PDF_Office/PDF Office/PDF Master/KMClass/KMNPDFPageEdit/KMNThumbnailView/KMNThumbnailBaseViewController.swift

//
//  KMNThumbnailBaseViewController.swift
//  PDF Reader Pro
//
//  Created by 丁林圭 on 2024/10/21.
//

import Cocoa

import KMComponentLibrary

@objc protocol KMNThumbnailBaseViewDelegate: AnyObject {
    @objc optional func clickThumbnailViewControlle(pageEditVC:KMNThumbnailBaseViewController?,currentIndex:Int)
    
    @objc optional func insertPDFThumbnailViewControlle(pageEditVC:KMNThumbnailBaseViewController?,pdfDocment:CPDFDocument?)
    
    @objc optional func changeIndexPathsThumbnailViewControlle(pageEditVC:KMNThumbnailBaseViewController?,selectionIndexPaths: Set<IndexPath>,selectionStrings:String )
}

enum KMNThumbnailChoosePageStyle: Int {
    case odd
    case even
    case horizontal
    case vertical
    case allPage
    case custom
}

internal let kmnThumLocalForDraggedTypes = NSPasteboard.PasteboardType(rawValue: "kmnThumLocalForDraggedTypes")

let topThumOffset: CGFloat = 12.0 // 缩图顶部高度
let infoThumTitleHeight: CGFloat = 16.0 //文字高度
let infoThumTitleBottom: CGFloat = 16.0 // 底部高度

let ThumbnailMenuIdentifier_Copy = "ThumbnailMenuIdentifier_Copy"
let ThumbnailMenuIdentifier_Cut = "ThumbnailMenuIdentifier_Cut"
let ThumbnailMenuIdentifier_Paste = "ThumbnailMenuIdentifier_Paste"
let ThumbnailMenuIdentifier_Delete = "ThumbnailMenuIdentifier_Delete"
let ThumbnailMenuIdentifier_RotateRight = "ThumbnailMenuIdentifier_RotateRight"
let ThumbnailMenuIdentifier_RotateLeft = "ThumbnailMenuIdentifier_RotateLeft"
let ThumbnailMenuIdentifier_InsertFile = "ThumbnailMenuIdentifier_InsertFile"
let ThumbnailMenuIdentifier_InsertBlank = "ThumbnailMenuIdentifier_InsertBlank"
let ThumbnailMenuIdentifier_Replace = "ThumbnailMenuIdentifier_Replace"
let ThumbnailMenuIdentifier_Share = "ThumbnailMenuIdentifier_Share"
let ThumbnailMenuIdentifier_Export = "ThumbnailMenuIdentifier_Export"
let ThumbnailMenuIdentifier_PastNull = "ThumbnailMenuIdentifier_PastNull"
let ThumbnailMenuIdentifier_FileShowSize = "ThumbnailMenuIdentifier_FileShowSize"

struct ThumbnailMenuStruct {
    var menuitems: [ComponentMenuitemProperty]
    var viewHeight: CGFloat          // 不可变属性
}

class KMNThumbnailBaseViewController: KMNBaseViewController,NSCollectionViewDelegate, NSCollectionViewDataSource,NSCollectionViewDelegateFlowLayout {
        
    let maxCellHeight: CGFloat = 320.0 - infoThumTitleBottom - infoThumTitleHeight - topThumOffset * 2
    let minCellHeight: CGFloat = 80.0 - infoThumTitleBottom - infoThumTitleHeight - topThumOffset - topThumOffset * 2
    
    weak open var thumbnailBaseViewDelegate: KMNThumbnailBaseViewDelegate?
    
    @IBOutlet var backViewBox: NSBox!
    @IBOutlet var scrollView: NSScrollView!
    @IBOutlet var collectionView: KMNThumbnailCollectionView!
    @IBOutlet var flowLayout: KMNThumCustomCollectionViewFlowLayout!

    private var currentDocument:CPDFDocument?
    private var isChangeIndexPaths = false
    
    var lockedFiles: [URL] = []
    var filePromiseQueue: OperationQueue = {
        let queue = OperationQueue()
        return queue
    }()
    
    fileprivate var dragFilePath: String?
    fileprivate var dragFlag = false
    
    public var thumbnails:[KMNThumbnail] = []
    
    public var dragLocalityPages: [CPDFPage] = []
    
    public var currentUndoManager:UndoManager?
    
