Added algorithm for pagination to PDF export, allowing to export consent forms with more than 1 page (#49)

.github/workflows/build-and-test.yml

@@ -107,7 +107,7 @@ jobs:
       runsonlabels: '["macOS", "self-hosted"]'
       path: 'Tests/UITests'
       scheme: TestApp
-      destination: 'platform=iOS Simulator,name=iPad Air (5th generation)'
+      destination: 'platform=iOS Simulator,name=iPad Pro 11-inch (M4)'
       buildConfig: ${{ matrix.buildConfig }}
       resultBundle: ${{ matrix.resultBundle }}
       artifactname: ${{ matrix.artifactname }}

Package.swift

@@ -25,7 +25,8 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/StanfordSpezi/Spezi", from: "1.2.1"),
         .package(url: "https://github.com/StanfordSpezi/SpeziViews", from: "1.3.1"),
-        .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.0")
+        .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.0"),
+        .package(url: "https://github.com/techprimate/TPPDF", from: "2.6.0")
     ],
     targets: [
         .target(
@@ -34,7 +35,8 @@ let package = Package(
                 .product(name: "Spezi", package: "Spezi"),
                 .product(name: "SpeziViews", package: "SpeziViews"),
                 .product(name: "SpeziPersonalInfo", package: "SpeziViews"),
-                .product(name: "OrderedCollections", package: "swift-collections")
+                .product(name: "OrderedCollections", package: "swift-collections"),
+                .product(name: "TPPDF", package: "TPPDF")
             ]
         ),
         .testTarget(

Sources/SpeziOnboarding/ConsentView/ConsentDocument+Export.swift

@@ -9,7 +9,7 @@
 import PDFKit
 import PencilKit
 import SwiftUI
-
+import TPPDF
 
 /// Extension of `ConsentDocument` enabling the export of the signed consent page.
 extension ConsentDocument {
@@ -18,7 +18,7 @@ extension ConsentDocument {
     /// force the ink used in the `UIImage` of the `PKDrawing` to always be black by adjusting the signature ink according to the color scheme.
     private var blackInkSignatureImage: UIImage {
         var updatedDrawing = PKDrawing()
-        
+
         for stroke in signature.strokes {
             let blackStroke = PKStroke(
                 ink: PKInk(stroke.ink.inkType, color: colorScheme == .light ? .black : .white),
@@ -43,100 +43,145 @@ extension ConsentDocument {
     }
     #endif
 
-
-    /// Creates a representation of the consent form that is ready to be exported via the SwiftUI `ImageRenderer`.
-    ///
-    /// - Parameters:
-    ///   - markdown: The markdown consent content as an `AttributedString`.
+    /// Generates a `PDFAttributedText` containing the timestamp of when the PDF was exported.
     ///
-    /// - Returns: A SwiftUI `View` representation of the consent content and signature.
+    /// - Returns: A TPPDF `PDFAttributedText` representation of the export time stamp.
+    func exportTimeStamp() -> PDFAttributedText {
+        let stampText = String(localized: "EXPORTED_TAG", bundle: .module) + ": " +
+                DateFormatter.localizedString(from: Date(), dateStyle: .medium, timeStyle: .short) + "\n\n\n\n"
+
+        #if !os(macOS)
+        let font = UIFont.preferredFont(forTextStyle: .caption1)
+        #else
+        let font = NSFont.preferredFont(forTextStyle: .caption1)
+        #endif
+
+        let attributedTitle = NSMutableAttributedString(
+            string: stampText,
+            attributes: [
+                NSAttributedString.Key.font: font
+            ]
+        )
+
+        return PDFAttributedText(text: attributedTitle)
+    }
+
+    /// Converts the header text (i.e., document title) to a PDFAttributedText, which can be
+    /// added to the exported PDFDocument.
     ///
-    /// - Note: This function avoids the use of asynchronous operations.
-    /// Asynchronous tasks are incompatible with SwiftUI's `ImageRenderer`,
-    /// which expects all rendering processes to be synchronous.
-    private func exportBody(markdown: AttributedString) -> some View {
-        VStack {
-            if exportConfiguration.includingTimestamp {
-                HStack {
-                    Spacer()
+    /// - Returns: A TPPDF `PDFAttributedText` representation of the document title.
+    func exportHeader() -> PDFAttributedText {
+        #if !os(macOS)
+        let largeTitleFont = UIFont.preferredFont(forTextStyle: .largeTitle)
+        let boldLargeTitleFont = UIFont.boldSystemFont(ofSize: largeTitleFont.pointSize)
+        #else
+        let largeTitleFont = NSFont.preferredFont(forTextStyle: .largeTitle)
+        let boldLargeTitleFont = NSFont.boldSystemFont(ofSize: largeTitleFont.pointSize)
+        #endif
 
