I've started to prepare this on the inline-editing branch. What I've done so far is to break out the ingredients list as a separate widget: GrIngredientsViewer, with a GrIngredientsViewerRow widget for individual rows. The new widget has a non-editable mode. It is used in both the details and edit page.

I have reimplemented most of the ingredients list manipulation with the new widget:
- adding/removing new lists
- changing list titles
- adding/removing ingredient rows
- reordering ingredient rows

The one thing that is missing is actual editing of ingredients and amounts. All the code for the popovers and searching/filtering has been removed. We will bring it back in a different form.

Suggested next steps:
1) Make basic editing (without any assistance) work by replacing the labels with entries when the edit button is clicked and saving changes upon Enter. Open question: separate entries for unit and amount ?
2) Bring back the filtering/searching for ingredients in a form that is more like entry completion
3) Bring back filtering/searching for units in the same form

Details about the first step:

Since we now have separate widgets, the editing needs to go into GrIngredientsViewerRow. It is gr-ingredients-viewer-row.c and .ui. I would suggest to change the widget hierarchy in the ui file from this:

GrIngredientsViewerRow
 GtkBox
   unit_label
   ingredient_label
   buttons_stack

to something like this:

GrIngredientsViewerRow
 GtkBox
   GtkStack
     unit_label
     unit_entry
   GtkStack
     ingredient_label
     ingredient_entry
   buttons_stack

and then switch the stacks to show the entries when the edit button is clicked. I suggest two separate stacks (instead of just one) here so we keep the same sizes between the labels and entries.

Created attachment 350365 [details] [review]
Add-Initial-Editing-for-GrIngredientsViewerRow

We are putting this together on the inline-editing branch

Most of this has landed now, some refinements are still happening.