Simplify image dimming to pure tintColorDidChange swap

The previous approach tried to detect original vs desaturated images
by comparing references in updateImageDimming(), which broke on undim:
the method read the desaturated image back from contentConfiguration
and overwrote the stored original with it.

Now tintColorDidChange simply saves the original on dim and restores
it on undim — no separate method, no flags, no heuristics. Cell
providers no longer need to call updateImageDimming() manually.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ivanvorobei

Sources/DiffableKit/Table/Cells/DiffableButtonTableViewCell.swift

@@ -16,15 +16,11 @@ open class DiffableButtonTableViewCell: DiffableTableViewCell {
         super.init(coder: coder)
     }
 
-    override func updateImageDimming() {
+    open override func tintColorDidChange() {
+        super.tintColorDidChange()
         guard var content = contentConfiguration as? UIListContentConfiguration else { return }
-        let dimmed = tintAdjustmentMode == .dimmed
-        let color: UIColor = dimmed ? .secondaryLabel : tintColor
-        if content.textProperties.color != color {
-            content.textProperties.color = color
-            contentConfiguration = content
-        }
-        super.updateImageDimming()
+        content.textProperties.color = tintAdjustmentMode == .dimmed ? .secondaryLabel : tintColor
+        contentConfiguration = content
     }
 
     open override func setHighlighted(_ highlighted: Bool, animated: Bool) {

Sources/DiffableKit/Table/Cells/DiffableTableViewCell.swift

@@ -27,21 +27,13 @@ open class DiffableTableViewCell: UITableViewCell {
 
     open override func tintColorDidChange() {
         super.tintColorDidChange()
-        updateImageDimming()
-    }
-
-    func updateImageDimming() {
         guard var content = contentConfiguration as? UIListContentConfiguration else { return }
-        if content.image !== originalImage {
+        if tintAdjustmentMode == .dimmed {
             originalImage = content.image
-        }
-        let dimmed = tintAdjustmentMode == .dimmed
-        if dimmed {
-            guard let desaturated = originalImage?.desaturated() else { return }
-            content.image = desaturated
-        } else {
-            guard let original = originalImage else { return }
+            content.image = originalImage?.desaturated()
+        } else if let original = originalImage {
             content.image = original
+            originalImage = nil
         }
         contentConfiguration = content
     }

Sources/DiffableKit/Table/DataSource/DiffableTableDataSource+CellProvider.swift

@@ -51,7 +51,6 @@ extension DiffableTableDataSource {
                 content.image = item.icon
                 applyImageLayout(&content)
                 cell.contentConfiguration = content
-                cell.updateImageDimming()
                 cell.accessoryType = item.accessoryType
                 cell.selectionStyle = item.selectionStyle
                 return cell
@@ -68,7 +67,6 @@ extension DiffableTableDataSource {
                 content.image = item.icon
                 applyImageLayout(&content)
                 cell.contentConfiguration = content
-                cell.updateImageDimming()
                 cell.accessoryType = item.accessoryType
                 cell.selectionStyle = item.selectionStyle
                 return cell
@@ -87,7 +85,6 @@ extension DiffableTableDataSource {
                 let descriptor = UIFontDescriptor.preferredFontDescriptor(withTextStyle: .body)
                 content.textProperties.font = UIFont.systemFont(ofSize: descriptor.pointSize, weight: .medium)
                 cell.contentConfiguration = content
-                cell.updateImageDimming()
                 cell.accessoryType = item.accessoryType
                 return cell
             }
@@ -102,8 +99,6 @@ extension DiffableTableDataSource {
                 content.image = item.icon
                 applyImageLayout(&content)
                 cell.contentConfiguration = content
-                cell.updateImageDimming()
-
                 if let control = cell.accessoryView as? DiffableSwitch {
                     control.action = item.action
                     control.isOn = item.isOn
@@ -127,8 +122,6 @@ extension DiffableTableDataSource {
                 content.image = item.icon
                 applyImageLayout(&content)
                 cell.contentConfiguration = content
-                cell.updateImageDimming()
-
                 if let control = cell.accessoryView as? DiffableStepper {
                     control.action = item.action
                     control.stepValue = item.stepValue