Track control viewport selection issues

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   we are using the Track Control to show historic activity of a system.  The timescale shown can vary from months down to minutes.

we are finding a problem with the linear mode of the "scrollbar" used to set position and window size.

When zooming right in, the tolerance / precision of the control goes out the window, so for instance 1px change in width of the control when zoomed right in, can make an enormous difference to the width of the blocks on the control.

e.g if the width of the selector is only 4px, then 1px change is 25%.  If the width is large, 1px difference is very small, so using a linear formula creates a non-linear sensitivity of the control.

This is because the mapping from time to track position divides by the width, and has the time window on the top.

I think we need a logarithmic mode or similar to make the thing actually usable.

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adrien Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 30 April 2007 Location: New Zealand Status: Offline Points: 449	Post Options Post Reply Quote adrien Report Post Thanks(0) Quote Reply Topic: Track control viewport selection issues Posted: 03 June 2010 at 10:58pm
	we are using the Track Control to show historic activity of a system. The timescale shown can vary from months down to minutes. we are finding a problem with the linear mode of the "scrollbar" used to set position and window size. When zooming right in, the tolerance / precision of the control goes out the window, so for instance 1px change in width of the control when zoomed right in, can make an enormous difference to the width of the blocks on the control. e.g if the width of the selector is only 4px, then 1px change is 25%. If the width is large, 1px difference is very small, so using a linear formula creates a non-linear sensitivity of the control. This is because the mapping from time to track position divides by the width, and has the time window on the top. I think we need a logarithmic mode or similar to make the thing actually usable.
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