chrome/android/features/autofill_assistant/javatests/src/org/chromium/chrome/browser/autofill_assistant/AutofillAssistantOverlayUiTest.java - chromium/src - Git at Google

 // Copyright 2019 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 package org.chromium.chrome.browser.autofill_assistant;

 import static android.support.test.espresso.Espresso.onView;
 import static android.support.test.espresso.assertion.ViewAssertions.matches;
 import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
 import static android.support.test.espresso.matcher.ViewMatchers.isRoot;

 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;

 import static org.chromium.content_public.browser.test.util.TestThreadUtils.runOnUiThreadBlocking;

 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.MediumTest;
 import android.util.DisplayMetrics;

 import org.json.JSONArray;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;

 import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.autofill_assistant.overlay.AssistantOverlayCoordinator;
 import org.chromium.chrome.browser.autofill_assistant.overlay.AssistantOverlayModel;
 import org.chromium.chrome.browser.autofill_assistant.overlay.AssistantOverlayState;
 import org.chromium.chrome.browser.customtabs.CustomTabActivityTestRule;
 import org.chromium.chrome.browser.customtabs.CustomTabsTestUtils;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.content_public.browser.test.util.TestCallbackHelperContainer;
 import org.chromium.content_public.browser.test.util.TestTouchUtils;

 import java.util.Collections;
 import java.util.concurrent.ExecutionException;

 /**
  * Tests for the Autofill Assistant overlay.
  */
 @CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE})
 @RunWith(ChromeJUnit4ClassRunner.class)
 public class AutofillAssistantOverlayUiTest {
     @Rule
     public CustomTabActivityTestRule mTestRule = new CustomTabActivityTestRule();

     // TODO(crbug.com/806868): Create a more specific test site for overlay testing.
     private static final String TEST_PAGE =
             "/components/test/data/autofill_assistant/html/autofill_assistant_target_website.html";

     @Before
     public void setUp() {
         mTestRule.startCustomTabActivityWithIntent(CustomTabsTestUtils.createMinimalCustomTabIntent(
                 InstrumentationRegistry.getTargetContext(),
                 mTestRule.getTestServer().getURL(TEST_PAGE)));
         mTestRule.getActivity().getScrim().disableAnimationForTesting(true);
     }

     private WebContents getWebContents() {
         return mTestRule.getWebContents();
     }

     /** Creates a coordinator for use in UI tests. */
     private AssistantOverlayCoordinator createCoordinator(AssistantOverlayModel model)
             throws ExecutionException {
         return runOnUiThreadBlocking(
                 () -> new AssistantOverlayCoordinator(mTestRule.getActivity(), model));
     }

     /** Tests assumptions about the initial state of the infobox. */
     @Test
     @MediumTest
     public void testInitialState() throws Exception {
         AssistantOverlayModel model = new AssistantOverlayModel();
         AssistantOverlayCoordinator coordinator = createCoordinator(model);

         assertScrimDisplayed(false);
         tapElement("touch_area_one");
         assertThat(checkElementExists("touch_area_one"), is(false));
     }

     /** Tests assumptions about the full overlay. */
     @Test
     @MediumTest
     public void testFullOverlay() throws Exception {
         AssistantOverlayModel model = new AssistantOverlayModel();
         AssistantOverlayCoordinator coordinator = createCoordinator(model);

         runOnUiThreadBlocking(
                 () -> model.set(AssistantOverlayModel.STATE, AssistantOverlayState.FULL));
         assertScrimDisplayed(true);
         tapElement("touch_area_one");
         assertThat(checkElementExists("touch_area_one"), is(true));

         runOnUiThreadBlocking(
                 () -> model.set(AssistantOverlayModel.STATE, AssistantOverlayState.HIDDEN));
         assertScrimDisplayed(false);
         tapElement("touch_area_one");
         assertThat(checkElementExists("touch_area_one"), is(false));
     }

     /** Tests assumptions about the partial overlay. */
     @Test
     @MediumTest
     public void testPartialOverlay() throws Exception {
         AssistantOverlayModel model = new AssistantOverlayModel();
         AssistantOverlayCoordinator coordinator = createCoordinator(model);

