internal diff for PR #209

Summary: https://github.com/Instagram/IGListKit/pull/209

Reviewed By: rnystrom

Differential Revision: D4190633

fbshipit-source-id: 9d382b9ba3f3d20c8b9c48d900650ec354bc9728

Examples/Examples-iOS/IGListKitExamples/SectionControllers/ExpandableSectionController.swift

@@ -0,0 +1,49 @@
+/**
+ Copyright (c) 2016-present, Facebook, Inc. All rights reserved.
+
+ The examples provided by Facebook are for non-commercial testing and evaluation
+ purposes only. Facebook reserves all rights not expressly granted.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+import UIKit
+import IGListKit
+
+final class ExpandableSectionController: IGListSectionController, IGListSectionType {
+
+    var expanded = false
+    var object: String?
+
+    func numberOfItems() -> Int {
+        return 1
+    }
+
+    func sizeForItem(at index: Int) -> CGSize {
+        let width = collectionContext!.containerSize.width
+        let height = expanded ? LabelCell.textHeight(object ?? "", width: width) : LabelCell.singleLineHeight
+        return CGSize(width: width, height: height)
+    }
+
+    func cellForItem(at index: Int) -> UICollectionViewCell {
+        let cell = collectionContext!.dequeueReusableCell(of: LabelCell.self, for: self, at: index) as! LabelCell
+        cell.label.numberOfLines = expanded ? 0 : 1
+        cell.label.text = object
+        return cell
+    }
+
+    func didUpdate(to object: Any) {
+        self.object = object as? String
+    }
+
+    func didSelectItem(at index: Int) {
+        expanded = !expanded
+        collectionContext?.reload(self)
+    }
+
+}