Android Accessibility always gets the content of previous page in ViewPager

Question

I'm using Accessibility to read the content in ViewPager, in the first page, everything is alright, Accessibility is reading the content of current page, But when I turn to next page, Accessibility still reading the the content of previous page.

For example:

Page1 -> TextView -> content1

Page2 -> TextView -> content2

Page3 -> TextView -> content3

Accessibility reads content1 when current page is Page1, then turn to Page2, Accessibility reads content1,Accessibility reads content2, this is so werid reading code is like this:

 List<AccessibilityNodeInfo> nodeInfoList = accessibilityNodeInfo.findAccessibilityNodeInfosByViewId(id);
    if (nodeInfoList != null && !nodeInfoList.isEmpty()) {
        for (AccessibilityNodeInfo nodeInfo : nodeInfoList) {
            if (nodeInfo != null) {
                return nodeInfo.text;
            }
        }
    }

Any body help me?

Could you provide more information? For example full code of Activity and XML with view? — TemaTre, Dec 09 '19 at 08:13
Does this answer your question? [Android TalkBack and fragment stack](https://stackoverflow.com/questions/30225636/android-talkback-and-fragment-stack) — isaaaaame, Dec 09 '19 at 08:18
Thanks for your reply, sorry, the code is a little complicated, wait a minute please — lucher, Dec 09 '19 at 08:24

score 0 · Answer 1 · answered Dec 13 '22 at 08:28

I had this problem with ViewPager, when manually dragged to a next page, TalkBack was OK, but when fake dragged by tapping on a button which had a fake drag code, then TalkBack on the ViewPager read position from the page before current page. So I turned off TalkBack on a fake drag and created new TalkBack event:

    animator.addListener(object : Animator.AnimatorListener {
        override fun onAnimationStart(animation: Animator?) {
            isFakeDrag = true
            viewPager.importantForAccessibility = View.IMPORTANT_FOR_ACCESSIBILITY_NO
            viewPager.beginFakeDrag()
        }
        override fun onAnimationEnd(animation: Animator?) {
            viewPager.endFakeDrag()
            viewPager.importantForAccessibility = View.IMPORTANT_FOR_ACCESSIBILITY_YES
            isFakeDrag = false
        }
        override fun onAnimationCancel(animation: Animator?) { /* Ignored */ }
        override fun onAnimationRepeat(animation: Animator?) { /* Ignored */ }
    })

and

viewPager.registerOnPageChangeCallback( object : ViewPager2.OnPageChangeCallback() {
        override fun onPageScrolled(
            position: Int,
            positionOffset: Float,
            positionOffsetPixels: Int
        ) {
            //some code
        }

        override fun onPageSelected(position: Int) {
            super.onPageSelected(position)
            if(isFakeDrag) {
                val event = AccessibilityEvent.obtain()
                event.eventType = AccessibilityEvent.TYPE_ANNOUNCEMENT
                val positionString = //create a string to be announced by TalkBack
                positionString.also { event.text.add(it) }
                val accessibilityManager = requireContext().getSystemService(Context.ACCESSIBILITY_SERVICE) as AccessibilityManager
                accessibilityManager.sendAccessibilityEvent(event)
            }
        }
    })

Android Accessibility always gets the content of previous page in ViewPager

1 Answers1