macOS: split AppMain into focused modules

apps/macos/Sources/Clawdis/Screenshotter.swift

@@ -0,0 +1,80 @@
+import AppKit
+import CoreGraphics
+import Foundation
+@preconcurrency import ScreenCaptureKit
+import VideoToolbox
+
+enum Screenshotter {
+    @MainActor
+    static func capture(displayID: UInt32?, windowID: UInt32?) async -> Data? {
+        guard let content = try? await SCShareableContent.current else { return nil }
+
+        let targetDisplay: SCDisplay? = if let displayID {
+            content.displays.first(where: { $0.displayID == displayID })
+        } else {
+            content.displays.first
+        }
+
+        let filter: SCContentFilter
+        if let windowID, let win = content.windows.first(where: { $0.windowID == windowID }) {
+            filter = SCContentFilter(desktopIndependentWindow: win)
+        } else if let display = targetDisplay {
+            filter = SCContentFilter(display: display, excludingWindows: [])
+        } else {
+            return nil
+        }
+
+        let config = SCStreamConfiguration()
+        if let display = targetDisplay {
+            config.width = display.width
+            config.height = display.height
+        }
+        config.scalesToFit = true
+        config.colorSpaceName = CGColorSpace.displayP3
+
+        let stream = SCStream(filter: filter, configuration: config, delegate: nil)
+        let grabber = FrameGrabber()
+        try? stream.addStreamOutput(
+            grabber,
+            type: .screen,
+            sampleHandlerQueue: DispatchQueue(label: "com.steipete.clawdis.sshot"))
+        do {
+            try await stream.startCapture()
+            let data = await grabber.awaitPNG()
+            try? await stream.stopCapture()
+            return data
+        } catch {
+            return nil
+        }
+    }
+}
+
+final class FrameGrabber: NSObject, SCStreamOutput {
+    private var continuation: CheckedContinuation<Data?, Never>?
+    private var delivered = false
+
+    func awaitPNG() async -> Data? {
+        await withCheckedContinuation { cont in
+            self.continuation = cont
+        }
+    }
+
+    nonisolated func stream(
+        _ stream: SCStream,
+        didOutputSampleBuffer sampleBuffer: CMSampleBuffer,
+        of outputType: SCStreamOutputType)
+    {
+        guard outputType == .screen else { return }
+        if self.delivered { return }
+        guard let imageBuffer = sampleBuffer.imageBuffer else { return }
+        var cgImage: CGImage?
+        let result = VTCreateCGImageFromCVPixelBuffer(imageBuffer, options: nil, imageOut: &cgImage)
+        guard result == noErr, let cgImage else { return }
+        let rep = NSBitmapImageRep(cgImage: cgImage)
+        guard let data = rep.representation(using: .png, properties: [:]) else { return }
+
+        self.delivered = true
+        self.continuation?.resume(returning: data)
+        self.continuation = nil
+    }
+}