# Ruler and grid system working

**URL:** <https://discourse.slicer.org/t/ruler-and-grid-system-working/18440>\
**Category:** Development\
**Created:** [June 30, 2021, 8:26pm UTC](https://discourse.slicer.org/t/ruler-and-grid-system-working/18440 "2021-06-30T20:26:12Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Kshitij\_Panchal](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/kshitij_panchal/32/10787_2.png) [@Kshitij\_Panchal](https://discourse.slicer.org/u/Kshitij_Panchal)\
**Post date:** [June 30, 2021, 8:26pm UTC](https://discourse.slicer.org/t/ruler-and-grid-system-working/18440/1 "2021-06-30T20:26:12Z")

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Hello. I am currently trying to understand the code of slicer and got stuck at how ruler and grid system works here.

I understand that there are three text types for ruler and according to that, the ruler get displayed. But I cannot understand that how actually these features works. What things happens at backend. Can anyone please help me to understand that? @lassoan @pieper

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [June 30, 2021, 8:51pm UTC](https://discourse.slicer.org/t/ruler-and-grid-system-working/18440/2 "2021-06-30T20:51:30Z")

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I don’t think anyone would want to write or maintain design documentation at such low level, but you can have a look at the source code and maybe run the Slicer in a debugger to see how it works exactly. We can also help with any specific questions that you may have.

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**Author:** ![Kshitij\_Panchal](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/kshitij_panchal/32/10787_2.png) [@Kshitij\_Panchal](https://discourse.slicer.org/u/Kshitij_Panchal)\
**Post date:** [July 1, 2021, 2:04am UTC](https://discourse.slicer.org/t/ruler-and-grid-system-working/18440/3 "2021-07-01T02:04:47Z")

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Ok. Thanks. I will try it.