         // Partial overlay, no touchable areas: equivalent to full overlay.
         runOnUiThreadBlocking(
                 () -> model.set(AssistantOverlayModel.STATE, AssistantOverlayState.PARTIAL));
         assertScrimDisplayed(true);
         tapElement("touch_area_one");
         assertThat(checkElementExists("touch_area_one"), is(true));

         Rect rect = getBoundingRectForElement("touch_area_one");
         runOnUiThreadBlocking(()
                                       -> model.set(AssistantOverlayModel.TOUCHABLE_AREA,
                                               Collections.singletonList(new RectF(rect))));

         // Touchable area set, but no viewport given: equivalent to full overlay.
         tapElement("touch_area_one");
         assertThat(checkElementExists("touch_area_one"), is(true));

         // Set viewport.
         Rect viewport = getViewport();
         runOnUiThreadBlocking(
                 () -> model.set(AssistantOverlayModel.VISUAL_VIEWPORT, new RectF(viewport)));

         // Now the partial overlay allows tapping the highlighted touch area.
         tapElement("touch_area_one");
         assertThat(checkElementExists("touch_area_one"), is(false));

         runOnUiThreadBlocking(
                 () -> model.set(AssistantOverlayModel.TOUCHABLE_AREA, Collections.emptyList()));
         tapElement("touch_area_three");
         assertThat(checkElementExists("touch_area_three"), is(true));
     }

     /** Scrolls a touchable area into view and then taps it. */
     @Test
     @MediumTest
     public void testSimpleScrollPartialOverlay() throws Exception {
         AssistantOverlayModel model = new AssistantOverlayModel();
         AssistantOverlayCoordinator coordinator = createCoordinator(model);

         Rect rect = getBoundingRectForElement("touch_area_two");
         Rect viewport = getViewport();
         runOnUiThreadBlocking(() -> {
             model.set(AssistantOverlayModel.STATE, AssistantOverlayState.PARTIAL);
             model.set(AssistantOverlayModel.TOUCHABLE_AREA,
                     Collections.singletonList(new RectF(rect)));
             model.set(AssistantOverlayModel.VISUAL_VIEWPORT, new RectF(viewport));
         });
         scrollIntoViewIfNeeded("touch_area_two");
         Rect newViewport = getViewport();
         runOnUiThreadBlocking(
                 () -> model.set(AssistantOverlayModel.VISUAL_VIEWPORT, new RectF(newViewport)));
         tapElement("touch_area_two");
         assertThat(checkElementExists("touch_area_two"), is(false));
     }

     private void assertScrimDisplayed(boolean expected) throws Exception {
         // Wait for UI thread to be idle.
         onView(isRoot()).check(matches(isDisplayed()));

         // The scrim view is only attached to the view hierarchy when needed, preventing us from
         // using regular espresso facilities.
         boolean scrimInHierarchy =
                 runOnUiThreadBlocking(() -> mTestRule.getActivity().getScrim().getParent() != null);
         if (expected && !scrimInHierarchy) {
             throw new Exception("Expected scrim view visible, but scrim was not in view hierarchy");
         }
         if (scrimInHierarchy) {
             if (expected) {
                 onView(is(mTestRule.getActivity().getScrim())).check(matches(isDisplayed()));
             } else {
                 onView(is(mTestRule.getActivity().getScrim())).check(matches(not(isDisplayed())));
             }
         }
     }

     /** Performs a single tap on the center of the specified element. */
     private void tapElement(String elementId) throws Exception {
         Rect coords = getAbsoluteBoundingRect(elementId);
         float x = coords.left + 0.5f * (coords.right - coords.left);
         float y = coords.top + 0.5f * (coords.bottom - coords.top);

         // Sanity check, can only click on coordinates on screen.
         DisplayMetrics displayMetrics = mTestRule.getActivity().getResources().getDisplayMetrics();
         if (x < 0 || x > displayMetrics.widthPixels || y < 0 || y > displayMetrics.heightPixels) {
             throw new IllegalArgumentException(elementId + " not on screen: tried to tap x=" + x
                     + ", y=" + y + ", which is outside of display with w="
                     + displayMetrics.widthPixels + ", h=" + displayMetrics.heightPixels);
         }
         TestTouchUtils.singleClick(InstrumentationRegistry.getInstrumentation(), x, y);
     }

