consolidate XPath code into ByXPath

dumpUiElementTree now includes invisible UiElements

Change-Id: Ib7e1346e4e16dac0a05bb911aec4389483daaf8a

9 files changed, 61 insertions, 43 deletions

diff --git a/src/com/google/android/droiddriver/DroidDriver.java b/src/com/google/android/droiddriver/DroidDriver.java
index 5421718..cd1caca 100644
--- a/src/com/google/android/droiddriver/DroidDriver.java
+++ b/src/com/google/android/droiddriver/DroidDriver.java
@@ -124,6 +124,10 @@ public interface DroidDriver {
    * Dumps the UiElement tree to a file to help debug. The tree is based on the
    * last used root UiElement if it exists, otherwise
    * {@link #refreshUiElementTree} is called.
+   * <p>
+   * The dump may contain invisible UiElements that are not used in the finding
+   * algorithm.
+   * </p>
    *
    * @param path the path of file to save the tree
    * @return whether the dumping succeeded
diff --git a/src/com/google/android/droiddriver/base/BaseUiElement.java b/src/com/google/android/droiddriver/base/BaseUiElement.java
index 9cddc71..8bac986 100644
--- a/src/com/google/android/droiddriver/base/BaseUiElement.java
+++ b/src/com/google/android/droiddriver/base/BaseUiElement.java
@@ -21,12 +21,10 @@ import android.graphics.Rect;
 import com.google.android.droiddriver.UiElement;
 import com.google.android.droiddriver.actions.Action;
 import com.google.android.droiddriver.actions.ClickAction;
-import com.google.android.droiddriver.actions.InputInjector;
 import com.google.android.droiddriver.actions.SwipeAction;
 import com.google.android.droiddriver.actions.TextAction;
 import com.google.android.droiddriver.exceptions.ElementNotVisibleException;
 import com.google.android.droiddriver.finders.Attribute;
-import com.google.android.droiddriver.finders.ByXPath;
 import com.google.android.droiddriver.scroll.Direction.PhysicalDirection;
 import com.google.android.droiddriver.util.Logs;
 import com.google.common.base.Objects;
@@ -36,9 +34,6 @@ import com.google.common.base.Predicates;
 import com.google.common.collect.Collections2;
 import com.google.common.collect.ImmutableList;
 
-import org.w3c.dom.Element;
-
-import java.lang.ref.WeakReference;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Callable;
@@ -48,8 +43,6 @@ import java.util.concurrent.FutureTask;
  * Base UiElement that implements the common operations.
  */
 public abstract class BaseUiElement implements UiElement {
-  private WeakReference<Element> domNode;
-
   @SuppressWarnings("unchecked")
   @Override
   public <T> T get(Attribute attribute) {
@@ -236,6 +229,11 @@ public abstract class BaseUiElement implements UiElement {
     for (Attribute attr : Attribute.values()) {
       addAttribute(toStringHelper, attr, get(attr));
     }
+    if (!isVisible()) {
+      toStringHelper.addValue("NOT visible");
+    } else {
+      toStringHelper.add("visibleBounds", getVisibleBounds());
+    }
     return toStringHelper.toString();
   }
 
@@ -250,19 +248,4 @@ public abstract class BaseUiElement implements UiElement {
       }
     }
   }
-
-  /**
-   * Used internally in {@link ByXPath}. Returns the DOM node representing this
-   * UiElement. The DOM is constructed from the UiElement tree.
-   * <p>
-   * TODO: move this to {@link ByXPath}. This requires a BiMap using
-   * WeakReference for both keys and values, which is error-prone. This will be
-   * deferred until we decide whether to clear cache upon getRootElement.
-   */
-  public Element getDomNode() {
-    if (domNode == null || domNode.get() == null) {
-      domNode = new WeakReference<Element>(ByXPath.buildDomNode(this));
-    }
-    return domNode.get();
-  }
 }
diff --git a/src/com/google/android/droiddriver/finders/ByXPath.java b/src/com/google/android/droiddriver/finders/ByXPath.java
index dbe4363..a96bd51 100644
--- a/src/com/google/android/droiddriver/finders/ByXPath.java
+++ b/src/com/google/android/droiddriver/finders/ByXPath.java
@@ -25,6 +25,9 @@ import com.google.android.droiddriver.util.FileUtils;
 import com.google.android.droiddriver.util.Logs;
 import com.google.common.base.Objects;
 import com.google.common.base.Preconditions;
+import com.google.common.base.Predicate;
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
 
