tests/framework/base/activitymanager/src/android/server/am/ActivityManagerConfigChangeTests.java - platform/cts - Git at Google

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * 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 android.server.am;

 import static android.server.am.ActivityManagerState.STATE_RESUMED;
 import static android.server.am.ComponentNameUtils.getLogTag;
 import static android.server.am.Components.FONT_SCALE_ACTIVITY;
 import static android.server.am.Components.FONT_SCALE_NO_RELAUNCH_ACTIVITY;
 import static android.server.am.Components.NO_RELAUNCH_ACTIVITY;
 import static android.server.am.Components.RESIZEABLE_ACTIVITY;
 import static android.server.am.Components.TEST_ACTIVITY;
 import static android.server.am.StateLogger.log;
 import static android.server.am.StateLogger.logE;
 import static android.view.Surface.ROTATION_0;
 import static android.view.Surface.ROTATION_180;
 import static android.view.Surface.ROTATION_270;
 import static android.view.Surface.ROTATION_90;

 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeFalse;
 import static org.junit.Assume.assumeTrue;

 import android.content.ComponentName;
 import android.platform.test.annotations.Presubmit;
 import android.provider.Settings;
 import android.server.am.settings.SettingsSession;

 import androidx.test.filters.FlakyTest;

 import org.junit.Test;

 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 /**
  * Build/Install/Run:
  *     atest CtsActivityManagerDeviceTestCases:ActivityManagerConfigChangeTests
  */
 public class ActivityManagerConfigChangeTests extends ActivityManagerTestBase {

     private static final float EXPECTED_FONT_SIZE_SP = 10.0f;

     @Test
     public void testRotation90Relaunch() throws Exception{
         assumeTrue("Skipping test: no rotation support", supportsRotation());

         // Should relaunch on every rotation and receive no onConfigurationChanged()
         testRotation(TEST_ACTIVITY, 1, 1, 0);
     }

     @Test
     public void testRotation90NoRelaunch() throws Exception {
         assumeTrue("Skipping test: no rotation support", supportsRotation());

         // Should receive onConfigurationChanged() on every rotation and no relaunch
         testRotation(NO_RELAUNCH_ACTIVITY, 1, 0, 1);
     }

     // TODO(b/110382028): Fix relaunch testing and use an activity that doesn't handle config change
     @Test
     public void testRotation180Relaunch() throws Exception {
         assumeTrue("Skipping test: no rotation support", supportsRotation());
         // TODO(b/110533226): Fix test on devices with display cutout
         assumeFalse("Skipping test: display cutout present, can't predict exact lifecycle",
                 hasDisplayCutout());

         // Should receive a relaunch
         testRotation(TEST_ACTIVITY, 2, 0, 0);
     }

     @Test
     public void testRotation180NoRelaunch() throws Exception {
         assumeTrue("Skipping test: no rotation support", supportsRotation());
         // TODO(b/110533226): Fix test on devices with display cutout
         assumeFalse("Skipping test: display cutout present, can't predict exact lifecycle",
                 hasDisplayCutout());

         // Should receive nothing
         testRotation(NO_RELAUNCH_ACTIVITY, 2, 0, 0);
     }

     @FlakyTest(bugId = 73701185)
     @Presubmit
     @Test
     public void testChangeFontScaleRelaunch() throws Exception {
         // Should relaunch and receive no onConfigurationChanged()
         testChangeFontScale(FONT_SCALE_ACTIVITY, true /* relaunch */);
     }

     @FlakyTest(bugId = 73812451)
     @Presubmit
     @Test
     public void testChangeFontScaleNoRelaunch() throws Exception {
         // Should receive onConfigurationChanged() and no relaunch
         testChangeFontScale(FONT_SCALE_NO_RELAUNCH_ACTIVITY, false /* relaunch */);
     }

     /**
      * Test activity configuration changes for devices with cutout(s). Landscape and
      * reverse-landscape rotations should result in same screen space available for apps.
      */
     @Test
     public void testConfigChangeWhenRotatingWithCutout() throws Exception {
         assumeTrue("Skipping test: no rotation support", supportsRotation());
         assumeTrue("Skipping test: no display cutout", hasDisplayCutout());

