Changeset 420 for trunk/Components

Timestamp:

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

Author:

ataylor

Message:

Improve DBCS string width calculations, other small tweaks.

Location:

trunk/Components

Files:

• CanvasFontManager.pas (modified) (1 diff)
• RichTextDocumentUnit.pas (modified) (3 diffs)
• RichTextLayoutUnit.pas (modified) (1 diff)
• RichTextView.PAS (modified) (6 diffs)

trunk/Components/CanvasFontManager.pas

@@ -1134 +1134 @@
   EnsureMetricsLoaded;
   GpiQueryTextBox( FCanvas.Handle, Length, S^, TXTBOX_COUNT, aptl[0] );
-  // The pad of 2.1 per character was chosen through experimentation, since the
-  // actual returned value always seems too narrow. I have no idea why. (ALT)
-  Result := ( 2.1 + aptl[ TXTBOX_BOTTOMRIGHT ].x) * FontWidthPrecisionFactor;
+  Result := aptl[ TXTBOX_CONCAT ].x * FontWidthPrecisionFactor;
 end;
 //

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;

trunk/Components/RichTextLayoutUnit.pas

@@ -834 +834 @@
   begin
     Element := ExtractNextTextElement( P, NextP );
-    CheckSpecialElementType( Element.Character, Element.ElementType, InsideDBC, Codepage );   // ALT
+
+    // ALT - handle double-byte characters
+    if InsideDBC and ( P < EndP ) then
+    begin
+      P := NextP;
+      Element := ExtractNextTextElement( P, NextP );
+      InsideDBC := false;
+    end;
+    CheckSpecialElementType( Element.Character, Element.ElementType, InsideDBC, Codepage );
+    // ALT done
 
     case Element.ElementType of

trunk/Components/RichTextView.PAS

@@ -472 +472 @@
   // ALT
   Offset := FCursorOffset;
-  MovetoCharacterBoundary( FText, SelectionStart, FCursorOffset, Offset, FLayout.Codepage );
+  MoveToCharacterBoundary( FText, SelectionStart, FCursorOffset, Offset, FLayout.Codepage, false );
 
   FSelectionStart := SelectionStart;
@@ -493 +493 @@
   // ALT
   Offset := FCursorOffset;
-  MovetoCharacterBoundary( FText, SelectionEnd, FCursorOffset, Offset, FLayout.Codepage );
+  MoveToCharacterBoundary( FText, SelectionEnd, FCursorOffset, Offset, FLayout.Codepage, false );
 
   if FSelectionStart = -1 then
@@ -1230 +1230 @@
   Descender: longint;
   MaxDescender: longint;
+  Index: longint;       // ALT
+  RowStart: longint;    // ALT
 begin
   RemoveCursor;
@@ -1252 +1254 @@
     // off top
     exit;
+
+  // ALT - move to nearest character boundary
+  Index := FLayout.GetCharIndex( Line.Text ) + FCursorOffset;
+  RowStart := FLayout.GetCharIndex( Line.Text );
+  MoveToCharacterBoundary( FText, Index, FCursorOffset, RowStart, FLayout.Codepage, false );
 
   FLayout.GetXFromOffset( FCursorOffset, CursorRow, X );
@@ -2035 +2042 @@
 //  InsideDBC: boolean;       // ALT
   RowStart: longint;        // ALT
+  MoveRight: boolean;       // ALT
   Index: longint;
 begin
@@ -2067 +2075 @@
 
   RowStart := FLayout.GetCharIndex( FLayout.FLines[ Row ].Text );
-  MoveToCharacterBoundary( FText, Index, Offset, RowStart, FLayout.Codepage );  // ALT
+
+  // ALT
+  if Offset = ( FCursorOffset + 1 ) then
+    MoveRight := true
+  else
+    MoveRight := false;
+  MoveToCharacterBoundary( FText, Index, Offset, RowStart, FLayout.Codepage, MoveRight );
 
   FCursorOffset := Offset;