Collaborative Drawing on a Canvas Component

Hi Thunkable folks,
Is it possible to do either of the following in a Canvas:

  • Detect press and drags. I can detect presses, but I don’t see an event for dragging or picking up the finger press.
  • Set the background image of the canvas to a dynamically downloaded image (like from a MediaDB). I know you can set the background to pre-loaded images.

The use case: I’m trying to make a collaborative drawing app where 2 people draw an image together. To do this, I need to get drawing data into the cloud so that drawings from one device are shown on another device in the same Canvas space. Idea 1 is to turn on Canvas “drawing” mode, then put an image of the Canvas in the cloud. I can do that, but the problem is that I cannot put that image on the Canvas of the other user. Idea 2 is to turn off drawing mode and to draw pictures myself using finger tap events and drawing blocks - then I’ll store color and coordinate data in the cloud. The problem here is that I cannot detect enough inputs on the Canvas to be able to draw shapes myself nicely - I can only detect the initial tap point (so I cannot tap and drag to draw a line, for example).

Any luck drawing with your finger on a photo and saving it ?


Nope! Still can’t do it.

To clarify - you can make drawings and save the resulting image. There’s a block available for the canvas that gets the stage image.

What you can’t do is dynamically put an image on to a canvas (an image that wasn’t preloaded as a Thunkable asset).