         // Start an activity that handles config changes
         launchActivity(RESIZEABLE_ACTIVITY);
         mAmWmState.assertVisibility(RESIZEABLE_ACTIVITY, true /* visible */);
         final int displayId = mAmWmState.getAmState().getDisplayByActivity(RESIZEABLE_ACTIVITY);

         // 0 - 180 rotation or 270 - 90 rotation should have same screen space
         boolean configSame0_180 = false, configSame270_90 = false;
         final int[] cutoutRotations = { ROTATION_180, ROTATION_90, ROTATION_270 };

         // Rotate the activity and check that the orientation doesn't change at least once
         try (final RotationSession rotationSession = new RotationSession()) {
             rotationSession.set(ROTATION_0);

             final ReportedSizes[] sizes = new ReportedSizes[cutoutRotations.length];
             for (int i = 0; i < cutoutRotations.length; i++) {
                 final int rotation = cutoutRotations[i];
                 final LogSeparator logSeparator = separateLogs();
                 rotationSession.set(rotation);
                 final int newDeviceRotation = getDeviceRotation(displayId);
                 if (rotation != newDeviceRotation) {
                     log("This device doesn't support locked user "
                             + "rotation mode. Not continuing the rotation checks.");
                     continue;
                 }

                 // Record configuration changes on rotations between opposite orientations
                 sizes[i] = getLastReportedSizesForActivity(RESIZEABLE_ACTIVITY, logSeparator);
                 if (i == 0) {
                     configSame0_180 = sizes[i] == null;
                 } else if (i == 2) {
                     configSame270_90 = sizes[i] == null;
                 }
             }

             assertThat("A device with cutout should have same available screen space in "
                     + "landscape and reverse-landscape", configSame0_180 || configSame270_90);
         }
     }

     private void testRotation(ComponentName activityName, int rotationStep, int numRelaunch,
             int numConfigChange) throws Exception {
         launchActivity(activityName);

         mAmWmState.computeState(activityName);

         final int initialRotation = 4 - rotationStep;
         try (final RotationSession rotationSession = new RotationSession()) {
             rotationSession.set(initialRotation);
             mAmWmState.computeState(activityName);
             final int actualStackId =
                     mAmWmState.getAmState().getTaskByActivity(activityName).mStackId;
             final int displayId = mAmWmState.getAmState().getStackById(actualStackId).mDisplayId;
             final int newDeviceRotation = getDeviceRotation(displayId);
             if (newDeviceRotation == INVALID_DEVICE_ROTATION) {
                 logE("Got an invalid device rotation value. "
                         + "Continuing the test despite of that, but it is likely to fail.");
             } else if (newDeviceRotation != initialRotation) {
                 log("This device doesn't support user rotation "
                         + "mode. Not continuing the rotation checks.");
                 return;
             }

             for (int rotation = 0; rotation < 4; rotation += rotationStep) {
                 final LogSeparator logSeparator = separateLogs();
                 rotationSession.set(rotation);
                 mAmWmState.computeState(activityName);
                 assertRelaunchOrConfigChanged(activityName, numRelaunch, numConfigChange,
                         logSeparator);
             }
         }
     }

     /** Helper class to save, set, and restore font_scale preferences. */
     private static class FontScaleSession extends SettingsSession<Float> {
         FontScaleSession() {
             super(Settings.System.getUriFor(Settings.System.FONT_SCALE),
                     Settings.System::getFloat,
                     Settings.System::putFloat);
         }
     }

     private void testChangeFontScale(
             ComponentName activityName, boolean relaunch) throws Exception {
         try (final FontScaleSession fontScaleSession = new FontScaleSession()) {
             fontScaleSession.set(1.0f);
             LogSeparator logSeparator = separateLogs();
             launchActivity(activityName);
             mAmWmState.computeState(activityName);

             final int densityDpi = getActivityDensityDpi(activityName, logSeparator);

             for (float fontScale = 0.85f; fontScale <= 1.3f; fontScale += 0.15f) {
                 logSeparator = separateLogs();
                 fontScaleSession.set(fontScale);
                 mAmWmState.computeState(activityName);
                 assertRelaunchOrConfigChanged(activityName, relaunch ? 1 : 0, relaunch ? 0 : 1,
                         logSeparator);

