Question: how to specify KeyMod of Control for all platforms?

[psobolewskiPhD]

KeyMod.CtrlCmd results in Ctrl on windows (and linux?) but Cmd on macOS
KeyMod.WinCtrl says it does Meta on Windows and Ctrl on macOS

Is there a way to specify a Control-Foo binding that uses Control on all platforms?
KeyMod.Ctrl does't exist, but there is KeyCode.Ctrl

Based on

app-model/src/app_model/backends/qt/_qkeymap.py

Lines 220 to 238 in a0d95b1

	KEYMOD_FROM_QT = {
	Qt.KeyboardModifier.NoModifier: KeyMod.NONE,
	QALT: KeyMod.Alt,
	QCTRL: KeyMod.CtrlCmd,
	QSHIFT: KeyMod.Shift,
	QMETA: KeyMod.WinCtrl,
	}
	MAC_KEYMOD_FROM_QT = {**KEYMOD_FROM_QT, QCTRL: KeyMod.WinCtrl, QMETA: KeyMod.CtrlCmd}
	KEYMOD_TO_QT = {
	KeyMod.NONE: Qt.KeyboardModifier.NoModifier,
	KeyMod.CtrlCmd: QCTRL,
	KeyMod.Alt: QALT,
	KeyMod.Shift: QSHIFT,
	KeyMod.WinCtrl: QMETA,
	}
	MAC_KEYMOD_TO_QT = {**KEYMOD_TO_QT, KeyMod.WinCtrl: QCTRL, KeyMod.CtrlCmd: QMETA}

it looks like it wouldn't be easy to have two different KeyMod map to the same QCTRL...

[tlambert03]

Is there a way to specify

can you clarify where exactly you're specifying these? You might be looking a bit low in the codebase...

My expectation was that, most of the time, keybindings would be declared as keybinding rules (either during the declaration of a plugin or in an Action for an application). is that what you're trying to do here? or are you doing something special at a lower level

[tlambert03]

a general answer to your question is that KeybindingRules allow for platform specific logic. So, if just saying KeyBindingRule(primary='ctrl+X') doesn't do what you need, you can do KeyBindingRule(primary='ctrl+X', mac='ctrl+X', linux='ctrl+X', win='ctrl+X').

since this all follows the vscode specification for declaring keybindings, you might find it useful to see how a vscode app/extensions declares stuff. Here's an example with a ton of keybindings declared:

https://github.com/microsoft/vscode-sublime-keybindings/blob/5d7eac6603cf57b8a8f1b5cff6f63c1f59529111/package.json#L262

I can also write up a short example of how you could test stuff out locally a little more directly if that would be helpful

[psobolewskiPhD]

Well, specifically here:
https://github.com/napari/napari/blob/b2edccd6e40e04467ccfeec0257c2160783f7187/napari/utils/shortcuts.py#L12

    'napari:delete_selected_layers': [KeyMod.CtrlCmd | KeyCode.Delete],

That resolves to Control-Del everywhere, but Command-Del on macOS which is a system keybind and as a result don't work. The idea was to make it Control-Del everywhere, so I naively tried KeyMod.Ctrl, but that doesn't exist.
I tried KeyCode.Ctrl but that made the binding resolve to PageDown on macOS for some reason!

[tlambert03]

I see, that list has lost the ability to declare platform specificity. Well, how about you try WinCtrl (regardless of what my comment said), and if it doesn't do what you need, you might need to extend the concept of your default key bindings to allow for platform specificity

[psobolewskiPhD]

I think it's best to make that a 2nd key binding. Thanks for the insight -- I will close as an explicit KeyMod.Ctrl isn't going to be a thing.

[tlambert03]

an explicit KeyMod.Ctrl isn't going to be a thing.

I'm not 100% sure about this yet :) reopening. been looking some more, I haven't found a good explanation yet of why not to have KeyMod.Ctrl (i find it surprising that vscode would have never needed to express that concept yet... so I want to look into why they don't have it, but then might add it)

[psobolewskiPhD]

Eeep! Sorry!
❤️

[tlambert03]

one additional thing I noted: if you use the string form: ctrl+X ... then you will get ctrl on both platforms (I think ... please double check). It's just the integer form using a KeyMod enum that doesn't have an "always ctrl" variant

[psobolewskiPhD]

Maybe i'm dense, but:
'napari:delete_selected_layers': [ctrl+Delete],
doesn't work:
NameError: name 'ctrl' is not defined

using " " instead of [ ] gives
TypeError: unsupported operand type(s) for &: 'str' and 'int'
so I think a secondary keybinding is the way to go for now

