山川湖海 - Android无障碍代理的那些事

val delegateCompat = object : AccessibilityDelegateCompat() {
    override fun onInitializeAccessibilityNodeInfo(
        host: View?,
        info: AccessibilityNodeInfoCompat?
    ) {
        super.onInitializeAccessibilityNodeInfo(host, info)
        // 你的自定义逻辑
        info?.isChecked = xxx 
        info?.isCheckable = true
    }
}
ViewCompat.setAccessibilityDelegate(this, delegateCompat)

inline fun lazyAcesDeleteSelectSimple(crossinline obj: () -> Boolean): Lazy<AccessibilityDelegateCompat> =
    lazy {
        object : AccessibilityDelegateCompat() {
            override fun onInitializeAccessibilityNodeInfo(
                host: View?,
                info: AccessibilityNodeInfoCompat?
            ) {
                super.onInitializeAccessibilityNodeInfo(host, info)
                info?.isChecked = obj.invoke()
                info?.isCheckable = true
            }
        }
    }
//使用处
val xxxViewAcesDelegate by lazyAcesDeleteSelectSimple{
  //你的逻辑
   true or false
}
val view=View(null)
ViewCompat.setAccessibilityDelegate(view, xxxViewAcesDelegate)

interface IAccessibilityDelegate {
    /** 无障碍下是否选中
     *
     * 默认会使用此字段来控制,如果实现了[setSelectedProvider],则此字段仅作为状态查看 */
    var isSelect: Boolean
    /** 使用回调的方式设置无障碍选中状态,某些业务场景下会用到,优先使用[isSelect]即可
     *
     * 注意:如果此方法被启用,则优先使用此回调,此时[isSelect]仅作为状态查看 */
    fun setSelectedProvider(obj: (() -> Boolean)?): IAccessibilityDelegate
    /** 此方法为无障碍服务提供有关视图状态的信息,增加此监听便于外部监听 */
    fun setInitializeNodeInfoListener(obj: (View, AccessibilityNodeInfoCompat) -> Unit): IAccessibilityDelegate
    /** 解绑所有回调 */
    fun unBind()
}

class CustomAccessibilityDelegateCompat : AccessibilityDelegateCompat(), IAccessibilityDelegate {
    override var isSelect: Boolean = false
    /**
     * 内部重写的一些方法,暂时只用到了这些,如果有其他的,可以加到下面,并更改[IAccessibilityDelegate]
     * -> */
    private var onSelectedProvider: (() -> Boolean)? = null
    private var onInitializeAccessibilityNodeInfo: ((View, AccessibilityNodeInfoCompat) -> Unit)? = null
    /** 此方法为无障碍服务提供有关视图状态的信息。 */
    override fun onInitializeAccessibilityNodeInfo(
        host: View?,
        info: AccessibilityNodeInfoCompat?
    ) {
        super.onInitializeAccessibilityNodeInfo(host, info)
        if (host == null || info == null) return
        onInitializeAccessibilityNodeInfo?.invoke(host, info)
        isSelect = onSelectedProvider?.invoke() ?: (isSelect || host.isSelected)
        info.isChecked = isSelect
        info.isCheckable = true
    }
    override fun setSelectedProvider(obj: (() -> Boolean)?): IAccessibilityDelegate {
        onSelectedProvider = obj
        return this
    }
    override fun setInitializeNodeInfoListener(obj: (View, AccessibilityNodeInfoCompat) -> Unit): IAccessibilityDelegate {
        onInitializeAccessibilityNodeInfo = obj
        return this
    }
    override fun unBind() {
        onInitializeAccessibilityNodeInfo = null
    }
}

@file:JvmName("AccessibilityUtils")
private const val ACCESS_DEFAULT_CONTENT_DESCRIPTION = "ACCESS_DEFAULT_CONTENT_DESCRIPTION"
/**
 * 设置当前View在无障碍下是否已选中
 * 使用view默认的isSelect也同样受用,前提是已经调用过[initXcfAccessDelegate]
 * */
var View.isAccessSelected: Boolean
    get() = accessDelegate.isSelect || isSelected
    set(value) {
        accessDelegate.isSelect = value
    }
/** 获取自定义的无障碍接口 */
val View.accessDelegate: IAccessibilityDelegate
    get() {
        val delegate = ViewCompat.getAccessibilityDelegate(this) as? IAccessibilityDelegate
        if (delegate == null) {
            val newDelegate = CustomAccessibilityDelegateCompat()
            ViewCompat.setAccessibilityDelegate(this, newDelegate)
            return newDelegate
        }
        return delegate
    }
/** 初始化无障碍委托,满足一些基础view的免操作适配 */
@JvmOverloads
fun View.initAccessDelegate(contentDescription: String = ACCESS_DEFAULT_CONTENT_DESCRIPTION):
    IAccessibilityDelegate {
    if (contentDescription != ACCESS_DEFAULT_CONTENT_DESCRIPTION)
        this.contentDescription = contentDescription
    return AccessDelegate
}

// 例如有一个使用ImageView做开关的 [历史代码]
fun test() {
    val toggleView = ImageView(context)
    // 通过扩展属性设置
    toggleView.isAccessSelected = false
    // 通过自定的逻辑去设置
    toggleView.initXcfAccessDelegate("xx开关").setSelectedProvider(::checkToggle)
}
/** 你的业务逻辑 */
fun checkToggle(): Boolean = false