                 // Verify that the display metrics are updated, and therefore the text size is also
                 // updated accordingly.
                 assertExpectedFontPixelSize(activityName,
                         scaledPixelsToPixels(EXPECTED_FONT_SIZE_SP, fontScale, densityDpi),
                         logSeparator);
             }
         }
     }

     /**
      * Test updating application info when app is running. An activity with matching package name
      * must be recreated and its asset sequence number must be incremented.
      */
     @Test
     public void testUpdateApplicationInfo() throws Exception {
         final LogSeparator firstLogSeparator = separateLogs();

         // Launch an activity that prints applied config.
         launchActivity(TEST_ACTIVITY);
         final int assetSeq = readAssetSeqNumber(TEST_ACTIVITY, firstLogSeparator);

         final LogSeparator logSeparator = separateLogs();
         // Update package info.
         executeShellCommand("am update-appinfo all " + TEST_ACTIVITY.getPackageName());
         mAmWmState.waitForWithAmState((amState) -> {
             // Wait for activity to be resumed and asset seq number to be updated.
             try {
                 return readAssetSeqNumber(TEST_ACTIVITY, logSeparator) == assetSeq + 1
                         && amState.hasActivityState(TEST_ACTIVITY, STATE_RESUMED);
             } catch (Exception e) {
                 logE("Error waiting for valid state: " + e.getMessage());
                 return false;
             }
         }, "Waiting asset sequence number to be updated and for activity to be resumed.");

         // Check if activity is relaunched and asset seq is updated.
         assertRelaunchOrConfigChanged(TEST_ACTIVITY, 1 /* numRelaunch */,
                 0 /* numConfigChange */, logSeparator);
         final int newAssetSeq = readAssetSeqNumber(TEST_ACTIVITY, logSeparator);
         assertEquals("Asset sequence number must be incremented.", assetSeq + 1, newAssetSeq);
     }

     private static final Pattern sConfigurationPattern = Pattern.compile(
             "(.+): Configuration: \\{(.*) as.(\\d+)(.*)\\}");

     /** Read asset sequence number in last applied configuration from logs. */
     private int readAssetSeqNumber(ComponentName activityName, LogSeparator logSeparator)
             throws Exception {
         final String[] lines = getDeviceLogsForComponents(logSeparator, getLogTag(activityName));
         for (int i = lines.length - 1; i >= 0; i--) {
             final String line = lines[i].trim();
             final Matcher matcher = sConfigurationPattern.matcher(line);
             if (matcher.matches()) {
                 final String assetSeqNumber = matcher.group(3);
                 try {
                     return Integer.valueOf(assetSeqNumber);
                 } catch (NumberFormatException e) {
                     // Ignore, asset seq number is not printed when not set.
                 }
             }
         }
         return 0;
     }

     // Calculate the scaled pixel size just like the device is supposed to.
     private static int scaledPixelsToPixels(float sp, float fontScale, int densityDpi) {
         final int DEFAULT_DENSITY = 160;
         float f = densityDpi * (1.0f / DEFAULT_DENSITY) * fontScale * sp;
         return (int) ((f >= 0) ? (f + 0.5f) : (f - 0.5f));
     }

     private static Pattern sDeviceDensityPattern = Pattern.compile("^(.+): fontActivityDpi=(.+)$");

     private int getActivityDensityDpi(ComponentName activityName, LogSeparator logSeparator)
             throws Exception {
         final String[] lines = getDeviceLogsForComponents(logSeparator, getLogTag(activityName));
         for (int i = lines.length - 1; i >= 0; i--) {
             final String line = lines[i].trim();
             final Matcher matcher = sDeviceDensityPattern.matcher(line);
             if (matcher.matches()) {
                 return Integer.parseInt(matcher.group(2));
             }
         }
         fail("No fontActivityDpi reported from activity " + activityName);
         return -1;
     }

     private static final Pattern sFontSizePattern = Pattern.compile("^(.+): fontPixelSize=(.+)$");

