Add scrolling using UiObject2 capabilities. DO NOT MERGE

Scrolling implemented in UiScrollable is considered obsolete, so a
scrolling using modern UiObject2 is implemented.

BUG:36898931

Change-Id: I086775447f371bb21b8345c28247e91d881d2086
(cherry picked from commit 38f581eb6ed227c0b8b8f67db2266c485e55873a)

1 files changed, 88 insertions, 2 deletions

diff --git a/libs/UiAutomatorLib/src/com/android/afwtest/uiautomator/utils/WidgetUtils.java b/libs/UiAutomatorLib/src/com/android/afwtest/uiautomator/utils/WidgetUtils.java
index 5265354..58e8c3f 100644
--- a/libs/UiAutomatorLib/src/com/android/afwtest/uiautomator/utils/WidgetUtils.java
+++ b/libs/UiAutomatorLib/src/com/android/afwtest/uiautomator/utils/WidgetUtils.java
@@ -16,6 +16,7 @@
 
 package com.android.afwtest.uiautomator.utils;
 
+import android.graphics.Rect;
 import android.support.test.uiautomator.BySelector;
 import android.support.test.uiautomator.Direction;
 import android.support.test.uiautomator.UiDevice;
@@ -44,6 +45,16 @@ public class WidgetUtils {
     private static final long DEFAULT_UI_WAIT_TIME_MS = TimeUnit.SECONDS.toMillis(5);
 
     /**
+     * Margin of swipe's starting and ending points inside the target.
+     */
+    private static final float DEFAULT_SWIPE_DEADZONE_PCT = 0.1f;
+
+    /**
+     * Swipe's length as object's dimension percentage.
+     */
+    private static final float DEFAULT_SWIPE_PCT = 0.7f;
+
+    /**
      * Clicks on given {@link UiObject2} without throwing any exception.
      *
      * @param obj {@link UiObject2} to click
@@ -321,7 +332,7 @@ public class WidgetUtils {
     }
 
     /**
-     * Scroll a scrollable UI widget so that an item with certain {@link TextView} text is in view.
+     * Scrolls a scrollable UI widget so that an item with certain {@link TextView} text is in view.
      *
      * @param container Selector for the scrollable widget.
      * @param item Text that appears in the target item.
@@ -336,7 +347,7 @@ public class WidgetUtils {
     }
 
     /**
-     * Scroll a scrollable UI widget so that a certain item is in view.
+     * Scrolls a scrollable UI widget so that a certain item is in view.
      *
      * @param container Selector for the scrollable widget.
      * @param item Selector that specifies the target item.
@@ -359,6 +370,81 @@ public class WidgetUtils {
     }
 
     /**
+     * Scrolls vertically a scrollable UI widget so that a certain item is in view.
+     *
+     * @param uiDevice current {@link UiDevice}.
+     * @param container {@link BySelector} of a scrollable container.
+     * @param item {@link BySelector} of an item to scroll to.
+     * @return The target item as a {@link UiObject2} when it first appears, or {@code null} if
+     *         not found.
+     * @throws UiObjectNotFoundException If the scrollable does not exist.
+     */
+    public static UiObject2 scrollToItem(UiDevice uiDevice,
+            BySelector container,
+            BySelector item) throws UiObjectNotFoundException {
+        return scrollToItem(uiDevice, container, item, false);
+    }
+
+    /**
+     * Scrolls a scrollable UI widget so that a certain item is in view.
+     *
+     * @param uiDevice current {@link UiDevice}.
+     * @param container {@link BySelector} of a scrollable container.
+     * @param item {@link BySelector} of an item to scroll to.
+     * @param isHorizontal {@code true} if scrollable is horizontal, {@code false} otherwise.
+     * @return The target item as a {@link UiObject2} when it first appears, or {@code null} if
+     *         not found.
+     * @throws UiObjectNotFoundException If the scrollable does not exist.
+     */
+    public static UiObject2 scrollToItem(UiDevice uiDevice,
+            BySelector container,
+            BySelector item,
+            boolean isHorizontal) throws UiObjectNotFoundException {
+
+        // Find scrollable object
+        final UiObject2 scrollable = safeWait(uiDevice, container);
+        if (scrollable == null) {
+            throw new UiObjectNotFoundException("Cannot find scrollable " + container);
+        }
+
+        // Check if given container is scrollable
+        if (!scrollable.isScrollable()) {
+            throw new IllegalArgumentException("Given container is not scrollable");
+        }
+
+        setGestureMargins(scrollable, DEFAULT_SWIPE_DEADZONE_PCT);
+
+        // Determine scrolling direction
+        final Direction scrollDirection = isHorizontal ? Direction.RIGHT : Direction.DOWN;
+        final Direction oppositeDirection = Direction.reverse(scrollDirection);
+
+        // Scroll to the beginning of the scrollable
+        while (scrollable.scroll(oppositeDirection, DEFAULT_SWIPE_PCT));
+
+        // Scroll while target item is not visible and scrolling is still possible
+        UiObject2 foundItem;
+        while ((foundItem = scrollable.findObject(item)) == null &&
+                scrollable.scroll(scrollDirection, DEFAULT_SWIPE_PCT));
+        uiDevice.waitForIdle();
+        return foundItem;
+    }
+
+    /**
+     * Set target object's gesture margins.
+     * @param target target object.
+     * @param marginPct gesture margin as target's dimension percentage.
+     */
+    private static void setGestureMargins(UiObject2 target, float marginPct) {
+        final Rect bounds = target.getVisibleBounds();
+        final int horizontalMargin = (int)(bounds.width() * marginPct);
+        final int verticalMargin = (int)(bounds.height() * marginPct);
+        target.setGestureMargins(horizontalMargin,
+                verticalMargin,
+                horizontalMargin,
+                verticalMargin);
+    }
+
+    /**
      * Gets properties of a {@link UiObject2} as a String, for debugging purpose.
      *
      * @param widget {@link UiObject2} to get properties from