[Fak Eid]

Code for Edit Box

  Page2Edit.FCreate(Page2.Handle);
  Page2Edit.SetBounds(NSSX(100), NSSY(190), NSSX(520), NSSY(35));
  Page2Edit.FontSetting('{#FontName}', VCLFontSizeToFMX2(13), ALGainsBoro);
  Page2Edit.CanFocus(True);
  Page2Edit.Enabled(True);
  Page2Edit.Text(MinimizePathName(WizardForm.DirEdit.Text, WizardForm.DirEdit.Font, WizardForm.DirEdit.Width));
  Page2Edit.OnTyping(@BrowseEditOnChange);

Logic for procedure

procedure BrowseEditOnChange(Sender: TObject);
var
  PrevDrive, CurrentDrive: String;
begin
  PrevDrive := ExtractFileDrive(WizardForm.DirEdit.Text);
  CurrentDrive := ExtractFileDrive(Page2Edit.GetText);

  // Set the installation path to the edited text value
  WizardForm.DirEdit.Text := Page2Edit.GetText;

  if PrevDrive <> CurrentDrive then
    DirUpdateProc(nil);
end;

Logic for Directory Update Procedure:

procedure DirUpdateProc(Sender: TObject);
begin
  DiskUsage.SetDir(WizardForm.DirEdit.Text);
  SelectDirLabel[3].Text('Total Space - ' + MbOrTb(DiskUsage.TotalSpace, 1) + #13 +
                         'Available Space - '+ MbOrTb(DiskUsage.FreeSpace, 1) + #13 +
                         'Repack Size - ' + MbOrTb({#RepackSize}, 1));
  if Round(DiskUsage.FreeSpace) > StrToInt('{#RequiredSpace}') then
  begin
    WizardBtn[4].Enabled(True);  //Install Button enabled if there is space
  end else
  begin
    WizardBtn[4].Enabled(False); //Install Button disabled if no space
    ShowMessage('Not Enough Space', 'Selected Directory does not have required space. Please select a different directory location.');
  end;
end;