-                    Text("EXPORTED_TAG", bundle: .module)
-                        + Text(verbatim: ": \(DateFormatter.localizedString(from: Date(), dateStyle: .medium, timeStyle: .short))")
-                }
-                .font(.caption)
-                .padding()
-            }
-
-            OnboardingTitleView(title: exportConfiguration.consentTitle)
-
-            Text(markdown)
-                .padding()
-
-            Spacer()
-
-            ZStack(alignment: .bottomLeading) {
-                SignatureViewBackground(name: name, backgroundColor: .clear)
+        let attributedTitle = NSMutableAttributedString(
+            string: exportConfiguration.consentTitle.localizedString() + "\n\n",
+            attributes: [
+                NSAttributedString.Key.font: boldLargeTitleFont
+            ]
+        )
+
+        return PDFAttributedText(text: attributedTitle)
+    }
+    /// Exports the signature to a `PDFGroup` which can be added to the exported PDFDocument.
+    /// The signature group will contain a prefix ("X"), the name of the signee as well as the signature image.
+    ///
+    /// - Returns: A TPPDF `PDFAttributedText` representation of the export time stamp.
+    func exportSignature() -> PDFGroup {
+        let personName = name.formatted(.name(style: .long))
 
-                #if !os(macOS)
-                Image(uiImage: blackInkSignatureImage)
-                #else
-                Text(signature)
-                    .padding(.bottom, 32)
-                    .padding(.leading, 46)
-                    .font(.custom("Snell Roundhand", size: 24))
-                #endif
-            }
-                #if !os(macOS)
-                .frame(width: signatureSize.width, height: signatureSize.height)
-                #else
-                .padding(.horizontal, 100)
-                #endif
-        }
+        #if !os(macOS)
+        let group = PDFGroup(
+            allowsBreaks: false,
+            backgroundImage: PDFImage(image: blackInkSignatureImage),
+            padding: EdgeInsets(top: 50, left: 50, bottom: 0, right: 100)
+        )
+
+        let signaturePrefixFont = UIFont.preferredFont(forTextStyle: .title2)
+        let nameFont = UIFont.preferredFont(forTextStyle: .subheadline)
+        let signatureColor = UIColor.secondaryLabel
+        let signaturePrefix = "X"
+        #else
+        // On macOS, we do not have a "drawn" signature, hence do
+        // not set a backgroundImage for the PDFGroup.
+        // Instead, we render the person name.
+        let group = PDFGroup(
+            allowsBreaks: false,
+            padding: EdgeInsets(top: 50, left: 50, bottom: 0, right: 100)
+        )
+
+        let signaturePrefixFont = NSFont.preferredFont(forTextStyle: .title2)
+        let nameFont = NSFont.preferredFont(forTextStyle: .subheadline)
+        let signatureColor = NSColor.secondaryLabelColor
+        let signaturePrefix = "X " + signature
+        #endif
+
+        group.set(font: signaturePrefixFont)
+        group.set(textColor: signatureColor)
+        group.add(PDFGroupContainer.left, text: signaturePrefix)
+
+        group.addLineSeparator(style: PDFLineStyle(color: .black))
+
+        group.set(font: nameFont)
+        group.add(PDFGroupContainer.left, text: personName)
+        return group
     }
 
-    /// Exports the signed consent form as a `PDFDocument` via the SwiftUI `ImageRenderer`.
+    /// Returns a  `TPPDF.PDFPageFormat` which corresponds to Spezi's `ExportConfiguration.PaperSize`.
     ///
+    /// - Parameters:
+    ///   - paperSize: The paperSize of an ExportConfiguration.
+    /// - Returns: A TPPDF `PDFPageFormat` according to the `ExportConfiguration.PaperSize`.
+    func getPDFFormat(paperSize: ExportConfiguration.PaperSize) -> PDFPageFormat {
+        switch paperSize {
+        case .dinA4:
+            return PDFPageFormat.a4
+        case .usLetter:
+            return PDFPageFormat.usLetter
+        }
+    }
+
+    /// Exports the signed consent form as a `PDFKit.PDFDocument`.
+    /// The PDF generated by TPPDF and then converted to a TPDFKit.PDFDocument.
     /// Renders the `PDFDocument` according to the specified ``ConsentDocument/ExportConfiguration``.
     ///
     /// - Returns: The exported consent form in PDF format as a PDFKit `PDFDocument`
     @MainActor
-    func export() async -> PDFDocument? {
+    func export() async -> PDFKit.PDFDocument? {
+        // swiftlint:disable:all
+
         let markdown = await asyncMarkdown()
-
         let markdownString = (try? AttributedString(
             markdown: markdown,
             options: .init(interpretedSyntax: .inlineOnlyPreservingWhitespace)
         )) ?? AttributedString(String(localized: "MARKDOWN_LOADING_ERROR", bundle: .module))
 
