JXSegmentedBaseDataSource.swift

//
//  JXSegmentedBaseDataSource.swift
//  JXSegmentedView
//
//  Created by jiaxin on 2018/12/28.
//  Copyright © 2018 jiaxin. All rights reserved.
//

import Foundation
import  UIKit

open class JXSegmentedBaseDataSource: JXSegmentedViewDataSource {
    /// 最终传递给JXSegmentedView的数据源数组
    open var dataSource = [JXSegmentedBaseItemModel]()
    /// cell的宽度。为JXSegmentedViewAutomaticDimension时就以内容计算的宽度为准，否则以itemWidth的具体值为准。
    open var itemWidth: CGFloat = JXSegmentedViewAutomaticDimension
    /// 真实的item宽度 = itemWidth + itemWidthIncrement。
    open var itemWidthIncrement: CGFloat = 0
    /// item之前的间距
    open var itemSpacing: CGFloat = 20
    /// 当collectionView.contentSize.width小于JXSegmentedView的宽度时，是否将itemSpacing均分。
    open var isItemSpacingAverageEnabled: Bool = true
    /// item左右滚动过渡时，是否允许渐变。比如JXSegmentedTitleDataSource的titleZoom、titleNormalColor、titleStrokeWidth等渐变。
    open var isItemTransitionEnabled: Bool = true
    /// 选中的时候，是否需要动画过渡。自定义的cell需要自己处理动画过渡逻辑，动画处理逻辑参考`JXSegmentedTitleCell`
    open var isSelectedAnimable: Bool = false
    /// 选中动画的时长
    open var selectedAnimationDuration: TimeInterval = 0.25
    /// 是否允许item宽度缩放
    open var isItemWidthZoomEnabled: Bool = false
    /// 是否允许item宽度缩放动画
    open var isItemWidthZoomAnimable: Bool = true
    /// item宽度选中时的scale
    open var itemWidthSelectedZoomScale: CGFloat = 1.5

    @available(*, deprecated, renamed: "itemWidth")
    open var itemContentWidth: CGFloat = JXSegmentedViewAutomaticDimension {
        didSet {
            itemWidth = itemContentWidth
        }
    }

    private var animator: JXSegmentedAnimator?

    deinit {
        animator?.stop()
        animator = nil
    }

    public init() {
    }

    /// 配置完各种属性之后，需要手动调用该方法，更新数据源
    ///
    /// - Parameter selectedIndex: 当前选中的index
    open func reloadData(selectedIndex: Int) {
        animator?.stop()
        animator = nil
        dataSource.removeAll()
        for index in 0..<preferredItemCount() {
            let itemModel = preferredItemModelInstance()
            preferredRefreshItemModel(itemModel, at: index, selectedIndex: selectedIndex)
            dataSource.append(itemModel)
        }
    }

    open func preferredItemCount() -> Int {
        return 0
    }

    /// 子类需要重载该方法，用于返回自己定义的JXSegmentedBaseItemModel子类实例
    open func preferredItemModelInstance() -> JXSegmentedBaseItemModel  {
        return JXSegmentedBaseItemModel()
    }

    /// 子类需要重载该方法，用于返回索引为index的item宽度
    open func preferredSegmentedView(_ segmentedView: JXSegmentedView, widthForItemAt index: Int) -> CGFloat {
        return itemWidthIncrement
    }

    /// 子类需要重载该方法，用于更新索引为index的itemModel
    open func preferredRefreshItemModel(_ itemModel: JXSegmentedBaseItemModel, at index: Int, selectedIndex: Int) {
        itemModel.index = index
        itemModel.isItemTransitionEnabled = isItemTransitionEnabled
        itemModel.isSelectedAnimable = isSelectedAnimable
        itemModel.selectedAnimationDuration = selectedAnimationDuration
        itemModel.isItemWidthZoomEnabled = isItemWidthZoomEnabled
        itemModel.itemWidthNormalZoomScale = 1
        itemModel.itemWidthSelectedZoomScale = itemWidthSelectedZoomScale
        if index == selectedIndex {
            itemModel.isSelected = true
            itemModel.itemWidthCurrentZoomScale = itemModel.itemWidthSelectedZoomScale
        }else {
            itemModel.isSelected = false
            itemModel.itemWidthCurrentZoomScale = itemModel.itemWidthNormalZoomScale
        }
    }

    //MARK: - JXSegmentedViewDataSource
    open func itemDataSource(in segmentedView: JXSegmentedView) -> [JXSegmentedBaseItemModel] {
        return dataSource
    }

