IGListKit/Source/IGListBindingSectionControllerSelectionDelegate.h
Ryan Nystrom 79348164a7 Auto diffing section controller
Summary:
Started work on the plane to get this moving since #418  is up and ready to land. We'll likely need to spend some time fleshing out the API of this, and I think I'll split it up into a couple different PRs once ready for review. Putting this up now to get early feedback.

This adds an auto-diffing section controller as outlined in #38. There are several key parts:

- Subclass a new section controller `IGListAutoSectionController` (naming wip)
- Connect a data source
- Implement the data source methods that do 3 things:
  - Given a top-level object, transform it into an array of **diffable** view models
  - Given a view model, return a cell
  - Given a view model, return a size for a cell
- A new protocol for the cell `IGListBindable` so that we can control when the cell is updated w/ the view model.
  - The most important part of this is that it unlocks moving and reloading a cell, which you can't do w/ `UICollectionView`

- [ ] Unit test `reloadObjects:`
- [x] Add
Closes https://github.com/Instagram/IGListKit/pull/494

Reviewed By: amonshiz

Differential Revision: D4696966

Pulled By: rnystrom

fbshipit-source-id: f21b8341b3ed4389f2a4a106d0d316f481ba6943
2017-03-15 07:47:24 -07:00

34 lines
1,020 B
Objective-C

/**
* Copyright (c) 2016-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import <Foundation/Foundation.h>
@class IGListBindingSectionController;
NS_ASSUME_NONNULL_BEGIN
/**
A protocol that handles cell selection events in an `IGListBindingSectionController`.
*/
@protocol IGListBindingSectionControllerSelectionDelegate <NSObject>
/**
Tells the delegate that a cell at a given index was selected.
@param sectionController The section controller the selection occured in.
@param index The index of the selected cell.
@param viewModel The view model that was bound to the cell.
*/
- (void)sectionController:(IGListBindingSectionController *)sectionController
didSelectItemAtIndex:(NSInteger)index
viewModel:(id)viewModel;
@end
NS_ASSUME_NONNULL_END