Line tracker class (KLineTracker) that I present here performs dragging and resizing of lines with left mouse button. It does for lines the same thing CRectTracker does for rectangles.
When I needed to add to my application possibility to draw, move and resize lines using mouse, I looked for line tracker class in MFC. Because I used CRectTracker for resizing and moving rectangles, I expected to see CLineTracker for moving and resizing lines. But unfortunately I did not find one. Then I went to the Internet (Deja News, Alta Vista, InfoSeek, etc.), but they did not give me the answer too. The only thing I saw were requests for line tracker class from other people.
Usage of the class is very similar to that of CRectTracker. Details should be obvious from the demo project (look at TrackerWnd.cpp). Suggessions for changes, improvements and bug reports are welcome. Although, I don't promise to fix all the bugs fast :-).