如何使用 Swift 和 Cocoa 獲取當前活動的 window

Question

我目前正在開發一個 Safari 應用擴展，它由兩部分組成：

• 僅主機狀態欄應用程序
• Safari 擴展

此外，主機應用程序提供了一個全局快捷方式，可在狀態欄中打開一個彈出窗口。 但是，我想檢查哪個應用程序的 window 當前處於活動狀態，因為如果 Safari window 當前處於活動狀態，我不想打開彈出窗口。 有什么方法可以使用 Swift 找出哪個應用程序的 window 當前處於活動狀態？

謝謝您的幫助。

Answer 1

因此，根據 Alexander 和 Wileke 的評論，我想我找到了解決方案。

使用NSWorkspace.shared.frontmostApplication您可以檢查 Safari 當前是否處於活動狀態。 但正如 Wileke 所指出的，這並不意味着它有一個活躍的 window。 因此，我們使用CGWindowListCopyWindowInfo首先獲取所有windows，並通過比較PID檢查其中是否至少有一個屬於Safari。

這樣，我們可以肯定地說 Safari 當前必須有一個活動的 window 接收關鍵事件。 This must be true as there is now way that Safari is front most without any windows or that Safari as an window but is not front most at the same time.

好吧，除非我錯過了什么。 但現在它有效。

這是我想出的代碼：

func safariIsActive() -> Bool {
        // Get the app that currently has the focus.
        let frontApp = NSWorkspace.shared.frontmostApplication!

        // Check if the front most app is Safari
        if frontApp.bundleIdentifier == "com.apple.Safari" {
            // If it is Safari, it still does not mean, that is receiving key events
            // (i.e., has a window at the front).
            // But what we can safely say is, that if Safari is the front most app
            // and it has at least one window, it has to be the window that
            // crrently receives key events.
            let safariPID = frontApp.processIdentifier

            // With this procedure, we get all available windows.
            let options = CGWindowListOption(arrayLiteral: CGWindowListOption.excludeDesktopElements, CGWindowListOption.optionOnScreenOnly)
            let windowListInfo = CGWindowListCopyWindowInfo(options, CGWindowID(0))
            let windowInfoList = windowListInfo as NSArray? as? [[String: AnyObject]]

            // Now that we have all available windows, we are going to check if at least one of them
            // is owned by Safari.
            for info in windowInfoList! {
                let windowPID = info["kCGWindowOwnerPID"] as! UInt32
                if  windowPID == safariPID {
                    return true
                }
            }
        }
        return false
    }