     /** Read the font size in the last log line. */
     private void assertExpectedFontPixelSize(ComponentName activityName, int fontPixelSize,
             LogSeparator logSeparator) throws Exception {
         final String[] lines = getDeviceLogsForComponents(logSeparator, getLogTag(activityName));
         for (int i = lines.length - 1; i >= 0; i--) {
             final String line = lines[i].trim();
             final Matcher matcher = sFontSizePattern.matcher(line);
             if (matcher.matches()) {
                 assertEquals("Expected font pixel size does not match", fontPixelSize,
                         Integer.parseInt(matcher.group(2)));
                 return;
             }
         }
         fail("No fontPixelSize reported from activity " + activityName);
     }
 }
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* 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 android.server.am;

	import static android.server.am.ActivityManagerState.STATE_RESUMED;
	import static android.server.am.ComponentNameUtils.getLogTag;
	import static android.server.am.Components.FONT_SCALE_ACTIVITY;
	import static android.server.am.Components.FONT_SCALE_NO_RELAUNCH_ACTIVITY;
	import static android.server.am.Components.NO_RELAUNCH_ACTIVITY;
	import static android.server.am.Components.RESIZEABLE_ACTIVITY;
	import static android.server.am.Components.TEST_ACTIVITY;
	import static android.server.am.StateLogger.log;
	import static android.server.am.StateLogger.logE;
	import static android.view.Surface.ROTATION_0;
	import static android.view.Surface.ROTATION_180;
	import static android.view.Surface.ROTATION_270;
	import static android.view.Surface.ROTATION_90;

	import static org.hamcrest.MatcherAssert.assertThat;
	import static org.junit.Assert.assertEquals;
	import static org.junit.Assert.fail;
	import static org.junit.Assume.assumeFalse;
	import static org.junit.Assume.assumeTrue;

	import android.content.ComponentName;
	import android.platform.test.annotations.Presubmit;
	import android.provider.Settings;
	import android.server.am.settings.SettingsSession;

	import androidx.test.filters.FlakyTest;

	import org.junit.Test;

	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	/**
	* Build/Install/Run:
	* atest CtsActivityManagerDeviceTestCases:ActivityManagerConfigChangeTests
	*/
	public class ActivityManagerConfigChangeTests extends ActivityManagerTestBase {

	private static final float EXPECTED_FONT_SIZE_SP = 10.0f;

	@Test
	public void testRotation90Relaunch() throws Exception{
	assumeTrue("Skipping test: no rotation support", supportsRotation());

	// Should relaunch on every rotation and receive no onConfigurationChanged()
	testRotation(TEST_ACTIVITY, 1, 1, 0);
	}

	@Test
	public void testRotation90NoRelaunch() throws Exception {
	assumeTrue("Skipping test: no rotation support", supportsRotation());

	// Should receive onConfigurationChanged() on every rotation and no relaunch
	testRotation(NO_RELAUNCH_ACTIVITY, 1, 0, 1);
	}

	// TODO(b/110382028): Fix relaunch testing and use an activity that doesn't handle config change
	@Test
	public void testRotation180Relaunch() throws Exception {
	assumeTrue("Skipping test: no rotation support", supportsRotation());
	// TODO(b/110533226): Fix test on devices with display cutout
	assumeFalse("Skipping test: display cutout present, can't predict exact lifecycle",
	hasDisplayCutout());

	// Should receive a relaunch
	testRotation(TEST_ACTIVITY, 2, 0, 0);
	}

	@Test
	public void testRotation180NoRelaunch() throws Exception {
	assumeTrue("Skipping test: no rotation support", supportsRotation());
	// TODO(b/110533226): Fix test on devices with display cutout
	assumeFalse("Skipping test: display cutout present, can't predict exact lifecycle",
	hasDisplayCutout());

