Estimated height

xai3 · Dec 28, 2016 · 3a381cf · 3a381cf
1 parent 35ea18a
commit 3a381cf
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Showing 4 changed files with 34 additions and 0 deletions.
diff --git a/Classes/Row.swift b/Classes/Row.swift
@@ -20,6 +20,7 @@ open class Row<T: UITableViewCell>: RowType {
 
     open var configureCell: ((T, RowInformation) -> Void)?
     open var heightFor: ((RowInformation) -> CGFloat?)?
+    open var estimatedHeightFor: ((RowInformation) -> CGFloat?)?
     open var canRemove: ((RowInformation) -> Bool)?
     open var canMove: ((RowInformation) -> Bool)?
     open var canMoveTo: ((RowMoveInformation) -> Bool)?
@@ -45,6 +46,7 @@ open class Row<T: UITableViewCell>: RowType {
     }
 
     open var height: CGFloat?
+    open var estimatedHeight: CGFloat?
 }
 
 extension Row: RowDelegateType {
@@ -59,6 +61,10 @@ extension Row: RowDelegateType {
         return heightFor?((self, tableView, indexPath)) ?? height
     }
 
+    func estimatedHeightFor(_ tableView: UITableView, indexPath: IndexPath) -> CGFloat? {
+        return estimatedHeightFor?((self, tableView, indexPath)) ?? estimatedHeight
+    }
+
     func canEdit(_ tableView: UITableView, indexPath: IndexPath) -> Bool {
         return canRemove(tableView, indexPath: indexPath) || canMove(tableView, indexPath: indexPath)
     }

diff --git a/Classes/RowType.swift b/Classes/RowType.swift
@@ -16,6 +16,7 @@ public protocol RowType {
 protocol RowDelegateType {
     func configureCell(_ tableView: UITableView, cell: UITableViewCell, indexPath: IndexPath)
     func heightFor(_ tableView: UITableView, indexPath: IndexPath) -> CGFloat?
+    func estimatedHeightFor(_ tableView: UITableView, indexPath: IndexPath) -> CGFloat?
     func canEdit(_ tableView: UITableView, indexPath: IndexPath) -> Bool
     func canRemove(_ tableView: UITableView, indexPath: IndexPath) -> Bool
     func canMove(_ tableView: UITableView, indexPath: IndexPath) -> Bool

diff --git a/Classes/Source.swift b/Classes/Source.swift
@@ -176,6 +176,15 @@ extension Source: UITableViewDelegate {
         return tableView.rowHeight
     }
 
+    public func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
+        let row = self.section(for: indexPath).rowFor(indexPath)
+        if let delegate = row as? RowDelegateType,
+            let estimatedHeight = delegate.estimatedHeightFor(tableView, indexPath: indexPath) {
+            return estimatedHeight
+        }
+        return tableView.estimatedRowHeight
+    }
+
     public func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
         guard let header = self.section(for: section).header else {
             return 0

diff --git a/ShoyuTests/RowTests.swift b/ShoyuTests/RowTests.swift
@@ -51,6 +51,24 @@ class RowTests: XCTestCase {
         XCTAssertEqual(height, 10)
     }
 
+    func testEstimatedHeightFor() {
+        let row = Row()
+
+        // Initialezed
+        XCTAssertEqual(row.estimatedHeightFor(UITableView(), indexPath: IndexPath()), nil)
+
+        // Constant
+        row.estimatedHeight = 15
+        XCTAssertEqual(row.estimatedHeightFor(UITableView(), indexPath: IndexPath()), 15)
+
+        // Configure
+        row.estimatedHeightFor = { _ -> CGFloat? in
+            return 30
+        }
+        let height = row.estimatedHeightFor(UITableView(), indexPath: IndexPath())
+        XCTAssertEqual(height, 30)
+    }
+
     func testDidSelect() {
         var called = false
         let row = Row()