildren.Add(resizeBottomRightThumb);
}
#endregion
// Resize Adorner Thumbs Handlers
#region ResizeAdornerThumbs Handlers
private void ResizeAdornerThumb_DragStarted(object sender, DragStartedEventArgs e)
{
ResizeAdornerThumb thumb = sender as ResizeAdornerThumb;
thumbHorizontalStartPoint = Canvas.GetLeft(thumb);
thumbVerticalStartPoint = Canvas.GetTop(thumb);
}
private void ResizeAdornerThumb_DragCompleted(object sender, DragCompletedEventArgs e)
{
//ResizeAdornerThumb thumb = sender as ResizeAdornerThumb;
//double thumbHorizontalChange = 0;
//double thumbVerticalChange = 0;
//// Calculate appropriate horisontal change for certain thumb
//if (mirrorAxisYCrossed)
//{
// // For Left thumbs
// if (thumb.Type == ResizeAdornerThumb.ThumbType.TopLeft ||
// thumb.Type == ResizeAdornerThumb.ThumbType.Left ||
// thumb.Type == ResizeAdornerThumb.ThumbType.BottomLeft)
// {
// thumbHorizontalChange = (Canvas.GetLeft(thumb) - thumbHorizontalStartPoint) + this.DrawingItem.Width; // +width because we were crossed Y axis and at that point left thumb is fixed at Y axis
// }
// else
// {
// // For right thumbs
// thumbHorizontalChange = (thumbHorizontalStartPoint - Canvas.GetLeft(thumb)) + this.DrawingItem.Width;
// thumbHorizontalChange = -thumbHorizontalChange; // negative move
// }
//}
//else
//{
// thumbHorizontalChange = Canvas.GetLeft(thumb) - thumbHorizontalStartPoint;
//}
//// Calculate appropriate vertical change for certain thumb
//if (mirrorAxisXCrossed)
//{
// // For Top thumbs
// if (thumb.Type == ResizeAdornerThumb.ThumbType.TopLeft ||
// thumb.Type == ResizeAdornerThumb.ThumbType.Top ||
// thumb.Type == ResizeAdornerThumb.ThumbType.TopRight)
// {
// thumbVerticalChange = (Canvas.GetTop(thumb) - thumbVerticalStartPoint) + this.DrawingItem.Height;
// }
// else
// {
// // For Bottom thumbs
// thumbVerticalChange = (thumbVerticalStartPoint - Canvas.GetTop(thumb)) + this.DrawingItem.Height;
// thumbVerticalChange = -thumbVerticalChange; // negative move
// }
//}
//else
//{
// thumbVerticalChange = Canvas.GetTop(thumb) - thumbVerticalStartPoint;
//}
//this.RaiseMoveResizeAdornerThumbEvent(thumb, thumbHorizontalChange, thumbVerticalChange, mirrorAxisXCrossed, mirrorAxisYCrossed);
// Reset mirror flags
this.mirrorAxisXCrossed = false;
this.mirrorAxisYCrossed = false;
}
private void ResizeAdornerThumb_DragDelta(object sender, DragDeltaEventArgs e)
{
ResizeAdornerThumb thumb = sender as ResizeAdornerThumb;
MoveResizeAdornerThumb(thumb, e.HorizontalChange, e.VerticalChange, false);
}
#endregion
protected override int VisualChildrenCount
{
get
{
return this.visualChildren.Count;
}
}
protected override Visual GetVisualChild(int index)
{
return this.visualChildren[index];
}
protected override Size ArrangeOverride(Size finalSize)
{
base.ArrangeOverride(finalSize);
double thumbWidth = resizeTopLeftThumb.Width;
double thumbHeight = resizeTopLeftThumb.Height;
double desiredWidth = AdornedElement.DesiredSize.Width;
double desiredHeight = AdornedElement.DesiredSize.Height;
resizeTopLeftThumb.Arrange(new Rect(-thumbWidth / 2, -thumbHeight / 2, thumbWidth, thumbHeight));
resizeTopThumb.Arrange(new Rect(desiredWidth / 2 - thumbWidth / 2, -thumbHeight / 2, thumbWidth, thumbHeight));
resizeTopRightThumb.Arrange(new Rect(desiredWidth - thumbWidth / 2, -thumbHeight / 2, thumbWidth, thumbHeight));
resizeLeftThumb.Arrange(new Rect(-thumbWidth / 2, desiredHeight/2 - thumbHeight / 2, thumbWidth, thumbHeight));
resizeRightThumb.Arrange(new Rect(desiredWidth - thumbWidth / 2, desiredHeight/2 - thumbHeight / 2, thumbWidth, thumbHeight));
resizeBottomLeftThumb.Arrange(new Rect(-thumbWidth / 2, desiredHeight - thumbHeight / 2, thumbWidth, thumbHeight));
