void Canvas_MouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
var canvas = sender as Canvas;
if (canvas != null && canvas == m_canvas && m_rect != null)
{
m_hitType = Canvas_GetHitType(m_rect, Mouse.GetPosition(m_canvas));
var desiredCursor = Canvas_GetMouseCursor(m_hitType);
if (Cursor != desiredCursor)
Cursor = desiredCursor;
if (m_hitType == RectangleHitType.None)
return;
m_lastPoint = Mouse.GetPosition(m_canvas);
m_dragInProgress = true;
}
}
private void Canvas_MouseMove(object sender, MouseEventArgs e)
{
var canvas = sender as Canvas;
if (canvas != null && canvas == m_canvas && m_dragInProgress && m_rect != null)
{
// See how much the mouse has moved
Point point = Mouse.GetPosition(m_canvas);
double offset_x = point.X - m_lastPoint.X;
double offset_y = point.Y - m_lastPoint.Y;
// Get the rectangle's current position
double new_x = Canvas.GetLeft(m_rect);
double new_y = Canvas.GetTop(m_rect);
double new_width = m_rect.Width;
double new_height = m_rect.Height;
// Update the rectangle
switch (m_hitType)
{
case RectangleHitType.Body:
new_x += offset_x;
new_y += offset_y;
break;
case RectangleHitType.Top:
new_y += offset_y;
new_height -= offset_y;
break;
case RectangleHitType.UpperRight:
new_y += offset_y;
new_width += offset_x;
new_height -= offset_y;
break;
case RectangleHitType.Right:
new_width += offset_x;
break;
case RectangleHitType.LowerRight:
new_width += offset_x;
new_height += offset_y;
break;
case RectangleHitType.Bottom:
new_height += offset_y;
break;
case RectangleHitType.LowerLeft:
new_x += offset_x;
new_width -= offset_x;
new_height += offset_y;
break;
case RectangleHitType.Left:
new_x += offset_x;
new_width -= offset_x;
break;
case RectangleHitType.UpperLeft:
new_x += offset_x;
new_y += offset_y;
new_width -= offset_x;
new_height -= offset_y;
break;
}
// Don't use negative width or height
if ((new_width > 0) && (new_height > 0))
{
// Update the rectangle
Canvas.SetLeft(m_rect, new_x);
Canvas.SetTop(m_rect, new_y);
m_rect.Width = new_width;
m_rect.Height = new_height;
// Save the mouse's new location
m_lastPoint = point;
}
}
else
{
m_hitType = Canvas_GetHitType(m_rect, Mouse.GetPosition(m_canvas));
var desiredCursor = Canvas_GetMouseCursor(m_hitType);
if (Cursor != desiredCursor)
Cursor = desiredCursor;
}
}
private Cursor Canvas_GetMouseCursor(RectangleHitType hitType)
{
Cursor desiredCursor = Cursors.Arrow;
switch (hitType)
{
case RectangleHitType.None:
desiredCursor = Cursors.Arrow;
break;
case RectangleHitType.Body:
desiredCursor = Cursors.ScrollAll;
break;
case RectangleHitType.Top:
case RectangleHitType.Bottom:
desiredCursor = Cursors.SizeNS;
break;
case RectangleHitType.LowerLeft:
case RectangleHitType.UpperRight:
desiredCursor = Cursors.SizeNESW;
break;
case RectangleHitType.Left:
case RectangleHitType.Right:
desiredCursor = Cursors.SizeWE;
break;
case RectangleHitType.UpperLeft:
case RectangleHitType.LowerRight:
desiredCursor = Cursors.SizeNWSE;
break;
}
return desiredCursor;
}