 import org.w3c.dom.DOMException;
 import org.w3c.dom.Document;
@@ -50,10 +53,17 @@ import javax.xml.xpath.XPathFactory;
  */
 public class ByXPath implements Finder {
   private static final XPath XPATH_COMPILER = XPathFactory.newInstance().newXPath();
-  private static final String UI_ELEMENT = "UiElement";
   // document needs to be static so that when buildDomNode is called recursively
   // on children they are in the same document to be appended.
+  // TODO: move the below two to DroidDriverContext?
   private static Document document;
+  private static BiMap<BaseUiElement, Element> domBiMap = HashBiMap.create();
+
+  public static void clearData() {
+    domBiMap.clear();
+    document = null;
+  }
+
   private final String xPathString;
   private final XPathExpression xPathExpression;
 
@@ -73,7 +83,7 @@ public class ByXPath implements Finder {
 
   @Override
   public UiElement find(UiElement context) {
-    Element domNode = ((BaseUiElement) context).getDomNode();
+    Element domNode = getDomNode((BaseUiElement) context, UiElement.VISIBLE);
     try {
       getDocument().appendChild(domNode);
       Element foundNode = (Element) xPathExpression.evaluate(domNode, XPathConstants.NODE);
@@ -82,7 +92,7 @@ public class ByXPath implements Finder {
         throw new ElementNotFoundException(this);
       }
 
-      UiElement match = (UiElement) foundNode.getUserData(UI_ELEMENT);
+      UiElement match = domBiMap.inverse().get(foundNode);
       Logs.log(Log.INFO, "Found match: " + match);
       return match;
     } catch (XPathExpressionException e) {
@@ -109,15 +119,24 @@ public class ByXPath implements Finder {
   }
 
   /**
-   * Used internally in {@link BaseUiElement}.
+   * Returns the DOM node representing this UiElement.
    */
-  public static Element buildDomNode(BaseUiElement uiElement) {
+  private static Element getDomNode(BaseUiElement uiElement, Predicate<? super UiElement> predicate) {
+    Element domNode = domBiMap.get(uiElement);
+    if (domNode == null) {
+      domNode = buildDomNode(uiElement, predicate);
+    }
+    return domNode;
+  }
+
+  private static Element buildDomNode(BaseUiElement uiElement,
+      Predicate<? super UiElement> predicate) {
     String className = uiElement.getClassName();
     if (className == null) {
       className = "UNKNOWN";
     }
     Element element = getDocument().createElement(XPaths.tag(className));
-    element.setUserData(UI_ELEMENT, uiElement, null /* UserDataHandler */);
+    domBiMap.put(uiElement, element);
 
     setAttribute(element, Attribute.CLASS, className);
     setAttribute(element, Attribute.RESOURCE_ID, uiElement.getResourceId());
@@ -136,12 +155,8 @@ public class ByXPath implements Finder {
     setAttribute(element, Attribute.SELECTED, uiElement.isSelected());
     element.setAttribute(Attribute.BOUNDS.getName(), uiElement.getBounds().toShortString());
 