    public var showDocument: CPDFDocument? {
        return currentDocument
    }
    
    public var changeDocument:CPDFDocument? {
        didSet {
            if(changeDocument != nil && changeDocument != currentDocument) {
                currentDocument = changeDocument
                refreshDatas()
                collectionView.reloadData()
            }
        }
    }
    
    public var thumbnailChoosePageStyle:KMNThumbnailChoosePageStyle = .custom {
        didSet {
            var tSelectionIndexPaths: Set<IndexPath> = []
            let pageCount = currentDocument?.pageCount ?? 0
            switch thumbnailChoosePageStyle {
            case .even:
                for i in 0 ..< pageCount {
                    if(i % 2 == 0) {
                        tSelectionIndexPaths.insert(IndexPath(item: Int(i), section: 0))
                    }
                }
                
            case .odd:
                for i in 0 ..< pageCount {
                    if(i % 2 != 0) {
                        tSelectionIndexPaths.insert(IndexPath(item: Int(i), section: 0))
                    }
                }
            case .allPage:
                for i in 0 ..< pageCount {
                    tSelectionIndexPaths.insert(IndexPath(item: Int(i), section: 0))
                    
                }
            case .vertical:
                for i in 0 ..< pageCount {
                    let page = showDocument?.page(at: i)
                    if(page != nil) {
                        if(page!.rotation % 180 != 0) {
                            tSelectionIndexPaths.insert(IndexPath(item: Int(i), section: 0))
                        }
                    }
                }
            case .horizontal:
                for i in 0 ..< pageCount {
                    let page = showDocument?.page(at: i)
                    if(page != nil) {
                        if(page!.rotation % 180 == 0) {
                            tSelectionIndexPaths.insert(IndexPath(item: Int(i), section: 0))
                        }
                    }
                }
            default: break
            }
            
            isChangeIndexPaths = true
            collectionView.selectionIndexPaths = tSelectionIndexPaths
            isChangeIndexPaths = false
        }
    }
    
    var selectionIndexPaths: Set<IndexPath> = [] {
        didSet {
            var indexpaths: Set<IndexPath> = []
            for indexpath in selectionIndexPaths {
                if (indexpath.section >= collectionView.numberOfSections) {
                    continue
                }
                if indexpath.section < 0 {
                    continue
                }
                if (indexpath.item >= collectionView.numberOfItems(inSection: indexpath.section)) {
                    continue
                }
                if indexpath.item < 0 {
                    continue
                }
                
                indexpaths.insert(indexpath)
            }
            
            if indexpaths.count > 0 {
                self.collectionView.scrollToItems(at: indexpaths, scrollPosition: .centeredVertically)
            }
            
            self.collectionView.selectionIndexPaths = indexpaths
        }
    }
    
    public var isShowPageSize:Bool = false {
        didSet {
            if oldValue != isShowPageSize {
                var pageSize = pageThumbnailSize
                if(isShowPageSize) {
                    pageSize.height += infoThumTitleHeight
                } else {
                    pageSize.height -= infoThumTitleHeight
                    
                }
                pageThumbnailSize = pageSize
                collectionView.reloadData()
            }
        }
    }
    
    public var pageThumbnailSize:CGSize = CGSizeMake(185.0, 260) {
        didSet {
            collectionView.reloadData()
        }
    }
    public let defaultItemSize = NSMakeSize(185.0, 260)
    
    deinit {
        thumbnailBaseViewDelegate = nil
        KMPrint("KMNThumbnailBaseViewController deinit.")
    }
    
    init(_ document: CPDFDocument?) {
        super.init(nibName: "KMNThumbnailBaseViewController", bundle: nil)
        currentDocument = document
    }
    
    init(_ filePath: String,password:String?) {
        super.init(nibName: "KMNThumbnailBaseViewController", bundle: nil)
        let document = CPDFDocument.init(url: URL(fileURLWithPath: filePath))
        if password != nil {
            document?.unlock(withPassword: password as String?)
        }
        
        if document?.allowsCopying == false || document?.allowsPrinting == false {
            exitCurrentView()
        } else {
            currentDocument = document
        }
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        collectionView.delegate = self
        collectionView.dataSource = self
        collectionView.isSelectable = true //支持拖拽需设置未True
        collectionView.allowsMultipleSelection = true
        collectionView.enclosingScrollView?.hasVerticalScroller = false
        collectionView.enclosingScrollView?.hasHorizontalScroller = false
        scrollView.scrollerStyle = .overlay
        
