# How to rewrite shift function Development

**URL:** https://discourse.slicer.org/t/how-to-rewrite-shift-function-development/17201
**Category:** Development
**Created:** [April 20, 2021, 12:05pm UTC](https://discourse.slicer.org/t/how-to-rewrite-shift-function-development/17201 "2021-04-20T12:05:57Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![luxiaoyang9999](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/luxiaoyang9999/32/9026_2.png) [@luxiaoyang9999](https://discourse.slicer.org/u/luxiaoyang9999)
#### Post date: [April 20, 2021, 12:05pm UTC](https://discourse.slicer.org/t/how-to-rewrite-shift-function-development/17201/1 "2021-04-20T12:05:57Z")

</div>

Hi all  
I want to rewrite the shift key function in Python,but I can not find the origin code about the function, could you tell me where to find the code about shift key and mouse move in slicer?

---

<div class="post-metadata">

### Author: ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)
#### Post date: [April 21, 2021, 6:43pm UTC](https://discourse.slicer.org/t/how-to-rewrite-shift-function-development/17201/2 "2021-04-21T18:43:01Z")

</div>

I’m not sure it will be easy to do that in python. You can study the code for [`vtkMRMLCrosshairNode`](https://github.com/Slicer/Slicer/search?q=vtkMRMLCrosshairNode) to see if it can do what you want.

---

<div class="post-metadata">

### Author: ![luxiaoyang9999](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/luxiaoyang9999/32/9026_2.png) [@luxiaoyang9999](https://discourse.slicer.org/u/luxiaoyang9999)
#### Post date: [April 22, 2021, 12:41pm UTC](https://discourse.slicer.org/t/how-to-rewrite-shift-function-development/17201/3 "2021-04-22T12:41:14Z")

</div>

thank you for your help.