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      1 /*
      2  * Copyright (C) 2013 DroidDriver committers
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package io.appium.droiddriver.finders;
     17 
     18 import android.util.Log;
     19 
     20 import org.w3c.dom.DOMException;
     21 import org.w3c.dom.Document;
     22 import org.w3c.dom.Element;
     23 
     24 import java.io.BufferedOutputStream;
     25 import java.util.HashMap;
     26 import java.util.Map;
     27 
     28 import javax.xml.parsers.DocumentBuilderFactory;
     29 import javax.xml.parsers.ParserConfigurationException;
     30 import javax.xml.transform.OutputKeys;
     31 import javax.xml.transform.Transformer;
     32 import javax.xml.transform.TransformerFactory;
     33 import javax.xml.transform.dom.DOMSource;
     34 import javax.xml.transform.stream.StreamResult;
     35 import javax.xml.xpath.XPath;
     36 import javax.xml.xpath.XPathConstants;
     37 import javax.xml.xpath.XPathExpression;
     38 import javax.xml.xpath.XPathExpressionException;
     39 import javax.xml.xpath.XPathFactory;
     40 
     41 import io.appium.droiddriver.UiElement;
     42 import io.appium.droiddriver.base.BaseUiElement;
     43 import io.appium.droiddriver.exceptions.DroidDriverException;
     44 import io.appium.droiddriver.exceptions.ElementNotFoundException;
     45 import io.appium.droiddriver.util.FileUtils;
     46 import io.appium.droiddriver.util.Logs;
     47 import io.appium.droiddriver.util.Preconditions;
     48 import io.appium.droiddriver.util.Strings;
     49 
     50 /**
     51  * Find matching UiElement by XPath.
     52  */
     53 public class ByXPath implements Finder {
     54   private static final XPath XPATH_COMPILER = XPathFactory.newInstance().newXPath();
     55   // document needs to be static so that when buildDomNode is called recursively
     56   // on children they are in the same document to be appended.
     57   private static Document document;
     58   // The two maps should be kept in sync
     59   private static final Map<BaseUiElement<?, ?>, Element> TO_DOM_MAP =
     60       new HashMap<BaseUiElement<?, ?>, Element>();
     61   private static final Map<Element, BaseUiElement<?, ?>> FROM_DOM_MAP =
     62       new HashMap<Element, BaseUiElement<?, ?>>();
     63 
     64   public static void clearData() {
     65     TO_DOM_MAP.clear();
     66     FROM_DOM_MAP.clear();
     67     document = null;
     68   }
     69 
     70   private final String xPathString;
     71   private final XPathExpression xPathExpression;
     72 
     73   protected ByXPath(String xPathString) {
     74     this.xPathString = Preconditions.checkNotNull(xPathString);
     75     try {
     76       xPathExpression = XPATH_COMPILER.compile(xPathString);
     77     } catch (XPathExpressionException e) {
     78       throw new DroidDriverException("xPathString=" + xPathString, e);
     79     }
     80   }
     81 
     82   @Override
     83   public String toString() {
     84     return Strings.toStringHelper(this).addValue(xPathString).toString();
     85   }
     86 
     87   @Override
     88   public UiElement find(UiElement context) {
     89     Element domNode = getDomNode((BaseUiElement<?, ?>) context, UiElement.VISIBLE);
     90     try {
     91       getDocument().appendChild(domNode);
     92       Element foundNode = (Element) xPathExpression.evaluate(domNode, XPathConstants.NODE);
     93       if (foundNode == null) {
     94         Logs.log(Log.DEBUG, "XPath evaluation returns null for " + xPathString);
     95         throw new ElementNotFoundException(this);
     96       }
     97 
     98       UiElement match = FROM_DOM_MAP.get(foundNode);
     99       Logs.log(Log.INFO, "Found match: " + match);
    100       return match;
    101     } catch (XPathExpressionException e) {
    102       throw new ElementNotFoundException(this, e);
    103     } finally {
    104       try {
    105         getDocument().removeChild(domNode);
    106       } catch (DOMException e) {
    107         Logs.log(Log.ERROR, e, "Failed to clear document");
    108         document = null; // getDocument will create new
    109       }
    110     }
    111   }
    112 
    113   private static Document getDocument() {
    114     if (document == null) {
    115       try {
    116         document = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
    117       } catch (ParserConfigurationException e) {
    118         throw new DroidDriverException(e);
    119       }
    120     }
    121     return document;
    122   }
    123 
    124   /**
    125    * Returns the DOM node representing this UiElement.
