ts95 · February 14, 2022 19:49 · Nov 17, 2015 · Nov 17, 2015 · Nov 17, 2015 · Nov 17, 2015
diff --git a/ScreenshotDetector.swift b/ScreenshotDetector.swift
@@ -53,8 +53,7 @@ class ScreenshotDetector: NSObject, NSMetadataQueryDelegate {
 // In a view controller for instance it should be allocated
 // in the class scope. If its reference is stored inside
 // a method it will be deallocated automatically when the
-// method returns and consequently it will stop obsering
-// any events.
+// method returns and consequently stop obsering any events.
 let detector = ScreenshotDetector()
 
 // The actual callback can be assigned anywhere there's

diff --git a/ScreenshotDetector.swift b/ScreenshotDetector.swift
@@ -53,7 +53,8 @@ class ScreenshotDetector: NSObject, NSMetadataQueryDelegate {
 // In a view controller for instance it should be allocated
 // in the class scope. If its reference is stored inside
 // a method it will be deallocated automatically when the
-// method returns, and it will stop obsering events.
+// method returns and consequently it will stop obsering
+// any events.
 let detector = ScreenshotDetector()
 
 // The actual callback can be assigned anywhere there's

diff --git a/ScreenshotDetector.swift b/ScreenshotDetector.swift
@@ -59,5 +59,5 @@ let detector = ScreenshotDetector()
 // The actual callback can be assigned anywhere there's
 // a reference to the instance.
 detector.newFileCallback = { fileURL in
-  // fileURL is a NSURL instance of the screenshot file.
+  // fileURL is an NSURL instance of the screenshot file.
 }
diff --git a/ScreenshotDetector.swift b/ScreenshotDetector.swift
@@ -0,0 +1,63 @@
+import Foundation
+
+typealias NewFileCallback = (fileURL: NSURL) -> Void
+
+class ScreenshotDetector: NSObject, NSMetadataQueryDelegate {
+
+    let query = NSMetadataQuery()
+
+    var newFileCallback: NewFileCallback?
+
+    override init() {
+        super.init()
+
+        let center = NSNotificationCenter.defaultCenter()
+        center.addObserver(self, selector: Selector("queryUpdated:"), name: NSMetadataQueryDidStartGatheringNotification, object: query)
+        center.addObserver(self, selector: Selector("queryUpdated:"), name: NSMetadataQueryDidUpdateNotification, object: query)
+        center.addObserver(self, selector: Selector("queryUpdated:"), name: NSMetadataQueryDidFinishGatheringNotification, object: query)
+
+        query.delegate = self
+        query.predicate = NSPredicate(format: "kMDItemIsScreenCapture = 1")
+        query.startQuery()
+    }
+
+    deinit {
+        query.stopQuery()
+    }
+
+    func queryUpdated(notification: NSNotification) {
+        if let userInfo = notification.userInfo {
+            for v in userInfo.values {
+                let items = v as! [NSMetadataItem]
+                if items.count > 0 {
+                    let item = items[0]
+                    if let filename = item.valueForAttribute("kMDItemFSName") as? String {
+                        let filenameWithPath = NSString(string: "~/Desktop/" + filename).stringByExpandingTildeInPath
+                        let url = NSURL(fileURLWithPath: filenameWithPath, isDirectory: false)
+                        if let cb = self.newFileCallback {
+                            cb(fileURL: url)
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+////////////////////////////
+// Usage                  //
+////////////////////////////
+
+// Because this object is observing events it should stay
+// in memory for the duration of its usage.
+// In a view controller for instance it should be allocated
+// in the class scope. If its reference is stored inside
+// a method it will be deallocated automatically when the
+// method returns, and it will stop obsering events.
+let detector = ScreenshotDetector()
+
+// The actual callback can be assigned anywhere there's
+// a reference to the instance.
+detector.newFileCallback = { fileURL in
+  // fileURL is a NSURL instance of the screenshot file.
+}