private void _imageViewer_MouseMove(object sender, MouseEventArgs e)
{
RasterImage image = _imageViewer.Image;
if (image == null)
{
return;
}
// Here is the point in viewer (physical or client) coordinates
// This point is the mouse position
LeadPoint viewerPoint = LeadPoint.Create(e.X, e.Y);
// Convert to image coordinates (top-left view perspective, since we are
// only interested in the zoom/scroll values and not trying to get to a
// certain pixel in the image data)
LeadPoint imagePoint = _imageViewer.ConvertPoint(null, ImageViewerCoordinateType.Control, ImageViewerCoordinateType.Image, viewerPoint);
ShowMousePositionAndImageColor(image, viewerPoint, imagePoint);
if (_isMovingOverlayRect)
{
// We are moving the overlay rect
// After we are done with moving the overlay rect to a new position,
// we need to re-paint to show the effect. To optimize the code, we will
// only repaint the combination of the old and new rects
// Get the current (soon to be old) overlay rect in viewer coordinates
LeadRect oldImageRect = LeadRect.Create(_overlayRect.X, _overlayRect.Y, _overlayRect.Width, _overlayRect.Height);
LeadRect oldViewerRect = _imageViewer.ConvertRect(null, ImageViewerCoordinateType.Image, ImageViewerCoordinateType.Control, oldImageRect);
// Get the difference
int dx = e.X - _lastMovePoint.X;
int dy = e.Y - _lastMovePoint.Y;
if (dx != 0 || dy != 0)
{
// Has moved
LeadRect newViewerRect = oldViewerRect;
newViewerRect.Offset(dx, dy);
// Now re-calculate new overlay rectangle in image coordinates
LeadRect newImageRect = _imageViewer.ConvertRect(null, ImageViewerCoordinateType.Control, ImageViewerCoordinateType.Image, newViewerRect);
// Make sure the image rectangle does not go outside the image boundaries
if (newImageRect.X < 0)
{
newImageRect.Offset(-newImageRect.X, 0);
}
if (newImageRect.Y < 0)
{
newImageRect.Offset(0, -newImageRect.Y);
}
if ((newImageRect.X + newImageRect.Width) > image.ImageWidth)
{
newImageRect.Offset(-(newImageRect.X + newImageRect.Width - image.ImageWidth), 0);
}
if ((newImageRect.Y + newImageRect.Height) > image.ImageHeight)
{
newImageRect.Offset(0, -(newImageRect.Y + newImageRect.Height - image.ImageHeight));
}
// Check if it has really changed
if (newImageRect.X != oldImageRect.X ||
newImageRect.Y != oldImageRect.Y ||
newImageRect.Width != oldImageRect.Width ||
newImageRect.Height != oldImageRect.Height)
{
// Yes
_overlayRect = new LeadRect(newImageRect.X, newImageRect.Y, newImageRect.Width, newImageRect.Height);
_imageViewer.Invalidate();
}
// Save the new moving position
_lastMovePoint = LeadPoint.Create(e.X, e.Y);
}
}
}