Filling in the Cells

A grid control fills in its contents cell-by-cell. In the case of the calendar, that means calculating which date, if any, belongs in each cell. The default drawing for grid cells takes place in a virtual method called DrawCell.

To fill in the contents of grid cells, override the DrawCell method.

The easiest part to fill in is the heading cells in the fixed row. The runtime library contains an array with short day names, so for the calendar, use the appropriate one for each column:

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type
  TSampleCalendar = class(TCustomGrid)
  protected
    procedure DrawCell(ACol, ARow: Longint; ARect: TRect; AState: TGridDrawState);
      override;
  end;
.
.
.
procedure TSampleCalendar.DrawCell(ACol, ARow: Longint; ARect: TRect;
  AState: TGridDrawState);
begin
  if ARow = 0 then
    Canvas.TextOut(ARect.Left, ARect.Top, ShortDayNames[ACol + 1]);    { use RTL strings }
end;

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void __fastcall TSampleCalendar::DrawCell(int ACol, int ARow, const Windows::TRect &ARect,
  TGridDrawState AState)
{
  String TheText;
  int TempDay;
  if (ARow == 0) TheText = ShortDayNames[ACol + 1];
  else
  {
    TheText = "";
    TempDay = DayNum(ACol, ARow);                   // DayNum is defined later
    if (TempDay != -1) TheText = IntToStr(TempDay);
  }
  Canvas->TextRect(ARect, ARect.Left + (ARect.Right - ARect.Left
   - Canvas->TextWidth(TheText)) / 2,
  ARect.Top + (ARect.Bottom - ARect.Top - Canvas->TextHeight(TheText)) / 2, TheText);
}

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