Screen doesn't pan consistently

[Nancy-Salpepi]

Test device
MacBook Air (m1 chip)

Operating System
macOS 12.4

Browser
Safari

Problem description
For phetsims/qa#809

The screen will pan when I remove a proton or neutron from the nucleus and drag it down, but doesn't pan when I grab a proton/neutron from the bottom of the play area and try to bring it towards the nucleus.

Steps to reproduce

1. Zoom in so that the protons and neutrons at the bottom are visible, but the nucleus is not.
2. Grab a proton and try to drag it towards the nucleus. --screen doesn't pan

Visuals

protonpanning.mp4

Troubleshooting information: !!!!! DO NOT EDIT !!!!! Name: ‪Build a Nucleus‬ URL: https://phet-dev.colorado.edu/html/build-a-nucleus/1.0.0-betaDecay.11/phet/build-a-nucleus_all_phet.html Version: 1.0.0-betaDecay.11 2022-06-04 01:06:50 UTC Features missing: applicationcache, applicationcache, touch Flags: pixelRatioScaling User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.5005.61 Safari/537.36 Language: en-US Window: 1365x694 Pixel Ratio: 2/1 WebGL: WebGL 1.0 (OpenGL ES 2.0 Chromium) GLSL: WebGL GLSL ES 1.0 (OpenGL ES GLSL ES 1.0 Chromium) Vendor: WebKit (WebKit WebGL) Vertex: attribs: 16 varying: 31 uniform: 1024 Texture: size: 16384 imageUnits: 16 (vertex: 16, combined: 32) Max viewport: 16384x16384 OES_texture_float: true Dependencies JSON: {}

[chrisklus]

Thanks @Nancy-Salpepi! This is likely related to phetsims/joist#769, so @Luisav1 marked on hold for now.

[jessegreenberg]

Pan and zoom should be working better for this case after the above commit. Now the ParticleView is set as the drag target for the forwarded event. I think that is correct and the pan zoom listener can use that target to keep the element in view.

@Luisav1 @zepumph can you please confirm?

[zepumph]

Ahh yes, much better. Thank you for the help there. I really appreciate it.