Full traceback for the record

Traceback (most recent call last):
  File "/Users/piotrsobolewski/Dev/miniforge3/envs/napari-dev/bin/napari", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/Users/piotrsobolewski/Dev/napari/napari/__main__.py", line 574, in main
    _maybe_rerun_with_macos_fixes()
  File "/Users/piotrsobolewski/Dev/napari/napari/__main__.py", line 452, in _maybe_rerun_with_macos_fixes
    from napari._qt import API_NAME
  File "/Users/piotrsobolewski/Dev/napari/napari/_qt/__init__.py", line 90, in <module>
    from napari._qt.qt_event_loop import get_app, get_qapp, gui_qt, quit_app, run
  File "/Users/piotrsobolewski/Dev/napari/napari/_qt/qt_event_loop.py", line 14, in <module>
    from napari import Viewer, __version__
  File "<frozen importlib._bootstrap>", line 1412, in _handle_fromlist
  File "/Users/piotrsobolewski/Dev/miniforge3/envs/napari-dev/lib/python3.12/site-packages/lazy_loader/__init__.py", line 82, in __getattr__
    submod = importlib.import_module(submod_path)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/piotrsobolewski/Dev/miniforge3/envs/napari-dev/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/piotrsobolewski/Dev/napari/napari/viewer.py", line 8, in <module>
    from napari.components.viewer_model import ViewerModel
  File "/Users/piotrsobolewski/Dev/napari/napari/components/__init__.py", line 19, in <module>
    from napari.components.layerlist import LayerList
  File "/Users/piotrsobolewski/Dev/napari/napari/components/layerlist.py", line 13, in <module>
    from napari.layers import Layer
  File "/Users/piotrsobolewski/Dev/napari/napari/layers/__init__.py", line 10, in <module>
    from napari.layers.base import Layer
  File "/Users/piotrsobolewski/Dev/napari/napari/layers/base/__init__.py", line 2, in <module>
    from napari.layers.base.base import Layer, no_op
  File "/Users/piotrsobolewski/Dev/napari/napari/layers/base/base.py", line 51, in <module>
    from napari.settings import get_settings
  File "/Users/piotrsobolewski/Dev/napari/napari/settings/__init__.py", line 5, in <module>
    from napari.settings._napari_settings import (
  File "/Users/piotrsobolewski/Dev/napari/napari/settings/_napari_settings.py", line 16, in <module>
    from napari.settings._shortcuts import ShortcutsSettings
  File "/Users/piotrsobolewski/Dev/napari/napari/settings/_shortcuts.py", line 6, in <module>
    from napari.utils.shortcuts import default_shortcuts
  File "/Users/piotrsobolewski/Dev/napari/napari/utils/shortcuts.py", line 106, in <module>
    name: [KeyBinding.from_int(kb) for kb in value]
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/piotrsobolewski/Dev/miniforge3/envs/napari-dev/lib/python3.12/site-packages/app_model/types/_keys/_keybindings.py", line 231, in from_int
    first_part = key_int & 0x0000FFFF
                 ~~~~~~~~^~~~~~~~~~~~
TypeError: unsupported operand type(s) for &: 'str' and 'int'

[tlambert03]

indeed. it would need to be a string :) 'ctrl+Delete'

[tlambert03]

let's back up a bit... keys can be encoded as strings 'ctrl+alt+delete or as integers using KeyMod and KeyCode: KeyMod.CtrlCmd | KeyMod.Alt | KeyCode.Delete ...

you definitely can't combine the two, so you can't do 'ctrl' + Key.Delete and you can't do KeyMod.CtrlCmd + 'delete', or you'll get the operand error you showed above.

when it comes time to actually convert those to an OS-bound keybinding, it will pass through Keybinding.validate:

app-model/src/app_model/types/_keys/_keybindings.py

Lines 295 to 305 in a0d95b1

	def validate(cls, v: Any) -> "KeyBinding":
	"""Validate a SimpleKeyBinding."""
	if isinstance(v, KeyBinding):
	return v
	if isinstance(v, SimpleKeyBinding):
	return cls(parts=[v])
	if isinstance(v, int):
	return cls.from_int(v)
	if isinstance(v, str):
	return cls.from_str(v)
	raise TypeError("invalid keybinding") # pragma: no cover

and there, it will receive slightly different behavior depending on if it's in a string or integer form:

app-model/src/app_model/types/_keys/_keybindings.py

Lines 71 to 93 in a0d95b1

	@classmethod
	def from_str(cls, key_str: str) -> "SimpleKeyBinding":
	"""Parse a string into a SimpleKeyBinding."""
	mods, remainder = _parse_modifiers(key_str.strip())
	key = KeyCode.from_string(remainder)
	return cls(**mods, key=key)
	@classmethod
	def from_int(
	cls, key_int: int, os: Optional[OperatingSystem] = None
	) -> "SimpleKeyBinding":
	"""Create a SimpleKeyBinding from an integer."""
	ctrl_cmd = bool(key_int & KeyMod.CtrlCmd)
	win_ctrl = bool(key_int & KeyMod.WinCtrl)
	shift = bool(key_int & KeyMod.Shift)
	alt = bool(key_int & KeyMod.Alt)
	os = OperatingSystem.current() if os is None else os
	ctrl = win_ctrl if os.is_mac else ctrl_cmd
	meta = ctrl_cmd if os.is_mac else win_ctrl
	key = key_int & 0x000000FF # keycode mask
	return cls(ctrl=ctrl, shift=shift, alt=alt, meta=meta, key=key)

note that the CtrlCmd logic is only differentiated in the int form (since it's an int)... but if you want always ctrl, i think you can just use 'ctrl'

so, without looking deeper at how napari actually processes those lists you have there, I would expect you should be able to use:

'napari:delete_selected_layers': ['ctrl+delete'],

[tlambert03]

but Command-Del on macOS which is a system keybind and as a result don't work. The idea was to make it Control-Del everywhere,

I would actually dig into this a bit more... i would 100% expect to be able to delete a layer with cmd+del on macos... and ctrl+del feels like an odd workaround. why can't you use cmd+del? what error exactly do you hit?