Capture pixel screenshots implementation on iOS (#99)

Author: Reflejo

platform/swift/source/CoreLogger.swift

@@ -87,9 +87,10 @@ extension CoreLogger: CoreLogging {
         )
     }
 
-    func logSessionReplayScreenshot(screen: SessionReplayCapture, duration: TimeInterval) {
+    func logSessionReplayScreenshot(screen: SessionReplayCapture?, duration: TimeInterval) {
+        let fields = screen.flatMap { screen in self.convertFields(fields: ["screen_px": screen]) } ?? []
         self.underlyingLogger.logSessionReplayScreenshot(
-            fields: self.convertFields(fields: ["screen": screen]),
+            fields: fields,
             duration: duration
         )
     }

platform/swift/source/CoreLogging.swift

@@ -55,9 +55,9 @@ protocol CoreLogging: AnyObject {
 
     /// Writes a session replay screen log.
     ///
-    /// - parameter screen:   The captured screenshot.
+    /// - parameter screen:   The captured screenshot. `nil` if screenshot couldn't be taken.
     /// - parameter duration: The duration of time the preparation of the log took.
-    func logSessionReplayScreenshot(screen: SessionReplayCapture, duration: TimeInterval)
+    func logSessionReplayScreenshot(screen: SessionReplayCapture?, duration: TimeInterval)
 
     /// Writes a resource utilization log.
     ///

platform/swift/source/replay/SessionReplayTarget.swift

@@ -7,6 +7,7 @@
 
 @_implementationOnly import CapturePassable
 import Foundation
+import UIKit
 
 final class SessionReplayTarget {
     private let queue = DispatchQueue.serial(withLabelSuffix: "ReplayController", target: .default)
@@ -41,14 +42,32 @@ extension SessionReplayTarget: CapturePassable.SessionReplayTarget {
     }
 
     func captureScreenshot() {
-        // TODO: Implement
-        //        DispatchQueue.main.async { [weak self] in
-        //            self?.queue.async {
-        //                self?.logger?.logSessionReplayScreenshot(
-        //                    screen: SessionReplayCapture(data: Data()),
-        //                    duration: 0
-        //                )
-        //            }
-        //        }
+        DispatchQueue.main.async {
+            guard let window = UIApplication.shared.sessionReplayWindows().first else {
+                self.logger?.logSessionReplayScreenshot(
+                    screen: nil,
+                    duration: 0
+                )
+                return
+            }
+
+            let layer = window.layer
+            let bounds = UIScreen.main.bounds.size
+
+            self.queue.async { [weak self] in
+                let start = Uptime()
+                let format = UIGraphicsImageRendererFormat()
+                format.scale = 1.0
+
+                let renderer = UIGraphicsImageRenderer(size: bounds, format: format)
+                let jpeg = renderer.jpegData(withCompressionQuality: 0.1) { context in
+                    layer.render(in: context.cgContext)
+                }
+                self?.logger?.logSessionReplayScreenshot(
+                    screen: SessionReplayCapture(data: jpeg),
+                    duration: Uptime().timeIntervalSince(start)
+                )
+            }
+        }
     }
 }

test/platform/swift/unit_integration/core/bridge/SessionReplayTargetTests.swift

@@ -30,7 +30,7 @@ final class SessionReplayTargetTests: XCTestCase {
     func testEmitsSessionReplayScreenLog() {
         let expectation = self.expectation(description: "screen log is emitted")
 
-        self.logger.logSessionReplayScreen = expectation
+        self.logger.logSessionReplayScreenExpectation = expectation
         self.target.captureScreen()
 
         XCTAssertEqual(.completed, XCTWaiter().wait(for: [expectation], timeout: 0.5))

test/platform/swift/unit_integration/mocks/MockCoreLogging.swift

@@ -44,7 +44,7 @@ public final class MockCoreLogging {
     public var logResourceUtilizationExpectation: XCTestExpectation?
 
     public private(set) var sessionReplayScreenLogs = [SessionReplayScreenLog]()
-    public var logSessionReplayScreen: XCTestExpectation?
+    public var logSessionReplayScreenExpectation: XCTestExpectation?
 
     public var shouldLogAppUpdateEvent = false
 
@@ -115,10 +115,10 @@ extension MockCoreLogging: CoreLogging {
         self.sessionReplayScreenLogs.append(SessionReplayScreenLog(
                                                 screen: screen, duration: duration)
         )
-        self.logSessionReplayScreen?.fulfill()
+        self.logSessionReplayScreenExpectation?.fulfill()
     }
 
-    public func logSessionReplayScreenshot(screen _: SessionReplayCapture, duration _: TimeInterval) {}
+    public func logSessionReplayScreenshot(screen _: SessionReplayCapture?, duration _: TimeInterval) {}
 
     public func logResourceUtilization(fields: Fields, duration: TimeInterval) {
         self.resourceUtilizationLogs.append(ResourceUtilizationLog(fields: fields, duration: duration))