-    // TODO: Make VISIBLE optional so that the DOM dump contains all children.
-    // This is especially useful for InstrumentationDriver which sees more than
-    // uiautomatorviewer does. For now users can temporarily change VISIBLE to
-    // null, rebuild test apk and run to get a more comprehensive dump.
-    for (BaseUiElement child : uiElement.getChildren(UiElement.VISIBLE)) {
-      element.appendChild(child.getDomNode());
+    for (BaseUiElement child : uiElement.getChildren(predicate)) {
+      element.appendChild(getDomNode(child, predicate));
     }
     return element;
   }
@@ -160,17 +175,22 @@ public class ByXPath implements Finder {
   }
 
   public static boolean dumpDom(String path, BaseUiElement uiElement) {
+    // find() filters invisible UiElements, but this is for debugging and
+    // invisible UiElements may be of interest.
+    clearData();
     BufferedOutputStream bos = null;
     try {
       bos = FileUtils.open(path);
       Transformer transformer = TransformerFactory.newInstance().newTransformer();
       transformer.setOutputProperty(OutputKeys.INDENT, "yes");
-      transformer.transform(new DOMSource(uiElement.getDomNode()), new StreamResult(bos));
+      transformer.transform(new DOMSource(getDomNode(uiElement, null)), new StreamResult(bos));
       Logs.log(Log.INFO, "Wrote dom to " + path);
     } catch (Exception e) {
       Logs.log(Log.ERROR, e, "Failed to transform node");
       return false;
     } finally {
+      // We built DOM with invisible UiElements. Don't use it for find()!
+      clearData();
       if (bos != null) {
         try {
           bos.close();
diff --git a/src/com/google/android/droiddriver/instrumentation/InstrumentationContext.java b/src/com/google/android/droiddriver/instrumentation/InstrumentationContext.java
index 27fa975..f535ccb 100644
--- a/src/com/google/android/droiddriver/instrumentation/InstrumentationContext.java
+++ b/src/com/google/android/droiddriver/instrumentation/InstrumentationContext.java
@@ -25,6 +25,7 @@ import android.view.View;
 import com.google.android.droiddriver.actions.InputInjector;
 import com.google.android.droiddriver.base.DroidDriverContext;
 import com.google.android.droiddriver.exceptions.ActionException;
+import com.google.android.droiddriver.finders.ByXPath;
 import com.google.common.collect.MapMaker;
 
 import java.util.Map;
@@ -80,5 +81,6 @@ class InstrumentationContext implements DroidDriverContext {
   @Override
   public void clearData() {
     map.clear();
+    ByXPath.clearData();
   }
 }
diff --git a/src/com/google/android/droiddriver/instrumentation/InstrumentationDriver.java b/src/com/google/android/droiddriver/instrumentation/InstrumentationDriver.java
index 11cf461..c8630ec 100644
--- a/src/com/google/android/droiddriver/instrumentation/InstrumentationDriver.java
+++ b/src/com/google/android/droiddriver/instrumentation/InstrumentationDriver.java
@@ -19,12 +19,10 @@ package com.google.android.droiddriver.instrumentation;
 import android.app.Activity;
 import android.app.Instrumentation;
 import android.graphics.Bitmap;
+import android.graphics.Bitmap.Config;
 import android.graphics.Canvas;
-import android.graphics.Matrix;
-import android.graphics.Paint;
 import android.graphics.Rect;
 import android.graphics.RectF;
-import android.graphics.Bitmap.Config;
 import android.os.SystemClock;
 import android.util.Log;
 import android.view.View;
diff --git a/src/com/google/android/droiddriver/scroll/Scrollers.java b/src/com/google/android/droiddriver/scroll/Scrollers.java
index ddf9610..6272955 100644
--- a/src/com/google/android/droiddriver/scroll/Scrollers.java
+++ b/src/com/google/android/droiddriver/scroll/Scrollers.java
@@ -18,6 +18,7 @@ package com.google.android.droiddriver.scroll;
 
 import android.app.UiAutomation;
 
+import com.google.android.droiddriver.scroll.Direction.Axis;
 import com.google.android.droiddriver.scroll.Direction.DirectionConverter;
 
