# ParaviewWeb selection error
**URL:** https://discourse.paraview.org/t/paraviewweb-selection-error/6733
**Category:** ParaView Support
**Created:** [March 18, 2021, 9:06am UTC](https://discourse.paraview.org/t/paraviewweb-selection-error/6733 "2021-03-18T09:06:27Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@jone](https://discourse.paraview.org/u/jone)
#### Post date: [March 18, 2021, 9:06am UTC](https://discourse.paraview.org/t/paraviewweb-selection-error/6733/1 "2021-03-18T09:06:27Z")
I want to pick a cell on the client side.First, I get the position of the mouse click on the canvas, using the following methods:
> var rect = canvas.getBoundingClientRect();
> var x= event.clientX - rect.left \* (canvas.width / rect.width);
> var y= event.clientY - rect.top \* (canvas.height / rect.height);
Then call the server-side protocol:
> ```
> @exportRPC("pvwsdprotocol.pick.point")
> def pickCone(self, positionx, positiony):
> selection.SelectSurfaceCells(Rectangle=[positionx,positiony,positionx,positiony])
> self.getApplication().InvokeEvent('UpdateEvent')
>
> ```
But the results are not precise. Does the canvas position contradict the SelectSurfaceCells parameter requirement? Thank you for you help in advance!
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### Author:  [@jourdain](https://discourse.paraview.org/u/jourdain)
#### Post date: [March 18, 2021, 5:26pm UTC](https://discourse.paraview.org/t/paraviewweb-selection-error/6733/2 "2021-03-18T17:26:55Z")
I think your issue is related to the fact that Y needs to be swap. (y=0 =\> bottom)
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### Author:  [@jone](https://discourse.paraview.org/u/jone)
#### Post date: [March 19, 2021, 1:21am UTC](https://discourse.paraview.org/t/paraviewweb-selection-error/6733/3 "2021-03-19T01:21:40Z")
After the modification, it really works!
I want to ask, is there a way to select the whole object?Just like the PropPicker in VTK. Thanks again for your guidance!
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### Author:  [@jourdain](https://discourse.paraview.org/u/jourdain)
#### Post date: [March 22, 2021, 9:13pm UTC](https://discourse.paraview.org/t/paraviewweb-selection-error/6733/4 "2021-03-22T21:13:03Z")
I would think so, just need to pick the right selection object.
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### Author:  [@jone](https://discourse.paraview.org/u/jone)
#### Post date: [March 23, 2021, 12:29am UTC](https://discourse.paraview.org/t/paraviewweb-selection-error/6733/5 "2021-03-23T00:29:29Z")
But I’ve only found a way to select point and cell, and maybe map from there to the whole object, right?
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### Author:  [@jourdain](https://discourse.paraview.org/u/jourdain)
#### Post date: [March 23, 2021, 3:16pm UTC](https://discourse.paraview.org/t/paraviewweb-selection-error/6733/6 "2021-03-23T15:16:31Z")
You should ask on the main ParaView topic “How to perform actor/block selection from Python?”.
I know that is possible but I will have to dig into the code to see how to do it as I don’t know it on top of my head.