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AccessibilityNodeInfoDumper.javaAPI DocAndroid 5.1 API11265Thu Mar 12 22:22:08 GMT 2015com.android.uiautomator.core

AccessibilityNodeInfoDumper

public class AccessibilityNodeInfoDumper extends Object
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Fields Summary
private static final String
LOGTAG
private static final String[]
NAF_EXCLUDED_CLASSES
Constructors Summary
Methods Summary
private static booleanchildNafCheck(android.view.accessibility.AccessibilityNodeInfo node)
This should be used when it's already determined that the node is NAF and a further check of its children is in order. A node maybe a container such as LinerLayout and may be set to be clickable but have no text or content description but it is counting on one of its children to fulfill the requirement for being accessibility friendly by having one or more of its children fill the text or content-description. Such a combination is considered by this dumper as acceptable for accessibility.

param
node
return
false if node fails the check.

        int childCount = node.getChildCount();
        for (int x = 0; x < childCount; x++) {
            AccessibilityNodeInfo childNode = node.getChild(x);

            if (!safeCharSeqToString(childNode.getContentDescription()).isEmpty()
                    || !safeCharSeqToString(childNode.getText()).isEmpty())
                return true;

            if (childNafCheck(childNode))
                return true;
        }
        return false;
private static voiddumpNodeRec(android.view.accessibility.AccessibilityNodeInfo node, org.xmlpull.v1.XmlSerializer serializer, int index, int width, int height)

        serializer.startTag("", "node");
        if (!nafExcludedClass(node) && !nafCheck(node))
            serializer.attribute("", "NAF", Boolean.toString(true));
        serializer.attribute("", "index", Integer.toString(index));
        serializer.attribute("", "text", safeCharSeqToString(node.getText()));
        serializer.attribute("", "resource-id", safeCharSeqToString(node.getViewIdResourceName()));
        serializer.attribute("", "class", safeCharSeqToString(node.getClassName()));
        serializer.attribute("", "package", safeCharSeqToString(node.getPackageName()));
        serializer.attribute("", "content-desc", safeCharSeqToString(node.getContentDescription()));
        serializer.attribute("", "checkable", Boolean.toString(node.isCheckable()));
        serializer.attribute("", "checked", Boolean.toString(node.isChecked()));
        serializer.attribute("", "clickable", Boolean.toString(node.isClickable()));
        serializer.attribute("", "enabled", Boolean.toString(node.isEnabled()));
        serializer.attribute("", "focusable", Boolean.toString(node.isFocusable()));
        serializer.attribute("", "focused", Boolean.toString(node.isFocused()));
        serializer.attribute("", "scrollable", Boolean.toString(node.isScrollable()));
        serializer.attribute("", "long-clickable", Boolean.toString(node.isLongClickable()));
        serializer.attribute("", "password", Boolean.toString(node.isPassword()));
        serializer.attribute("", "selected", Boolean.toString(node.isSelected()));
        serializer.attribute("", "bounds", AccessibilityNodeInfoHelper.getVisibleBoundsInScreen(
                node, width, height).toShortString());
        int count = node.getChildCount();
        for (int i = 0; i < count; i++) {
            AccessibilityNodeInfo child = node.getChild(i);
            if (child != null) {
                if (child.isVisibleToUser()) {
                    dumpNodeRec(child, serializer, i, width, height);
                    child.recycle();
                } else {
                    Log.i(LOGTAG, String.format("Skipping invisible child: %s", child.toString()));
                }
            } else {
                Log.i(LOGTAG, String.format("Null child %d/%d, parent: %s",
                        i, count, node.toString()));
            }
        }
        serializer.endTag("", "node");
public static voiddumpWindowToFile(android.view.accessibility.AccessibilityNodeInfo root, int rotation, int width, int height)
Using {@link AccessibilityNodeInfo} this method will walk the layout hierarchy and generates an xml dump into the /data/local/window_dump.xml

param
root The root accessibility node.
param
rotation The rotaion of current display
param
width The pixel width of current display
param
height The pixel height of current display


                                                        
          
                
        File baseDir = new File(Environment.getDataDirectory(), "local");
        if (!baseDir.exists()) {
            baseDir.mkdir();
            baseDir.setExecutable(true, false);
            baseDir.setWritable(true, false);
            baseDir.setReadable(true, false);
        }
        dumpWindowToFile(root,
                new File(new File(Environment.getDataDirectory(), "local"), "window_dump.xml"),
                rotation, width, height);
public static voiddumpWindowToFile(android.view.accessibility.AccessibilityNodeInfo root, java.io.File dumpFile, int rotation, int width, int height)
Using {@link AccessibilityNodeInfo} this method will walk the layout hierarchy and generates an xml dump to the location specified by dumpFile

param
root The root accessibility node.
param
dumpFile The file to dump to.
param
rotation The rotaion of current display
param
width The pixel width of current display
param
height The pixel height of current display

