Question About the Pen Control in Project Siena

Question

Hi, good day.
I'am working on some tech demos with Project Siena, and I need to use the pen control so that the user draw some lines in the main page of the app. I decided to hide the pen controls, so there's only a white canvas. Sometimes the user will need to erase
some strokes... and because I hide the controls, I need a way to toggle between Draw Mode and Erase Mode.
I added a Toggle Switch so that in the OnCheck method I could add this expression "PenMode!Draw" or "PenMode!Erase",
but it doesn't help. I think I am using a wrong way. Are there any suggestions on how to switch between draw and erase mode within the pen control, without showing the controls?
Also, is there any way to erase or reset ALL the strokes in the pen control? For example, drawing some lines inside the pen control, and that the user can clean all the strokes at once.
Thanks,
Antonio S.

Answer 1

Antonio,
It is possible to do both.  
I have uploaded an example of this called Pen Control to the following:
https://onedrive.live.com/#cid=5CEEF21796F5830D&id=5CEEF21796F5830D%218724
For the Mode Toggle:
Set the Mode (Design > More > Mode) to CTRLpen
Create a Slider with the Min set to 0, and the Max set to 1.
Set the Slider's On Change to the following:
If(Slider1!Value = 0,UpdateContext({CTRLpen: PenMode!Draw}),UpdateContext({CTRLpen: PenMode!Erase}))
For the Erase All
Set the Pen's Clear to PenClear
Create a button.
Set the Button's On Select to the following:
UpdateContext({PenClear: true}); UpdateContext({PenClear: false})
Note:
CTRLpen and PenClear are names I made up.  You can replace them with whatever names you want to use, as long as they are not names reserved by Siena.
-Bruton