using System;  
 using System.Collections.Generic;  
 using System.Linq;  
 using System.Windows.Forms;  
 
 namespace ScalingTextStyleForPolygon  
 {  
     static class Program  
     {  
         /// <summary>  
         /// The main entry point for the application.  
         /// </summary>  
         [STAThread]  
         static void Main()  
         {  
             Application.EnableVisualStyles();  
             Application.SetCompatibleTextRenderingDefault(false);  
             Application.Run(new TestForm());  
         }  
     }  
 }  
 

 using System.Collections.Generic;  
 using System.Collections.ObjectModel;  
 using ThinkGeo.MapSuite.Core;  
 
 namespace ScalingTextStyleForPolygon  
 {  
     class ScalingTextStyle : TextStyle  
     {  
         private GeographyUnit mapUnit;  
         private double maximumScale;  
         private double minimumScale;  
         private float maximumLabelSize;  
         private float minimumLabelSize;  
 
         public ScalingTextStyle()  
             : this(GeographyUnit.DecimalDegree, string.Empty, double.MaxValue, 0, 8, 16)  
         { }  
 
         public ScalingTextStyle(GeographyUnit MapUnit, string TextColumnName, double MaximumScale, double MinimumScale, float MaximumLabelSize, float MinimumLabelSize)  
         {  
             this.mapUnit = MapUnit;  
             this.TextColumnName = TextColumnName;  
             this.maximumScale = MaximumScale;  
             this.minimumScale = MinimumScale;  
             this.maximumLabelSize = MaximumLabelSize;  
             this.minimumLabelSize = MinimumLabelSize;  
         }  
 
         // This is the map unit to determine the scale.  
         public GeographyUnit MapUnit  
         {  
             get { return mapUnit; }  
             set { mapUnit = value; }  
         }  
 
         // The maximum scale will be the largest scale used to calculate the size of the label.  
         // If the scale gets larger than the maximum, then we compute the scaling based on  
         // this number instead.  This means that after this scale, the size of the label will not get  
         // any smaller no matter how much more you zoom out.  
         public double MaximumScale  
         {  
             get { return maximumScale; }  
             set { maximumScale = value; }  
         }  
 
         // The minimum scale will be the smallest scale used to calculate the size of the label.  
         // If the scale gets smaller than the minimum, then we compute the scaling based on  
         // this number instead.  This means that after this scale, the size of the label will not get  
         // any larger no matter how much more you zoom in.  
         public double MinimumScale  
         {  
             get { return minimumScale; }  
             set { minimumScale = value; }  
         }  
 
         // The MaximumSize is the size of the label at MinimumScale and lower.  
         public float MaximumLabelSize  
         {  
             get { return maximumLabelSize; }  
             set { maximumLabelSize = value; }  
         }  
 
         // The MinimumSize is the size of the label at MaximumScale and higher.  
         public float MinimumLabelSize  
         {  
             get { return minimumLabelSize; }  
             set { minimumLabelSize = value; }  
         }  
 
         protected override void DrawCore(IEnumerable<Feature> features, GeoCanvas canvas,  
             System.Collections.ObjectModel.Collection<SimpleCandidate> labelsInThisLayer,  
             System.Collections.ObjectModel.Collection<SimpleCandidate> labelsInAllLayers)  
         {  
 
             // Loop through all of the features being passed in to draw.  
             foreach (Feature feature in features)  
             {  
                 Collection<LabelingCandidate> labelingCandidates = GetLabelingCandidates(feature, canvas);  
                 foreach (LabelingCandidate labelingCandidate in labelingCandidates)  
                 {  
 
                     // Let's make sure the features being passed in are Polygon or multi polygons  
                     WellKnownType shapeWellKnownType = feature.GetWellKnownType();  
 
                     if (shapeWellKnownType == WellKnownType.Polygon || shapeWellKnownType == WellKnownType.Multipolygon)  
                     {  
                         double currentScale = ExtentHelper.GetScale(canvas.CurrentWorldExtent, canvas.Width, mapUnit);  
                         // Enforce the minimum and maximum scale properties  
                         if (currentScale > maximumScale) { currentScale = maximumScale; }  
                         if (currentScale < minimumScale) { currentScale = minimumScale; }  
 