        if (root == null) {
            return;
        }
        final long startTime = SystemClock.uptimeMillis();
        try {
            FileWriter writer = new FileWriter(dumpFile);
            XmlSerializer serializer = Xml.newSerializer();
            StringWriter stringWriter = new StringWriter();
            serializer.setOutput(stringWriter);
            serializer.startDocument("UTF-8", true);
            serializer.startTag("", "hierarchy");
            serializer.attribute("", "rotation", Integer.toString(rotation));
            dumpNodeRec(root, serializer, 0, width, height);
            serializer.endTag("", "hierarchy");
            serializer.endDocument();
            writer.write(stringWriter.toString());
            writer.close();
        } catch (IOException e) {
            Log.e(LOGTAG, "failed to dump window to file", e);
        }
        final long endTime = SystemClock.uptimeMillis();
        Log.w(LOGTAG, "Fetch time: " + (endTime - startTime) + "ms");
private static booleannafCheck(android.view.accessibility.AccessibilityNodeInfo node)
We're looking for UI controls that are enabled, clickable but have no text nor content-description. Such controls configuration indicate an interactive control is present in the UI and is most likely not accessibility friendly. We refer to such controls here as NAF controls (Not Accessibility Friendly)

param
node
return
false if a node fails the check, true if all is OK

        boolean isNaf = node.isClickable() && node.isEnabled()
                && safeCharSeqToString(node.getContentDescription()).isEmpty()
                && safeCharSeqToString(node.getText()).isEmpty();

        if (!isNaf)
            return true;

        // check children since sometimes the containing element is clickable
        // and NAF but a child's text or description is available. Will assume
        // such layout as fine.
        return childNafCheck(node);
private static booleannafExcludedClass(android.view.accessibility.AccessibilityNodeInfo node)
The list of classes to exclude my not be complete. We're attempting to only reduce noise from standard layout classes that may be falsely configured to accept clicks and are also enabled.

param
node
return
true if node is excluded.

        String className = safeCharSeqToString(node.getClassName());
        for(String excludedClassName : NAF_EXCLUDED_CLASSES) {
            if(className.endsWith(excludedClassName))
                return true;
        }
        return false;
private static java.lang.StringsafeCharSeqToString(java.lang.CharSequence cs)

        if (cs == null)
            return "";
        else {
            return stripInvalidXMLChars(cs);
        }
private static java.lang.StringstripInvalidXMLChars(java.lang.CharSequence cs)

        StringBuffer ret = new StringBuffer();
        char ch;
        /* http://www.w3.org/TR/xml11/#charsets
        [#x1-#x8], [#xB-#xC], [#xE-#x1F], [#x7F-#x84], [#x86-#x9F], [#xFDD0-#xFDDF],
        [#x1FFFE-#x1FFFF], [#x2FFFE-#x2FFFF], [#x3FFFE-#x3FFFF],
        [#x4FFFE-#x4FFFF], [#x5FFFE-#x5FFFF], [#x6FFFE-#x6FFFF],
        [#x7FFFE-#x7FFFF], [#x8FFFE-#x8FFFF], [#x9FFFE-#x9FFFF],
        [#xAFFFE-#xAFFFF], [#xBFFFE-#xBFFFF], [#xCFFFE-#xCFFFF],
        [#xDFFFE-#xDFFFF], [#xEFFFE-#xEFFFF], [#xFFFFE-#xFFFFF],
        [#x10FFFE-#x10FFFF].
         */
        for (int i = 0; i < cs.length(); i++) {
            ch = cs.charAt(i);

            if((ch >= 0x1 && ch <= 0x8) || (ch >= 0xB && ch <= 0xC) || (ch >= 0xE && ch <= 0x1F) ||
                    (ch >= 0x7F && ch <= 0x84) || (ch >= 0x86 && ch <= 0x9f) ||
                    (ch >= 0xFDD0 && ch <= 0xFDDF) || (ch >= 0x1FFFE && ch <= 0x1FFFF) ||
                    (ch >= 0x2FFFE && ch <= 0x2FFFF) || (ch >= 0x3FFFE && ch <= 0x3FFFF) ||
                    (ch >= 0x4FFFE && ch <= 0x4FFFF) || (ch >= 0x5FFFE && ch <= 0x5FFFF) ||
                    (ch >= 0x6FFFE && ch <= 0x6FFFF) || (ch >= 0x7FFFE && ch <= 0x7FFFF) ||
                    (ch >= 0x8FFFE && ch <= 0x8FFFF) || (ch >= 0x9FFFE && ch <= 0x9FFFF) ||
                    (ch >= 0xAFFFE && ch <= 0xAFFFF) || (ch >= 0xBFFFE && ch <= 0xBFFFF) ||
                    (ch >= 0xCFFFE && ch <= 0xCFFFF) || (ch >= 0xDFFFE && ch <= 0xDFFFF) ||
                    (ch >= 0xEFFFE && ch <= 0xEFFFF) || (ch >= 0xFFFFE && ch <= 0xFFFFF) ||
                    (ch >= 0x10FFFE && ch <= 0x10FFFF))
                ret.append(".");
            else
                ret.append(ch);
        }
        return ret.toString();