[feature/suffix-protection] File extension / suffix protection (#1298)

* - NamingViewController: add option .requiredFileExtension that enforces a particular suffix when set
- CreateDocumentAction: take advantage of NamingViewController.requiredFileExtension to prevent changing file suffix for new files

* - ThemeCSSTextField: add support for requiring a file extension (.requiredFileExtension)
- NamingViewController: remove delegate code for .requiredFileExtension and use ThemeCSSTextField.requiredFileExtension instead
- StaticTableViewRow: add support for requiring a file extension (.requiredFileExtension) based on ThemeCSSTextField.requiredFileExtension
- ScanViewController: use StaticTableViewRow.requiredFileExtension to prevent deletion of required file extension

* - ios-sdk update: fixes crash (finding #1 in #1298)
- ScanViewController, NamingViewController: when enforcing file suffixes: prevent choice of filenames consisting just of a suffix (since these would be hidden files) by disabling the primary action button

* Calens changelog updated

---------

Co-authored-by: felix-schwarz <felix-schwarz@users.noreply.github.com>
Co-authored-by: Matthias Hühne <github@hosy.de>

ownCloud/Client/Actions/Actions+Extensions/CreateDocumentAction.swift

@@ -270,6 +270,7 @@ class CreateDocumentAction: Action {
 							}
 						})
 
+						documentNameViewController.requiredFileExtension = fileType.extension
 						documentNameViewController.navigationItem.title = "Pick a name".localized
 
 						navigationViewController.pushViewController(documentNameViewController, animated: true)

ownCloud/Client/Actions/Scanner/ScanViewController.swift

@@ -287,6 +287,11 @@ class ScanViewController: StaticTableViewController {
 		didSet {
 			if let fileName = fileNameRow?.value as? NSString {
 				fileNameRow?.value = fileName.deletingPathExtension + "." + (exportFormat?.suffix ?? "")
+				fileNameRow?.requiredFileExtension = exportFormat?.suffix
+
+				if let textField = fileNameRow?.textField, textField.isFirstResponder {
+					textField.selectedTextRange = textField.textRange(from: textField.beginningOfDocument, to: textField.beginningOfDocument)
+				}
 			}
 
 			guard let oneFilePerPageRow = oneFilePerPageRow else { return }
@@ -315,7 +320,9 @@ class ScanViewController: StaticTableViewController {
 		self.isModalInPresentation = true
 		self.navigationItem.title = "Scan".localized
 		self.navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action: #selector(ScanViewController.cancel))
-		self.navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .save, target: self, action: #selector(ScanViewController.save))
+
+		let saveBarButtonItem = UIBarButtonItem(barButtonSystemItem: .save, target: self, action: #selector(ScanViewController.save))
+		self.navigationItem.rightBarButtonItem = saveBarButtonItem
 
 		self.core = core
 		self.targetFolderItem = item
@@ -353,7 +360,7 @@ class ScanViewController: StaticTableViewController {
 		// Save section
 
 		// - Name
-		fileNameRow = StaticTableViewRow(textFieldWithAction: { [weak self] (row, textField, type) in
+		fileNameRow = StaticTableViewRow(textFieldWithAction: { [weak self, weak saveBarButtonItem] (row, textField, type) in
 			self?.navigationItem.rightBarButtonItem?.isEnabled = ((row.value as? String)?.count ?? 0) > 0
 
 			if type == .didBegin, let nameTextField = textField as? UITextField {
@@ -369,6 +376,10 @@ class ScanViewController: StaticTableViewController {
 					nameTextField.selectedTextRange = nameTextField.textRange(from: nameTextField.beginningOfDocument, to: nameTextField.endOfDocument)
 				}
 			}
+
+			if let fileName = (textField as? UITextField)?.text, let requiredFileExtension = row.requiredFileExtension {
+				saveBarButtonItem?.isEnabled = (fileName.count > (requiredFileExtension.count + 1))
+			}
 		}, placeholder: "Name".localized, value: fileName ?? "", keyboardType: .default, autocorrectionType: .no, enablesReturnKeyAutomatically: true, returnKeyType: .default, identifier: "name", accessibilityLabel: "Name".localized)
 		saveSection.add(row: fileNameRow!)
 		self.addSection(saveSection)

ownCloudAppShared/Client/User Interface/NamingViewController.swift

@@ -19,15 +19,16 @@
 import UIKit
 import ownCloudSDK
 
-public typealias StringValidatorResult = (Bool, String?, String?)
-public typealias StringValidatorHandler = (String) -> StringValidatorResult
+public typealias StringValidatorResult = (Bool, String?, String?) // (validationPassed, validationErrorTitle, validationErrorMessage)
+public typealias StringValidatorHandler = (_ stringToCheck: String) -> StringValidatorResult
 
 open class NamingViewController: UIViewController {
 	weak open var item: OCItem?
 	weak open var core: OCCore?
 	open var completion: (String?, NamingViewController) -> Void
 	open var stringValidator: StringValidatorHandler?
 	open var defaultName: String?
+	open var requiredFileExtension: String?
 