 /**
@@ -35,14 +36,22 @@ public class Scrollers {
    * the case of dynamic list, which shows more items when scrolling beyond the
    * end. On the other hand, it's complex and needs more configuration.</li>
    * </ul>
+   * Note if a {@link StepBasedScroller} is returned, it is constructed with
+   * arguments that apply to typical cases. You may want to customize them for
+   * specific cases. For instance, {@code perScrollTimeoutMillis} can be 0L if
+   * there are no asynchronously updated views. To that extent, this method
+   * serves as an example of how to construct rather {@link Scroller}s than
+   * providing the "official" {@link Scroller}.
    */
   public static Scroller newScroller(UiAutomation uiAutomation) {
     if (uiAutomation != null) {
-      return new StepBasedScroller(new AccessibilityEventScrollStepStrategy(uiAutomation, 1000L,
-          DirectionConverter.STANDARD_CONVERTER));
+      return new StepBasedScroller(100/* maxScrolls */, 1000L/* perScrollTimeoutMillis */,
+          Axis.VERTICAL, new AccessibilityEventScrollStepStrategy(uiAutomation, 1000L,
+              DirectionConverter.STANDARD_CONVERTER), true/* startFromBeginning */);
     }
     // TODO: A {@link Scroller} that directly jumps to the view if an
     // InstrumentationDriver is used.
-    return new StepBasedScroller(StaticSentinelStrategy.DEFAULT);
+    return new StepBasedScroller(100/* maxScrolls */, 1000L/* perScrollTimeoutMillis */,
+        Axis.VERTICAL, StaticSentinelStrategy.DEFAULT, true/* startFromBeginning */);
   }
 }
diff --git a/src/com/google/android/droiddriver/scroll/StepBasedScroller.java b/src/com/google/android/droiddriver/scroll/StepBasedScroller.java
index 07d7fb6..2ba8ceb 100644
--- a/src/com/google/android/droiddriver/scroll/StepBasedScroller.java
+++ b/src/com/google/android/droiddriver/scroll/StepBasedScroller.java
@@ -56,7 +56,8 @@ public class StepBasedScroller implements Scroller {
    * @param maxScrolls the maximum number of scrolls. It should be large enough
    *        to allow any reasonable list size
    * @param perScrollTimeoutMillis the timeout in millis that we poll for the
-   *        item after each scroll
+   *        item after each scroll. 1000L is usually safe; if there are no
+   *        asynchronously updated views, 0L is also a reasonable value.
    * @param axis the axis this scroller can scroll
    * @param startFromBeginning if {@code true},
    *        {@link #scrollTo(DroidDriver, Finder, Finder)} starts from the
diff --git a/src/com/google/android/droiddriver/uiautomation/UiAutomationContext.java b/src/com/google/android/droiddriver/uiautomation/UiAutomationContext.java
index 0b56d33..b85803b 100644
--- a/src/com/google/android/droiddriver/uiautomation/UiAutomationContext.java
+++ b/src/com/google/android/droiddriver/uiautomation/UiAutomationContext.java
@@ -23,6 +23,7 @@ import android.view.accessibility.AccessibilityNodeInfo;
 
 import com.google.android.droiddriver.actions.InputInjector;
 import com.google.android.droiddriver.base.DroidDriverContext;
+import com.google.android.droiddriver.finders.ByXPath;
 import com.google.common.collect.MapMaker;
 
 import java.util.Map;
@@ -74,6 +75,7 @@ class UiAutomationContext implements DroidDriverContext {
   @Override
   public void clearData() {
     map.clear();
+    ByXPath.clearData();
   }
 
   public UiAutomation getUiAutomation() {
diff --git a/src/com/google/android/droiddriver/uiautomation/UiAutomationElement.java b/src/com/google/android/droiddriver/uiautomation/UiAutomationElement.java
index 7fc5056..c5f975a 100644
--- a/src/com/google/android/droiddriver/uiautomation/UiAutomationElement.java
+++ b/src/com/google/android/droiddriver/uiautomation/UiAutomationElement.java
@@ -128,7 +128,6 @@ public class UiAutomationElement extends BaseUiElement {
 
   private Rect getVisibleBounds(AccessibilityNodeInfo node) {
     if (!visible) {
-      Logs.log(Log.DEBUG, "Node is invisible: " + node);
       return new Rect();
     }
     Rect visibleBounds = getBounds();