protected override void OnPaint(PaintEventArgs e)
{
if (_isCapturing && _snapshot != null)
{
//Draw the screenshot scaled
e.Graphics.InterpolationMode = InterpolationMode.NearestNeighbor;
var snapBounds = new Rectangle
{
Width = _snapshot.Width * Zoom,
Height = _snapshot.Height * Zoom
};
e.Graphics.DrawImage(_snapshot, snapBounds);
e.Graphics.InterpolationMode = InterpolationMode.Default;
//Draw the square around the middle pixel
var pt = GetSnapShotSelectedPixelLocation();
LayoutAndPaintUtils.ScalePoint(ref pt, Zoom);
var rectBounds = new Rectangle
{
X = pt.X - Zoom / 2,
Y = pt.Y - Zoom / 2,
Width = Zoom - 1,
Height = Zoom - 1
};
//In both cases, minus 1 is the typical GDI+ compensation
//Use a black and white dotted pattern to ensure the
//rectangle is visible with all background colors.
using (var p = new Pen(Color.Black))
{
p.DashStyle = DashStyle.Dot;
e.Graphics.DrawRectangle(p, rectBounds);
p.DashOffset = 1F;
p.Color = Color.White;
e.Graphics.DrawRectangle(p, rectBounds);
}
}
else
{
//Draw the placeholder icon
var imgRect = ClientRectangle;
imgRect.Inflate(-5, -5);
e.Graphics.Clear(BackColor);
e.Graphics.DrawImage(_icon, imgRect);
}
base.OnPaint(e);
}
protected override void OnMouseDown(MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
Focus();
_panning = true;
//"Unscale" the provided point so that the panning follow the mouse.
var scaleFactor = GetControlScaleFactor();
var location = e.Location;
LayoutAndPaintUtils.ScalePoint(ref location, new SizeF(1 / scaleFactor, 1 / scaleFactor));
_startingPoint = new Point(location.X - _movingPoint.X,
location.Y - _movingPoint.Y);
}
base.OnMouseDown(e);
}
protected override void OnMouseMove(MouseEventArgs e)
{
if (_panning && PannablePictureBoxImage.Image != null && e.Button == MouseButtons.Left)
{
//"Unscale" the provided point so that the panning follow the mouse.
var scaleFactor = GetControlScaleFactor();
var location = e.Location;
LayoutAndPaintUtils.ScalePoint(ref location, new SizeF(1 / scaleFactor, 1 / scaleFactor));
_movingPoint = new Point(location.X - _startingPoint.X,
location.Y - _startingPoint.Y);
if (_movingPoint.X + PannablePictureBoxImage.Width > _maxWidth * 2)
{
_movingPoint.X = _maxWidth * 2 - PannablePictureBoxImage.Width;
}
if (_movingPoint.Y + PannablePictureBoxImage.Height > _maxHeight * 2)
{
_movingPoint.Y = _maxHeight * 2 - PannablePictureBoxImage.Height;
}
if (_movingPoint.X < _minWidth * 2)
{
_movingPoint.X = _minWidth * 2;
}
if (_movingPoint.Y < _minHeight * 2)
{
_movingPoint.Y = _minHeight * 2;
}
PannablePictureBoxImage.X = _movingPoint.X;
PannablePictureBoxImage.Y = _movingPoint.Y;
Invalidate(ImageRectangle);
}
base.OnMouseMove(e);
}