/// <summary>
/// Renders the layer
/// </summary>
/// <param name="g">Graphics object reference</param>
/// <param name="map">Map which is rendered</param>
public override void Render(Graphics g, MapViewport map)
{
if (DataSource == null)
{
throw (new ApplicationException("DataSource property not set on layer '" + LayerName + "'"));
}
var layerEnvelope = ToSource(map.Envelope); //View to render
List <BaseLabel> labels = null;
using (var ds = new FeatureDataSet())
{
DataSource.Open();
DataSource.ExecuteIntersectionQuery(layerEnvelope, ds);
DataSource.Close();
if (ds.Tables.Count > 0)
{
g.TextRenderingHint = TextRenderingHint;
g.SmoothingMode = SmoothingMode;
labels = CreateLabelDefinitions(g, map, ds.Tables[0]);
}
}
if (labels == null || labels.Count == 0)
{
// Obsolete (and will cause infinite loop)
//base.Render(g, map);
return;
}
if (Style.CollisionDetection)
{
_labelFilter?.Invoke(labels);
}
var combinedArea = RectangleF.Empty;
for (int i = 0; i < labels.Count; i++)
{
var baseLabel = labels[i];
if (!baseLabel.Show)
{
continue;
}
var font = baseLabel.Style.GetFontForGraphics(g);
if (labels[i] is Label)
{
var label = baseLabel as Label;
var canvasArea = VectorRenderer.DrawLabelEx(
g, label.Location, label.Style.Offset,
font, label.Style.ForeColor, label.Style.BackColor,
label.Style.Halo, label.Rotation, label.Text, map,
label.Style.HorizontalAlignment, label.LabelPoint);
combinedArea = canvasArea.ExpandToInclude(combinedArea);
}
else if (labels[i] is PathLabel)
{
var pathLabel = labels[i] as PathLabel;
var lblStyle = pathLabel.Style;
var background = pathLabel.AffectedArea.ExteriorRing.TransformToImage(map);
if (lblStyle.BackColor != null && lblStyle.BackColor != Brushes.Transparent)
{
using (var gp = new GraphicsPath())
{
gp.AddPolygon(background);
g.FillPath(lblStyle.BackColor, gp);
}
}
g.DrawString(lblStyle.Halo, new SolidBrush(lblStyle.ForeColor),
pathLabel.Text, font.FontFamily, (int)font.Style, font.Size,
lblStyle.GetStringFormat(), lblStyle.IgnoreLength, pathLabel.Location, pathLabel.Box.Height);
combinedArea = background.ToRectangleF().ExpandToInclude(combinedArea);
}
}
CanvasArea = combinedArea;
// Obsolete (and will cause infinite loop)
//base.Render(g, map);
}
