For some drawings I am working in layers (about 20 to 50) to better seperate objects. In order to select some objects in some layer it is convenient to hide all the other layers. This can be done by two mousclicks. Fine!
Then, I am doing my modifications on these objects and now I want to continue working as before.
However, if I hid all layers I only have two options:
a) Show all layers and hide the unwanted one after another
b) Individually select all the layers I want to see again
This can be pretty tedious e.g. if you had 24 layers of your 50 layers visible. This hide & seek will recur again and again and again...
Is there maybe anything like a "Layer visibility history"?
Maybe worth a feature request?
Any other ideas to avoid tedious clicking?

You could try selection sets panel and objects panel:

Select the layers to hide and change their mode to group using the objects panel (layer icon.. hard to see)
add the layers to a selection set in the selection sets panel
hide selected layers in objects panel
Change selected layers back to layer mode
show layers using objects panel
edit other layers, etc.
Click on selection set to select previously added layers and use objects panel to hide them

Layers panel not needed for this method, AFAICT.
Different sets could provide control for hiding different groups/layers.
Note that document cleanup may wipe selection sets!

I think there either is already a feature request....or it seems like I read about a new button that hides all layers at once. Keeping in mind my memory is not very dependable, there's a chance it might be available in the dev version. Let me try and find what I read....

Oh ok, my bad. I misread your message.

Actually what I was thinking of is already available, which is hide all layers.

I've worked a lot in files with many layers, and I know it's frustrating hiding and unhiding. I've partially improved the situation by using sublayers. That allows you to hide as many sublayers as you've created by hiding the parent layer. And among the sublayers, some can remain open and some remain closed. And when you unhide the parent layer, only the sublayers which were visible before, are visible again.

You have to think through how you're planning to organize your drawing before you start.

Here's an example:
When Set "Five and Three" is clicked in the sets panel, layers 3 and 5 are selected and can be hidden by clicking on just one of their eye icons in the objects panel.


They are still layers and the hierarchy has not changed .

tylerdurden wrote:...add the layers to a selection set in the selection sets panel...

Sorry, how do I add a layer into a selection set?
Tool tip says: '+': Add selection to set; 'x': Remove from selection set
Left-Mouseclick? Drag&Drop? Type the layer name? ... I don't see how... Really not intuitive at all...

Ja, it's still a little wonky, especially hard to see the icon change the layer to group mode...



Switching the layer to group allows making it part of a set. Then it can be changed back to a layer and still work in the set.

(The tooltip says "x" to remove from a set, but it's actually the trashcan.)

Thank you @tylerdurden for clarification.
In the meantime, I found this here:
http://inkscape.13.x6.nabble.com/Select ... 73823.html
I will further try to understand your process...

For me, it's an x, depends on the desktop theme, I think (related: the discussion about some icons not being configurable).