android.support.v4.view.accessibility.AccessibilityNodeInfoCompat#isVisibleToUser ( )源码实例Demo

/**
 * Returns whether the supplied {@link View} and {@link AccessibilityNodeInfoCompat} would
 * produce spoken feedback if it were accessibility focused.  NOTE: not all speaking nodes are
 * focusable.
 *
 * @param view The {@link View} to evaluate
 * @param node The {@link AccessibilityNodeInfoCompat} to evaluate
 * @return {@code true} if it meets the criterion for producing spoken feedback
 */
public static boolean isSpeakingNode(
    @Nullable AccessibilityNodeInfoCompat node,
    @Nullable View view) {
  if (node == null || view == null) {
    return false;
  }

  if (!node.isVisibleToUser()) {
    return false;
  }

  int important = ViewCompat.getImportantForAccessibility(view);
  if (important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS ||
      (important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO &&
          node.getChildCount() <= 0)) {
    return false;
  }

  return node.isCheckable() || hasText(node) || hasNonActionableSpeakingDescendants(node, view);
}
 

/**
 * Determines if the provided {@link View} and {@link AccessibilityNodeInfoCompat} meet the
 * criteria for gaining accessibility focus.
 *
 * @param view The {@link View} to evaluate
 * @param node The {@link AccessibilityNodeInfoCompat} to evaluate
 * @return {@code true} if it is possible to gain accessibility focus
 */
public static boolean isAccessibilityFocusable(
    @Nullable AccessibilityNodeInfoCompat node,
    @Nullable View view) {
  if (node == null || view == null) {
    return false;
  }

  // Never focus invisible nodes.
  if (!node.isVisibleToUser()) {
    return false;
  }

  // Always focus "actionable" nodes.
  if (isActionableForAccessibility(node)) {
    return true;
  }

  // only focus top-level list items with non-actionable speaking children.
  return isTopLevelScrollItem(node, view) && isSpeakingNode(node, view);
}
 

/**
 * Formats {@code node} and its descendants, appending the result
 * to {@code sb}.
 */
private void formatSubtree(AccessibilityNodeInfoCompat node,
        Editable result) {
    if (!node.isVisibleToUser()) {
        return;
    }

    BrailleRule rule = mRuleRepository.find(node);
    SpannableStringBuilder subtreeResult = new SpannableStringBuilder();
    rule.format(subtreeResult, mContext, node);
    if (rule.includeChildren(node, mContext)) {
        int childCount = node.getChildCount();
        for (int i = 0; i < childCount; ++i) {
            AccessibilityNodeInfoCompat child = node.getChild(i);
            if (child == null) {
                continue;
            }
            formatSubtree(child, subtreeResult);
            child.recycle();
        }
    }
    if (!TextUtils.isEmpty(subtreeResult)) {
        // If the node is accessibility focused, add the focus span
        // here to cover the node and its formatted children.
        // This is a fallback in case the formatting rule hasn't set
        // focus by itself.
        if (node.isAccessibilityFocused()
                && subtreeResult.getSpans(0, subtreeResult.length(),
                        DisplaySpans.FocusSpan.class).length == 0) {
            DisplaySpans.addFocus(subtreeResult, 0,
                    subtreeResult.length());
        }
        addNodeSpanForUncovered(node, subtreeResult);
        StringUtils.appendWithSpaces(result, subtreeResult);
    }
}
 

private boolean onPanLeftOverflowInternal(DisplayManager.Content content) {
    AccessibilityNodeInfoCompat currentNode = null;
    AccessibilityNodeInfoCompat firstNode = null;
    try {
        // If the currently focused node is a web view, we attempt
        // to delegate navigation to the web view first.
        currentNode = getFocusedNode(true);
        if (currentNode != null
                && WebInterfaceUtils.hasLegacyWebContent(currentNode)
                && WebInterfaceUtils.performNavigationAtGranularityAction(
                        currentNode, DIRECTION_BACKWARD,
                        AccessibilityNodeInfoCompat
                        .MOVEMENT_GRANULARITY_LINE)) {
            return true;
        }

        // Check if we need to scroll.
        if (autoScrollItem(currentNode,
                AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD)) {
            return true;
        }

        firstNode = AccessibilityNodeInfoUtils.refreshNode(
                content.getFirstNode());
        // If the content doesn't have a first node, fall back on the
        // currently focused node.
        if (firstNode == null || !firstNode.isVisibleToUser()) {
            AccessibilityNodeInfoUtils.recycleNodes(firstNode);
            firstNode = currentNode;
            currentNode = null;
        }
        if (firstNode == null) {
            return false;
        }
        return moveFocus(firstNode, DIRECTION_BACKWARD);
    } finally {
        AccessibilityNodeInfoUtils.recycleNodes(currentNode, firstNode);
    }
}
 

public static String getIgnoredReasons(View view) {
  int important = ViewCompat.getImportantForAccessibility(view);

  if (important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO) {
    return "View has importantForAccessibility set to 'NO'.";
  }

  if (important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS) {
    return "View has importantForAccessibility set to 'NO_HIDE_DESCENDANTS'.";
  }

