Scrollbars part 11: Towards an even deeper understanding of the WM_NCCALCSIZE message

Raymond ChenSeptember 15, 2003Sep 15, 200309/15/03

The other form of the WM_NCCALCSIZE message is the complicated one, when the WPARAM is TRUE. In this case, the LPARAM is a pointer to a NCCALCSIZE_PARAMS structure. When Windows sends the WM_NCCALCSIZE message, the NCCALCSIZE_PARAMS structure is filled out like this...

Eric's complete guide to BSTR semantics

Raymond ChenSeptember 15, 2003Sep 15, 200309/15/03

Eric Lippert has posted Eric's Complete Guide to BSTR Semantics. This is a document that is widely valued within Microsoft, since BSTR semantics are rather tricky, and I'm glad he's willing to share it with the world. In particular, Eric spends quite a bit of time discussion the very ...

Answers to exercises from Scrollbars Part 10

Raymond ChenSeptember 13, 2003Sep 13, 200309/13/03

Answers to exercises from Scrollbars Part 10.

Scrollbars part 10 – Towards a deeper understanding of the WM_NCCALCSIZE message

Raymond ChenSeptember 11, 2003Sep 11, 200309/11/03

When your window is resized, Windows uses the WM_NCCALCSIZE message to determine where your window's client area lives inside your window rectangle. There are two forms of the WM_NCCALCSIZE message. The simple form merely takes a window rectangle and returns a client rectangle. This is useful for...

Scrollbars part 9 – Maintaining the metaphor

Raymond ChenSeptember 9, 2003Sep 9, 200309/9/03

When a document is displayed with scrollbars, the metaphor is that the window is a viewport onto the entire document, only a portion of which is visible at the moment. The default behavior of a resize, however, is to maintain the origin at the upper left corner of the client area, which breaks the metaphor...

Where is my program running from?

Raymond ChenSeptember 5, 2003Sep 5, 200309/5/03

Another common question: "How do I find out where my program is? I want to be able to access support files in that same directory." Answer: GetModuleFileName(NULL...

Case mapping on Unicode is hard

Raymond ChenSeptember 5, 2003Sep 5, 200309/5/03

Occasionally, I'm asked, "I have to identify strings that are identical, case-insensitively.  How do I do it?" The answer is, "Well, it depends. Whose case-mapping rules do you want to use?" Sometimes the reply is, "I want this to be language-independent." Now ...

How to recognize different types of timestamps from quite a long way away

Raymond ChenSeptember 5, 2003Sep 5, 200309/5/03

The great thing about timestamps is that there are so many to choose from. Sometimes, while debugging (or reading incomplete documentation) you'll find a timestamp and wonder how to convert it into something readable. Here are some tips. We will use November 26, 2002 at 7:25p PST as our sample time. UNIX timestamps are in seconds since ...

Determining whether your window is covered

Raymond ChenSeptember 2, 2003Sep 2, 200309/2/03

The method described in the previous coding blog entry works great if you are using the window visibility state to control painting, since you're using the paint system itself to do the heavy lifting for you. To obtain this information outside of the paint loop, use GetDC and GetClipBox...

Painting only when your window is visible on the screen

Raymond ChenAugust 29, 2003Aug 29, 200308/29/03

Sometimes you want to perform an activity, such as updating a status window, only as long as the window is not covered by another window. The easiest way to determine this is by not actually trying to determine it. For example, here's how the taskbar clock updates itself...