	// Should receive nothing
	testRotation(NO_RELAUNCH_ACTIVITY, 2, 0, 0);
	}

	@FlakyTest(bugId = 73701185)
	@Presubmit
	@Test
	public void testChangeFontScaleRelaunch() throws Exception {
	// Should relaunch and receive no onConfigurationChanged()
	testChangeFontScale(FONT_SCALE_ACTIVITY, true /* relaunch */);
	}

	@FlakyTest(bugId = 73812451)
	@Presubmit
	@Test
	public void testChangeFontScaleNoRelaunch() throws Exception {
	// Should receive onConfigurationChanged() and no relaunch
	testChangeFontScale(FONT_SCALE_NO_RELAUNCH_ACTIVITY, false /* relaunch */);
	}

	/**
	* Test activity configuration changes for devices with cutout(s). Landscape and
	* reverse-landscape rotations should result in same screen space available for apps.
	*/
	@Test
	public void testConfigChangeWhenRotatingWithCutout() throws Exception {
	assumeTrue("Skipping test: no rotation support", supportsRotation());
	assumeTrue("Skipping test: no display cutout", hasDisplayCutout());

	// Start an activity that handles config changes
	launchActivity(RESIZEABLE_ACTIVITY);
	mAmWmState.assertVisibility(RESIZEABLE_ACTIVITY, true /* visible */);
	final int displayId = mAmWmState.getAmState().getDisplayByActivity(RESIZEABLE_ACTIVITY);

	// 0 - 180 rotation or 270 - 90 rotation should have same screen space
	boolean configSame0_180 = false, configSame270_90 = false;
	final int[] cutoutRotations = { ROTATION_180, ROTATION_90, ROTATION_270 };

	// Rotate the activity and check that the orientation doesn't change at least once
	try (final RotationSession rotationSession = new RotationSession()) {
	rotationSession.set(ROTATION_0);

	final ReportedSizes[] sizes = new ReportedSizes[cutoutRotations.length];
	for (int i = 0; i < cutoutRotations.length; i++) {
	final int rotation = cutoutRotations[i];
	final LogSeparator logSeparator = separateLogs();
	rotationSession.set(rotation);
	final int newDeviceRotation = getDeviceRotation(displayId);
	if (rotation != newDeviceRotation) {
	log("This device doesn't support locked user "
	+ "rotation mode. Not continuing the rotation checks.");
	continue;
	}

	// Record configuration changes on rotations between opposite orientations
	sizes[i] = getLastReportedSizesForActivity(RESIZEABLE_ACTIVITY, logSeparator);
	if (i == 0) {
	configSame0_180 = sizes[i] == null;
	} else if (i == 2) {
	configSame270_90 = sizes[i] == null;
	}
	}

	assertThat("A device with cutout should have same available screen space in "
	+ "landscape and reverse-landscape", configSame0_180 \|\| configSame270_90);
	}
	}

	private void testRotation(ComponentName activityName, int rotationStep, int numRelaunch,
	int numConfigChange) throws Exception {
	launchActivity(activityName);

	mAmWmState.computeState(activityName);

	final int initialRotation = 4 - rotationStep;
	try (final RotationSession rotationSession = new RotationSession()) {
	rotationSession.set(initialRotation);
	mAmWmState.computeState(activityName);
	final int actualStackId =
	mAmWmState.getAmState().getTaskByActivity(activityName).mStackId;
	final int displayId = mAmWmState.getAmState().getStackById(actualStackId).mDisplayId;
	final int newDeviceRotation = getDeviceRotation(displayId);
	if (newDeviceRotation == INVALID_DEVICE_ROTATION) {
	logE("Got an invalid device rotation value. "
	+ "Continuing the test despite of that, but it is likely to fail.");
	} else if (newDeviceRotation != initialRotation) {
	log("This device doesn't support user rotation "
	+ "mode. Not continuing the rotation checks.");
	return;
	}

	for (int rotation = 0; rotation < 4; rotation += rotationStep) {
	final LogSeparator logSeparator = separateLogs();
	rotationSession.set(rotation);
	mAmWmState.computeState(activityName);
	assertRelaunchOrConfigChanged(activityName, numRelaunch, numConfigChange,
	logSeparator);
	}
	}
	}

