WrapText function question

[typo]

In the project attached I use SynEdit.CharsInWindow to set the MaxColum parameter for the function, but it seems not to result fine. Why?

MaxColum seems to be not observed.

[Edson]

It's because WrapText() don't do what it is supposed to do (I see it breaks the line where find the first space after Maxcol).

SynEdit.CharsInWindow is OK.

Maybe you need to write your own WrapText(). And it would consider to work with UTF-8.

[engkin]

It does what it is supposed to do, but not what you want it to do.

In your sample: MyMemo.CharsInWindow is 30 chars
MyMemo.CharsInWindow - 8 is 22 chars
The line that shows the problem is:

a estas aventuras que arruinaram

The blue color is 22 chars
The green color is within 30 chars
The red color is more than 30 chars

The code does not break a word except at end of line or at one of [' ', '-', #9]

A line of code might explain it better. Try:

Code: [Select]

  MyMemo.Text := WrapText(MyMemo.Text, sLineBreak, ['A'..'Z','a'..'z',' ', '-', #9], MyMemo.CharsInWindow);


[typo]

You mean that the function breaks the line after MaxColum value and not before as expected?

[taazz]

You mean that the function breaks the line after MaxColum value and not before as expected?

Yes. Max column is not an absolute value.

[engkin]

It breaks words AFTER MaxCol at BreakStr or BreakChars only

Code: [Select]

    While ((P<=Len) and ((P<=MaxCol) or not IBC)) and ((LQ<>#0) or Not HB) do


[engkin]

One more thing, it does not break a quote.

Code: [Select]

      If (C=LQ) then
        LQ:=#0
      else If (C in Quotes) then
        LQ:=C;
      If (LQ<>#0) then
        Inc(P)

Mind you a quote starts with ' or ":

Code: [Select]

const
  Quotes = ['''', '"'];


[typo]

Delphi seems to break the line before MaxColum value. See here:

http://www.delphibasics.co.uk/RTL.asp?Name=WrapText

Could it be a bug?

[engkin]

If they are meant to be identical then yes it is a bug. they are not identical. Someone with Delphi could confirm it.

[typo]

I have gone to write my own WrapText function and here it is:

Code: [Select]

function MyWrapText(S :string; MaxCol:integer): string;
var
  P :PChar;
  CharLen, i :integer;
  C :string;
  RightSpace : Integer;
  LastLineEnding : Integer;
begin
  Result := '';
  P := PChar(S);
  LastLineEnding := 0;
  i := 1;
  while P^ <> #0 {i <= Length(S)} do
  begin
    CharLen := UTF8CharacterLength(P);
    C := UTF8Copy(P, 1, 1);
    Result := Result + C;
    if P^ = #10 then
      LastLineEnding := i;
    if (i - LastLineEnding >= MaxCol) then 
    begin
      RightSpace := Length((Result)) - RPos(' ', (Result));
      Dec(p, RightSpace);
      Dec(i, RightSpace);
      SetLength(Result, Length(Result) - RightSpace);
      Result := Result + LineEnding;
      LastLineEnding := i;
    end;
    Inc(P, CharLen);
    Inc(i, Charlen);
  end;
end;

I have noticed that sometimes it fails (for very narrow SynEdits, typically letting the last line unwrapped), but I don't know why.

My usage:

Code: [Select]

procedure TForm1.Button1Click(Sender : TObject);
begin
  MyMemo.Text := MyWrapText(MyMemo.Text, MyMemo.CharsInWindow);
end;


[engkin]

shouldn't this line:

Code: [Select]

    if i - LastLineEnding = MaxCol then
be:

Code: [Select]

    if i - LastLineEnding >= MaxCol then
?

[typo]

You have reason. It seems to work fine now.

[typo]

I have just edited a bit the code above.

For till 1000 lines of final text, for instance, this routine works fine for wordwrapping SynEdit, although it is not optimized. But making SynEdit itself wrap words is another issue.

WrapText function implementation does not work fine.