        collectionView.register(KMNThumbnailCollectionViewItem.self, forItemWithIdentifier: NSUserInterfaceItemIdentifier(rawValue: "thumbnailCollectionViewItem"))
        
        collectionView.registerForDraggedTypes([.fileURL,.string,.pdf])
        collectionView.setDraggingSourceOperationMask(.every, forLocal: false)
        collectionView.setDraggingSourceOperationMask(.every, forLocal: true)
        
        collectionView.collectionSelectChanges = {[weak self] in
            if self?.isChangeIndexPaths == false {
                let indexpathsz = self?.collectionView.selectionIndexPaths
                let dex:IndexSet = KMNTools.indexpathsToIndexs(indexpaths: indexpathsz ?? [])
                let selectedIndexPathsString = KMNTools.parseIndexSet(indexSet: dex)
                
                self?.thumbnailBaseViewDelegate?.changeIndexPathsThumbnailViewControlle?(pageEditVC: self, selectionIndexPaths: indexpathsz ?? [], selectionStrings: selectedIndexPathsString)
            }
        }
        
        refreshDatas()
    }
    
    public func exitCurrentView() {
        let minIndexPath = selectionIndexPaths.max(by: { $0.item < $1.item })
        thumbnailBaseViewDelegate?.clickThumbnailViewControlle?(pageEditVC: self, currentIndex: minIndexPath?.item ?? 0)
    }
    
    public func supportDragFileTypes()->[String] {
        let supportFiles = KMNConvertTool.pdfExtensions + KMConvertPDFManager.supportFileType()
        return supportFiles
    }
    
    public func refreshDatas() {
        thumbnails = []
        if currentDocument != nil {
            for i in 0 ..< currentDocument!.pageCount {
                let thumbnail = KMNThumbnail.init(document: currentDocument!, currentPageIndex: Int(i))
                thumbnails.append(thumbnail)
            }
        }
    }
    
    public func reloadDatas() {
        refreshDatas()
        collectionView.reloadData()
    }
    
    public func reloadDataWithIndexs(pageIndexs: IndexSet) {
        if currentDocument != nil {
            for i in pageIndexs {
                if i < currentDocument?.pageCount ?? 0 {
                    let thumbnail = KMNThumbnail.init(document: currentDocument!, currentPageIndex: i)
                    thumbnail.removeCacheImage()
                }
            }
            reloadDatas()
        }
    }
    
    // MARK: - private
    public func clickMenu(point:NSPoint)->ThumbnailMenuStruct {
        let copyPages: [CPDFPage] = KMNThumbnailManager.manager.copyPages
        let selectedIndexPaths = collectionView.selectionIndexPaths

        var viewHeight: CGFloat = 8
        var menuItemArr: [ComponentMenuitemProperty] = []
        
        var items: [(String, String)] = []
        if selectedIndexPaths.count > 0 {
            items.append(("Copy", ThumbnailMenuIdentifier_Copy))
            items.append(("Cut", ThumbnailMenuIdentifier_Cut))
            if(copyPages.count > 0) {
                items.append(("Paste", ThumbnailMenuIdentifier_Paste))
            }
            items.append(("Delete", ThumbnailMenuIdentifier_Delete))
            items.append(("", ""))
            items.append(("90° CW", ThumbnailMenuIdentifier_RotateRight))
            items.append(("90° CCW", ThumbnailMenuIdentifier_RotateLeft))
            items.append(("", ""))
            
            if(selectedIndexPaths.count == 1) {
                items.append(("Insert File", ThumbnailMenuIdentifier_InsertFile))
                items.append(("Insert a Blank Page", ThumbnailMenuIdentifier_InsertBlank))
                items.append(("Replace", ThumbnailMenuIdentifier_Replace))
            }
            
            items.append(("Extract", ThumbnailMenuIdentifier_Export))
            items.append(("Share", ThumbnailMenuIdentifier_Share))
            items.append(("", ""))
            items.append(("Display Page Size", ThumbnailMenuIdentifier_FileShowSize))
        } else {
            if(copyPages.count > 0) {
                items.append(("Paste", ThumbnailMenuIdentifier_Paste))
                items.append(("", ""))
            } else {
                items.append(("Paste", ThumbnailMenuIdentifier_PastNull))
                items.append(("", ""))
            }
            items.append(("Display Page Size", ThumbnailMenuIdentifier_FileShowSize))
        }
        for (i, value) in items {
            if value.count == 0 {
                let property: ComponentMenuitemProperty = ComponentMenuitemProperty.divider()
                menuItemArr.append(property)
                viewHeight += 8
            } else {
                var isDisabled = false
                if(value == ThumbnailMenuIdentifier_PastNull) {
                    isDisabled = true
                }
                
