Re: [Rd] getWindowsHandle()

From: Duncan Murdoch <>
Date: Mon 19 Jul 2004 - 23:27:28 EST

On Fri, 16 Jul 2004 16:05:57 -0400 (EDT), Peng Liu <> wrote :

>On Thu, 15 Jul 2004, Duncan Murdoch wrote:
>> You'll need to read Windows documentation.
>> Currently R has no way to get the list of MDI document windows. I
>> think the function you want is EnumChildWindows, but you might need to
>> use EnumWindows. I can't remember whether MDI documents are child
>> windows or top level windows.
>Hi Dr. Murdoch,
>Thanks for you advice. I checked WIN32API documents and write the
>following codes. So far, the call just gives all the hwnd's of child
>windows. Many window widgets are treated as child windows, such as
>tool bar, shortcut buttons, workspace, and so on. Therefore, the output
>can be a long list. Probably, I need to redefine the maximum number of
>handles. Moreover, it does not make sense to give a list of hwnd's only. I
>will add more information to the output later.

As a general principle, I don't think we should put things in R if they done more easily in C. It's relatively tricky to figure out R's window handles if you start from nothing, so I put in getWindowsHandle. But I don't have a clear picture of what you want the MDI child window handles for. Is there something you can do with those with R code? If not, why not just write code like your C code whenever you need the child window?

The problem with putting functions into R is that it increases the maintenance burden. Functions need to add value to justify this. I'm not saying a function like yours wouldn't add value, just that it's not obvious to me how it would.

Could I suggest that you write all of this up as a package? Let me know when you come to something that just can't be done because of something missing from R itself.

Duncan Murdoch mailing list Received on Mon Jul 19 23:32:40 2004

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