System.Windows.Forms: Choose a size that fits what we'll draw.

[madewokherd]

Pixel-accuracy is of dubious value. Programs that rely on this aren't likely to work outside of .NET Framework. Even .NET Core's winforms has diverged by changing its default font.

But, we do need to allocate enough space to draw the abbreviations for all the days of the week.

Surprisingly, this approach seems to match .NET Framework at the default size, judging by the hard-coded default.

For #58

[ris-work]

Thanks for this, I also had the same problem (with Eto.Forms, was not sure if it's an Eto issue)

[sancheolz]

@madewokherd Your solution in my distribution does not display the calendar, without these changes it does. But in another version of the distribution, the opposite is true.

The following solution works for both versions of the distribution.

diff --git a/System.Windows.Forms/System.Windows.Forms/MonthCalendar.cs b/System.Windows.Forms/System.Windows.Forms/MonthCalendar.cs
index d38576e..4d80ae1 100644
--- a/System.Windows.Forms/System.Windows.Forms/MonthCalendar.cs
+++ b/System.Windows.Forms/System.Windows.Forms/MonthCalendar.cs
@@ -700,18 +700,30 @@ namespace System.Windows.Forms {
 			get {
 				if (this.Font == null) {
 					throw new InvalidOperationException();
 				}

 				// multiplier is sucked out from the font size
 				int multiplier = this.Font.Height;
 				// establis how many columns and rows we have
 				int column_count = (ShowWeekNumbers) ? 8 : 7;
 				int row_count = 7; // not including the today date
 
-				// set the date_cell_size and the title_size
-				date_cell_size = new Size ((int) Math.Ceiling (1.8 * multiplier), multiplier);
-				
+				// Calculate date_cell_size
+				int maxWidth = 0;
+				int maxHeight = 0;
+				DateTime dt = new DateTime(0, DateTimeKind.Utc);
+
+				for (int day = 0; day < 7; day++)
+				{
+					string dayStr = dt.AddDays(day).ToString("ddd");
+					Size textSize = TextRenderer.MeasureText(dayStr, this.Font);
+					maxWidth = Math.Max(maxWidth, textSize.Width);
+					maxHeight = Math.Max(maxHeight, textSize.Height);
+				}
+
+				date_cell_size = new Size(maxWidth + 2, maxHeight + 2);
+
 				title_size = new Size ((date_cell_size.Width * column_count), 2 * multiplier);
 
 				return new Size (column_count * date_cell_size.Width, row_count * date_cell_size.Height + title_size.Height);
 			}

[madewokherd]

Oh. That makes sense.

Mind submitting your version?

[sancheolz]

done #63