AccessibilityNodeInfoWrapper.java

/*
 * Copyright (c) 2014-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

package com.facebook.stetho.inspector.elements.android;

import android.support.annotation.Nullable;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat.AccessibilityActionCompat;
import android.text.TextUtils;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.widget.EditText;

import com.facebook.stetho.common.android.AccessibilityUtil;

public final class AccessibilityNodeInfoWrapper {

  public AccessibilityNodeInfoWrapper() {
  }

  public static AccessibilityNodeInfoCompat createNodeInfoFromView(View view) {
    AccessibilityNodeInfoCompat nodeInfo = AccessibilityNodeInfoCompat.obtain();
    ViewCompat.onInitializeAccessibilityNodeInfo(view, nodeInfo);
    return nodeInfo;
  }

  public static boolean getIsAccessibilityFocused(View view) {
    AccessibilityNodeInfoCompat node = createNodeInfoFromView(view);
    boolean isAccessibilityFocused = node.isAccessibilityFocused();
    node.recycle();

    return isAccessibilityFocused;
  }

  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();
    }
  }

  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();
    }
  }

  @Nullable
  public static String getFocusableReasons(View view) {
    AccessibilityNodeInfoCompat node = createNodeInfoFromView(view);
    try {
      boolean hasText = AccessibilityUtil.hasText(node);
      boolean isCheckable = node.isCheckable();
      boolean hasNonActionableSpeakingDescendants =
          AccessibilityUtil.hasNonActionableSpeakingDescendants(node, view);

      if (AccessibilityUtil.isActionableForAccessibility(node)) {
        if (node.getChildCount() <= 0) {
          return "View is actionable and has no children.";
        } else if (hasText) {
          return "View is actionable and has a description.";
        } else if (isCheckable) {
          return "View is actionable and checkable.";
        } else if (hasNonActionableSpeakingDescendants) {
          return "View is actionable and has non-actionable descendants with descriptions.";
        }
      }

      if (AccessibilityUtil.isTopLevelScrollItem(node, view)) {
        if (hasText) {
          return "View is a direct child of a scrollable container and has a description.";
        } else if (isCheckable) {
          return "View is a direct child of a scrollable container and is checkable.";
        } else if (hasNonActionableSpeakingDescendants) {
          return
              "View is a direct child of a scrollable container and has non-actionable " +
              "descendants with descriptions.";
        }
      }

      if (hasText) {
        return "View has a description and is not actionable, but has no actionable ancestor.";
      }

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

  @Nullable
  public static String getActions(View view) {
    AccessibilityNodeInfoCompat node = createNodeInfoFromView(view);
    try {
      final StringBuilder actionLabels = new StringBuilder();
      final String separator = ", ";

      for (AccessibilityActionCompat action : node.getActionList()) {
        if (actionLabels.length() > 0) {
          actionLabels.append(separator);
        }
        switch (action.getId()) {
          case AccessibilityNodeInfoCompat.ACTION_FOCUS:
            actionLabels.append("focus");
            break;
          case AccessibilityNodeInfoCompat.ACTION_CLEAR_FOCUS:
            actionLabels.append("clear-focus");
            break;
          case AccessibilityNodeInfoCompat.ACTION_SELECT:
            actionLabels.append("select");
            break;
          case AccessibilityNodeInfoCompat.ACTION_CLEAR_SELECTION:
            actionLabels.append("clear-selection");
            break;
          case AccessibilityNodeInfoCompat.ACTION_CLICK:
            actionLabels.append("click");
            break;
          case AccessibilityNodeInfoCompat.ACTION_LONG_CLICK:
            actionLabels.append("long-click");
            break;
          case AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS:
            actionLabels.append("accessibility-focus");
            break;
          case AccessibilityNodeInfoCompat.ACTION_CLEAR_ACCESSIBILITY_FOCUS:
            actionLabels.append("clear-accessibility-focus");
            break;
          case AccessibilityNodeInfoCompat.ACTION_NEXT_AT_MOVEMENT_GRANULARITY:
            actionLabels.append("next-at-movement-granularity");
            break;
          case AccessibilityNodeInfoCompat.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY:
            actionLabels.append("previous-at-movement-granularity");
            break;
          case AccessibilityNodeInfoCompat.ACTION_NEXT_HTML_ELEMENT:
            actionLabels.append("next-html-element");
            break;
          case AccessibilityNodeInfoCompat.ACTION_PREVIOUS_HTML_ELEMENT:
            actionLabels.append("previous-html-element");
            break;
          case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD:
            actionLabels.append("scroll-forward");
            break;
          case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD:
            actionLabels.append("scroll-backward");
            break;
          case AccessibilityNodeInfoCompat.ACTION_CUT:
            actionLabels.append("cut");
            break;
          case AccessibilityNodeInfoCompat.ACTION_COPY:
            actionLabels.append("copy");
            break;
          case AccessibilityNodeInfoCompat.ACTION_PASTE:
            actionLabels.append("paste");
            break;
          case AccessibilityNodeInfoCompat.ACTION_SET_SELECTION:
            actionLabels.append("set-selection");
            break;
          default:
            CharSequence label = action.getLabel();
            if (label != null) {
              actionLabels.append(label);
            } else {
              actionLabels.append("unknown");
            }
            break;
        }
      }

      return actionLabels.length() > 0 ? actionLabels.toString() : null;
    } finally {
      node.recycle();
    }
  }

  @Nullable
  public static CharSequence getDescription(View view) {
    AccessibilityNodeInfoCompat node = createNodeInfoFromView(view);
    try {
      CharSequence contentDescription = node.getContentDescription();
      CharSequence nodeText = node.getText();

      boolean hasNodeText = !TextUtils.isEmpty(nodeText);
      boolean isEditText = view instanceof EditText;

      // EditText's prioritize their own text content over a contentDescription
      if (!TextUtils.isEmpty(contentDescription) && (!isEditText || !hasNodeText)) {
        return contentDescription;
      }

      if (hasNodeText) {
        return nodeText;
      }

      // If there are child views and no contentDescription the text of all non-focusable children,
      // comma separated, becomes the description.
      if (view instanceof ViewGroup) {
        final StringBuilder concatChildDescription = new StringBuilder();
        final String separator = ", ";
        ViewGroup viewGroup = (ViewGroup) view;

        for (int i = 0, count = viewGroup.getChildCount(); i < count; i++) {
          final View child = viewGroup.getChildAt(i);

          AccessibilityNodeInfoCompat childNodeInfo = AccessibilityNodeInfoCompat.obtain();
          ViewCompat.onInitializeAccessibilityNodeInfo(child, childNodeInfo);

          CharSequence childNodeDescription = null;
          if (AccessibilityUtil.isSpeakingNode(childNodeInfo, child) &&
              !AccessibilityUtil.isAccessibilityFocusable(childNodeInfo, child)) {
            childNodeDescription = getDescription(child);
          }

          if (!TextUtils.isEmpty(childNodeDescription)) {
            if (concatChildDescription.length() > 0) {
              concatChildDescription.append(separator);
            }
            concatChildDescription.append(childNodeDescription);
          }
          childNodeInfo.recycle();
        }

        return concatChildDescription.length() > 0 ? concatChildDescription.toString() : null;
      }

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