 	private var blurView: UIVisualEffectView
 
@@ -37,7 +38,7 @@ open class NamingViewController: UIViewController {
 	private var thumbnailImageView: ResourceViewHost
 
 	private var nameContainer: UIView
-	private var nameTextField: UITextField
+	private var nameTextField: ThemeCSSTextField
 
 	private var textfieldTopAnchorConstraint: NSLayoutConstraint
 	private var textfieldCenterYAnchorConstraint: NSLayoutConstraint
@@ -152,6 +153,7 @@ open class NamingViewController: UIViewController {
 
 		// Name textfield
 		nameTextField.translatesAutoresizingMaskIntoConstraints = false
+		nameTextField.requiredFileExtension = requiredFileExtension
 		nameContainer.addSubview(nameTextField)
 		NSLayoutConstraint.activate([
 			nameTextField.heightAnchor.constraint(equalToConstant: 40),
@@ -267,7 +269,9 @@ open class NamingViewController: UIViewController {
 	}
 
 	@objc open func textfieldDidChange(_ sender: UITextField) {
-		if sender.text != "" {
+		let filename = sender.text
+
+		if filename != "", requiredFileExtension == nil || ((requiredFileExtension != nil) && filename != ".\(requiredFileExtension!)") {
 			doneButton?.isEnabled = true
 		} else {
 			doneButton?.isEnabled = false
@@ -351,7 +355,15 @@ extension NamingViewController: UITextFieldDelegate {
 		} else {
 			textField.selectedTextRange = nameTextField.textRange(from: nameTextField.beginningOfDocument, to: nameTextField.endOfDocument)
 		}
+	}
 
+	public func textFieldShouldClear(_ textField: UITextField) -> Bool {
+		if let requiredFileExtension {
+			textField.text = "." + requiredFileExtension
+			textField.selectedTextRange = textField.textRange(from: textField.beginningOfDocument, to: textField.beginningOfDocument)
+			return false
+		}
+		return true
 	}
 
 	open func textFieldShouldReturn(_ textField: UITextField) -> Bool {

ownCloudAppShared/User Interface/StaticTableView/StaticTableViewRow.swift

@@ -528,6 +528,21 @@ open class StaticTableViewRow : NSObject, UITextFieldDelegate {
 		return true
 	}
 
+	public func textFieldShouldClear(_ textField: UITextField) -> Bool {
+		if let requiredFileExtension {
+			textField.text = "." + requiredFileExtension
+			textField.selectedTextRange = textField.textRange(from: textField.beginningOfDocument, to: textField.beginningOfDocument)
+			return false
+		}
+		return true
+	}
+
+	open var requiredFileExtension: String? {
+		didSet {
+			(textField as? ThemeCSSTextField)?.requiredFileExtension = requiredFileExtension
+		}
+	}
+
 	// MARK: - Labels
 	convenience public init(label: String, accessoryView: UIView? = nil, identifier: String? = nil) {
 		self.init()

ownCloudAppShared/User Interface/Theme/CSS/Views/ThemeCSSTextField.swift

@@ -18,9 +18,20 @@
 
 import UIKit
 
+public extension UITextInput {
+	func range(from textRange: UITextRange) -> NSRange {
+		let startOffset = offset(from: beginningOfDocument, to: textRange.start)
+		let endOffset = offset(from: beginningOfDocument, to: textRange.end)
+
+		return NSRange(location: startOffset, length: endOffset-startOffset+1)
+	}
+}
+
 public class ThemeCSSTextField: UITextField, Themeable {
 	private var hasRegistered : Bool = false
 
+	open var requiredFileExtension: String?
+
 	override open func didMoveToWindow() {
 		super.didMoveToWindow()
 
@@ -41,4 +52,26 @@ public class ThemeCSSTextField: UITextField, Themeable {
 	open func applyThemeCollection(theme: Theme, collection: ThemeCollection, event: ThemeEvent) {
 		self.applyThemeCollection(collection)
 	}
+
+	public override func shouldChangeText(in range: UITextRange, replacementText: String) -> Bool {
+		if let requiredFileExtension, let previousText = text,
+		   let textRange = Range(self.range(from: range), in: previousText) {
+			let newName = previousText.replacingCharacters(in: textRange, with: replacementText)
+			return (newName as NSString).pathExtension == requiredFileExtension || (newName == ".\(requiredFileExtension)")
+		}
+
+		return super.shouldChangeText(in: range, replacementText: replacementText)
+	}
+
+	public override var selectedTextRange: UITextRange? {
+		didSet {
+			if let requiredFileExtension {
+				if let selectedTextRange,
+				   let maxAllowedPosition = position(from: endOfDocument, offset: -requiredFileExtension.count-1),
+				   compare(selectedTextRange.end, to: maxAllowedPosition) == .orderedDescending {
+					self.selectedTextRange = textRange(from: selectedTextRange.start, to: maxAllowedPosition)
+				}
+			}
+		}
+	}
 }