unit uscaledpi;
 
{$mode objfpc}{$H+}
 
interface
 
uses
  Forms, Graphics, Controls;
 
procedure HighDPI(FromDPI: Integer);
procedure ScaleDPI(Control: TControl; FromDPI: Integer);
 
implementation
 
procedure HighDPI(FromDPI: Integer);
var
  i: Integer;
begin
  for i:=0 to Screen.FormCount-1 do
    ScaleDPI(Screen.Forms[i],FromDPI);
end;
 
procedure ScaleDPI(Control: TControl; FromDPI: Integer);
var
  n: Integer;
  WinControl: TWinControl;
begin
  if Screen.PixelsPerInch = FromDPI then exit;
 
  with Control do begin
    Left:=ScaleX(Left,FromDPI);
    Top:=ScaleY(Top,FromDPI);
    Width:=ScaleX(Width,FromDPI);
    Height:=ScaleY(Height,FromDPI);
    Font.Height := ScaleY(Font.GetTextHeight('Hg'),FromDPI);
  end;
 
  if Control is TWinControl then begin
    WinControl:=TWinControl(Control);
    if WinControl.ControlCount > 0 then begin
      for n:=0 to WinControl.ControlCount-1 do begin
        if WinControl.Controls[n] is TControl then begin
          ScaleDPI(WinControl.Controls[n],FromDPI);
        end;
      end;
    end;
  end;
end;
 
end.