resizeBottomThumb.Arrange(new Rect(desiredWidth / 2 - thumbWidth / 2, desiredHeight - thumbHeight / 2, thumbWidth, thumbHeight));
resizeBottomRightThumb.Arrange(new Rect(desiredWidth - thumbWidth / 2, desiredHeight - thumbHeight / 2, thumbWidth, thumbHeight));
return finalSize;
}
public override GeneralTransform GetDesiredTransform(GeneralTransform transform)
{
ZoomControl zc = GetParentZoomControl(this.DrawingItem);
double zoomFactor = zc.Zoom;
resizeTopLeftThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeTopLeftThumb.RenderTransformOrigin = new Point(0.5, 0.5);
resizeTopThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeTopThumb.RenderTransformOrigin = new Point(0.5, 0.5);
resizeTopRightThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeTopRightThumb.RenderTransformOrigin = new Point(0.5, 0.5);
resizeLeftThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeLeftThumb.RenderTransformOrigin = new Point(0.5, 0.5);
resizeRightThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeRightThumb.RenderTransformOrigin = new Point(0.5, 0.5);
resizeBottomLeftThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeBottomLeftThumb.RenderTransformOrigin = new Point(0.5, 0.5);
resizeBottomThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeBottomThumb.RenderTransformOrigin = new Point(0.5, 0.5);
resizeBottomRightThumb.RenderTransform = new ScaleTransform(1 / zoomFactor, 1 / zoomFactor);
resizeBottomRightThumb.RenderTransformOrigin = new Point(0.5, 0.5);
return base.GetDesiredTransform(transform);
}
public ZoomControl GetParentZoomControl(Visual referenceVisual)
{
Visual parent = referenceVisual;
while (parent != null)
{
parent = VisualTreeHelper.GetParent(parent) as Visual;
if ((parent.GetType() == typeof(ZoomControl)))
{
return parent as ZoomControl;
}
}
return parent as ZoomControl;
}
}
public class EllipseResizeAdorner : ResizeAdorner
{
public EllipseResizeAdorner(FrameworkElement itemCanvas, DrawingItem drawingItem)
: base(itemCanvas, drawingItem)
{
}
protected override void MoveLeft(double horizontalMove)
{
// The Right of the Y-axis
if (MirrorAxisYCrossed)
{
if (horizontalMove < 0)
{
// At this moment we were crossed Y-axis. Direction RIGHT-LEFT
Canvas.SetLeft(DrawingItem, Canvas.GetLeft(DrawingItem) - DrawingItem.Width); // Neutralize drag delta
MirrorAxisYCrossed = false; // Set corssing flag
}
else
{
// Still the right of the Y-axis
DrawingItem.Width = horizontalMove; // Drag dleta depends on top of ellipse.
}
}
else
{
// The Left of the Y-axis
if (horizontalMove > DrawingItem.Width)
{
// At this moment we were crossed Y-axis. Direction LEFT-RIGHT; Drag dleta depends on Left side of ellipse.
if (!MirrorAxisYCrossed)
{
// Crossing flag isn`t set yet.
Canvas.SetLeft(DrawingItem, Canvas.GetLeft(DrawingItem) + DrawingItem.Width); // Move top of ellipse on a appropriate distance
horizontalMove = horizontalMove - DrawingItem.Width; // Recalculate new horizontalMove for Y - axis mirrored ellipse
DrawingItem.Width = horizontalMove;
}
MirrorAxisYCrossed = true;
}
else
{
// Still Left of the Y-axis
DrawingItem.Width = DrawingItem.Width - horizontalMove;
Canvas.SetLeft(DrawingItem, Canvas.GetLeft(DrawingItem) + horizontalMove);
}
}
}
protected override void MoveTop(double verticalMove)
{
if (MirrorAxisXCrossed)
{
// Below X-axis
if (verticalMove < 0)
{
// At this moment we were crossed X-axis. Direction BOTTOM-TOP
Canvas.SetTop(DrawingItem, Canvas.GetTop(DrawingItem) - DrawingItem.Height); // Neutralize drag delta
MirrorAxisXCrossed = false; // Set corssing flag
}
else
{
// Still below X-Axis
DrawingItem.Height = verticalMove; // Drag dleta depends on top of ellipse.
