it is possible to make guides invisible/visible
and to make them magnetic/nonmagnetic.
Both features are independent, which is good for some situations.
To make them invisible as well as non-magnetic at the same time,
two check boxes must be enabled/disabled.
The possibility to make both with one click would be fine:
visible && magnetic / invisible && non-magnetic.
Also it would be fine to have keyboard-shortcuts for all those
an even more advaned usage of Guides would be, to have Guide-layers.
One could disable guides on a guide-layer completely, when swictching off
the eye for that layer, and enable them again like any other layer,
when clicking on the corresponding layers-eye.
With that feature one could do very complex graphics easily.
Together with layer-groups, one could have layer-group specific guides,
which will make it even more powerful.
Guides that will not be part of a group would be acting globally,
and guides that are part of a layer-group would be activated
only together with that group.
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