Ely Office: six offline-first desktop apps in Rust and GPUI

ElyDoc, ElyTable, ElyShow (LibreOfficeKit), ElyPDF (MuPDF), ElyTree (Git),
ElyMark (Milkdown and CodeMirror in CEF). ElyMail and ElyAgent follow.

tests/scripts/window-share.swift

@@ -0,0 +1,39 @@
+// The share of a window's pixels near one colour.
+import CoreGraphics
+import Foundation
+import ImageIO
+
+let args = CommandLine.arguments
+let pid = Int32(args[1])!
+let want = args[2].split(separator: ",").map { Int($0)! }
+let windows = CGWindowListCopyWindowInfo([.optionOnScreenOnly], kCGNullWindowID) as! [[String: Any]]
+guard let window = windows.first(where: {
+    ($0[kCGWindowOwnerPID as String] as? Int32) == pid && ($0[kCGWindowLayer as String] as? Int) == 0
+}) else {
+    print("none")
+    exit(0)
+}
+let id = window[kCGWindowNumber as String] as! Int
+let file = NSTemporaryDirectory() + "ely-share-\(pid).png"
+let shot = Process()
+shot.executableURL = URL(fileURLWithPath: "/usr/sbin/screencapture")
+shot.arguments = ["-x", "-o", "-l", "\(id)", file]
+try shot.run()
+shot.waitUntilExit()
+guard let source = CGImageSourceCreateWithURL(URL(fileURLWithPath: file) as CFURL, nil),
+      let image = CGImageSourceCreateImageAtIndex(source, 0, nil) else {
+    print("denied")
+    exit(0)
+}
+let (width, height) = (image.width, image.height)
+var pixels = [UInt8](repeating: 0, count: width * height * 4)
+let context = CGContext(
+    data: &pixels, width: width, height: height, bitsPerComponent: 8, bytesPerRow: width * 4,
+    space: CGColorSpaceCreateDeviceRGB(), bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)!
+context.draw(image, in: CGRect(x: 0, y: 0, width: width, height: height))
+var near = 0
+for at in stride(from: 0, to: pixels.count, by: 4) {
+    let off = abs(Int(pixels[at]) - want[0]) + abs(Int(pixels[at + 1]) - want[1]) + abs(Int(pixels[at + 2]) - want[2])
+    if off < 40 { near += 1 }
+}
+print(String(format: "%.4f", Double(near) / Double(width * height)))