Holding Ctrl right after trackpad scrolling makes unwanted zoom (OSX)
Closed, ResolvedPublic

Description

System Information
Operating system and graphics card
OSX 10.10.3, NVIDIA GeForce 320M 256 MB

Blender Version
Broken: 2.75 RC1 bff8b5d

Short description of error
Scrolling panels in Blender sometimes makes them zoom when user doesn't want it.

Exact steps for others to reproduce the error

  1. Open default scene and press N to show Properties (this is what I have on screenshots, but it works the same with every panel).
  2. Move 2 fingers on macbook's trackpad to scroll
  3. Release fingers and immediately press and hold CTRL
  4. Result: Blender zooms in or out depending on if you were scrolling up or down.

Please see attached images: before and after scrolling.

Chris Slazinski (mallow) updated the task description. (Show Details)
Chris Slazinski (mallow) raised the priority of this task from to Needs Triage.
Chris Slazinski (mallow) set Type to Bug.

This thing happens not only to panels, but also in 3D View, as I just checked.

Campbell Barton (campbellbarton) renamed this task from using Ctrl right after scrolling makes unwanted zoom to Holding Ctrl right after trackpad scrolling makes unwanted zoom (OSX).Jun 24 2015, 5:28 AM

@Martijn Berger (juicyfruit), feel free to poke me if this needs some attention/tweaks in WM event system (although it should better be solved on GHOST level).

The problem is the inertial scrolling where it keeps scrolling a while longer after you release the trackpad.

Perhaps the proper way to solve this would be to have a modal event handler that checks if the ctrl key is pressed when you start scrolling, and ignores any changes to the ctrl key as long as you're scrolling. The problem is that the way these events are implemented there is no start scrolling / stop scrolling event, it a separate event for every scrolling increment.