                         // Calculate the size of the label based on the scale.  
                         //If the scale is between minimum scale and maximum scale, the size of the label will be calculated according  
                         //to the maximum scale/minimum scale ratio.  
                         //For example:  
                         //Minimum Scale:100,000  
                         //Maximum Scale:200,000  
                         //Minimum Size:9  
                         //Maximum Size:16  
                         //If the scale is 150,000 (mid value between 100,000 and 200,000), the size of the image will be  
                         //13 (mid value between 9 and 16).  
 
                         float labelSize = (float)(maximumLabelSize - ((currentScale - minimumScale) * (maximumLabelSize - minimumLabelSize)) /  
                                            (maximumScale - minimumScale));  
 
                             string Text = feature.ColumnValues[TextColumnName];  
                             // Call the canvas method to draw the label scaled.  
                             //Gets the MultipolygonShape for the feature  
                             MultipolygonShape multipolygonShape = new MultipolygonShape(feature.GetWellKnownBinary());  
                             //Loops thru each of the Polygon to be labeled if no overlapping occurs.  
                             foreach (PolygonShape polygonShape in multipolygonShape.Polygons)  
                             {  
                                 if (CheckOverlapping(labelingCandidate, canvas, labelsInThisLayer, labelsInAllLayers) == false)  
                                 {  
                                 //Finds the center of the bouding bos of the polygon.  
                                 PointShape pointShape = polygonShape.GetBoundingBox().GetCenterPoint();  
 
                                 //Convert from world coordinate to screen coordinate the location of the feature.  
                                 ScreenPointF textScreenPoint = ExtentHelper.ToScreenCoordinate(canvas.CurrentWorldExtent, pointShape, canvas.Width, canvas.Height);  
 
                                 //Use DrawText method of canvas to label according to the values previously set.  
                                 canvas.DrawText(Text, new GeoFont("Arial", labelSize), this.TextSolidBrush, //new GeoSolidBrush(GeoColor.StandardColors.Black),  
                                                 null, new ScreenPointF[] { textScreenPoint }, DrawingLevel.LevelFour,  
                                                 this.XOffsetInPixel, this.YOffsetInPixel - labelSize, (float)this.RotationAngle);  
                                 }  
                                 SimpleCandidate simpleCandidate = new SimpleCandidate(labelingCandidate.OriginalText, labelingCandidate.ScreenArea);  
                                 if (labelsInAllLayers != null) { labelsInAllLayers.Add(simpleCandidate); }  
                                 if (labelsInThisLayer != null) { labelsInThisLayer.Add(simpleCandidate); }  
                             }  
                       }  
                 }  
             }  
         }  
 
         protected override System.Collections.ObjectModel.Collection<string> GetRequiredColumnNamesCore()  
         {  
             // Here we grab the column from the textStyle and then add  
             // the required columns to make sure we pull back the column  
             //  that we need for labeling.  
             Collection<string> columns = new Collection<string>();  
             if (!columns.Contains(TextColumnName))  
             {  
                 columns.Add(TextColumnName);  
             }  
             return columns;  
         }  
     }  
 }  
 

 using System;  
 using System.Collections.ObjectModel;  
 using System.Drawing;  
 using System.Windows.Forms;  
 using ThinkGeo.MapSuite.Core;  
 
 namespace ScalingTextStyleForPolygon  
 {  
     public partial class TestForm : Form  
     {  
         private MapEngine mapEngine = new MapEngine();  
         private Bitmap bitmap = null;  
 
        public TestForm()  
         {  
             InitializeComponent();  
         }  
 
         private void TestForm_Load(object sender, EventArgs e)  
         {  
             // Sets the full extent and the background color  
             mapEngine.CurrentExtent = ExtentHelper.GetDrawingExtent(new RectangleShape(63.78,33.33,115.11,3.57), Map.Width, Map.Height);  
             mapEngine.BackgroundFillBrush = new GeoSolidBrush(GeoColor.GeographicColors.ShallowOcean);  
 
