GerixSoft

With advance of modern monitors, their screen pixel resolutions are growing larger and larger. Back in 2003, typical development requirement was to support 800×600 resolution, nowadays it is 1024×768.

Actually, according to my webserver logs, screen resolution of 1280×1024 is set on 50% of all monitors. This percentage could bigger, but users complain fonts are getting too small to be read, and decrease their screen resolutions to 1024×768. Meanwhile their monitors support larger resolutions…

Most advanced users increase DPI setting in Display properties, and start to experience problems, because most applications do not support non-default DPI settings.

For example, in my case, my typical screen configuration, which I recommend, looks as follows:

1. Screen resolution is set to maximum (1280×1024, 1600×1200 or bigger…)
2. DPI setting is set to 120 pixels per inch (Large Fonts)
3. Font smoothing option is set to ClearType for TFT monitors, and Standard for CRT monitors.

90% of Delphi applications I have seen, do not support Large Fonts, or support it very ugly. This is due to the fact, that VCL implementation of custom DPI is very ugly. There is a Scaled property in TForm, which was about to handle form scaling in case of non-default DPI setting, but it is not working correctly.

So here is my minimal code to support custom DPI/Large Fonts in Delphi applications correctly:

procedure TgxCustomForm.FormCreate(Sender: TObject);
begin
  Assert(not Scaled, 'You should set Scaled property of Form to False!');   
  case Screen.PixelsPerInch of
    96:
    begin
      // default resolution at which application is developed
      ///ScaleBy(96, 96);
    end;
    120:
    begin
      ScaleBy(120, 96);
    end;
    else
    begin
      ScaleBy(Screen.PixelsPerInch, 96);
    end;
  end;
end;