     /** Computes the bounding rectangle of the specified DOM element in absolute screen space. */
     private Rect getAbsoluteBoundingRect(String elementId) throws Exception {
         // Get bounding rectangle in viewport space.
         Rect elementRect = getBoundingRectForElement(elementId);

         /*
          * Conversion from viewport space to screen space is done in two steps:
          * - First, convert viewport to compositor space (scrolling offset, multiply with factor).
          * - Then, convert compositor space to screen space (add content offset).
          */
         Rect viewport = getViewport();
         float cssToPysicalPixels =
                 (((float) mTestRule.getActivity().getCompositorViewHolder().getWidth()
                         / (float) viewport.width()));

         int[] compositorLocation = new int[2];
         mTestRule.getActivity().getCompositorViewHolder().getLocationOnScreen(compositorLocation);
         int offsetY = compositorLocation[1]
                 + mTestRule.getActivity().getFullscreenManager().getContentOffset();
         return new Rect((int) ((elementRect.left - viewport.left) * cssToPysicalPixels),
                 (int) ((elementRect.top - viewport.top) * cssToPysicalPixels + offsetY),
                 (int) ((elementRect.right - viewport.left) * cssToPysicalPixels),
                 (int) ((elementRect.bottom - viewport.top) * cssToPysicalPixels + offsetY));
     }

     /**
      * Retrieves the bounding rectangle for the specified element in the DOM tree in CSS pixel
      * coordinates.
      */
     private Rect getBoundingRectForElement(String elementId) throws Exception {
         if (!checkElementExists(elementId)) {
             throw new IllegalArgumentException(elementId + " does not exist");
         }
         TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
                 new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
         javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
                 "(function() {"
                         + " rect = document.getElementById('" + elementId
                         + "').getBoundingClientRect();"
                         + " return [window.scrollX + rect.left, window.scrollY + rect.top, "
                         + "         window.scrollX + rect.right, window.scrollY + rect.bottom];"
                         + "})()");
         javascriptHelper.waitUntilHasValue();
         JSONArray rectJson = new JSONArray(javascriptHelper.getJsonResultAndClear());
         return new Rect(
                 rectJson.getInt(0), rectJson.getInt(1), rectJson.getInt(2), rectJson.getInt(3));
     }

     /** Checks whether the specified element exists in the DOM tree. */
     private boolean checkElementExists(String elementId) throws Exception {
         TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
                 new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
         javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
                 "(function() {"
                         + " return [document.getElementById('" + elementId + "') != null]; "
                         + "})()");
         javascriptHelper.waitUntilHasValue();
         JSONArray result = new JSONArray(javascriptHelper.getJsonResultAndClear());
         return result.getBoolean(0);
     }

     /**
      * Retrieves the visual viewport of the webpage in CSS pixel coordinates.
      */
     private Rect getViewport() throws Exception {
         TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
                 new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
         javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
                 "(function() {"
                         + " const v = window.visualViewport;"
                         + " return [v.pageLeft, v.pageTop, v.width, v.height]"
                         + "})()");
         javascriptHelper.waitUntilHasValue();
         JSONArray values = new JSONArray(javascriptHelper.getJsonResultAndClear());
         return new Rect(values.getInt(0), values.getInt(1), values.getInt(2), values.getInt(3));
     }

     /**
      * Scrolls to the specified element on the webpage, if necessary.
      */
     private void scrollIntoViewIfNeeded(String elementId) throws Exception {
         TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
                 new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
         javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
                 "(function() {" + elementId + ".scrollIntoViewIfNeeded();"
                         + " return true;"
                         + "})()");
         javascriptHelper.waitUntilHasValue();
     }
 }
	// Copyright 2019 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	package org.chromium.chrome.browser.autofill_assistant;

	import static android.support.test.espresso.Espresso.onView;
	import static android.support.test.espresso.assertion.ViewAssertions.matches;
	import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
	import static android.support.test.espresso.matcher.ViewMatchers.isRoot;

