PDF_Office/PDF Office/PDF Master/Class/PDFTools/AutoFlow/KMAotuFlowExtension.swift

//
//  KMAotuFlowExtension.swift
//  PDF Reader Pro
//
//  Created by lizhe on 2024/1/16.
//
import Cocoa

private var autoFlowTimerKey: UInt8 = 0
private var fastFlowTimerKey: UInt8 = 0

extension CPDFView {

    var autoFlowTimer: Timer? {
        get {
            return objc_getAssociatedObject(self, &autoFlowTimerKey) as? Timer
        }
        set {
            objc_setAssociatedObject(self, &autoFlowTimerKey, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }

    var fastFlowTimer: Timer? {
        get {
            return objc_getAssociatedObject(self, &fastFlowTimerKey) as? Timer
        }
        set {
            objc_setAssociatedObject(self, &fastFlowTimerKey, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }

    func startAutoFlow() {
        let timeInterval = KMAutoFlowOptionsSheetController.timeInterval()
        let timer = Timer.scheduledTimer(timeInterval: TimeInterval(timeInterval), target: self, selector: #selector(updateAutoFlow), userInfo: nil, repeats: true)
        autoFlowTimer = timer

        CustomAlertView.alertView(message: NSLocalizedString("AutoScroll On", comment: ""), fromView: self, withStyle: .black)
    }

    @objc func updateAutoFlow() {
        self.setDisplay(.singlePage)
        let jumpSpace = KMAutoFlowOptionsSheetController.jumpSpace()
        if self.displayMode() == .singlePage ||
            self.displayMode() == .twoUp {
            if canGoToNextPage() {
                goToNextPage(nil)
            } else {
                stopAutoFlow()
            }
        } else {
            if let scrollView = documentView() {
                let clipView = scrollView.contentView
                var newOrigin = clipView.bounds.origin
                newOrigin.y = newOrigin.y + CGFloat(jumpSpace)
                clipView.animator().setBoundsOrigin(newOrigin)

                if newOrigin.y <= 0 {
                    stopAutoFlow()
                }
            }
        }
    }

    func stopAutoFlow() {
        autoFlowTimer?.invalidate()
        autoFlowTimer = nil

        CustomAlertView.alertView(message: NSLocalizedString("AutoScroll Off", comment: ""), fromView: self, withStyle: .black)
    }

    func isAutoFlow() -> Bool {
        return autoFlowTimer != nil && autoFlowTimer!.isValid
    }

    func autoFlow() {
        if isAutoFlow() {
            stopAutoFlow()
        } else {
            startAutoFlow()
        }
    }

    func startFastFlow() {
        let timeInterval: TimeInterval = 0.1
        let timer = Timer.scheduledTimer(timeInterval: timeInterval, target: self, selector: #selector(updateFastFlow), userInfo: nil, repeats: true)
        fastFlowTimer = timer
    }

    @objc func updateFastFlow() {
        let jumpSpace: CGFloat = 200
        
        updateScrollView(with: jumpSpace)
        
    }

    func updateScrollView(with jumpSpace: CGFloat) {
        if self.displayMode() == .singlePage || self.displayMode() == .twoUp {
            if canGoToNextPage() {
                goToNextPage(nil)
            } else {
                stopFastFlow()
            }
        } else {
            if let scrollView = documentView().enclosingScrollView {
                let clipView = scrollView.contentView
                var newOrigin = clipView.bounds.origin
                newOrigin.y -= jumpSpace

                clipView.animator().setBoundsOrigin(newOrigin)

                if newOrigin.y <= 0 /*&& isScrollUp*/ {
                    stopFastFlow()
                } else if newOrigin.y >= documentView().frame.size.height /*&& !isScrollUp*/ {
                    stopFastFlow()
                }
            }
        }
    }

    func stopFastFlow() {
        fastFlowTimer?.invalidate()
        fastFlowTimer = nil
    }

    func isFastFlow() -> Bool {
        return fastFlowTimer != nil && fastFlowTimer!.isValid
    }

    func fastFlow() {
        if isFastFlow() {
            stopFastFlow()
        } else {
            startFastFlow()
        }
    }
}