[BUG] Keyboard shorts with CTR+SHIFT+ALT prints special characters

Rhino Rhino for Windows
, ,
1

One windows 11 pressing CTRL+SHIFT+ALT+ nn prints special characters, for example: § or Æ
When such keyboard combination used to bind a command in Rhino, it executes the command just fine, however it also prints the character in command prompt.

2

Hi Vano,

Had to google this one. Are you using a german keyboard layout by chance? or something similar..

On non-US keyboard layouts (German, French, Spanish, etc.), Windows treats Ctrl+Alt as AltGr. If a Rhino shortcut uses a Ctrl+Alt+<key> combo, Windows may intercept it before Rhino does, inserting a special character (e.g. @, €, {) into the command line instead of triggering the alias.

Potential Workarounds

  • Avoid Ctrl+Alt+<key> shortcuts in Rhino’s keyboard shortcuts/aliases. Use Ctrl+Shift+<key> or Alt+Shift+<key> combos instead, which don’t conflict with AltGr.
  • Reassign the conflicting alias in Rhino Options > Aliases or Options > Keyboard to a non-conflicting key combination.
  • Temporarily switch to a US keyboard layout in Windows if they need to use those specific shortcuts.
3

Indeed, I use custom based on US-International keyboard. However on another computer with the same keyboard layout, I have no such issue with another software that use CTR+ALT+SHIFT+<key> hotkeys (although it’s registered as global hotkey)
So, perhaps windows treat global hotkeys differently than in-application only.

The reason why I’m using these combinations is because they are available and easier to remember like L = line, S = spline, C = circle, etc. and in stupid razer synapsis which doesn’t allow adding labels to commands on buttons it easier to understand what button does what.

4

Even if windows is intercepting it before Rhino, it still should not capture character if shortcut key was pressed. In autoit script and in .NET plugin I have no issues suppress the default behavior.

The plugin installs WH_GETMESSAGE hook on Rhino’s main UI thread and checks If a key combination matched any of the set shortcuts, then it suppresses the translated character.
Windows interprets Ctrl+Alt as AltGr and may subsequently generate a WM_CHAR, WM_SYSCHAR, or dead-character message, but plugin replaces that character message with WM_NULL before Rhino’s command line receives it.

It is definitely “fixable”, it’s probably was overlooked and I hope devs will look into it.