-        let renderer = ImageRenderer(content: exportBody(markdown: markdownString))
-        let paperSize = CGSize(
-            width: exportConfiguration.paperSize.dimensions.width,
-            height: exportConfiguration.paperSize.dimensions.height
-        )
-        renderer.proposedSize = .init(paperSize)
+        let document = TPPDF.PDFDocument(format: getPDFFormat(paperSize: exportConfiguration.paperSize))
+
+        if exportConfiguration.includingTimestamp {
+            document.add(.contentRight, attributedTextObject: exportTimeStamp())
+        }
+
+        document.add(.contentCenter, attributedTextObject: exportHeader())
+        document.add(attributedText: NSAttributedString(markdownString))
+        document.add(group: exportSignature())
+
+        // Convert TPPDF.PDFDocument to PDFKit.PDFDocument
+        let generator = PDFGenerator(document: document)
 
-        return await withCheckedContinuation { continuation in
-            renderer.render { _, context in
-                var box = CGRect(origin: .zero, size: paperSize)
-
-                /// Create in-memory `CGContext` that stores the PDF
-                guard let mutableData = CFDataCreateMutable(kCFAllocatorDefault, 0),
-                      let consumer = CGDataConsumer(data: mutableData),
-                      let pdf = CGContext(consumer: consumer, mediaBox: &box, nil) else {
-                    continuation.resume(returning: nil)
-                    return
-                }
-
-                pdf.beginPDFPage(nil)
-                pdf.translateBy(x: 0, y: 0)
-
-                context(pdf)
-
-                pdf.endPDFPage()
-                pdf.closePDF()
-
-                continuation.resume(returning: PDFDocument(data: mutableData as Data))
+        if let data = try? generator.generateData() {
+            if let pdfKitDocument = PDFKit.PDFDocument(data: data) {
+                return pdfKitDocument
+            } else {
+                return nil
             }
+        } else {
+            return nil
         }
     }
 }

Tests/UITests/TestAppUITests/SpeziOnboardingTests.swift

@@ -49,7 +49,7 @@
             throw XCTSkip("PKCanvas view-related tests are currently skipped on Intel-based iOS simulators due to a metal bug on the simulator.")
         #endif
 
         XCTAssert(app.staticTexts["First Name"].waitForExistence(timeout: 2))
         try app.textFields["Enter your first name ..."].enter(value: "Leland")
 
         XCTAssert(app.staticTexts["Last Name"].waitForExistence(timeout: 2))
@@ -174,7 +174,7 @@
             throw XCTSkip("PKCanvas view-related tests are currently skipped on Intel-based iOS simulators due to a metal bug on the simulator.")
         #endif
 
         XCTAssert(app.staticTexts["First Name"].waitForExistence(timeout: 2))
         try app.textFields["Enter your first name ..."].enter(value: "Leland")
 
         XCTAssert(app.staticTexts["Last Name"].waitForExistence(timeout: 2))
@@ -232,7 +232,7 @@
             throw XCTSkip("PKCanvas view-related tests are currently skipped on Intel-based iOS simulators due to a metal bug on the simulator.")
         #endif
 
         XCTAssert(app.staticTexts["First Name"].waitForExistence(timeout: 2))
         try app.textFields["Enter your first name ..."].enter(value: "Leland")
 
         XCTAssert(app.staticTexts["Last Name"].waitForExistence(timeout: 2))
@@ -256,11 +256,9 @@
     }
 
     #if !os(macOS)  // Only test export on non macOS platforms
-    func testOnboardingConsentPDFExport() throws {  // swiftlint:disable:this function_body_length
+    @MainActor
+    func testOnboardingConsentPDFExport() async throws {
         let app = XCUIApplication()
-        let filesApp = XCUIApplication(bundleIdentifier: "com.apple.DocumentsApp")
-        let maxRetries = 10
-
         app.launch()
 
