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Printing and Previewing Rich Edit Controls

Part 1: About TRichEdit::Print()

Rich Edit controls are very flexible – you can insert text of different formats, embed objects such as bitmaps and other graphics, have them wrap text to match the controls’ windows or the target printer, etc. Depending upon your point of view, printing a Rich Edit control is both simple and complicated.

First, let's look at the TRichEdit class's Print() method. On the surface, this looks like a great way to get the contents of a Rich Edit control onto paper. Add a print button or menu item and add the following line to the OnClick handler:

RichEdit1->Print("");

Click on the button/menu and the text from the control is printed. What could be simpler?

After the initial excitement subsides, you realize that there is no obvious way to control the margins on the printed page. Even if you solve that problem, there are several other limitations:

You can only print to the global TPrinter device (the TPrinter that is automatically created by the VCL and available to your program through the global Printer() function). If you want to implement a print preview feature for your program, TRichEdit::Print() will not help you.
There is no way to print a single page of a multi-page document. TRichEdit::Print() prints the entire document every time.
TRichEdit::Print() does a BeginDoc() before printing and an EndDoc() after printing. This means that you cannot print anything else on the page. You cannot, for example, print two TRichEdits on the same page.

There must be a better way, you think. There is, but it is not pretty….

On to Part 2: Printing Rich Edit Controls

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