Summary:
I had a desire for interactive reordering in a personal project, so here's a first attempt at adding support in IGListKit.
I figured I might as well get a WIP PR up for comments before I continue further as there are a few aspects to interactive reordering that don't interplay perfectly with IGListKit.
As discussed in #291, I went after two prime use cases:
1. Moving items amongst a section
2. Rearranging whole sections
I also "disabled" moving items between sections by having those moves revert, to mimic interactive reordering cancellation as closely as possible.
You can see both in the Mixed Data example. Grid items can be moved within a section, while users can be moved to reorder whole sections. But trying to move a grid item out of a grid or a user item into a grid will auto-revert. The revert animation isn't as tight as it should be. It may be more desirable to disable the animation - though you lose the visual cue.
There is a also a new example, `ReorderableViewController`, that demonstrates 2 in its pure form (likely the most desired use case), where all sections are reorderable single rows.
Happy to take feedback -- this is my first experience working on IGListKit, so I would expect there to be gaps. (Ex. I haven't used `IGListStackedSectionController`, and its tests failed as I hadn't implemented reordering delegates for it. Those are simply stubbed out for now.)
Issue fixed: #291
- [x] All tests pass. Demo project builds and runs.
- [x] I added tests, an experiment, or detailed why my change isn't tested.
- [x] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [x] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)
- [x] Proper support in `IGListStackedSectionController`
Closes https://github.com/Instagram/IGListKit/pull/976
Differential Revision: D6674493
Pulled By: rnystrom
fbshipit-source-id: cd53c5fdc6fb59636edc4747c4bbd0f81a4610e5
Summary:
a415ef5552 exposed a bug in `UICollectionView` where its state gets corrupted when deleting the same index path more than once in a single batch update block. This resulted crashes like
```
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x4)
Closes https://github.com/Instagram/IGListKit/pull/657
Reviewed By: jessesquires
Differential Revision: D4913790
Pulled By: rnystrom
fbshipit-source-id: 8f6fcdd2e2438da309fc64ca0ac111b9a0980149
Summary:
Adding an API to do item-level (cell) moves on the collection view. This complicates things a little bit because of all the issues that moving sections have while in batch updates (e.g. simultaneous animation UICV bugs). Thankfully we use pretty strict types so the compiler does most of the work for us.
Closes#145
- [x] Tests build and pass
- [x] Add `IGListBatchUpdateData` tests to check moves during
- [x] ~~Moving within a reloaded section (no op)~~ can't reload sections
- [x] Moving within a deleted section (no op)
- [x] Moving within a moved section (convert section ops to delete+insert)
- [x] Moving an index path that is also reloaded (convert to delete+insert path)
- [x] Add move unit tests to `IGListAdapterUpdater`
- [x] Add move unit tests to `IGListReloadDataUpdater` (mostly for code coverage...)
- [x] Add move unit tests to `IGListStackedSectionController`
- [x] Add `CHANGELOG.md` entry for 3.0.0
- [x] Test moving without batch
Closes https://github.com/Instagram/IGListKit/pull/418
Reviewed By: jessesquires
Differential Revision: D4521732
Pulled By: rnystrom
fbshipit-source-id: 99a46d1cbb0cc1f857a62ff6ca257aff6e8b7f25