                let properties_Menuitem: ComponentMenuitemProperty = ComponentMenuitemProperty(multipleSelect: false,
                                                                                               itemSelected: false,
                                                                                               isDisabled: isDisabled,
                                                                                               keyEquivalent: nil,
                                                                                               text: KMLocalizedString(i),
                                                                                               identifier: value,representedObject: point)
                
                if value == ThumbnailMenuIdentifier_Copy {
                    properties_Menuitem.keyEquivalent = "⌘ C"
                } else if value == ThumbnailMenuIdentifier_Cut {
                    properties_Menuitem.keyEquivalent = "⌘ x"
                } else if value == ThumbnailMenuIdentifier_Paste {
                    properties_Menuitem.keyEquivalent = "⌘ v"
                } else if value == ThumbnailMenuIdentifier_PastNull {
                    properties_Menuitem.keyEquivalent = "⌘ v"
                } else if value == ThumbnailMenuIdentifier_Delete {
                    properties_Menuitem.keyEquivalent = "⌘ " + String(Unicode.Scalar(NSBackspaceCharacter)!)
                }  else if value == ThumbnailMenuIdentifier_RotateRight {
                    properties_Menuitem.keyEquivalent = "⌥ ⌘ R"
                } else if value == ThumbnailMenuIdentifier_RotateLeft {
                    properties_Menuitem.keyEquivalent = "⌥ ⌘ L"
                }
                
                if(value == ThumbnailMenuIdentifier_FileShowSize && isShowPageSize) {
                    properties_Menuitem.righticon = NSImage(named: "KMNImageNameMenuSelect")
                }
                
                menuItemArr.append(properties_Menuitem)
                viewHeight += 36
            }
        }
        
        let menuStruct = ThumbnailMenuStruct(menuitems: menuItemArr, viewHeight: viewHeight)
        
        return menuStruct
    }
    
    // MARK: - NSCollectionViewDataSource
    func collectionView(_ collectionView: NSCollectionView, numberOfItemsInSection section: Int) -> Int {
        return thumbnails.count
    }
    
    func collectionView(_ collectionView: NSCollectionView, itemForRepresentedObjectAt indexPath: IndexPath) -> NSCollectionViewItem {
        let item: KMNThumbnailCollectionViewItem = collectionView.makeItem(withIdentifier: NSUserInterfaceItemIdentifier(rawValue: "thumbnailCollectionViewItem"), for: indexPath) as! KMNThumbnailCollectionViewItem
        item.isShowFileSize = isShowPageSize
        item.doubleClickBack = { [weak self] in
            self?.thumbnailBaseViewDelegate?.clickThumbnailViewControlle?(pageEditVC: self, currentIndex: indexPath.item)
        }
        
        item.thumbnailMode = thumbnails[indexPath.item]
        return item
    }
    
    func collectionView(_ collectionView: NSCollectionView, didSelectItemsAt indexPaths: Set<IndexPath>) {
        if isChangeIndexPaths == false {
            let indexpathsz = collectionView.selectionIndexPaths
            let dex:IndexSet = KMNTools.indexpathsToIndexs(indexpaths: indexpathsz)
            let selectedIndexPathsString = KMNTools.parseIndexSet(indexSet: dex)
            
            thumbnailBaseViewDelegate?.changeIndexPathsThumbnailViewControlle?(pageEditVC: self, selectionIndexPaths: indexpathsz, selectionStrings: selectedIndexPathsString)
        }
    }
    
    func collectionView(_ collectionView: NSCollectionView, didDeselectItemsAt indexPaths: Set<IndexPath>) {
        if isChangeIndexPaths == false {
            let indexpathsz = self.collectionView.selectionIndexPaths
            let dex:IndexSet = KMNTools.indexpathsToIndexs(indexpaths: indexpathsz)
            let selectedIndexPathsString = KMNTools.parseIndexSet(indexSet: dex)
            
            thumbnailBaseViewDelegate?.changeIndexPathsThumbnailViewControlle?(pageEditVC: self, selectionIndexPaths: indexpathsz, selectionStrings: selectedIndexPathsString)
        }
    }
    
