Detect and use standard font for function name offset

Author: govert

Source/ExcelDna.IntelliSense/IntelliSenseDisplay.cs

@@ -53,6 +53,8 @@ void InitializeOptions()
         {
             Logger.Display.Verbose("InitializeOptions");
             string listSeparator = ",";
+            string standardFontName = "Calibri";
+            double standardFontSize = 11.0;
             object result;
             if (XlCallInt.TryExcel(XlCallInt.xlfGetWorkspace, out result, 37) == XlCallInt.XlReturn.XlReturnSuccess)
             {
@@ -65,6 +67,20 @@ void InitializeOptions()
             }
             FormulaParser.ListSeparator = listSeparator[0];
             _argumentSeparator = listSeparator + " ";
+
+            if (XlCallInt.TryExcel(XlCallInt.xlfGetWorkspace, out result, 56) == XlCallInt.XlReturn.XlReturnSuccess)
+            {
+                // Standard Font Name
+                standardFontName = (string)result;
+                Logger.Initialization.Verbose($"InitializeOptions - Set StandardFontName to {standardFontName}");
+            }
+            if (XlCallInt.TryExcel(XlCallInt.xlfGetWorkspace, out result, 57) == XlCallInt.XlReturn.XlReturnSuccess)
+            {
+                // Standard Font Size
+                standardFontSize = (double)result;
+                Logger.Initialization.Verbose($"InitializeOptions - Set StandardFontSize to {standardFontSize}");
+            }
+            ToolTipForm.SetStandardFont(standardFontName, standardFontSize);
         }
 
         // TODO: Still not sure how to delete / unregister...

Source/ExcelDna.IntelliSense/ToolTipForm.cs

@@ -40,6 +40,8 @@ class ToolTipForm  : Form
         Dictionary<FontStyle, Font> _fonts;
         ToolTip tipDna;
 
+        static Font s_standardFont;
+
         public ToolTipForm(IntPtr hwndOwner)
         {
             Debug.Assert(hwndOwner != IntPtr.Zero);
@@ -180,13 +182,12 @@ public IntPtr OwnerHandle
         }
 
         // TODO: Move or clean up or something...
-        Font StandardFont = new Font("Calibri", 11);
         int MeasureFormulaStringWidth(string formulaString)
         {
             if (string.IsNullOrEmpty(formulaString))
                 return 0;
 
-            var size = TextRenderer.MeasureText(formulaString, StandardFont);
+            var size = TextRenderer.MeasureText(formulaString, s_standardFont);
             return size.Width;
         }
 
@@ -461,7 +462,12 @@ void InitializeComponent()
             this.ResumeLayout(false);
 
         }
-        
+
+        internal static void SetStandardFont(string standardFontName, double standardFontSize)
+        {
+            s_standardFont = new Font(standardFontName, (float)standardFontSize);
+        }
+
         class Win32Window : IWin32Window
         {
             public IntPtr Handle