Using scalable images in your documentation

When writing FlexCel documentation at tms, we often need to include document screenshots.

In many cases, a simple screen capture will do. But in others, we'd like something that can scale with the monitor resolution, and a bitmap is not enough. In those cases, we use FlexCel to export the images as SVG (scalar vector graphics).

We will discuss two different cases here:

1. Sometimes you want to render a simple object. Like for example the chart at the top of this blog post We created that image from the file in the Chart API example, using the following code:

      var
           svg: String;
         ...
           svg := xls.RenderObjectAsSVG(-1, '@lines of code', 'Lines of code over time', 'This chart was rendered with RenderObjectAsSVG', TEncoding.UTF8);
           begin
             TFile.WriteAllText('flexcel-lines-of-code.svg', svg);
           end;
      

2. Other times, you might want to render a part of a sheet, as we did in the diagram at the end of this article. On those cases, we use code similar to the following:

      var
           svg: TFlexCelSVGExport;
         ...
           svg := TFlexCelSVGExport.Create(xls, true);
           try
              // Set a page size that has the size of the image you want. 
              // You will need to experiment a little to get the correct size.
             svg.PageSize := TPaperDimensions.Create('custom', $30C, $12C);
             svg.SaveAsImage(
               procedure (x: TSVGExportParameters)
               begin
                 x.FileName := 'result' + IntToStr(x.PageNumber) + '.svg';
               end);
           finally
             svg.Free;
           end;
      

You might change the print scaling of the xlsx file to get a smaller or bigger image.