CODEWITHSUNDEEP
cwinapi
Emerick Rogul
Emerick Rogul

Reputation: 6804

Retrieve the entire rectangle of a scrollable window

I'm trying to retrieve the entire rectangle of a scrollable window using the WIN32 API. I thought that GetClientRect would return what I need, but that function appears to return only the current viewport. Is there a specific function call that returns the entire scrollable region as a RECT or must I call GetScrollRange to calculate the region myself?

Upvotes: 1

Views: 361

Answers (2)

Brian Nixon
Brian Nixon

Reputation: 9818

It doesn't work like that. As far as Windows is concerned, a scrollable window isn't a small viewport onto a larger region whose dimensions you can set or retrieve, it's just a rectangle with a scroll bar control at the edge. It's up to you to determine the appearance of the scroll bar by calculating the portion of the notional region that is visible within the viewport provided by the window, and to paint the window contents accordingly.

Upvotes: 4

Ben Voigt
Ben Voigt

Reputation: 283624

It sounds as if that particular window is using virtual scrolling. Even GetScrollRange doesn't necessarily tell you the dimensions, because there's no requirement that a delta of 1 on the scrollbar equals 1 pixel, in fact in many cases it is one record, one row, etc.

Another thing to try is to enumerate all the child windows, and find the minimum and maximum x and y coordinates (don't forget to include the width and height of each child window). Of course this won't help if the content is directly drawn and not a hierarchy of windows.

Upvotes: 2

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