    126    */
    127   private static Element getDomNode(BaseUiElement<?, ?> uiElement,
    128       Predicate<? super UiElement> predicate) {
    129     Element domNode = TO_DOM_MAP.get(uiElement);
    130     if (domNode == null) {
    131       domNode = buildDomNode(uiElement, predicate);
    132     }
    133     return domNode;
    134   }
    135 
    136   private static Element buildDomNode(BaseUiElement<?, ?> uiElement,
    137       Predicate<? super UiElement> predicate) {
    138     String className = uiElement.getClassName();
    139     if (className == null) {
    140       className = "UNKNOWN";
    141     }
    142     Element element = getDocument().createElement(XPaths.tag(className));
    143     TO_DOM_MAP.put(uiElement, element);
    144     FROM_DOM_MAP.put(element, uiElement);
    145 
    146     setAttribute(element, Attribute.CLASS, className);
    147     setAttribute(element, Attribute.RESOURCE_ID, uiElement.getResourceId());
    148     setAttribute(element, Attribute.PACKAGE, uiElement.getPackageName());
    149     setAttribute(element, Attribute.CONTENT_DESC, uiElement.getContentDescription());
    150     setAttribute(element, Attribute.TEXT, uiElement.getText());
    151     setAttribute(element, Attribute.CHECKABLE, uiElement.isCheckable());
    152     setAttribute(element, Attribute.CHECKED, uiElement.isChecked());
    153     setAttribute(element, Attribute.CLICKABLE, uiElement.isClickable());
    154     setAttribute(element, Attribute.ENABLED, uiElement.isEnabled());
    155     setAttribute(element, Attribute.FOCUSABLE, uiElement.isFocusable());
    156     setAttribute(element, Attribute.FOCUSED, uiElement.isFocused());
    157     setAttribute(element, Attribute.SCROLLABLE, uiElement.isScrollable());
    158     setAttribute(element, Attribute.LONG_CLICKABLE, uiElement.isLongClickable());
    159     setAttribute(element, Attribute.PASSWORD, uiElement.isPassword());
    160     if (uiElement.hasSelection()) {
    161       element.setAttribute(Attribute.SELECTION_START.getName(),
    162           Integer.toString(uiElement.getSelectionStart()));
    163       element.setAttribute(Attribute.SELECTION_END.getName(),
    164           Integer.toString(uiElement.getSelectionEnd()));
    165     }
    166     setAttribute(element, Attribute.SELECTED, uiElement.isSelected());
    167     element.setAttribute(Attribute.BOUNDS.getName(), uiElement.getBounds().toShortString());
    168 
    169     // If we're dumping for debugging, add extra information
    170     if (!UiElement.VISIBLE.equals(predicate)) {
    171       if (!uiElement.isVisible()) {
    172         element.setAttribute(BaseUiElement.ATTRIB_NOT_VISIBLE, "");
    173       } else if (!uiElement.getVisibleBounds().equals(uiElement.getBounds())) {
    174         element.setAttribute(BaseUiElement.ATTRIB_VISIBLE_BOUNDS, uiElement.getVisibleBounds()
    175             .toShortString());
    176       }
    177     }
    178 
    179     for (BaseUiElement<?, ?> child : uiElement.getChildren(predicate)) {
    180       element.appendChild(getDomNode(child, predicate));
    181     }
    182     return element;
    183   }
    184 
    185   private static void setAttribute(Element element, Attribute attr, String value) {
    186     if (value != null) {
    187       element.setAttribute(attr.getName(), value);
    188     }
    189   }
    190 
    191   // add attribute only if it's true
    192   private static void setAttribute(Element element, Attribute attr, boolean value) {
    193     if (value) {
    194       element.setAttribute(attr.getName(), "");
    195     }
    196   }
    197 
    198   public static boolean dumpDom(String path, BaseUiElement<?, ?> uiElement) {
    199     BufferedOutputStream bos = null;
    200     try {
    201       bos = FileUtils.open(path);
    202       Transformer transformer = TransformerFactory.newInstance().newTransformer();
    203       transformer.setOutputProperty(OutputKeys.INDENT, "yes");
    204       // find() filters invisible UiElements, but this is for debugging and
    205       // invisible UiElements may be of interest.
    206       clearData();
    207       Element domNode = getDomNode(uiElement, null);
    208       transformer.transform(new DOMSource(domNode), new StreamResult(bos));
    209       Logs.log(Log.INFO, "Wrote dom to " + path);
    210     } catch (Exception e) {
    211       Logs.log(Log.ERROR, e, "Failed to transform node");
    212       return false;
    213     } finally {
    214       // We built DOM with invisible UiElements. Don't use it for find()!
    215       clearData();
    216       if (bos != null) {
    217         try {
    218           bos.close();
    219         } catch (Exception e) {
    220           // ignore
    221         }
    222       }
    223     }
    224     return true;
    225   }
    226 }
    227