TV 應用程式有時具有某些用途,會導致仰賴 TalkBack 的使用者難以使用應用程式。如要為這些使用者提供更優質的 TalkBack 體驗,請詳閱本指南中的各節,並視需要在應用程式中實作變更。如果您的應用程式使用自訂檢視畫面,您也應參閱對應指南,瞭解如何以自訂檢視畫面支援無障礙功能。
處理巢狀檢視區塊
TalkBack 使用者可能難以瀏覽巢狀檢視畫面。請盡可能讓 TalkBack 的父項或子項檢視畫面可聚焦,但請勿兩者並用。
如要讓 TalkBack 可聚焦檢視畫面,請將 focusable
和 focusableInTouchMode
屬性設為 true
。這是必要步驟,因為部分電視裝置可能會在 TalkBack 啟用時進入及退出觸控模式。
如要將檢視畫面設為不可聚焦,只要將 focusable
屬性設為 false
即可。不過,如果檢視畫面可以操作 (也就是其對應的 AccessibilityNodeInfo
具有 ACTION_CLICK
),則可能仍可聚焦。
變更動作的說明
根據預設,TalkBack 會針對可操作的檢視畫面朗讀「按下選取即可啟動」。在某些動作中,「啟用」一詞可能較不適合。如要提供更準確的說明,您可以進行變更:
Kotlin
findViewById<View>(R.id.custom_actionable_view).accessibilityDelegate = object : View.AccessibilityDelegate() { override fun onInitializeAccessibilityNodeInfo(host: View, info: AccessibilityNodeInfo) { super.onInitializeAccessibilityNodeInfo(host, info) info.addAction( AccessibilityAction( AccessibilityAction.ACTION_CLICK.id, getString(R.string.custom_label) ) ) } }
Java
findViewById(R.id.custom_actionable_view).setAccessibilityDelegate(new AccessibilityDelegate() { @Override public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) { super.onInitializeAccessibilityNodeInfo(host, info); AccessibilityAction action = new AccessibilityAction( AccessibilityAction.ACTION_CLICK.getId(), getString(R.string.custom_label)); info.addAction(action); } });
新增滑桿支援功能
電視的 TalkBack 特別支援滑桿。如要啟用滑桿模式,請將 ACTION_SET_PROGRESS
和 RangeInfo
物件一起加入檢視畫面。
使用者按下電視遙控器中間的按鈕,即可進入滑桿模式。在此模式下,箭頭按鈕會產生 ACTION_SCROLL_FORWARD
和 ACTION_SCROLL_BACKWARD
無障礙動作。
以下範例會實作等級介於 1 到 10 的音量滑桿:
Kotlin
/** * This example only provides slider functionality for TalkBack users. Additional logic should * be added for other users. Such logic may reuse the increase and decrease methods. */ class VolumeSlider(context: Context?, attrs: AttributeSet?) : LinearLayout(context, attrs) { private val min = 1 private val max = 10 private var current = 5 private var textView: TextView? = null init { isFocusable = true isFocusableInTouchMode = true val rangeInfo = AccessibilityNodeInfo.RangeInfo( AccessibilityNodeInfo.RangeInfo.RANGE_TYPE_INT, min.toFloat(), max.toFloat(), current.toFloat() ) accessibilityDelegate = object : AccessibilityDelegate() { override fun onInitializeAccessibilityNodeInfo(host: View, info: AccessibilityNodeInfo) { super.onInitializeAccessibilityNodeInfo(host, info) info.addAction(AccessibilityNodeInfo.AccessibilityAction.ACTION_SET_PROGRESS) info.rangeInfo = rangeInfo } override fun performAccessibilityAction(host: View, action: Int, args: Bundle?): Boolean { if (action == AccessibilityNodeInfo.AccessibilityAction.ACTION_SCROLL_FORWARD.id) { increase() return true } if (action == AccessibilityNodeInfo.AccessibilityAction.ACTION_SCROLL_BACKWARD.id) { decrease() return true } return super.performAccessibilityAction(host, action, args) } } } override fun onFinishInflate() { super.onFinishInflate() textView = findViewById(R.id.text) textView!!.text = context.getString(R.string.level, current) } private fun increase() { update((current + 1).coerceAtMost(max)) } private fun decrease() { update((current - 1).coerceAtLeast(min)) } private fun update(newLevel: Int) { if (textView == null) { return } val newText = context.getString(R.string.level, newLevel) // Update the user interface with the new volume. textView!!.text = newText // Announce the new volume. announceForAccessibility(newText) current = newLevel } }
Java
/** * This example only provides slider functionality for TalkBack users. Additional logic should * be added for other users. Such logic can reuse the increase and decrease methods. */ public class VolumeSlider extends LinearLayout { private final int min = 1; private final int max = 10; private int current = 5; private TextView textView; public VolumeSlider(Context context, AttributeSet attrs) { super(context, attrs); setFocusable(true); setFocusableInTouchMode(true); RangeInfo rangeInfo = new RangeInfo(RangeInfo.RANGE_TYPE_INT, min, max, current); setAccessibilityDelegate( new AccessibilityDelegate() { @Override public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) { super.onInitializeAccessibilityNodeInfo(host, info); info.addAction(AccessibilityAction.ACTION_SET_PROGRESS); info.setRangeInfo(rangeInfo); } @Override public boolean performAccessibilityAction(View host, int action, Bundle args) { if (action == AccessibilityAction.ACTION_SCROLL_FORWARD.getId()) { increase(); return true; } if (action == AccessibilityAction.ACTION_SCROLL_BACKWARD.getId()) { decrease(); return true; } return super.performAccessibilityAction(host, action, args); } }); } @Override protected void onFinishInflate() { super.onFinishInflate(); textView = findViewById(R.id.text); textView.setText(getContext().getString(R.string.level, current)); } private void increase() { update(Math.min(current + 1, max)); } private void decrease() { update(Math.max(current - 1, min)); } private void update(int newLevel) { if (textView == null) { return; } String newText = getContext().getString(R.string.level, newLevel); // Update the user interface with the new volume. textView.setText(newText); // Announce the new volume. announceForAccessibility(newText); current = newLevel; } }