// See if we're over a polygon or corner point.
private void picCanvas_MouseMove_NotDrawing(object sender, MouseEventArgs e)
{
Cursor new_cursor = Cursors.Cross;
// See what we're over.
Point mouse_pt = SnapToGrid(e.Location);
if (MouseUtils.MouseIsOverCornerPoint(mouse_pt, Polygons))
{
new_cursor = Cursors.Arrow;
}
else if (MouseUtils.MouseIsOverEdge(mouse_pt, Polygons))
{
new_cursor = AddPointCursor;
}
else if (MouseUtils.MouseIsOverPolygon(mouse_pt, Polygons))
{
new_cursor = Cursors.Hand;
}
// Set the new cursor.
if (picCanvas.Cursor != new_cursor)
{
picCanvas.Cursor = new_cursor;
}
}
// Start or continue drawing a new polygon,
// or start moving a corner or polygon.
private void picCanvas_MouseDown(object sender, MouseEventArgs e)
{
// See what we're over.
Point mouse_pt = SnapToGrid(e.Location);
Polygon hit_polygon;
int hit_point, hit_point2;
Point closest_point;
if (NewPolygon != null)
{
// We are already drawing a polygon.
// If it's the right mouse button, finish this polygon.
if (e.Button == MouseButtons.Right)
{
// Finish this polygon.
if (NewPolygon.Count > 2)
{
Polygons.Add(NewPolygon);
}
NewPolygon = null;
// We no longer are drawing.
picCanvas.MouseMove += picCanvas_MouseMove_NotDrawing;
picCanvas.MouseMove -= picCanvas_MouseMove_Drawing;
}
else
{
// Add a point to this polygon.
if (NewPolygon[NewPolygon.Count - 1] != mouse_pt)
{
NewPolygon.Add(mouse_pt);
}
}
}
else if (MouseUtils.MouseIsOverCornerPoint(mouse_pt, Polygons, out hit_polygon, out hit_point))
{
// Start dragging this corner.
picCanvas_MouseDown_MoveCorner(hit_polygon, hit_point, e);
}
else if (MouseUtils.MouseIsOverEdge(mouse_pt, Polygons, out hit_polygon,
out hit_point, out hit_point2, out closest_point))
{
// Add a point.
hit_polygon.Insert(hit_point + 1, closest_point);
// Start dragging this corner.
picCanvas_MouseDown_MoveCorner(hit_polygon, hit_point + 1, e);
}
else if (MouseUtils.MouseIsOverPolygon(mouse_pt, Polygons, out hit_polygon))
{
// Start moving this polygon.
picCanvas.MouseMove -= picCanvas_MouseMove_NotDrawing;
picCanvas.MouseMove += picCanvas_MouseMove_MovingPolygon;
picCanvas.MouseUp += picCanvas_MouseUp_MovingPolygon;
// Remember the polygon.
MovingPolygon = hit_polygon;
// Remember the offset from the mouse to the segment's first point.
OffsetX = hit_polygon[0].X - e.X;
OffsetY = hit_polygon[0].Y - e.Y;
}
else
{
// Start a new polygon.
NewPolygon = new Polygon();
NewPoint = mouse_pt;
NewPolygon.Add(mouse_pt);
// Get ready to work on the new polygon.
picCanvas.MouseMove -= picCanvas_MouseMove_NotDrawing;
picCanvas.MouseMove += picCanvas_MouseMove_Drawing;
}
// Redraw.
picCanvas.Invalidate();
}