using System;

using System.Drawing;

using System.IO;

using System.Reflection;

using System.Windows.Forms;

using GeoAPI.Geometries;

using SharpMap;

using SharpMap.Forms;

using SharpMap.Forms.Tools;

namespace WinFormSamples

{

public class MagnifierTool : MapTool

{

private readonly MapBox _parentMapBox;

private readonly PictureBox _magnified;

private Map _map;

private double _magnification = 2;

private Size _offset;

/// <summary>

/// Creates an instance of this class

/// </summary>

public MagnifierTool(MapBox parentMapBox)

: base("Magnifier", "A tool to magnify the portion of the map below the cursor")

{

_parentMapBox = parentMapBox;

_parentMapBox.MapChanged += HandleMapChanged;

Map = _parentMapBox.Map;

MagnificationFactor = 1.10;

Offset = new Size(5,5);

_magnified = new PictureBox();

_magnified.Size = new Size(75, 75);

_magnified.BorderStyle = BorderStyle.FixedSingle;

_magnified.Visible = false;

_parentMapBox.Controls.Add(_magnified);

Map = _parentMapBox.Map;

_map = Map.Clone();

_map.Size = _magnified.Size;

_map.Zoom = _map.Size.Width*(Map.Envelope.Width/Map.Size.Width) / _magnification;

_map.Center = _map.Center;

_magnified.Image = _map.GetMap();

Enabled = true;

var ms = Assembly.GetExecutingAssembly().GetManifestResourceStream("WinFormSamples.Magnifier.cur");

if (ms != null)

Cursor = new Cursor(ms);

}

private void HandleMapChanged(object sender, EventArgs e)

{

_map = Map.Clone();

_map.Size = _magnified.Size;

_map.Zoom = _map.Size.Width * (Map.Envelope.Width / Map.Size.Width) / _magnification;

_map.Center = _map.Center;

//_magnified.Image = _map.GetMap();

}

/// <summary>

/// Finalizer

/// </summary>

~MagnifierTool()

{

if (_magnified.IsHandleCreated)

{

var mb = _magnified;

if (!_parentMapBox.IsDisposed)

{

_parentMapBox.Invoke(new MethodInvoker(() => _parentMapBox.Controls.Remove(mb)));

}

mb.Dispose();

}

}

public override bool DoKeyUp(Coordinate mapPosition, KeyEventArgs keyEventArgs)

{

switch (keyEventArgs.KeyCode)

{

case Keys.Add:

Magnification = Magnification * MagnificationFactor;

return true;

case Keys.Subtract:

Magnification = Magnification / MagnificationFactor;

return true;

}

return base.DoKeyUp(mapPosition, keyEventArgs);

}

public override bool DoMouseLeave()

{

if (!Enabled) return false;

_magnified.Visible = false;

return true;

}

public override bool DoMouseWheel(Coordinate mapPosition, MouseEventArgs mouseEventArgs)

{

var factor = 1d;

if (Math.Sign(_parentMapBox.WheelZoomMagnitude)*mouseEventArgs.Delta > 0)

factor = MagnificationFactor;

else

factor = 1/MagnificationFactor;

Magnification *= factor;

//_map.Zoom *= Math.Sign(mouseEventArgs.Delta)*MagnificationFactor * Math.Sign(_parentMapBox.WheelZoomMagnitude);

//_magnified.Image = _map.GetMap();

return base.DoMouseWheel(mapPosition, mouseEventArgs);

}

public override bool DoMouseEnter()

{

if (!Enabled) return false;

_magnified.Visible = true;

return true;

}

public double Magnification

{

get { return _magnification; }

set

{

if (value <= 1d) value = 1d;

if (value == _magnification)

return;

var old = _magnification;

_magnification = value;

OnMagnificationChanged(_magnification/old);

}

}

/// <summary>

/// Event raised when the magnification factor has changed

/// </summary>

public event EventHandler MagnificationChanged;

/// <summary>

/// Event invoker for the <see cref="MagnificationChanged"/> event

/// </summary>

/// <param name="change"></param>

private void OnMagnificationChanged(double change)

{

_map.Zoom /= change;

var h = MagnificationChanged;

if (h != null) h(this, EventArgs.Empty);

}

/// <summary>

/// Gets or sets a value indicating by which factor the magnification has to change on scroll or key

/// </summary>

public double MagnificationFactor { get; set; }

public override bool DoMouseMove(Coordinate mapPosition, MouseEventArgs mouseEventArgs)

{

if (!Enabled) return false;

_map.Center = mapPosition;

_magnified.Image = _map.GetMap();

_magnified.Visible = true;

var newLocation = Point.Add(mouseEventArgs.Location, Offset);

if (newLocation.X + _magnified.Size.Width > _parentMapBox.ClientSize.Width)

newLocation.X = mouseEventArgs.Location.X - Offset.Width - _magnified.Size.Width;

if (newLocation.Y + _magnified.Size.Height > _parentMapBox.ClientSize.Height)

newLocation.Y = mouseEventArgs.Location.Y - Offset.Height - _magnified.Size.Height;

_magnified.Location = newLocation;

_parentMapBox.Refresh();

return base.DoMouseMove(mapPosition, mouseEventArgs);

}

public Size Offset

{

get { return _offset; }

set

{

if (value.Width < 0 || value.Height < 0)

throw new ArgumentException("value");

if (value == _offset)

return;

var old = _offset;

_offset = value;

if (Enabled)

_magnified.Location = Point.Add(Point.Subtract(_magnified.Location, old), _offset);

}

}

protected override void OnEnabledChanged(EventArgs e)

{

if (!Enabled)

{

_magnified.Visible = false;

}

else

{

_magnified.BringToFront();

}

}

}

}