Various fixes for empty text blocks + don't add ellipsis if last line includes all text.

SandboxDriver/SandboxDriver.cs

@@ -7,7 +7,7 @@ namespace SandboxDriver
 {
     public class SandboxDriver
     {
-        public int ContentModeCount = 10;
+        public int ContentModeCount = 11;
         public int ContentMode = 0;
         public TextDirection BaseDirection = TextDirection.LTR;
         public TextAlignment TextAlignment = TextAlignment.Auto;
@@ -185,6 +185,10 @@ namespace SandboxDriver
                     _textBlock.AddText("Hello World", styleNormal);
                     break;
 
+                case 10:
+                    _textBlock.AddText("", styleNormal);
+                    break;
+
             }
 
             var sw = new Stopwatch();

Topten.RichTextKit/CaretInfo.cs

@@ -52,7 +52,7 @@ namespace Topten.RichTextKit
         /// <summary>
         /// The X-coordinate where the caret should be displayed for this code point.
         /// </summary>
-        public float CaretXCoord => FontRun.GetXCoordOfCodePointIndex(CodePointIndex);
+        public float CaretXCoord => CodePointIndex < 0 ? 0 : FontRun.GetXCoordOfCodePointIndex(CodePointIndex);
 
         /// <summary>
         /// A rectangle describing where the caret should be drawn, relative to the top-left
@@ -79,6 +79,9 @@ namespace Topten.RichTextKit
         {
             get
             {
+                if (CodePointIndex < 0)
+                    return SKRect.Empty;
+
                 // Get the font run to be used for caret metrics
                 var fr = GetFontRunForCaretMetrics();
 

Topten.RichTextKit/TextBlock.cs

@@ -248,14 +248,18 @@ namespace Topten.RichTextKit
             _minLeftMargin = 0;
             _requiredLeftMargin = null;
 
-            // Build font runs
-            BuildFontRuns();
+            // Only layout if actually have some text
+            if (_codePoints.Length != 0)
+            {
+                // Build font runs
+                BuildFontRuns();
 
-            // Break font runs into lines
-            BreakLines();
+                // Break font runs into lines
+                BreakLines();
 
-            // Finalize lines
-            FinalizeLines();
+                // Finalize lines
+                FinalizeLines();
+            }
         }
 
         /// <summary>
@@ -609,6 +613,18 @@ namespace Topten.RichTextKit
         /// <returns>A CaretInfo struct</returns>
         public CaretInfo GetCaretInfo(int codePointIndex)
         {
+            if (_codePoints.Length == 0 || codePointIndex < 0)
+            {
+                return new CaretInfo()
+                {
+                    CodePointIndex = -1,
+                    NextCodePointIndex = -1,
+                    PreviousCodePointIndex = -1,
+                    FontRun = null,
+                    StyleRun = null,
+                };
+            }
+
             // Look up the caret index
             int cpii = LookupCaretIndex(codePointIndex);
 
@@ -1476,6 +1492,11 @@ namespace Topten.RichTextKit
         {
             var lastRun = line.Runs[line.Runs.Count - 1];
 
+            // Don't add ellipsis if the last run actually
+            // has all the text...
+            if (lastRun.End == _codePoints.Length)
+                return;
+
             // Remove all trailing whitespace from the line
             for (int i = line.Runs.Count - 1; i >= 0; i--)
             {