Changeset 420 for trunk/Components/RichTextDocumentUnit.pas

Timestamp:

Feb 28, 2019, 4:17:24 AM (6 years ago)

Author:

ataylor

Message:

Improve DBCS string width calculations, other small tweaks.

File:

• trunk/Components/RichTextDocumentUnit.pas (modified) (3 diffs)

trunk/Components/RichTextDocumentUnit.pas

@@ -143 +143 @@
                            const Codepage: LongInt ): boolean;
 
-// Adjusts the character position to the beginning of any multi-byte character.
+// Adjusts the character position to the beginning or end of any multi-byte
+// character.
 procedure MoveToCharacterBoundary(     TextPointer: PChar;
                                    var Index:       LongInt;
                                    var Offset:      LongInt;
                                        RowStart:    LongInt;
-                                       Codepage:    LongInt );
+                                       Codepage:    LongInt;
+                                       Advance:     Boolean; );
 //
 // ALT ends
@@ -967 +969 @@
                                    var Offset:      LongInt;
                                        RowStart:    LongInt;
-                                       Codepage:    LongInt  );
+                                       Codepage:    LongInt;
+                                       Advance:     Boolean; );
 var
   P:         PChar;
@@ -989 +992 @@
       inc( RowStart );
     end;
-{
+
     // We've reached the target position, and the current parsing state should
     // be correctly set. So now we can safely determine the target byte's type.
     Element := ExtractNextTextElement( P, NextP );
     CheckSpecialElementType( Element.Character, Element.ElementType, InsideDBC, Codepage );
-}
     if InsideDBC then
     begin
-      // If this the first byte of a double byte character, move back by one.
-      dec( Index );
-      dec( Offset );
+      // If this the first byte of a double byte character, move position by one.
+      if Advance Then
+      Begin
+        inc( Index );
+        inc( Offset );
+      End
+      Else
+      Begin
+        dec( Index );
+        dec( Offset );
+      End
     end;
   end;