	import static org.hamcrest.MatcherAssert.assertThat;
	import static org.hamcrest.Matchers.is;
	import static org.hamcrest.Matchers.not;

	import static org.chromium.content_public.browser.test.util.TestThreadUtils.runOnUiThreadBlocking;

	import android.graphics.Rect;
	import android.graphics.RectF;
	import android.support.test.InstrumentationRegistry;
	import android.support.test.filters.MediumTest;
	import android.util.DisplayMetrics;

	import org.json.JSONArray;
	import org.junit.Before;
	import org.junit.Rule;
	import org.junit.Test;
	import org.junit.runner.RunWith;

	import org.chromium.base.test.util.CommandLineFlags;
	import org.chromium.chrome.browser.ChromeSwitches;
	import org.chromium.chrome.browser.autofill_assistant.overlay.AssistantOverlayCoordinator;
	import org.chromium.chrome.browser.autofill_assistant.overlay.AssistantOverlayModel;
	import org.chromium.chrome.browser.autofill_assistant.overlay.AssistantOverlayState;
	import org.chromium.chrome.browser.customtabs.CustomTabActivityTestRule;
	import org.chromium.chrome.browser.customtabs.CustomTabsTestUtils;
	import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
	import org.chromium.content_public.browser.WebContents;
	import org.chromium.content_public.browser.test.util.TestCallbackHelperContainer;
	import org.chromium.content_public.browser.test.util.TestTouchUtils;

	import java.util.Collections;
	import java.util.concurrent.ExecutionException;

	/**
	* Tests for the Autofill Assistant overlay.
	*/
	@CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE})
	@RunWith(ChromeJUnit4ClassRunner.class)
	public class AutofillAssistantOverlayUiTest {
	@Rule
	public CustomTabActivityTestRule mTestRule = new CustomTabActivityTestRule();

	// TODO(crbug.com/806868): Create a more specific test site for overlay testing.
	private static final String TEST_PAGE =
	"/components/test/data/autofill_assistant/html/autofill_assistant_target_website.html";

	@Before
	public void setUp() {
	mTestRule.startCustomTabActivityWithIntent(CustomTabsTestUtils.createMinimalCustomTabIntent(
	InstrumentationRegistry.getTargetContext(),
	mTestRule.getTestServer().getURL(TEST_PAGE)));
	mTestRule.getActivity().getScrim().disableAnimationForTesting(true);
	}

	private WebContents getWebContents() {
	return mTestRule.getWebContents();
	}

	/** Creates a coordinator for use in UI tests. */
	private AssistantOverlayCoordinator createCoordinator(AssistantOverlayModel model)
	throws ExecutionException {
	return runOnUiThreadBlocking(
	() -> new AssistantOverlayCoordinator(mTestRule.getActivity(), model));
	}

	/** Tests assumptions about the initial state of the infobox. */
	@Test
	@MediumTest
	public void testInitialState() throws Exception {
	AssistantOverlayModel model = new AssistantOverlayModel();
	AssistantOverlayCoordinator coordinator = createCoordinator(model);

	assertScrimDisplayed(false);
	tapElement("touch_area_one");
	assertThat(checkElementExists("touch_area_one"), is(false));
	}

	/** Tests assumptions about the full overlay. */
	@Test
	@MediumTest
	public void testFullOverlay() throws Exception {
	AssistantOverlayModel model = new AssistantOverlayModel();
	AssistantOverlayCoordinator coordinator = createCoordinator(model);

	runOnUiThreadBlocking(
	() -> model.set(AssistantOverlayModel.STATE, AssistantOverlayState.FULL));
	assertScrimDisplayed(true);
	tapElement("touch_area_one");
	assertThat(checkElementExists("touch_area_one"), is(true));

	runOnUiThreadBlocking(
	() -> model.set(AssistantOverlayModel.STATE, AssistantOverlayState.HIDDEN));
	assertScrimDisplayed(false);
	tapElement("touch_area_one");
	assertThat(checkElementExists("touch_area_one"), is(false));
	}