    /// 自定义子类请继承方法`func preferredWidthForItem(at index: Int) -> CGFloat`
    public final func segmentedView(_ segmentedView: JXSegmentedView, widthForItemAt index: Int) -> CGFloat {
        return preferredSegmentedView(segmentedView, widthForItemAt: index)
    }

    public func segmentedView(_ segmentedView: JXSegmentedView, widthForItemContentAt index: Int) -> CGFloat {
        return self.segmentedView(segmentedView, widthForItemAt: index)
    }

    open func registerCellClass(in segmentedView: JXSegmentedView) {

    }

    open func segmentedView(_ segmentedView: JXSegmentedView, cellForItemAt index: Int) -> JXSegmentedBaseCell {
        return JXSegmentedBaseCell()
    }

    open func refreshItemModel(_ segmentedView: JXSegmentedView, currentSelectedItemModel: JXSegmentedBaseItemModel, willSelectedItemModel: JXSegmentedBaseItemModel, selectedType: JXSegmentedViewItemSelectedType) {
        currentSelectedItemModel.isSelected = false
        willSelectedItemModel.isSelected = true

        if isItemWidthZoomEnabled {
            if (selectedType == .scroll && !isItemTransitionEnabled) ||
                selectedType == .click ||
                selectedType == .code {
                animator = JXSegmentedAnimator()
                animator?.duration = selectedAnimationDuration
                animator?.progressClosure = {[weak self] (percent) in
                    guard let self = self else { return }
                    currentSelectedItemModel.itemWidthCurrentZoomScale = JXSegmentedViewTool.interpolate(from: currentSelectedItemModel.itemWidthSelectedZoomScale, to: currentSelectedItemModel.itemWidthNormalZoomScale, percent: percent)
                    currentSelectedItemModel.itemWidth = self.itemWidthWithZoom(at: currentSelectedItemModel.index, model: currentSelectedItemModel)
                    willSelectedItemModel.itemWidthCurrentZoomScale = JXSegmentedViewTool.interpolate(from: willSelectedItemModel.itemWidthNormalZoomScale, to: willSelectedItemModel.itemWidthSelectedZoomScale, percent: percent)
                    willSelectedItemModel.itemWidth = self.itemWidthWithZoom(at: willSelectedItemModel.index, model: willSelectedItemModel)
                    segmentedView.collectionView.collectionViewLayout.invalidateLayout()
                }
                if isItemWidthZoomAnimable {
                    animator?.start()
                }else {
                    animator?.stop()
                }
            }
        }else {
            currentSelectedItemModel.itemWidthCurrentZoomScale = currentSelectedItemModel.itemWidthNormalZoomScale
            willSelectedItemModel.itemWidthCurrentZoomScale = willSelectedItemModel.itemWidthSelectedZoomScale
        }
    }

    open func refreshItemModel(_ segmentedView: JXSegmentedView, leftItemModel: JXSegmentedBaseItemModel, rightItemModel: JXSegmentedBaseItemModel, percent: CGFloat) {
        //如果正在进行itemWidth缩放动画，用户又立马滚动了contentScrollView，需要停止动画。
        animator?.stop()
        animator = nil
        if isItemWidthZoomEnabled && isItemTransitionEnabled {
            //允许itemWidth缩放动画且允许item渐变过渡
            leftItemModel.itemWidthCurrentZoomScale = JXSegmentedViewTool.interpolate(from: leftItemModel.itemWidthSelectedZoomScale, to: leftItemModel.itemWidthNormalZoomScale, percent: percent)
            leftItemModel.itemWidth = itemWidthWithZoom(at: leftItemModel.index, model: leftItemModel)
            rightItemModel.itemWidthCurrentZoomScale = JXSegmentedViewTool.interpolate(from: rightItemModel.itemWidthNormalZoomScale, to: rightItemModel.itemWidthSelectedZoomScale, percent: percent)
            rightItemModel.itemWidth = itemWidthWithZoom(at: rightItemModel.index, model: rightItemModel)
            segmentedView.collectionView.collectionViewLayout.invalidateLayout()
        }
    }

    /// 自定义子类请继承方法`func preferredRefreshItemModel(_ itemModel: JXSegmentedBaseItemModel, at index: Int, selectedIndex: Int)`
    public final func refreshItemModel(_ segmentedView: JXSegmentedView, _ itemModel: JXSegmentedBaseItemModel, at index: Int, selectedIndex: Int) {
        preferredRefreshItemModel(itemModel, at: index, selectedIndex: selectedIndex)
    }

    private func itemWidthWithZoom(at index: Int, model: JXSegmentedBaseItemModel) -> CGFloat {
        var width = self.segmentedView(JXSegmentedView(), widthForItemAt: index)
        if isItemWidthZoomEnabled {
            width *= model.itemWidthCurrentZoomScale
        }
        return width
    }
}