ConstraintLayoutAccessibilityHelper

ConstraintLayoutAccessibilityHelper.kt

package com.julienarzul.android.accessibility

import android.content.Context
import android.os.Build
import android.util.AttributeSet
import android.view.View
import android.view.accessibility.AccessibilityEvent
import androidx.constraintlayout.widget.ConstraintHelper
import androidx.constraintlayout.widget.ConstraintLayout

class ConstraintLayoutAccessibilityHelper
@JvmOverloads constructor(
        context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : ConstraintHelper(context, attrs, defStyleAttr) {

    init {
        importantForAccessibility = View.IMPORTANT_FOR_ACCESSIBILITY_YES

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
            isScreenReaderFocusable = true
        } else {
            isFocusable = true
        }
    }

    override fun updatePreLayout(container: ConstraintLayout) {
        super.updatePreLayout(container)

        if (this.mReferenceIds != null) {
            this.setIds(this.mReferenceIds)
        }

        mIds.forEach {
            container.getViewById(it)?.importantForAccessibility = View.IMPORTANT_FOR_ACCESSIBILITY_NO
        }
    }

    override fun onPopulateAccessibilityEvent(event: AccessibilityEvent) {
        super.onPopulateAccessibilityEvent(event)

        val constraintLayoutParent = parent as? ConstraintLayout
        if (constraintLayoutParent != null) {
            event.text.clear()

            mIds.forEach { id ->
                val view: View? = constraintLayoutParent.getViewById(id)
                // Adds this View to the Accessibility Event only if it is currently visible
                if (view?.isVisible == true) {
                    view.onPopulateAccessibilityEvent(event)
                }
            }
        }
    }
}