	/** Tests assumptions about the partial overlay. */
	@Test
	@MediumTest
	public void testPartialOverlay() throws Exception {
	AssistantOverlayModel model = new AssistantOverlayModel();
	AssistantOverlayCoordinator coordinator = createCoordinator(model);

	// Partial overlay, no touchable areas: equivalent to full overlay.
	runOnUiThreadBlocking(
	() -> model.set(AssistantOverlayModel.STATE, AssistantOverlayState.PARTIAL));
	assertScrimDisplayed(true);
	tapElement("touch_area_one");
	assertThat(checkElementExists("touch_area_one"), is(true));

	Rect rect = getBoundingRectForElement("touch_area_one");
	runOnUiThreadBlocking(()
	-> model.set(AssistantOverlayModel.TOUCHABLE_AREA,
	Collections.singletonList(new RectF(rect))));

	// Touchable area set, but no viewport given: equivalent to full overlay.
	tapElement("touch_area_one");
	assertThat(checkElementExists("touch_area_one"), is(true));

	// Set viewport.
	Rect viewport = getViewport();
	runOnUiThreadBlocking(
	() -> model.set(AssistantOverlayModel.VISUAL_VIEWPORT, new RectF(viewport)));

	// Now the partial overlay allows tapping the highlighted touch area.
	tapElement("touch_area_one");
	assertThat(checkElementExists("touch_area_one"), is(false));

	runOnUiThreadBlocking(
	() -> model.set(AssistantOverlayModel.TOUCHABLE_AREA, Collections.emptyList()));
	tapElement("touch_area_three");
	assertThat(checkElementExists("touch_area_three"), is(true));
	}

	/** Scrolls a touchable area into view and then taps it. */
	@Test
	@MediumTest
	public void testSimpleScrollPartialOverlay() throws Exception {
	AssistantOverlayModel model = new AssistantOverlayModel();
	AssistantOverlayCoordinator coordinator = createCoordinator(model);

	Rect rect = getBoundingRectForElement("touch_area_two");
	Rect viewport = getViewport();
	runOnUiThreadBlocking(() -> {
	model.set(AssistantOverlayModel.STATE, AssistantOverlayState.PARTIAL);
	model.set(AssistantOverlayModel.TOUCHABLE_AREA,
	Collections.singletonList(new RectF(rect)));
	model.set(AssistantOverlayModel.VISUAL_VIEWPORT, new RectF(viewport));
	});
	scrollIntoViewIfNeeded("touch_area_two");
	Rect newViewport = getViewport();
	runOnUiThreadBlocking(
	() -> model.set(AssistantOverlayModel.VISUAL_VIEWPORT, new RectF(newViewport)));
	tapElement("touch_area_two");
	assertThat(checkElementExists("touch_area_two"), is(false));
	}

	private void assertScrimDisplayed(boolean expected) throws Exception {
	// Wait for UI thread to be idle.
	onView(isRoot()).check(matches(isDisplayed()));

	// The scrim view is only attached to the view hierarchy when needed, preventing us from
	// using regular espresso facilities.
	boolean scrimInHierarchy =
	runOnUiThreadBlocking(() -> mTestRule.getActivity().getScrim().getParent() != null);
	if (expected && !scrimInHierarchy) {
	throw new Exception("Expected scrim view visible, but scrim was not in view hierarchy");
	}
	if (scrimInHierarchy) {
	if (expected) {
	onView(is(mTestRule.getActivity().getScrim())).check(matches(isDisplayed()));
	} else {
	onView(is(mTestRule.getActivity().getScrim())).check(matches(not(isDisplayed())));
	}
	}
	}

	/** Performs a single tap on the center of the specified element. */
	private void tapElement(String elementId) throws Exception {
	Rect coords = getAbsoluteBoundingRect(elementId);
	float x = coords.left + 0.5f * (coords.right - coords.left);
	float y = coords.top + 0.5f * (coords.bottom - coords.top);

