Girly/Pods/JXSegmentedView/Sources/TitleImage/JXSegmentedTitleImageCell.swift

//
//  JXSegmentedTitleImageCell.swift
//  JXSegmentedView
//
//  Created by jiaxin on 2018/12/29.
//  Copyright © 2018 jiaxin. All rights reserved.
//

import UIKit

open class JXSegmentedTitleImageCell: JXSegmentedTitleCell {
    public let imageView = UIImageView()
    private var currentImageInfo: String?

    open override func prepareForReuse() {
        super.prepareForReuse()

        currentImageInfo = nil
    }

    open override func commonInit() {
        super.commonInit()

        imageView.contentMode = .scaleAspectFit
        contentView.insertSubview(imageView, belowSubview: titleLabel)
    }

    open override func layoutSubviews() {
        super.layoutSubviews()
        
        guard let myItemModel = itemModel as? JXSegmentedTitleImageItemModel else {
            return
        }
        
        let imageSize = myItemModel.imageSize
        switch myItemModel.titleImageType {
        case .topImage:
            let contentHeight = imageSize.height + myItemModel.titleImageSpacing + titleLabel.bounds.size.height
            imageView.center = CGPoint(x: contentView.bounds.size.width/2, y: (contentView.bounds.size.height - contentHeight)/2 + imageSize.height/2)
            titleLabel.center = CGPoint(x: contentView.bounds.size.width/2, y: imageView.frame.maxY + myItemModel.titleImageSpacing + titleLabel.bounds.size.height/2)
        case .leftImage:
            let contentWidth = imageSize.width + myItemModel.titleImageSpacing + titleLabel.bounds.size.width
            imageView.center = CGPoint(x: (contentView.bounds.size.width - contentWidth)/2 + imageSize.width/2, y: contentView.bounds.size.height/2)
            titleLabel.center = CGPoint(x: imageView.frame.maxX + myItemModel.titleImageSpacing + titleLabel.bounds.size.width/2, y: contentView.bounds.size.height/2)
        case .bottomImage:
            let contentHeight = imageSize.height + myItemModel.titleImageSpacing + titleLabel.bounds.size.height
            titleLabel.center = CGPoint(x: contentView.bounds.size.width/2, y: (contentView.bounds.size.height - contentHeight)/2 + titleLabel.bounds.size.height/2)
            imageView.center = CGPoint(x: contentView.bounds.size.width/2, y: titleLabel.frame.maxY + myItemModel.titleImageSpacing + imageSize.height/2)
        case .rightImage:
            let contentWidth = imageSize.width + myItemModel.titleImageSpacing + titleLabel.bounds.size.width
            titleLabel.center = CGPoint(x: (contentView.bounds.size.width - contentWidth)/2 + titleLabel.bounds.size.width/2, y: contentView.bounds.size.height/2)
            imageView.center = CGPoint(x: titleLabel.frame.maxX + myItemModel.titleImageSpacing + imageSize.width/2, y: contentView.bounds.size.height/2)
        case .onlyImage:
            imageView.center = CGPoint(x: contentView.bounds.size.width/2, y: contentView.bounds.size.height/2)
        case .onlyTitle:
            titleLabel.center = CGPoint(x: contentView.bounds.size.width/2, y: contentView.bounds.size.height/2)
        case .backgroundImage:
            imageView.center = CGPoint(x: contentView.bounds.size.width/2, y: contentView.bounds.size.height/2)
            titleLabel.center = CGPoint(x: contentView.bounds.size.width/2, y: contentView.bounds.size.height/2)
        }
        maskTitleLabel.center = titleLabel.center
    }

    open override func reloadData(itemModel: JXSegmentedBaseItemModel, selectedType: JXSegmentedViewItemSelectedType) {
        super.reloadData(itemModel: itemModel, selectedType: selectedType )

        guard let myItemModel = itemModel as? JXSegmentedTitleImageItemModel else {
            return
        }

        titleLabel.isHidden = false
        imageView.isHidden = false
        if myItemModel.titleImageType == .onlyTitle {
            imageView.isHidden = true
        }else if myItemModel.titleImageType == .onlyImage {
            titleLabel.isHidden = true
        }

        imageView.bounds = CGRect(x: 0, y: 0, width: myItemModel.imageSize.width, height: myItemModel.imageSize.height)

        var normalImageInfo = myItemModel.normalImageInfo
        if myItemModel.isSelected && myItemModel.selectedImageInfo != nil {
            normalImageInfo = myItemModel.selectedImageInfo
        }

        //因为`func reloadData(itemModel: JXSegmentedBaseItemModel, selectedType: JXSegmentedViewItemSelectedType)`方法会回调多次，尤其是左右滚动的时候会调用无数次。如果每次都触发图片加载，会非常消耗性能。所以只会在图片发生了变化的时候，才进行图片加载。
        if normalImageInfo != nil && normalImageInfo != currentImageInfo {
            currentImageInfo = normalImageInfo
            if myItemModel.loadImageClosure != nil {
                myItemModel.loadImageClosure!(imageView, normalImageInfo!)
            }else {
                imageView.image = UIImage(named: normalImageInfo!)
            }
        }

        if myItemModel.isImageZoomEnabled {
            imageView.transform = CGAffineTransform(scaleX: myItemModel.imageCurrentZoomScale, y: myItemModel.imageCurrentZoomScale)
        }else {
            imageView.transform = .identity
        }

        setNeedsLayout()
    }
}