Swiftgram/submodules/MediaPickerUI/Sources/MediaGroupsHeaderItem.swift

import Foundation
import UIKit
import Display
import AsyncDisplayKit
import SwiftSignalKit
import TelegramPresentationData
import ItemListUI

final class MediaGroupsHeaderItem: ListViewItem {
    let presentationData: ItemListPresentationData
    let title: String
    
    public init(presentationData: ItemListPresentationData, title: String) {
        self.presentationData = presentationData
        self.title = title
    }
    
    public func nodeConfiguredForParams(async: @escaping (@escaping () -> Void) -> Void, params: ListViewItemLayoutParams, synchronousLoads: Bool, previousItem: ListViewItem?, nextItem: ListViewItem?, completion: @escaping (ListViewItemNode, @escaping () -> (Signal<Void, NoError>?, (ListViewItemApply) -> Void)) -> Void) {
        async {
            let node = MediaGroupsHeaderItemNode()
            let makeLayout = node.asyncLayout()
            let (nodeLayout, nodeApply) = makeLayout(self, params)
            node.contentSize = nodeLayout.contentSize
            node.insets = nodeLayout.insets
            
            completion(node, nodeApply)
        }
    }
    
    public func updateNode(async: @escaping (@escaping () -> Void) -> Void, node: @escaping () -> ListViewItemNode, params: ListViewItemLayoutParams, previousItem: ListViewItem?, nextItem: ListViewItem?, animation: ListViewItemUpdateAnimation, completion: @escaping (ListViewItemNodeLayout, @escaping (ListViewItemApply) -> Void) -> Void) {
        Queue.mainQueue().async {
            if let nodeValue = node() as? MediaGroupsHeaderItemNode {
                let layout = nodeValue.asyncLayout()
                async {
                    let (nodeLayout, apply) = layout(self, params)
                    Queue.mainQueue().async {
                        completion(nodeLayout, { info in
                            apply().1(info)
                        })
                    }
                }
            }
        }
    }
    
    public var selectable: Bool {
        return false
    }
}

private let titleFont = Font.bold(22.0)

private class MediaGroupsHeaderItemNode: ListViewItemNode {
    private let titleNode: TextNode
    
    private var item: MediaGroupsHeaderItem?
    private var layoutParams: ListViewItemLayoutParams?
    
    init() {
        self.titleNode = TextNode()
        
        super.init(layerBacked: false, dynamicBounce: false, rotated: false, seeThrough: false)
        
        self.addSubnode(self.titleNode)
    }
    
    override func layoutForParams(_ params: ListViewItemLayoutParams, item: ListViewItem, previousItem: ListViewItem?, nextItem: ListViewItem?) {
        if let item = self.item {
            let makeLayout = self.asyncLayout()
            let (nodeLayout, nodeApply) = makeLayout(item, params)
            self.contentSize = nodeLayout.contentSize
            self.insets = nodeLayout.insets
            let _ = nodeApply()
        }
    }
    
    func asyncLayout() -> (_ item: MediaGroupsHeaderItem, _ params: ListViewItemLayoutParams) -> (ListViewItemNodeLayout, () -> (Signal<Void, NoError>?, (ListViewItemApply) -> Void)) {
        let makeTitleLayout = TextNode.asyncLayout(self.titleNode)
    
    
        return { [weak self] item, params in
            let titleString = NSAttributedString(string: item.title, font: titleFont, textColor: item.presentationData.theme.list.itemPrimaryTextColor)
            
            let (titleLayout, titleApply) = makeTitleLayout(TextNodeLayoutArguments(attributedString: titleString, backgroundColor: nil, maximumNumberOfLines: 1, truncationType: .end, constrainedSize: CGSize(width: params.width - params.leftInset - params.rightInset - 16.0, height: 100.0), alignment: .natural, cutout: nil, insets: UIEdgeInsets()))
            
            let contentSize = CGSize(width: params.width, height: 45.0)
            let nodeLayout = ListViewItemNodeLayout(contentSize: contentSize, insets: UIEdgeInsets())
            
            return (nodeLayout, { [weak self] in
                return (nil, { _ in
                    if let strongSelf = self {
                        strongSelf.item = item
                        strongSelf.layoutParams = params
                         
                        let _ = titleApply()
                        strongSelf.titleNode.frame = CGRect(origin: CGPoint(x: params.leftInset + 17.0, y: floor((nodeLayout.contentSize.height - titleLayout.size.height) / 2.0) + 2.0), size: titleLayout.size)
                    }
                })
            })
        }
    }
    
    override func animateInsertion(_ currentTimestamp: Double, duration: Double, options: ListViewItemAnimationOptions) {
        self.layer.animateAlpha(from: 0.0, to: 1.0, duration: duration * 0.5)
    }
    
    override func animateRemoved(_ currentTimestamp: Double, duration: Double) {
        self.layer.animateAlpha(from: 1.0, to: 0.0, duration: duration * 0.5, removeOnCompletion: false)
    }
}