In iOS, a toolbar can be added to any view. In macOS however, it seems only possible to add a toolbar to a window.
I'm working on an app with a split view controller with a toolbar but the toolbar's items only have a meaning with respect to the right view controller's context.
E.g. let's say I have a text editor of some sort, where the left pane shows all documents (like in the Notes app) and the right pane shows the actual text which can be edited. The formatting buttons only affect the text in the right pane. Thus, it seems very intuitive to place the toolbar within that right pane instead of stretching it over the full width of the window.
Is there some way to achieve this?
(Or is there a good UX reason why this would be a bad practice?)
I've noticed how Apple solved this problem in terms of UX in their Notes app: They still use a full-width toolbar but align the button items that are only related to the right pane with the leading edge of that pane.
So in case, there is no way to place a toolbar in a view controller, how can I align the toolbar items with the leading edge of the right view controller as seen in the screenshot above?
Edit:
According to TimTwoToes' answer and the posts linked by Willeke in the comments, it seems to be possible to use Auto Layout for constraining a toolbar item with the split view's child view. This solution would work if there was a fixed toolbar layout. However, Apple encourages (for a good reason) to let users customize your app's toolbar.
Thus, I cannot add constraints to a fixed item in the toolbar. Instead, a viable solution seems to be to use a leading flexible space and adjust its size accordingly.
There is no native way to achieve a "local" toolbar. You would have to create the control yourself, but I believe it would be simpel to make.
Aligning the toolbar items using autolayout is described here. Align with custom toolbar item described by Mischa.The macOS way is to use the Toolbar solution and make them context sensitive. In this instance the text attribute buttons would enable when the right pane has the focus and disable when it looses the focus.