Update "Categories" picker to indicate multiple selection

RELEASE-NOTES.txt

@@ -8,6 +8,7 @@
 * [*] Add "File Size" to Site Media Details [#24947]
 * [*] Add "Email to Subscribers" row to "Publishing" sheet [#24946]
 * [*] Add permalink preview in the slug editor and make other improvements [#24949]
+* [*] Update "Categories" picker to indicate multiple selection [#24952]
 
 26.4
 -----

WordPress/Classes/ViewRelated/Post/Categories/PostCategoriesViewController.swift

@@ -78,12 +78,12 @@ import WordPressUI
         switch selectionMode {
         case .post:
             navigationItem.rightBarButtonItem = rightBarButtonItem
-            title = NSLocalizedString("Post Categories", comment: "Title for selecting categories for a post")
+            title = Strings.postCategoriesTitle
         case .parent:
             navigationItem.rightBarButtonItem = rightBarButtonItem
-            title = NSLocalizedString("Parent Category", comment: "Title for selecting parent category of a category")
+            title = Strings.parentCategoryTitle
         case .blogDefault:
-            title = NSLocalizedString("Default Category", comment: "Title for selecting a default category for a post")
+            title = Strings.defaultCategoryTitle
         }
     }
 
@@ -170,7 +170,7 @@ import WordPressUI
     private func configureNoCategoryRow(cell: WPTableViewCell) {
         WPStyleGuide.configureTableViewDestructiveActionCell(cell)
         cell.textLabel?.textAlignment = .natural
-        cell.textLabel?.text = NSLocalizedString("No Category", comment: "Text shown (to select no-category) in the parent-category-selection screen when creating a new category.")
+        cell.textLabel?.text = Strings.noCategoryText
         if selectedCategories.isEmpty {
             cell.accessoryType = selectedCategories.isEmpty ? .checkmark : .none
         }  else {
@@ -184,11 +184,14 @@ import WordPressUI
         cell.indentationWidth = Constants.categoryCellIndentation
         cell.textLabel?.text = category.categoryName.stringByDecodingXMLCharacters()
         WPStyleGuide.configureTableViewCell(cell)
-        if selectedCategories.contains(category) {
-            cell.accessoryType = .checkmark
-        } else {
-            cell.accessoryType = .none
-        }
+        cell.accessoryView = makeAccessoryView(isSelected: selectedCategories.contains(category))
+    }
+
+    private func makeAccessoryView(isSelected: Bool) -> UIView {
+        let image = UIImage(systemName: isSelected ? "checkmark.circle.fill" : "circle")
+        let view = UIImageView(image: image)
+        view.tintColor = isSelected ? UIAppColor.primary : .opaqueSeparator
+        return view
     }
 
     //tableView
@@ -255,10 +258,10 @@ import WordPressUI
                 if selectedCategories.contains(category),
                     let index = selectedCategories.firstIndex(of: category) {
                     selectedCategories.remove(at: index)
-                    tableView.cellForRow(at: indexPath)?.accessoryType = .none
+                    tableView.cellForRow(at: indexPath)?.accessoryView = makeAccessoryView(isSelected: false)
                 } else {
                     selectedCategories.append(category)
-                    tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark
+                    tableView.cellForRow(at: indexPath)?.accessoryView = makeAccessoryView(isSelected: true)
                 }
 
                 delegate?.postCategoriesViewController?(self, didUpdateSelectedCategories: NSSet(array: selectedCategories))
@@ -284,4 +287,30 @@ private extension PostCategoriesViewController {
         static let categoryCellIdentifier = "CategoryCellIdentifier"
         static let categoryCellIndentation = CGFloat(16.0)
     }
+
+    enum Strings {
+        static let postCategoriesTitle = NSLocalizedString(
+            "postCategories.title",
+            value: "Categories",
+            comment: "Title for selecting categories for a post or a page"
+        )
+
+        static let parentCategoryTitle = NSLocalizedString(
+            "parentCategory.title",
+            value: "Parent Category",
+            comment: "Title for selecting parent category of a category"
+        )
+
+        static let defaultCategoryTitle = NSLocalizedString(
+            "defaultCategory.title",
+            value: "Default Category",
+            comment: "Title for selecting a default category for a post"
+        )
+
+        static let noCategoryText = NSLocalizedString(
+            "parentCategory.noCategory",
+            value: "No Category",
+            comment: "Text shown (to select no-category) in the parent-category-selection screen when creating a new category."
+        )
+    }
 }