    // MARK: - NSCollectionViewDelegateFlowLayout
    
    func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> NSSize {
        return pageThumbnailSize
    }
    
    func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        return 16.0
    }
    
    func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
        return 24.0
    }
    
    public func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, insetForSectionAt section: Int) -> NSEdgeInsets {
        return NSEdgeInsetsMake(24.0, 24.0, 24.0, 24.0)
    }
    
    //MARK: - NSCollectionViewDelegate
    
    func collectionView(_ collectionView: NSCollectionView,
                        pasteboardWriterForItemAt indexPath: IndexPath) -> NSPasteboardWriting? {
        var provider: NSFilePromiseProvider?
        
        // 创建数据提供者
        let fileExtension = "pdf"
        if #available(macOS 11.0, *) {
            if let typeIdentifier = UTType(filenameExtension: fileExtension) {
                provider = KMFilePromiseProvider(fileType: typeIdentifier.identifier, delegate: self)
            }
        } else {
            if let typeIdentifier =
                UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, fileExtension as CFString, nil) {
                provider = KMFilePromiseProvider(fileType: typeIdentifier.takeRetainedValue() as String, delegate: self)
            }
        }
        
        do {
            if let _url = showDocument?.documentURL {
                let data = try NSKeyedArchiver.archivedData(withRootObject: indexPath, requiringSecureCoding: false)
                provider?.userInfo = [KMFilePromiseProvider.UserInfoKeys.urlKey: _url,
                                      KMFilePromiseProvider.UserInfoKeys.indexPathKey: data]
            } else {
                let data = try NSKeyedArchiver.archivedData(withRootObject: indexPath, requiringSecureCoding: false)
                provider?.userInfo = [KMFilePromiseProvider.UserInfoKeys.indexPathKey: data]
            }
        } catch {
            fatalError("failed to archive indexPath to pasteboard")
        }
        return provider
    }
    
    func collectionView(_ collectionView: NSCollectionView,
                        draggingSession session: NSDraggingSession,
                        willBeginAt screenPoint: NSPoint,
                        forItemsAt indexPaths: Set<IndexPath>) {
        let sortedIndexPaths = indexPaths.sorted { (ip1, ip2) -> Bool in
            if ip1.section == ip2.section {
                return ip1.item < ip2.item
            }
            return ip1.section < ip2.section
        }
        dragLocalityPages = []
        for fromIndexPath in sortedIndexPaths {
            let page = thumbnails[fromIndexPath.item].thumbnaiPage
            if(page != nil) {
                dragLocalityPages.append(page!)
            }
        }
        
        var docmentName = currentDocument?.documentURL.lastPathComponent.deletingPathExtension ?? ""
        let pagesName = indexPaths.count > 1 ? " pages" : " page"
        var tFileName = pagesName + KMNTools.parseIndexPathsSet(indexSets: collectionView.selectionIndexPaths)
        if tFileName.count > 50 {
            tFileName = String(tFileName.prefix(50))
        }
        
        var cachesDir = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first!
        cachesDir =  cachesDir.appendingPathComponent("PageEdit_Pasteboard")
        let fileManager = FileManager.default
        if !fileManager.fileExists(atPath: cachesDir.path) {
            try? FileManager.default.createDirectory(atPath: cachesDir.path, withIntermediateDirectories: true, attributes: nil)
        }
        docmentName = "\(docmentName)\(tFileName)"
        if docmentName.count > 50 {
            docmentName = String(docmentName.prefix(50))
        }
        
        // 将拖拽的page插入临时路径(文档)
        var indexs = IndexSet()
        for indexpath in indexPaths {
            indexs.insert(indexpath.item)
        }
        