             // Adds the static layers to the MapEngine  
             ShapeFileFeatureLayer worldLayer = new ShapeFileFeatureLayer(@"..\..\Data\Countries02.shp", ShapeFileReadWriteMode.ReadOnly);  
             worldLayer.ZoomLevelSet.ZoomLevel01.CustomStyles.Clear();  
             worldLayer.ZoomLevelSet.ZoomLevel01.CustomStyles.Add (new AreaStyle(new GeoPen(GeoColor.StandardColors.Black),  
                                                                     new GeoSolidBrush(GeoColor.StandardColors.LightPink)));  
             //Adds the ScalingTextStyle to countries to have the country name displayed at a font size proportional to the scale.  
             ScalingTextStyle scalingTextStyle = new ScalingTextStyle(GeographyUnit.DecimalDegree, "CNTRY_NAME", 31000000, 3000000, 18, 8);  
             scalingTextStyle.TextSolidBrush = new GeoSolidBrush(GeoColor.StandardColors.Brown);  
             scalingTextStyle.DuplicateRule = LabelDuplicateRule.NoDuplicateLabels;  
             worldLayer.ZoomLevelSet.ZoomLevel01.CustomStyles.Add(scalingTextStyle);  
             worldLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;  
             mapEngine.StaticLayers.Add("WorldLayer", worldLayer);  
 
             DrawImage();  
         }  
 
 
         private void DrawImage()  
         {  
             if (bitmap != null) { bitmap.Dispose(); }  
             bitmap = new Bitmap(Map.Width, Map.Height);  
             mapEngine.OpenAllLayers();  
             mapEngine.DrawStaticLayers(bitmap, GeographyUnit.DecimalDegree);  
             mapEngine.DrawDynamicLayers(bitmap, GeographyUnit.DecimalDegree);  
             mapEngine.CloseAllLayers();  
 
             Map.Image = bitmap;  
         }  
 
         private void ToolBar_ButtonClick(object sender, ToolBarButtonClickEventArgs e)  
         {  
             switch (e.Button.Tag.ToString())  
             {  
                 case "Zoom In":  
                     mapEngine.CurrentExtent.ScaleDown(50);  
                     break;  
                 case "Zoom Out":  
                     mapEngine.CurrentExtent.ScaleUp(50);  
                     break;  
                 case "Full Extent":  
                     mapEngine.CurrentExtent = ExtentHelper.GetDrawingExtent(new RectangleShape(-180.0, 83.0, 180.0, -90.0), Map.Width, Map.Height);  
                     break;  
                 case "Pan Left":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Left, 20);  
                     break;  
                 case "Pan Right":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Right, 20);  
                     break;  
                 case "Pan Up":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Up, 20);  
                     break;  
                 case "Pan Down":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Down, 20);  
                     break;  
                 default:  
                     break;  
             }  
             DrawImage();  
         }  
 
         private void btnClose_Click(object sender, EventArgs e)  
         {  
             this.Close();  
         }  
 
         private void Map_MouseMove(object sender, MouseEventArgs e)  
         {  
             //Displays the X and Y in screen coordinates.  
             statusStrip1.Items["toolStripStatusLabelScreen"].Text = "X:" + e.X + " Y:" + e.Y;  
 
             //Gets the PointShape in world coordinates from screen coordinates.  
             PointShape pointShape = ExtentHelper.ToWorldCoordinate(mapEngine.CurrentExtent, new ScreenPointF(e.X, e.Y), Map.Width, Map.Height);  
 
             //Displays world coordinates.  
             statusStrip1.Items["toolStripStatusLabelWorld"].Text = "(world) X:" + Math.Round(pointShape.X, 4) + " Y:" + Math.Round(pointShape.Y, 4);  
         }  
     }  
 }