         XCTAssert(app.buttons["Consent View (Markdown)"].waitForExistence(timeout: 2))
@@ -280,82 +278,21 @@
         XCTAssert(app.scrollViews["Signature Field"].waitForExistence(timeout: 2))
         app.scrollViews["Signature Field"].swipeRight()
 
-        sleep(1)
-
-        for _ in 0...maxRetries {
-            // Export consent form via share sheet button
-            XCTAssert(app.buttons["Share consent form"].waitForExistence(timeout: 2))
-            app.buttons["Share consent form"].tap()
-
-            // Store exported consent form in Files
-            #if os(visionOS)
-            // on visionOS the save to files button has no label
-            XCTAssert(app.cells["XCElementSnapshotPrivilegedValuePlaceholder"].waitForExistence(timeout: 10))
-            app.cells["XCElementSnapshotPrivilegedValuePlaceholder"].tap()
-            #else
-            XCTAssert(app.staticTexts["Save to Files"].waitForExistence(timeout: 10))
-            app.staticTexts["Save to Files"].tap()
-            #endif
-            sleep(3)
-            XCTAssert(app.buttons["Save"].waitForExistence(timeout: 2))
-            app.buttons["Save"].tap()
-            sleep(10)    // Wait until file is saved
-
-            if app.staticTexts["Replace Existing Items?"].waitForExistence(timeout: 5) {
-                XCTAssert(app.buttons["Replace"].waitForExistence(timeout: 2))
-                app.buttons["Replace"].tap()
-                sleep(3)    // Wait until file is saved
-            }
-
-            // Wait until share sheet closed and back on the consent form screen
-            XCTAssert(app.staticTexts["Consent"].waitForExistence(timeout: 10))
-
-            XCUIDevice.shared.press(.home)
-
-            // Launch the Files app
-            filesApp.launch()
-
-            // Handle already open files
-            if filesApp.buttons["Done"].waitForExistence(timeout: 2) {
-                filesApp.buttons["Done"].tap()
-            }
-
-            // Check if file exists - If not, try the export procedure again
-            // Saving to files is very flakey on the runners, needs multiple attempts to succeed
-            if filesApp.staticTexts["Signed Consent Form"].waitForExistence(timeout: 2) {
-                break
-            }
-
-            // Launch test app and try another export
-            app.launch()
-        }
-
-        // Open File
-        XCTAssert(filesApp.staticTexts["Signed Consent Form"].waitForExistence(timeout: 2))
-        XCTAssert(filesApp.collectionViews["File View"].cells["Signed Consent Form, pdf"].waitForExistence(timeout: 2))
-
-        XCTAssert(filesApp.collectionViews["File View"].cells["Signed Consent Form, pdf"].images.firstMatch.waitForExistence(timeout: 2))
-        filesApp.collectionViews["File View"].cells["Signed Consent Form, pdf"].images.firstMatch.tap()
-
-        sleep(3)    // Wait until file is opened
-
+        try await Task.sleep(for: .seconds(1))
 
+        // Export consent form via share sheet button
+        XCTAssert(app.buttons["Share consent form"].waitForExistence(timeout: 2))
+        app.buttons["Share consent form"].tap()
+        try await Task.sleep(for: .seconds(5))
+
+        // Store exported consent form in Files.
+        // We stop here as don't want to test the iOS Files Sheet behavior as it changes across iOS Versions and
+        // Apple doesn't have a great API to test UI tests for share sheets ...
         #if os(visionOS)
-        let fileView = XCUIApplication(bundleIdentifier: "com.apple.MRQuickLook")
+        // on visionOS the save to files button has no label
+        XCTAssert(app.cells["XCElementSnapshotPrivilegedValuePlaceholder"].waitForExistence(timeout: 10))
         #else
-        let fileView = filesApp
-        #endif
-
-        // Check if PDF contains consent title, name, and markdown message
-        for searchString in ["Spezi Consent", "This is a markdown example", "Leland Stanford"] {
-            let predicate = NSPredicate(format: "label CONTAINS[c] %@", searchString)
-            XCTAssert(fileView.otherElements.containing(predicate).firstMatch.waitForExistence(timeout: 2))
-        }
-
-        #if os(iOS)
-        // Close File
-        XCTAssert(fileView.buttons["Done"].waitForExistence(timeout: 2))
-        fileView.buttons["Done"].tap()
+        XCTAssert(app.staticTexts["Save to Files"].waitForExistence(timeout: 10))
         #endif
     }
     #endif