}
}
else
{
FrameworkElement adornedElement = DrawingItem as FrameworkElement;
EnforceSize(adornedElement);
// Above X-axis
if (verticalMove > DrawingItem.Height)
{
// At this moment we were crossed X-axis. Direction TOP-BOTTOM; Drag dleta depends on top of ellipse.
if (!MirrorAxisXCrossed)
{
// Crossing flag isn`t set yet.
Canvas.SetTop(DrawingItem, Canvas.GetTop(DrawingItem) + DrawingItem.Height); // Move top of ellipse on a appropriate distance
EnforceSize(adornedElement);
verticalMove = verticalMove - DrawingItem.Height; // Recalculate new verticalMove for X - axis mirrored ellipse
DrawingItem.Height = verticalMove;
}
MirrorAxisXCrossed = true;
}
else
{
// Still above X-Axis
DrawingItem.Height = DrawingItem.Height - verticalMove;
Canvas.SetTop(DrawingItem, Canvas.GetTop(DrawingItem) + verticalMove);
}
}
}
protected override void MoveRight(double horizontalMove)
{
if (MirrorAxisYCrossed)
{
// The Left of the Y-axis
if (horizontalMove <= 0)
{
Canvas.SetLeft(DrawingItem, Canvas.GetLeft(DrawingItem) + DrawingItem.Width + horizontalMove);
DrawingItem.Width = (-horizontalMove);
}
else
{
// We were crossed Y-axis. Direction LEFT-RIGHT; ActualMove = horizontalMove + Ellipse.Width
Canvas.SetLeft(DrawingItem, Canvas.GetLeft(DrawingItem) + DrawingItem.Width);
DrawingItem.Width = horizontalMove;
MirrorAxisYCrossed = false;
}
}
else
{
// The Right of the Y-axis
if ((-horizontalMove) > DrawingItem.Width)
{
// At this moment we were crossed Y-axis. Direction RIGHT-LEFT; Drag dleta depends on Left side of ellipse.
double delta = -horizontalMove - DrawingItem.Width;
Canvas.SetLeft(DrawingItem, Canvas.GetLeft(DrawingItem) - delta);
DrawingItem.Width = delta;
MirrorAxisYCrossed = true;
}
else
{
// Still Right of the Y-axis
DrawingItem.Width = DrawingItem.Width + horizontalMove;
}
}
}
protected override void MoveBottom(double verticalMove)
{
if (MirrorAxisXCrossed)
{
// Above X-axis
// VerticalMove gorws proportionally becaouse Canvas.SetTop() method repaint ellipse
// so the bottomThomb location is allways on the X-axis(bootom od ellipse).As we drag up, the delta grows propotionally.
if (verticalMove <= 0)
{
Canvas.SetTop(DrawingItem, Canvas.GetTop(DrawingItem) + DrawingItem.Height + verticalMove);
DrawingItem.Height = (-verticalMove);
}
else
{
// We were crossed X-axis. Direction TOP-BOTTOM; ActualMove = verticalMove + Ellipse.Heihgt
Canvas.SetTop(DrawingItem, Canvas.GetTop(DrawingItem) + DrawingItem.Height);
DrawingItem.Height = verticalMove;
MirrorAxisXCrossed = false;
}
}
else
{
// Below X-axis
// Because of fixed top of ellipse and changeable Height, verticalMove delta(step) is 1;
if (-verticalMove > DrawingItem.Height)
{
// At this moment we have been crossed X-axis. Direction BOTTOM-TOP;
double delta = -verticalMove - DrawingItem.Height;
Canvas.SetTop(DrawingItem, Canvas.GetTop(DrawingItem) - delta);
DrawingItem.Height = delta;
MirrorAxisXCrossed = true;
}
else
{
// Still below X-Axis
DrawingItem.Height = DrawingItem.Height + verticalMove;
}
}
}
