Best practice for addon key bindings - own preferences or Blender's?

[bertieb]

Q (1) What’s the best practice with addon key bindings?

I couldn’t find clear consensus on this. It seems that addon authors do as they see best.

However, there is an approach laid out by Bookyakuno which attmepts to make this easier by creating a layout for items in a list of keymap items (addon_keymaps). This code might be helpful for others as-is, or as a starting point:

Keymap for addons

I’ve made a user-modifiable keymap menu with a more concise source code, so share it. There is no need to specify the key map name or registration location in the menu. [2020-07-17_07h41_21] Keys that match add-on keymaps registered in the “addon_keymaps” list, Search from the key map settings of Blender and display. The key map registration location is also displayed. # Search for keymap items in the addon's keymap list (addon_keymaps) from within Blender settings and display the menu i…

I would welcome further input on this

Q (2) How can I associate a keymap item with a property (like colour) in addon preferences?

I felt like I was going in circles on this one!

@bertieb

Even if I point the preferences panel at kmi.properties.colour directly, it doesn’t work as expected- the colour associated with the key binding only updates when I add a new binding!

Demo/example:

I’m not sure why this happens, but seems that if, say, the .active property is set to True on the keybinding, this causes the binding to update. This is the case even if kmi.active == True already!

This feels like a bug, but I don’t have the experience to say for sure.

Obviously guddling with the console to update a key binding-associated property is not convenient!

Thankfully there is a workaround- a “save key bindings” operator can set the required property:

How to draw a custom KeyMapItem.properties

Code

class SAMPLE_OT_DirtyKeymap(bpy.types.Operator) :
    bl_idname = "addon.sample_dirty_keymap"
    bl_label = "Save Keymap"

    def execute(self, context):
        km = context.window_manager.keyconfigs.user.keymaps["MyAddon"] :
        km.show_expanded_items = km.show_expanded_items
        for kmi in km.keymap_items :
            kmi.active = kmi.active
        context.preferences.is_dirty = True
        return {'FINISHED'}

This seems to work:

But it is very much a workaround!