// Save the selected layer as a file (that can be imported into other layer sets)
tempView := TImageEnView.Create(nil);
try
  tempView.LayersAdd(ImageEnView1.CurrentLayer);
  // Reset layer position to ensure good preview
  tempView.Layers[idx].PosX := 0;
  tempView.Layers[idx].PosY := 0;
  tempView.IO.Params.IEN_StoreBackground := False;
  tempView.IO.SaveToFileIEN( SelLayerFilename );
finally
  tempView.Free;
end;

function PAIsFilenameValid(const AFilename: string; var errorchar: Char): Boolean;
begin
  Result := True;

  for var i := 1 to Length(AFilename) do
  begin
    if not System.IOUtils.TPath.IsValidFileNameChar(AFilename[i]) then
    begin
      errorchar := AFilename[i];
      Result := False;
      BREAK;
    end;
  end;
end;

procedure TForm1.ButtonAddSelectedLayerAsClick(Sender: TObject);
// save the Layer in the Exe folder
begin
  var LValue: string := '';
  var LFileExists: Boolean;
  var LSaveOK: Boolean := True;
  var IsFileNameValid: Boolean;
  var C: Char;
  repeat
    if not InputQuery('Add selected Layer to the Collection', 'Layer Name:', LValue) then EXIT;

    IsFileNameValid := PAIsFilenameValid(LValue, C);
    if not IsFileNameValid then
    begin
      Application.MessageBox(PChar('This character is not allowed in file-names: ' + C),
        PChar('Application'), MB_OK + MB_ICONINFORMATION + MB_DEFBUTTON2 + MB_TOPMOST);
    end;

    LFileExists := FileExists(GetLayerFilePath(LValue));
    if LFileExists then
    begin
      case
        Application.MessageBox('This file already exists. Do you want to save anyway?',
          PChar('Application'), MB_OKCANCEL + MB_ICONQUESTION + MB_DEFBUTTON2 + MB_TOPMOST)
        of
        IDOK: LSaveOK := True;
        IDCANCEL: LSaveOK := False;
      end;
    end;
  until (Trim(LValue) <> '') and LSaveOK and IsFileNameValid;

  var TempIEV := TImageEnView.Create(nil);
  try
    // copy the Layer selected from ImageEnView1 to TempIEV:
    var idx := TempIEV.LayersAdd(ImageEnView1.CurrentLayer);

    TempIEV.IO.Params.IEN_StoreBackground := False; // do not save the background Layer
    TempIEV.LayersCropBackground(); // the background still needs to be cropped because it is still present in the saved file!
    TempIEV.Layers[idx].Name := LValue;             // set the name of the new Layer
    var LFile := GetLayerFilePath(LValue);          // determine the file path
    TempIEV.IO.SaveToFileIEN(LFile);                // save the Layer file
    ImageEnFolderMView1.RefreshFileList;            // refresh the collection view
  finally
    TempIEV.Free;
  end;
end;

function TForm1.GetLayerFilePath(const ALayerName: string): string;
begin
  Result := IncludeTrailingPathDelimiter(FExeFolder) + ALayerName + '.ien';
end;

procedure TForm1.ButtonAddSelectedLayerAsClick(Sender: TObject);
// save the Layer in the Exe folder
begin
  var LValue: string := '';
  var LFileExists: Boolean;
  repeat
    if not InputQuery('Add selected Layer to the Collection', 'Layer Name:', LValue) then EXIT;
    // Todo: also validate valid chars, existing file
    LFileExists := FileExists(GetLayerFilePath(LValue));
    CodeSite.Send('TForm1.ButtonAddSelectedLayerAsClick: LFileExists', LFileExists);
  until Trim(LValue) <> '';

  var TempIEV := TImageEnView.Create(nil);
  try
    // copy the Layer selected from ImageEnView1 to TempIEV:
    var idx := TempIEV.LayersAdd(ImageEnView1.CurrentLayer);

    TempIEV.IO.Params.IEN_StoreBackground := False; // do not save the background Layer
    //TempIEV.LayersCropBackground();
    TempIEV.Layers[idx].Name := LValue;             // set the name of the new Layer
    var LFile := GetLayerFilePath(LValue);          // determine the file path
    TempIEV.IO.SaveToFileIEN(LFile);                // save the Layer file
    ImageEnFolderMView1.RefreshFileList;            // refresh the collection view
  finally
    TempIEV.Free;
  end;
end;

function TForm1.GetLayerFilePath(const ALayerName: string): string;
begin
  Result := IncludeTrailingPathDelimiter(FExeFolder) + ALayerName + '.ien';
end;

TempIEV.LayersCropBackground();

// Save the selected layer as a file (that can be imported into other layer sets)
tempView := TImageEnView.Create(nil);
try
  tempView.LayersAdd(ImageEnView1.CurrentLayer);
  tempView.IO.Params.IEN_StoreBackground := False;
  tempView.IO.SaveToFileIEN( SelLayerFilename );
finally
  tempView.Free;
end;