问无法调整UI测试的DatePicker值:类型为6的PickerWheel

EN

func adjustDatePicker(wheel: XCUIElement, to newValue: String) -> Bool {    
    let x = wheel.frame.width / 2.0
    let y = wheel.frame.height / 2.0
    // each wheel notch is about 30px high, so tapping y - 30 rotates up. y + 30 rotates down.
    var offset: CGFloat = -30.0
    var reversed = false
    let previousValue = wheel.value as? String
    while wheel.value as? String != newValue {
        wheel.coordinate(withNormalizedOffset: .zero).withOffset(CGVector(dx: x, dy: y + offset)).tap()
        let briefWait = expectation(description: "Wait for wheel to rotate")
        briefWait.isInverted = true
        wait(for: [briefWait], timeout: 0.25)
        if previousValue == wheel.value as? String {
            if reversed {
                // we already tried reversing, can't find the desired value
                break
            }
            // we didn't move the wheel. try reversing direction
            offset = 30.0
            reversed = true
        }
    }
    
    return wheel.value as? String == newValue
}

import Foundation
import XCTest

struct ScrollParameters {
    let halfX: CGFloat
    let dy: CGFloat
    let tapCount: Int
    
    // how many notches to rotate with one tap
    let notchCountToRotate: Int
    
    // To rotate n notches with one tap, we have to multiply notch height with nth value in following array
    // e.g. To rotate 3 notches, multiply notch height with 2.7
    static let reverseScrollingOffset:[CGFloat] = [0, 1, 2, 2.7]
    static let forwardScrollingOffset:[CGFloat] = [0, 1, 2, 2.5]
    
    // each wheel notch is about 30px high, so tapping y - 30 rotates up. y + 30 rotates down.
    static let wheelNotchHeight:CGFloat = 30.0
    
    static let maxAttempts = 50
}

/// Given the number of notches to be rotated with one tap, this function determines how many taps are required in order to minimize the difference between current picker value and the value to be set.
private func calculateTapCount(forZeroing difference: Int, withNotchRotationCount notchRotationCount: Int) -> Int {
    if difference == 0 {
        return 0
    }
    let positiveDiff = difference < 0 ? (difference * -1) : difference
    return positiveDiff / notchRotationCount
}

private func scroll(_ wheel: XCUIElement, with scrollParams: ScrollParameters) {
    var currentTapCount = 0
    while currentTapCount < scrollParams.tapCount {
        wheel.coordinate(withNormalizedOffset: .zero)
            .withOffset(CGVector(dx: scrollParams.halfX, dy: scrollParams.dy))
            .tap()
        currentTapCount += 1
    }
}

/// Determines number of notches to be rotated with one tap.
private func getNotchRotationCountWithOneTap(_ difference: Int) -> Int {
    if difference == 0 {
        return 0
    }
    
    if (difference >= 3) || (difference <= -3) {
        return 3
    }
    
    return (difference % 2 == 0) ? 2 : 1
}

/// Returns the y-axis offset required for rotating n notches of pickerwheel with 1 tap.
/// The offset values are stored in static arrays in ScrollParameters.
/// If we want to rotate the wheel in reverse direction, we have to subtract the offset from center coordinate.
/// Hence, offset value is multiplied by -1.
private func getTappingOffset(_ difference: Int, _ notchRotationCountForOneTap: Int) -> CGFloat {
    if difference > 0 {
        return ScrollParameters.reverseScrollingOffset[notchRotationCountForOneTap] * (-1.0)
    } else {
        return ScrollParameters.forwardScrollingOffset[notchRotationCountForOneTap]
    }
}