	// Sanity check, can only click on coordinates on screen.
	DisplayMetrics displayMetrics = mTestRule.getActivity().getResources().getDisplayMetrics();
	if (x < 0 \|\| x > displayMetrics.widthPixels \|\| y < 0 \|\| y > displayMetrics.heightPixels) {
	throw new IllegalArgumentException(elementId + " not on screen: tried to tap x=" + x
	+ ", y=" + y + ", which is outside of display with w="
	+ displayMetrics.widthPixels + ", h=" + displayMetrics.heightPixels);
	}
	TestTouchUtils.singleClick(InstrumentationRegistry.getInstrumentation(), x, y);
	}

	/** Computes the bounding rectangle of the specified DOM element in absolute screen space. */
	private Rect getAbsoluteBoundingRect(String elementId) throws Exception {
	// Get bounding rectangle in viewport space.
	Rect elementRect = getBoundingRectForElement(elementId);

	/*
	* Conversion from viewport space to screen space is done in two steps:
	* - First, convert viewport to compositor space (scrolling offset, multiply with factor).
	* - Then, convert compositor space to screen space (add content offset).
	*/
	Rect viewport = getViewport();
	float cssToPysicalPixels =
	(((float) mTestRule.getActivity().getCompositorViewHolder().getWidth()
	/ (float) viewport.width()));

	int[] compositorLocation = new int[2];
	mTestRule.getActivity().getCompositorViewHolder().getLocationOnScreen(compositorLocation);
	int offsetY = compositorLocation[1]
	+ mTestRule.getActivity().getFullscreenManager().getContentOffset();
	return new Rect((int) ((elementRect.left - viewport.left) * cssToPysicalPixels),
	(int) ((elementRect.top - viewport.top) * cssToPysicalPixels + offsetY),
	(int) ((elementRect.right - viewport.left) * cssToPysicalPixels),
	(int) ((elementRect.bottom - viewport.top) * cssToPysicalPixels + offsetY));
	}

	/**
	* Retrieves the bounding rectangle for the specified element in the DOM tree in CSS pixel
	* coordinates.
	*/
	private Rect getBoundingRectForElement(String elementId) throws Exception {
	if (!checkElementExists(elementId)) {
	throw new IllegalArgumentException(elementId + " does not exist");
	}
	TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
	new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
	javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
	"(function() {"
	+ " rect = document.getElementById('" + elementId
	+ "').getBoundingClientRect();"
	+ " return [window.scrollX + rect.left, window.scrollY + rect.top, "
	+ " window.scrollX + rect.right, window.scrollY + rect.bottom];"
	+ "})()");
	javascriptHelper.waitUntilHasValue();
	JSONArray rectJson = new JSONArray(javascriptHelper.getJsonResultAndClear());
	return new Rect(
	rectJson.getInt(0), rectJson.getInt(1), rectJson.getInt(2), rectJson.getInt(3));
	}

	/** Checks whether the specified element exists in the DOM tree. */
	private boolean checkElementExists(String elementId) throws Exception {
	TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
	new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
	javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
	"(function() {"
	+ " return [document.getElementById('" + elementId + "') != null]; "
	+ "})()");
	javascriptHelper.waitUntilHasValue();
	JSONArray result = new JSONArray(javascriptHelper.getJsonResultAndClear());
	return result.getBoolean(0);
	}

	/**
	* Retrieves the visual viewport of the webpage in CSS pixel coordinates.
	*/
	private Rect getViewport() throws Exception {
	TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
	new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
	javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
	"(function() {"
	+ " const v = window.visualViewport;"
	+ " return [v.pageLeft, v.pageTop, v.width, v.height]"
	+ "})()");
	javascriptHelper.waitUntilHasValue();
	JSONArray values = new JSONArray(javascriptHelper.getJsonResultAndClear());
	return new Rect(values.getInt(0), values.getInt(1), values.getInt(2), values.getInt(3));
	}

	/**
	* Scrolls to the specified element on the webpage, if necessary.
	*/
	private void scrollIntoViewIfNeeded(String elementId) throws Exception {
	TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper javascriptHelper =
	new TestCallbackHelperContainer.OnEvaluateJavaScriptResultHelper();
	javascriptHelper.evaluateJavaScriptForTests(getWebContents(),
	"(function() {" + elementId + ".scrollIntoViewIfNeeded();"
	+ " return true;"
	+ "})()");
	javascriptHelper.waitUntilHasValue();
	}
	}