NSPathControl和NSPathControlItem是否充满了bug或者是我？(约塞米蒂)

Question

Apple将NSPathControl改为与Yosemite中的NSPathControlItem一起使用.

但是从我所在的地方来看,这些新课程根本不起作用.我试图在我的数据结构中显示自定义路径,但我有一个常规文件路径的类似问题.是我还是Apple？

这是我的代码:

第一个代码段工作,它将显示一个路径.但这就是一切有效.

//MARK: notifications
func selectionDidChange(notification : NSNotification)
{
    if let item = notification.object as? Group
    {
        //get "path" components
        var components : [String] = [item.title ?? "a"]
        var ancestor : Group? = item.parent
        while (ancestor != nil)
        {
            components.append(ancestor?.title ?? "b")
            ancestor = ancestor?.parent
        }
        components.append("")

       //convert to url
        let path = ("MyScheme:/" + "/".join(components.reverse()))
        pathControl?.URL = NSURL(string: path.stringByAddingPe
     }
 }

单击路径的任何部分以尝试从NSPathControlItem中获取任何属性根本不起作用.一切都归零.

@IBAction func select(sender : AnyObject)
{
    println(sender.clickedPathItem??.title)
    println(sender.clickedPathItem??.URL)
}

如果我尝试使用NSPathControlItem构建路径,则无法设置任何属性(title,url).

    pathComponent.URL = NSURL(string: path.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!)
    //let url : NSURL? = NSURL(string: "/")
    //let path = NSURL(fileURLWithPath: "/") 
    //pathComponent.URL = path as NSURL
    pathComponent.attributedTitle = NSAttributedString(string: "/atttributes")
    self.pathControl?.pathItems = [pathComponent]
    println(pathComponent.description)

NSPathControlItem也不应该是子类.

这里发生了什么？

编辑

据我所知,NSPathControlItem存在问题.用于创建NSPathControlItem的辅助函数.

    func pathItem(title: String, imageName: String) -> NSPathControlItem
{
    let item = NSPathControlItem()
    item.title = title
    item.image = NSImage(named: imageName)
    return item
}

一个测试函数,用于创建NSPathControlItem并打印出标题.

    var pathItems : [NSPathControlItem] = []
    for title in ["a","b","c"]
    {
        pathItems.append(self.pathItem(title, imageName: NSImageNameFolder))
    }

    for item in pathItems
    {
        println(item.title)
    }

预期的输出是三行a,b和c.我没有,b,没有.

如果直接在NSPathControl上设置pathItems,它将起作用.

self.pathControl?.pathItems = [
self.pathItem("a", imageName: NSImageNameFolder),
self.pathItem("b", imageName: NSImageNameFolder),
self.pathItem("c", imageName: NSImageNameFolder)]

但是,如果间接设置pathItems,那么一切都会变成地狱.

self.pathControl?.pathItems = pathItems //array of NSPathControl (see above)

编辑2

我再看看这个.我在pathItem函数中配置NSPathControlItem.我在这里设置标题.如果我设置了attributesTitle,则没有任何区别.使用lldb检查项目会显示正确的(属性)标题值.

但是,当我将NSPathControlItem的数组分配给NSPathControl时,标题的值为"",而attributesTitle未初始化.

Answer 1

NSPathControlItem严重破碎.从10.11.3开始,它包含以下方法,由Hopper反编译:

int -[NSPathControlItem release](int arg0) {
    [arg0->_secretCell autorelease];
    objc_assign_ivar(0x0, arg0, *_OBJC_IVAR_$_NSPathControlItem._secretCell);
    rax = [[arg0 super] release];
    return rax;
}

这显然是一个标准的dealloc覆盖,它释放了ivar,将其归零,然后调用super.但相反,由于某些未知的原因可能与非法药物有关,这是一种release超越.这意味着即使在一些无害的操作过程中释放其中一个物体的那一刻,它也会自毁并变得无法使用.

我创建了一些代码来使用运行时消除坏的release覆盖并替换正确的dealloc覆盖.这几乎没有经过测试,使用风险由您自行承担:

extension NSPathControl {
    class func fix() {
        let itemClass = NSPathControlItem.self
        let superclass: AnyClass = class_getSuperclass(itemClass)

        let releaseSelector = Selector("release")
        let releaseMethod = class_getInstanceMethod(itemClass, releaseSelector)
        let superReleaseIMP = class_getMethodImplementation(superclass, releaseSelector)

        if method_getImplementation(releaseMethod) != superReleaseIMP {
            method_setImplementation(releaseMethod, superReleaseIMP)

            let ivars = class_copyIvarList(itemClass, nil)
            var offsets: [Int] = []
            var cursor = ivars
            while cursor.memory != nil {
                let ivar = cursor.memory
                if String.fromCString(ivar_getTypeEncoding(ivar))?.hasPrefix("@") == true {
                    offsets.append(ivar_getOffset(ivar))
                }
                cursor++
            }
            free(ivars)

            let superDeallocIMP = class_getMethodImplementation(superclass, "dealloc")

            let dealloc: @convention(block) UnsafeMutablePointer<Int8> -> Void = { obj in
                for offset in offsets {
                    let ivarPtr = UnsafeMutablePointer<COpaquePointer>(obj + offset)
                    let unmanaged = Unmanaged<AnyObject>.fromOpaque(ivarPtr.memory)
                    unmanaged.release()
                    ivarPtr.memory = nil
                }

                typealias DeallocF = @convention(c) (UnsafeMutablePointer<Int8>, Selector) -> Void
                let superDeallocF = unsafeBitCast(superDeallocIMP, DeallocF.self)
                superDeallocF(obj, "dealloc")
            }
            let deallocIMP = imp_implementationWithBlock(unsafeBitCast(dealloc, AnyObject.self))

            class_addMethod(itemClass, "dealloc", deallocIMP, "v@:")
        }
    }
}