/// Returns the metadata for rotating pickerwheel notches.
private func getRotationMetadata(for difference: Int, with wheel:XCUIElement) -> ScrollParameters {
    let notchRotationCountForOneTap = getNotchRotationCountWithOneTap(difference) // 0, 1, 2, 3
    let tapCount = calculateTapCount(forZeroing: difference, withNotchRotationCount: notchRotationCountForOneTap)
    let halfX:CGFloat = wheel.frame.width / 2.0
    let halfY:CGFloat = wheel.frame.height / 2.0
    let dy:CGFloat = halfY + (ScrollParameters.wheelNotchHeight * getTappingOffset(difference, notchRotationCountForOneTap))
    return ScrollParameters(halfX: halfX, dy: dy, tapCount: tapCount, notchCountToRotate: notchRotationCountForOneTap)
}

private func getYearWheelValue(_ wheel: XCUIElement) -> Int {
    sleep(for: 250) //will sleep for 250 milliseconds (.025 seconds)
    return Int(wheel.value as! String)!
}

private func setYear(_ wheel: XCUIElement, _ yearToSet: Int) {
    var pickerWheelValue = getYearWheelValue(wheel)
    var counter = 0
    repeat {
        let diff = pickerWheelValue - yearToSet
        let scrollParams = getRotationMetadata(for: diff, with: wheel)
        scroll(wheel, with: scrollParams)
        pickerWheelValue = getYearWheelValue(wheel)
        counter += 1
    } while (pickerWheelValue != yearToSet) && (counter < ScrollParameters.maxAttempts)
}

private func getMonthWheelIndex(_ wheel: XCUIElement) -> Int {
    sleep(for: 250)
    let pickerValue = wheel.value as! String
    let monthNames:[String] = DateFormatter().monthSymbols
    return monthNames.firstIndex(of: pickerValue)!
}
 
private func selectMonth(_ wheel: XCUIElement, _ valueToSet: Int) {
    let expectedValueIndex = valueToSet - 1
    var pickerValueIndex: Int = getMonthWheelIndex(wheel)
    var counter = 0
    repeat {
        let diff = pickerValueIndex - expectedValueIndex
        let scrollParams = getRotationMetadata(for: diff, with: wheel)
        scroll(wheel, with: scrollParams)
        pickerValueIndex = getMonthWheelIndex(wheel)
        counter += 1
    } while (pickerValueIndex != expectedValueIndex) && (counter < ScrollParameters.maxAttempts)
}

private func getButtonForDay(with predicateForDayButton: NSPredicate) -> XCUIElement? {
    let datepicker = GlobalTestContext.shared.app?.datePickers.element(boundBy: 1)
    let buttons = datepicker?.buttons.allElementsBoundByIndex
    for button in buttons! {
        let query = button.descendants(matching: .staticText).matching(predicateForDayButton)
        if query.count == 1 {
            return button
        }
    }
    XCTAssertFalse(true, "No matching day found in the datepicker")
    return nil
}

private func selectDay(_ day: Int) {
    let predicateForDayButton = NSPredicate(format: "label == %@", String(describing: day))
    let dayButton = getButtonForDay(with: predicateForDayButton)
    dayButton?.tap()
}
 
private func dismissDatePicker(_ app: XCUIApplication) {
    let start = app.coordinate(withNormalizedOffset: CGVector(dx: 1.0, dy: 0.8))
    // tapping bottom right corner to dismiss the datepicker
    let end = app.coordinate(withNormalizedOffset: CGVector(dx: 1.0, dy: 1.0))
    start.press(forDuration: 0.1, thenDragTo: end)
}
 
func isNewDatePicker(_ datePicker: XCUIElement) -> Bool {
    return datePicker.pickerWheels.count == 0
}

// entry point 
func setDateInNewDatepicker(_ datePicker: XCUIElement, _ dateComponents: DateComponents) -> Any {
    let app = XCUIApplication()
    app.descendants(matching: .other).matching(identifier: "Date Picker").element.tap()
    app.descendants(matching: .button).matching(identifier: "Show year picker").element.tap()
    
    let yearPicker = (app.descendants(matching: .pickerWheel).element(boundBy: 1))
    setYear(yearPicker, dateComponents.year!)
    
    let monthPicker = (app.descendants(matching: .pickerWheel).element(boundBy: 0))
    selectMonth(monthPicker, dateComponents.month!)
    
    app.descendants(matching: .button).matching(identifier: "Hide year picker").element.tap()
    
    selectDay(dateComponents.day!)
    dismissDatePicker(app)
    return datePicker
}