October 26th, 2005

When programs assume that the system will never change, episode 1

An example, all too frequent, of ways programs assume that the user interface will never change is reaching into system binaries and sucking out undocumented resources. In the shell, we have fallen into the reluctant position of carrying “dead” icons around for the benefit of programs that assumed that they would always be available. However, we often make these “orphaned” icons blank so that these programs don’t crash, but they don’t necessarily look all that wonderful either.

Recently, I learned of a new type of resource stealing: Stealing animations. For Windows Vista, there have been many changes to the way the system internally organizes its resources in order to support the Multilingual User Interface feature. One of the things we found was a handful of programs that reach directly into Shell32.dll in order to obtain the file copy animation. Too bad (1) the animation isn’t kept there any more, and even if we moved the animation back to its original location, (2) the animation uses a new compression scheme that older programs can’t handle.

Remember, resources in system DLLs should be treated as implementation details, unless explicitly documented otherwise.

I’m not sure what we’re going to do about the animation resource problem. Suggestions anyone? Should we declare these programs broken and make the people who bought them go back to their vendors for upgrades? (What if there is no vendor?) Should we develop a shim and hope that those four are the only programs that need it? Should we carry the original animation in shell32.dll as junk? If I told you that one of the programs that did this won “Game of the Year” recently, would that change your answer? What if another turned out to be a top-rated anti-spyware program?

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Raymond has been involved in the evolution of Windows for more than 30 years. In 2003, he began a Web site known as The Old New Thing which has grown in popularity far beyond his wildest imagination, a development which still gives him the heebie-jeebies. The Web site spawned a book, coincidentally also titled The Old New Thing (Addison Wesley 2007). He occasionally appears on the Windows Dev Docs Twitter account to tell stories which convey no useful information.

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