IOS Widget（4-2）：创建可配置小组件（动态修改配置数据）

//
//  IntentHandler.swift
//  DynamicTimer
//

import Intents

// TimeTypeConfigurationIntentHandling 这个类在
// TimeTypeConfigurationIntent.swift文件中，这个文件是Xcode生成的。
// 这个文件名怎么来的？ =>
// Target的属性的“Gneral”选项卡中，在“Supported Intents”部分中添加一个条目，
// 并将“Class Name”设置为 "TimeTypeConfigurationIntent".
// Xcode会自动把xxx.intentdefinition中的配置转为代码，放到这个文件中。
class IntentHandler: INExtension, TimeTypeConfigurationIntentHandling {
    func provideDynamicTimeTypeOptionsCollection(
        for intent: TimeTypeConfigurationIntent,
        with completion: @escaping (INObjectCollection<DynamicTimeType>?, Error?) -> Void) {
        
        let time = DynamicTimeType(identifier: "time", display: "时间")
        time.dynamicTime = "time"
        let date = DynamicTimeType(identifier: "date", display: "时期")
        date.dynamicTime = "date"
        let timer = DynamicTimeType(identifier: "timer", display: "计时器")
        timer.dynamicTime = "timer"
        let allTimeType = [
            time, date, timer
        ]
        // 生成一个数组，把数据通过回调方法传出去
        completion(INObjectCollection(items: allTimeType), nil)
    }
    
    override func handler(for intent: INIntent) -> Any {
        // This is the default implementation.  If you want different objects to handle different intents,
        // you can override this and return the handler you want for that particular intent.
        return self
    }    
}

//
//  WidgetConfigIntent.swift
//  WidgetConfigIntent
//

import WidgetKit
import SwiftUI
import Intents

struct Provider: IntentTimelineProvider {
    func placeholder(in context: Context) -> SimpleEntry {
        // 不同点3：传递默认参数
        SimpleEntry(date: Date(), configuration: TimeTypeConfigurationIntent())
    }

    // 不同点4：比使用StaticConfiguration时多了一个配置参数
    func getSnapshot(for configuration: TimeTypeConfigurationIntent, in context: Context, completion: @escaping (SimpleEntry) -> ()) {
        let entry = SimpleEntry(date: Date(), configuration: configuration)
        completion(entry)
    }

    // 不同点5：比使用StaticConfiguration时多了一个配置参数
    func getTimeline(for configuration: TimeTypeConfigurationIntent, in context: Context, completion: @escaping (Timeline<Entry>) -> ()) {
        var entries: [SimpleEntry] = []

        // Generate a timeline consisting of five entries an hour apart, starting from the current date.
        let currentDate = Date()
        for hourOffset in 0 ..< 5 {
            let entryDate = Calendar.current.date(byAdding: .hour, value: hourOffset, to: currentDate)!
            let entry = SimpleEntry(date: entryDate, configuration: configuration)
            entries.append(entry)
        }

        let timeline = Timeline(entries: entries, policy: .atEnd)
        completion(timeline)
    }
}

struct SimpleEntry: TimelineEntry {
    let date: Date
    // 不同点2： 多了一个配置参数，小组件编辑界面设置参数会通过这个传递进来
    let configuration: TimeTypeConfigurationIntent
}

struct WidgetConfigIntentEntryView : View {
    var entry: Provider.Entry

    var body: some View {
        // 根据静态配置信息动态改变布局
//        if (entry.configuration.timeType == TimeTypeEnum.time) {
//            Text(entry.date, style: .time)
//        } else {
//            Text(entry.date, style: .date)
//        }
        // 根据动态配置信息动态改变布局
        if (entry.configuration.dynamicTimeType?.dynamicTime == "time") {
            Text(entry.date, style: .time)
        } else if (entry.configuration.dynamicTimeType?.dynamicTime == "timer") {
            Text(entry.date, style: .timer)
                .multilineTextAlignment(.center)
        } else {
            Text(entry.date, style: .date)
        }
    }
}

// 小组件入口
@main
struct WidgetConfigIntent: Widget {
    let kind: String = "WidgetConfigIntent"

    var body: some WidgetConfiguration {
        //不同点1： 这里使用 IntentConfiguration， 对比 StaticConfiguration，这里还多了一个参数 intent: ConfigurationIntent.self
        IntentConfiguration(kind: kind, intent: TimeTypeConfigurationIntent.self, provider: Provider()) { entry in
            WidgetConfigIntentEntryView(entry: entry)
        }
        .configurationDisplayName("可配置小组件")
        .description("选择不同的时间类型")
    }
}

// Debug调试代码
struct WidgetConfigIntent_Previews: PreviewProvider {
    static var previews: some View {
        WidgetConfigIntentEntryView(entry: SimpleEntry(date: Date(), configuration: TimeTypeConfigurationIntent()))
            .previewContext(WidgetPreviewContext(family: .systemSmall))
    }
}