  ViewParent parent = view.getParent();
  while (parent instanceof View) {
    if (ViewCompat.getImportantForAccessibility((View) parent)
            == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS) {
      return "An ancestor View has importantForAccessibility set to 'NO_HIDE_DESCENDANTS'.";
    }
    parent = parent.getParent();
  }

  AccessibilityNodeInfoCompat node = createNodeInfoFromView(view);
  try {
    if (!node.isVisibleToUser()) {
      return "View is not visible.";
    }

    if (AccessibilityUtil.isAccessibilityFocusable(node, view)) {
      return "View is actionable, but has no description.";
    }

    if (AccessibilityUtil.hasText(node)) {
      return "View is not actionable, and an ancestor View has co-opted its description.";
    }

    return "View is not actionable and has no description.";
  } finally {
    node.recycle();
  }
}
 

/**
 * Gets a description of the properties of a node.
 */
public static CharSequence nodeDebugDescription(AccessibilityNodeInfoCompat node) {
    StringBuilder sb = new StringBuilder();
    sb.append(node.getWindowId());

    if (node.getClassName() != null) {
        appendSimpleName(sb, node.getClassName());
    } else {
        sb.append("??");
    }

    if (!node.isVisibleToUser()) {
        sb.append(":invisible");
    }

    if (node.getText() != null) {
        sb.append(":");
        sb.append(node.getText().toString().trim());
    }

    if (node.getContentDescription() != null) {
        sb.append(":");
        sb.append(node.getContentDescription().toString().trim());
    }

    int actions = node.getActions();
    if (actions != 0) {
        sb.append(":");
        if ((actions & AccessibilityNodeInfoCompat.ACTION_FOCUS) != 0) {
            sb.append("F");
        }
        if ((actions & AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS) != 0) {
            sb.append("A");
        }
        if ((actions & AccessibilityNodeInfoCompat.ACTION_CLEAR_ACCESSIBILITY_FOCUS) != 0) {
            sb.append("a");
        }
        if ((actions & AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD) != 0) {
            sb.append("-");
        }
        if ((actions & AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD) != 0) {
            sb.append("+");
        }
    }

    if (node.isCheckable()) {
        sb.append(":");
        if (node.isChecked()) {
            sb.append("(X)");
        } else {
            sb.append("( )");
        }
    }

    if (node.isFocusable()) {
        sb.append(":focusable");
    }

    if (node.isFocused()) {
        sb.append(":focused");
    }

    if (node.isSelected()) {
        sb.append(":selected");
    }

    if (node.isClickable()) {
        sb.append(":clickable");
    }

    if (node.isLongClickable()) {
        sb.append(":longClickable");
    }

    if (node.isAccessibilityFocused()) {
        sb.append(":accessibilityFocused");
    }

    if (!node.isEnabled()) {
        sb.append(":disabled");
    }

    return sb.toString();
}
 

public static boolean getIgnored(View view) {
  int important = ViewCompat.getImportantForAccessibility(view);
  if (important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO ||
      important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS) {
    return true;
  }

  // Go all the way up the tree to make sure no parent has hidden its descendants
  ViewParent parent = view.getParent();
  while (parent instanceof View) {
    if (ViewCompat.getImportantForAccessibility((View) parent)
        == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS) {
      return true;
    }
    parent = parent.getParent();
  }

  AccessibilityNodeInfoCompat node = createNodeInfoFromView(view);
  try {
    if (!node.isVisibleToUser()) {
      return true;
    }

    if (AccessibilityUtil.isAccessibilityFocusable(node, view)) {
      if (node.getChildCount() <= 0) {
        // Leaves that are accessibility focusable are never ignored, even if they don't have a
        // speakable description
        return false;
      } else if (AccessibilityUtil.isSpeakingNode(node, view)) {
        // Node is focusable and has something to speak
        return false;
      }

      // Node is focusable and has nothing to speak
      return true;
    }

    // If this node has no focusable ancestors, but it still has text,
    // then it should receive focus from navigation and be read aloud.
    if (!AccessibilityUtil.hasFocusableAncestor(node, view) && AccessibilityUtil.hasText(node)) {
      return false;
    }

    return true;
  } finally {
    node.recycle();
  }
}
 

/**
 * Helper method that returns {@code true} if the specified node is visible
 * to the user or if the current SDK doesn't support checking visibility.
 */
public static  boolean isVisibleOrLegacy(AccessibilityNodeInfoCompat node) {
    return (!AccessibilityNodeInfoUtils.SUPPORTS_VISIBILITY || node.isVisibleToUser());
}