TOPIC:

//TrimLine: Splits off from LS any characters beyond the allowed width
//breaking at the end of a word if possible. Leftover chars -> RS.
procedure TrimLine(canvas: TCanvas; var ls: string; out rs: string; LineWidthInPxls: integer);
var
  i, len, NumCharWhichFit: integer;
  dummy: TSize;
begin
  if ls = '' then
    exit;
  len := length(ls);

  { TODO -oTC -cLazarus_Port_Step2 : find a linux replacement for GeTplTextExtentExPoint }
  //TCQ
  ////get the number of characters which will fit within LineWidth...
  //if not GeTplTextExtentExPoint(canvas.handle,
  //  pchar(ls),len,LineWidthInPxls,NumCharWhichFit,0,dummy) then
  //  begin
  //    ls := '';
  //    rs := '';
  //    exit; //oops!!
  //  end;
  //TCQ replaced by
  NumCharWhichFit := len;

  if NumCharWhichFit = len then
    exit //if everything fits then stop here
  else if NumCharWhichFit = 0 then
  begin
    rs := ls;
    ls := '';
  end
  else
  begin
    i := NumCharWhichFit;
    //find the end of the last whole word which will fit...
    while (NumCharWhichFit > 0) and (ls[NumCharWhichFit] > ' ') do
      Dec(NumCharWhichFit);
    if (NumCharWhichFit = 0) then
      NumCharWhichFit := i;

    i := NumCharWhichFit + 1;
    //ignore trailing blanks in LS...
    while (ls[NumCharWhichFit] = ' ') do
      Dec(NumCharWhichFit);
    //ignore beginning blanks in RS...
    while (i < len) and (ls[i] = ' ') do
      Inc(i);
    rs := copy(ls, i, len);
    ls := copy(ls, 1, NumCharWhichFit);        //nb: assign ls AFTER rs here
  end;
end;

//TrimLine: Splits off from LS any characters beyond the allowed width
//breaking at the end of a word if possible. Leftover chars -> RS.
procedure TrimLine(canvas: TCanvas; var ls: string; out rs: string; LineWidthInPxls: integer);
const
     word_delimiter:string=';,:.+-<>*!"§$%&/()=?';
var
  i, j,len, NumCharWhichFit: integer;
  dummy: TSize;
  charlen_w: integer; // Char length of widest Character ='W';
  charlen_s:integer; // Char length of smallest Character = ''';
  maxcount_w:integer; // maximum number of widest character 'W' in linewidthinpixels
  maxcount_s:integer; // maximum number of smallest character in linewidthinPixels
  pixellen_s, pixellen_w, pixellen_actual,w:integer; // Pixellength of smallest and widest charaters and actual character length

begin
  rs:='';  // new
  if ls = '' then
    exit;
  len := length(ls);


  { TODO -oTC -cLazarus_Port_Step2 : find a linux replacement for GeTplTextExtentExPoint }
  //TCQ
  ////get the number of characters which will fit within LineWidth...
  //if not GeTplTextExtentExPoint(canvas.handle,
  //  pchar(ls),len,LineWidthInPxls,NumCharWhichFit,0,dummy) then
  //  begin
  //    ls := '';
  //    rs := '';
  //    exit; //oops!!
  //  end;
  //TCQ replaced by

  charlen_w:=canvas.TextWidth('W');
  if charlen_w=0 then charlen_w:=1;    // no division by zero
  maxcount_w:=LineWidthInPxls div charlen_w;
  if len < maxcount_w then exit;

  //NumCharWhichFit := len;
  NumCharWhichFit:=maxcount_w;

  if NumCharWhichFit > len then        // was  NumCharWhichFit = len
    exit //if everything fits then stop here
  else if NumCharWhichFit = 0 then
  begin
    rs := ls;
    ls := '';
  end
  else
  begin
    charlen_s:=canvas.TextWidth('''');      // width of smallest character
    maxcount_s:=LineWidthInPxls div charlen_s;
    if maxcount_s=0 then maxcount_s:=1; // no division by zero;

    // situation:  len > maxcount_w, so that ls possibly doesn't fit
    // maxcount_s is the maximum number of the smallest character, so left(ls,1,maxcount_s) fits
    // solution
    //  find number of chars which are >= maxcount_w and <= maxcount_s which fits
    // left(ls, maxcount_w) should always fit
    // left(ls, maxcount_s) should not fit
    // starting point: textwidth(left(ls, maxcount_s)) and counting down to maxcount_w
    i:=maxcount_s;

    pixellen_actual:=canvas.textwidth(copy(ls,1,maxcount_s-1));
    while (pixellen_actual > LineWidthInPxls) do begin
      w:=canvas.textwidth(copy(ls,i,1));
      dec(i);
      pixellen_actual:=pixellen_actual-w;
    end;
    NumCharWhichFit:=i;
    j:=i;

    // so  left(ls,i) should fit
    // looking for delimiters
    while (j>0) and (
           (ls[j]>chr(32)) and (pos(ls[j],word_delimiter)=0) ) do dec(j);

    if j>1 then NumCharWhichFit:=j-1;

    {
    i := NumCharWhichFit;
    //find the end of the last whole word which will fit...
    while (NumCharWhichFit > 0) and (ls[NumCharWhichFit] > ' ') do
      Dec(NumCharWhichFit);
    if (NumCharWhichFit = 0) then
      NumCharWhichFit := i;

    i := NumCharWhichFit + 1;
    //ignore trailing blanks in LS...
    while (ls[NumCharWhichFit] = ' ') do
      Dec(NumCharWhichFit);
    //ignore beginning blanks in RS...
    while (i < len) and (ls[i] = ' ') do
      Inc(i);
      }

    //rs := copy(ls, i, len);

    rs := copy(ls, NumCharWhichFit+1, len);
    ls := copy(ls, 1, NumCharWhichFit);        //nb: assign ls AFTER rs here
  end;
end; 

begin
  with aCanvas do
  begin
    lineHeight := TextHeight('Yy');
    pad := padding + (Pen.Width div 2);
    if odd(Pen.Width) then
      Inc(pad);
    XCenter := (BtnPoints[0].X + BtnPoints[1].X) div 2;
    YPos := BtnPoints[0].Y + padding;
    YLimit := BtnPoints[1].Y - lineHeight - pad;
    space := BtnPoints[1].X - BtnPoints[0].X - pad * 2;
    CalcOnlyOrTextOut(True);
    i := BtnPoints[1].Y - pad - YPos;
    YPos := BtnPoints[0].Y + pad;
    if i > 1 then
      Inc(YPos, i div 2);
    CalcOnlyOrTextOut(False);
  end;
end;
 

begin
 ls:='';  // no strange Text anymore
  rs:='';
  with aCanvas do
  begin
    lineHeight := TextHeight('Yy');
    pad := padding + pen.width+abs(ShadowSize); //(Pen.Width div 2);  changed because text was written right of the border
    if odd(Pen.Width) then
      Inc(pad);
    XCenter := (BtnPoints[0].X + BtnPoints[1].X) div 2;
    YPos := BtnPoints[0].Y + padding;
    YLimit := BtnPoints[1].Y - lineHeight - pad;
    space := BtnPoints[1].X - BtnPoints[0].X - pad * 2;
    CalcOnlyOrTextOut(True);
    i := BtnPoints[1].Y - pad - YPos;
    YPos := BtnPoints[0].Y + pad;
    if i > 1 then
      Inc(YPos, i div 2);
    CalcOnlyOrTextOut(False);
  end;
end;