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Embedded window DLL support

The embedded window DLL support option is to be used entirely at your own risk. While the vast majority of conversions will be uneventful, there is an ever-present risk when converting embedding data to printable graphic images. Depending on the behavior of a given DLL, attempting to convert embedded window displays to graphical data could result in Windows instability and could even crash your operating system. It is strongly recommended that all open programs be closed prior to using this conversion option. Neither Herd Software Development nor its distributors and agents will accept any responsibility for any loss or inconvenience caused by incompatibility between Help to RTF and an embedded window DLL.

When Microsoft first developed Help, they couldnt possibly have imagined the uses to which it would be put, and even the Help viewers developers have expressed astonishment at the creativity which authors have applied to Help. It was designed almost exclusively as a documentation presentation system, but it became the de facto standard for hypertext delivery of all types, and continues in 1997 to be the first choice for Windows hypertext even with the onrush of HTML.

Today there are literally dozens of unique and useful extensions available to Help authors. These tools and gadgets permit Windows Help to include everything from editable forms (our own HSFORM technology is a world leader in Help forms capability) to animation (our ThinHelp package is a respected industry standard for image display in Help). They can even allow the insertion of complete programs as part of Helps topic window. In most cases embedded windows are used to generate high resolution or high quality graphic images and tab or button effects.

These unique features are made possible through the use of embedded window technology, and the resulting effects are alternately referred to as either embedded windows or custom controls.

Helpfiles created using these technologies require that the DLL which produces the embedding be available and ready to run when WINHELP.EXE opens the file for display.

When you select the pre-print processing support option for embedded windows and custom controls from Help to RTFs wizard”, it will check the helpfile for references to custom embeddings. It will also try to find and load the DLLs required to produce these embeddings into memory during the decompilation process. If it is successful, and it usually is, the pre-print output will contain a BMP format image virtually identical to the image you would see if the helpfile was open and the embedding control was enabled.

Once Help to RTF has attempted to generate the image, it releases the DLL responsible for the image from Windows memory to conserve resources. If Help to RTF is successful in converting the embedded window into a bitmap image, you will see the embedded window image when you load your RTF document into your word processor.

Please be aware that many embedded window DLLs behave in such a way that Help to RTF will not be able to reproduce what the DLL is designed to show you onscreen. In fact, some embedded window DLLs are specifically designed to prevent you from printing what they display.

Points to consider when selecting embedded window support:

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The DLL responsible for the embedding must be located either in Windows path or in the directory containing the helpfile.

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The DLL in question must not currently be in use by Windows Help. If the helpfile you are attempting to convert is open on your desktop, you must close it first. (Under Windows NT you can bypass this restriction by starting HLP2RTF.EXE in a separate memory environment. You cannot cheat” this restriction simply by making copies of the helpfile and DLLs.) If the DLL was developed in a particularly dirty” fashion and leaves traces of itself in your computers memory after the helpfile is closed, you may need to restart Windows before performing the conversion.

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Embedded window technology can be difficult to predict or control if you are not the actual developer of the embedded window software itself. As mentioned previously, Help to RTF cannot produce accurate representations of all embedded window controls. However, we can promise you that it has been tested and found to be compatible with our own THNHLP.DLL, THNBMP.DLL, HSFORM.DLL, LZANI.DLL, JPANI.DLL and GRHLP.DLL. HLP_CTRL.DLLs embedded buttons are also known to be fully compatible with Help to RTF. Earlier versions of Olson Softwares OSHTOOLS.DLL will produce blank white regions. More recent versions have implemented print support.

Other known embedded window DLLs which will not produce printable output include:
  

EW256BMP.DLL (embedded window bitmaps)
  

ARSENAL.DLL (embedded window bitmaps)
  

HLPUTIL2.DLL (embedded resources)
  

EWDLL.DLL (embedded window bitmaps)
  

HLP256.DLL (watermarks)
  

D2HTOOLS.DLL (watermarks)
  

HDKANIMx.DLL (watermarks and possibly some custom controls)

Embedded windows DLLs that cannot print their contents from Windows Help are not likely to produce a printable result with Help to RTF, so if you need to know in advance if an interesting-looking embedding will print, try Printing the topic from Helps File menu.

DLLs known to be crash-prone with Help to RTF include:

  

BTHAxxxx.DLL (Bennet-Tec Help Animator)

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