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diff --git a/src/io/appium/droiddriver/scroll/SentinelStrategy.java b/src/io/appium/droiddriver/scroll/SentinelStrategy.java
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+/*
+ * Copyright (C) 2013 DroidDriver committers
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.appium.droiddriver.scroll;
+
+import android.util.Log;
+
+import java.util.List;
+
+import io.appium.droiddriver.DroidDriver;
+import io.appium.droiddriver.UiElement;
+import io.appium.droiddriver.exceptions.ElementNotFoundException;
+import io.appium.droiddriver.finders.By;
+import io.appium.droiddriver.finders.Finder;
+import io.appium.droiddriver.finders.Predicate;
+import io.appium.droiddriver.finders.Predicates;
+import io.appium.droiddriver.scroll.Direction.DirectionConverter;
+import io.appium.droiddriver.scroll.Direction.LogicalDirection;
+import io.appium.droiddriver.scroll.Direction.PhysicalDirection;
+import io.appium.droiddriver.util.Logs;
+
+/**
+ * A {@link ScrollStepStrategy} that determines whether scrolling is possible
+ * based on a sentinel.
+ */
+public abstract class SentinelStrategy implements ScrollStepStrategy {
+  /**
+   * A {@link Finder} for sentinel. Note that unlike {@link Finder}, invisible
+   * UiElements are not skipped by default.
+   */
+  public static abstract class Getter implements Finder {
+    protected final Predicate<? super UiElement> predicate;
+
+    protected Getter() {
+      // Include invisible children by default.
+      this(null);
+    }
+
+    protected Getter(Predicate<? super UiElement> predicate) {
+      this.predicate = predicate;
+    }
+
+    /**
+     * Gets the sentinel, which must be an immediate child of {@code container}
+     * - not a descendant. Note sentinel may not exist if {@code container} has
+     * not finished updating.
+     */
+    @Override
+    public UiElement find(UiElement container) {
+      UiElement sentinel = getSentinel(container.getChildren(predicate));
+      if (sentinel == null) {
+        throw new ElementNotFoundException(this);
+      }
+      Logs.log(Log.INFO, "Found sentinel: " + sentinel);
+      return sentinel;
+    }
+
+
+    protected abstract UiElement getSentinel(List<? extends UiElement> children);
+
+    @Override
+    public abstract String toString();
+  }
+
+  /**
+   * Returns the first child as the sentinel.
+   */
+  public static final Getter FIRST_CHILD_GETTER = new Getter() {
+    @Override
+    protected UiElement getSentinel(List<? extends UiElement> children) {
+      return children.isEmpty() ? null : children.get(0);
+    }
+
+    @Override
+    public String toString() {
+      return "FIRST_CHILD";
+    }
+  };
+  /**
+   * Returns the last child as the sentinel.
+   */
+  public static final Getter LAST_CHILD_GETTER = new Getter() {
+    @Override
+    protected UiElement getSentinel(List<? extends UiElement> children) {
+      return children.isEmpty() ? null : children.get(children.size() - 1);
+    }
+
+    @Override
+    public String toString() {
+      return "LAST_CHILD";
+    }
+  };
+  /**
+   * Returns the second last child as the sentinel. Useful when the activity
+   * always shows the last child as an anchor (for example a footer).
+   * <p>
+   * Sometimes uiautomatorviewer may not show the anchor as the last child, due
+   * to the reordering by layout described in {@link UiElement#getChildren}.
+   * This is not a problem with UiAutomationDriver because it sees the same as
+   * uiautomatorviewer does, but could be a problem with InstrumentationDriver.
+   * </p>
+   */
+  public static final Getter SECOND_LAST_CHILD_GETTER = new Getter() {
+    @Override
+    protected UiElement getSentinel(List<? extends UiElement> children) {
+      return children.size() < 2 ? null : children.get(children.size() - 2);
+    }
+
+    @Override
+    public String toString() {
+      return "SECOND_LAST_CHILD";
+    }
+  };
+  /**
+   * Returns the second child as the sentinel. Useful when the activity shows a
+   * fixed first child.
+   */
+  public static final Getter SECOND_CHILD_GETTER = new Getter() {
+    @Override
+    protected UiElement getSentinel(List<? extends UiElement> children) {
+      return children.size() <= 1 ? null : children.get(1);
+    }
+
+    @Override
+    public String toString() {
+      return "SECOND_CHILD";
+    }
+  };
+
+  /**
+   * Decorates a {@link Getter} by adding another {@link Predicate}.
+   */
+  public static class MorePredicateGetter extends Getter {
+    private final Getter original;
+
+    public MorePredicateGetter(Getter original, Predicate<? super UiElement> extraPredicate) {
+      super(Predicates.allOf(original.predicate, extraPredicate));
+      this.original = original;
+    }
+
+    @Override
+    protected UiElement getSentinel(List<? extends UiElement> children) {
+      return original.getSentinel(children);
+    }
+
+    @Override
+    public String toString() {
+      return predicate.toString() + " " + original;
+    }
+  }
+
+  private final Getter backwardGetter;
+  private final Getter forwardGetter;
+  private final DirectionConverter directionConverter;
+
+  protected SentinelStrategy(Getter backwardGetter, Getter forwardGetter,
+      DirectionConverter directionConverter) {
+    this.backwardGetter = backwardGetter;
+    this.forwardGetter = forwardGetter;
+    this.directionConverter = directionConverter;
+  }
+
+  protected UiElement getSentinel(DroidDriver driver, Finder containerFinder,
+      PhysicalDirection direction) {
+    Logs.call(this, "getSentinel", driver, containerFinder, direction);
+    Finder sentinelFinder;
+    LogicalDirection logicalDirection = directionConverter.toLogicalDirection(direction);
+    if (logicalDirection == LogicalDirection.BACKWARD) {
+      sentinelFinder = By.chain(containerFinder, backwardGetter);
+    } else {
+      sentinelFinder = By.chain(containerFinder, forwardGetter);
+    }
+    return driver.on(sentinelFinder);
+  }
+
+  @Override
+  public final DirectionConverter getDirectionConverter() {
+    return directionConverter;
+  }
+
+  @Override
+  public void beginScrolling(DroidDriver driver, Finder containerFinder, Finder itemFinder,
+      PhysicalDirection direction) {}
+
+  @Override
+  public void endScrolling(DroidDriver driver, Finder containerFinder, Finder itemFinder,
+      PhysicalDirection direction) {}
+
+  @Override
+  public String toString() {
+    return String.format("{backwardGetter=%s, forwardGetter=%s}", backwardGetter, forwardGetter);
+  }
+
+  @Override
+  public void doScroll(UiElement container, PhysicalDirection direction) {
+    container.scroll(direction);
+  }
+}