Improved right-cursor movement over utf8 codepoints

BeefLibs/Beefy2D/src/widgets/EditWidget.bf

@@ -2226,15 +2226,18 @@ namespace Beefy.widgets
 			    else if (lineIdx < GetLineCount() - 1)
 			        MoveCursorTo(lineIdx + 1, 0, false, 0, .SelectRight);
 
-			    if (!mWidgetWindow.IsKeyDown(KeyCode.Control))
-			        break;
-
 			    GetLineCharAtIdx(CursorTextPos, out lineIdx, out lineChar);
 			    anIndex = GetTextIdx(lineIdx, lineChar);
 			    if (anIndex == mData.mTextLength)
 			        break;
 
 			    char8 c = (char8)mData.mText[anIndex].mChar;
+				if ((uint8)c & 0xC0 == 0x80)
+					continue;
+
+				if (!mWidgetWindow.IsKeyDown(KeyCode.Control))
+					break;
+
 			    CharType char8Type = GetCharType(c);
 			    if (char8Type == .Opening)
 			        break;

BeefLibs/corlib/src/String.bf

@@ -359,6 +359,23 @@ namespace System
 			}
 		}
 
+		public int NumCodePoints
+		{
+			get
+			{
+				char8* ptr = Ptr;
+
+				int count = 0;
+				for (int i < mLength)
+				{
+					char8 c = ptr[i];
+					if (((uint8)c & 0xC0) != 0x80)
+						count++;
+				}
+				return count;
+			}
+		}
+
 		public int AllocSize
 		{
 			[Inline]
@@ -3594,6 +3611,23 @@ namespace System
 			}
 		}
 
+		public int NumCodePoints
+		{
+			get
+			{
+				char8* ptr = Ptr;
+
+				int count = 0;
+				for (int i < mLength)
+				{
+					char8 c = ptr[i];
+					if (((uint8)c & 0xC0) != 0x80)
+						count++;
+				}
+				return count;
+			}
+		}
+
 		private int GetRangeStart(IndexRange range)
 		{
 			switch (range.Start)

IDE/src/ui/SourceEditWidgetContent.bf

@@ -5366,7 +5366,7 @@ namespace IDE.ui
 
 			String curLineStr = scope String();
 			GetLineText(line, curLineStr);
-			int32 lineEnd = (int32)curLineStr.Length;
+			int32 lineEnd = (int32)curLineStr.NumCodePoints;
 
 			mVirtualCursorPos.ValueRef.mColumn = (.)Math.Min(mVirtualCursorPos.Value.mColumn, Math.Max(virtualEnd, lineEnd));
 		}