        // 重置拖拽标识
        self.dragFlag = false
        if (indexs.count > 0) {
            let writePDFDocument = CPDFDocument()
            writePDFDocument?.importPages(indexs, from: self.showDocument, at: 0)
            
            let filePathURL = cachesDir.appendingPathComponent(docmentName).appendingPathExtension("pdf")
            let success = writePDFDocument?.write(to: filePathURL, isSaveFontSubset:false)
            
            if(success == true) {
                self.dragFilePath = filePathURL.path
            }
        }
    }
    
    func collectionView(_ collectionView: NSCollectionView, validateDrop draggingInfo: NSDraggingInfo, proposedIndexPath proposedDropIndexPath: AutoreleasingUnsafeMutablePointer<NSIndexPath>, dropOperation proposedDropOperation: UnsafeMutablePointer<NSCollectionView.DropOperation>) -> NSDragOperation {
        let pboard = draggingInfo.draggingPasteboard
        
        if dragLocalityPages.count != 0 {
            if proposedDropOperation.pointee == .on {
                proposedDropOperation.pointee = .before
            }
            return .move
        } else if ((pboard.availableType(from: [.fileURL])) != nil) {
            guard let pbItems = pboard.pasteboardItems else {
                return NSDragOperation(rawValue: 0)
            }
            
            var hasValidFile = false
            for item in pbItems {
                guard let data = item.string(forType: .fileURL), let url = URL(string: data) else {
                    continue
                }
                let type = url.pathExtension.lowercased()
                if (supportDragFileTypes().contains(type)) {
                    hasValidFile = true
                    break
                }
            }
            
            if (!hasValidFile) {
                return NSDragOperation(rawValue: 0)
            }
        }
        return .copy
    }
    
    func collectionView(_ collectionView: NSCollectionView,
                        acceptDrop draggingInfo: NSDraggingInfo,
                        indexPath: IndexPath,
                        dropOperation: NSCollectionView.DropOperation) -> Bool {
        let pboard = draggingInfo.draggingPasteboard
        if dragLocalityPages.count != 0 {
            movePages(dragPages: dragLocalityPages, destinationDex: indexPath.item)
            return true
        } else if ((pboard.availableType(from: [.fileURL])) != nil) {
            let index = indexPath.item
            
            guard let pbItems = pboard.pasteboardItems else {
                return false
            }
            
            //获取url
            var fileNames: [String] = []
            for item in pbItems {
                guard let data = item.string(forType: .fileURL), let url = URL(string: data) else {
                    continue
                }
                let type = url.pathExtension.lowercased()
                if (supportDragFileTypes().contains(type)) {
                    if(FileManager.default.fileExists(atPath: url.path)) {
                        fileNames.append(url.path)
                    }
                }
            }
            if(fileNames.count > 0) {
                insertFromFilePath(fileNames: fileNames, formDex: 0, indexDex: UInt(index), selectIndexs: []) { newSelectIndexs in
                }
                
                return true
            }
        }
        return false
    }
    
    func collectionView(_ collectionView: NSCollectionView,
                        draggingSession session: NSDraggingSession,
                        endedAt screenPoint: NSPoint,
                        dragOperation operation: NSDragOperation) {
        dragLocalityPages = []
    }
}

// MARK: - NSFilePromiseProviderDelegate
extension KMNThumbnailBaseViewController: NSFilePromiseProviderDelegate {
    func operationQueue(for filePromiseProvider: NSFilePromiseProvider) -> OperationQueue {
        return self.filePromiseQueue
    }
    
    func filePromiseProvider(_ filePromiseProvider: NSFilePromiseProvider,
                             writePromiseTo url: URL,
                             completionHandler: @escaping (Error?) -> Void) {
        do {
            /** Copy the file to the location provided to you. You always do a copy, not a move.
             It's important you call the completion handler.
             */
            if let _urlString = dragFilePath, !dragFlag {
                dragFlag = true
                try FileManager.default.copyItem(at: URL(fileURLWithPath: _urlString), to: url)
            }
            
            completionHandler(nil)
        } catch let error {
            OperationQueue.main.addOperation {
                if let win = self.view.window {
                    self.presentError(error, modalFor: win,
                                      delegate: nil, didPresent: nil, contextInfo: nil)
                }
            }
            completionHandler(error)
        }
    }
    
    func filePromiseProvider(_ filePromiseProvider: NSFilePromiseProvider, fileNameForType fileType: String) -> String {
        var fileName: String = "Untitle"
        if let _string = showDocument?.documentURL.deletingPathExtension().lastPathComponent {
            fileName = _string
        }
        fileName.append(" pages")
        var indexs = IndexSet()
        for page in dragLocalityPages {
            indexs.insert(Int(page.pageIndex()))
        }
        fileName.append(" ")
        fileName.append(KMPageRangeTools.newParseSelectedIndexs(selectedIndex: indexs.sorted()))
        fileName.append(".pdf")
        
        return fileName
    }
    
}