	/** Helper class to save, set, and restore font_scale preferences. */
	private static class FontScaleSession extends SettingsSession<Float> {
	FontScaleSession() {
	super(Settings.System.getUriFor(Settings.System.FONT_SCALE),
	Settings.System::getFloat,
	Settings.System::putFloat);
	}
	}

	private void testChangeFontScale(
	ComponentName activityName, boolean relaunch) throws Exception {
	try (final FontScaleSession fontScaleSession = new FontScaleSession()) {
	fontScaleSession.set(1.0f);
	LogSeparator logSeparator = separateLogs();
	launchActivity(activityName);
	mAmWmState.computeState(activityName);

	final int densityDpi = getActivityDensityDpi(activityName, logSeparator);

	for (float fontScale = 0.85f; fontScale <= 1.3f; fontScale += 0.15f) {
	logSeparator = separateLogs();
	fontScaleSession.set(fontScale);
	mAmWmState.computeState(activityName);
	assertRelaunchOrConfigChanged(activityName, relaunch ? 1 : 0, relaunch ? 0 : 1,
	logSeparator);

	// Verify that the display metrics are updated, and therefore the text size is also
	// updated accordingly.
	assertExpectedFontPixelSize(activityName,
	scaledPixelsToPixels(EXPECTED_FONT_SIZE_SP, fontScale, densityDpi),
	logSeparator);
	}
	}
	}

	/**
	* Test updating application info when app is running. An activity with matching package name
	* must be recreated and its asset sequence number must be incremented.
	*/
	@Test
	public void testUpdateApplicationInfo() throws Exception {
	final LogSeparator firstLogSeparator = separateLogs();

	// Launch an activity that prints applied config.
	launchActivity(TEST_ACTIVITY);
	final int assetSeq = readAssetSeqNumber(TEST_ACTIVITY, firstLogSeparator);

	final LogSeparator logSeparator = separateLogs();
	// Update package info.
	executeShellCommand("am update-appinfo all " + TEST_ACTIVITY.getPackageName());
	mAmWmState.waitForWithAmState((amState) -> {
	// Wait for activity to be resumed and asset seq number to be updated.
	try {
	return readAssetSeqNumber(TEST_ACTIVITY, logSeparator) == assetSeq + 1
	&& amState.hasActivityState(TEST_ACTIVITY, STATE_RESUMED);
	} catch (Exception e) {
	logE("Error waiting for valid state: " + e.getMessage());
	return false;
	}
	}, "Waiting asset sequence number to be updated and for activity to be resumed.");

	// Check if activity is relaunched and asset seq is updated.
	assertRelaunchOrConfigChanged(TEST_ACTIVITY, 1 /* numRelaunch */,
	0 /* numConfigChange */, logSeparator);
	final int newAssetSeq = readAssetSeqNumber(TEST_ACTIVITY, logSeparator);
	assertEquals("Asset sequence number must be incremented.", assetSeq + 1, newAssetSeq);
	}

	private static final Pattern sConfigurationPattern = Pattern.compile(
	"(.+): Configuration: \\{(.) as.(\\d+)(.)\\}");

	/** Read asset sequence number in last applied configuration from logs. */
	private int readAssetSeqNumber(ComponentName activityName, LogSeparator logSeparator)
	throws Exception {
	final String[] lines = getDeviceLogsForComponents(logSeparator, getLogTag(activityName));
	for (int i = lines.length - 1; i >= 0; i--) {
	final String line = lines[i].trim();
	final Matcher matcher = sConfigurationPattern.matcher(line);
	if (matcher.matches()) {
	final String assetSeqNumber = matcher.group(3);
	try {
	return Integer.valueOf(assetSeqNumber);
	} catch (NumberFormatException e) {
	// Ignore, asset seq number is not printed when not set.
	}
	}
	}
	return 0;
	}

	// Calculate the scaled pixel size just like the device is supposed to.
	private static int scaledPixelsToPixels(float sp, float fontScale, int densityDpi) {
	final int DEFAULT_DENSITY = 160;
	float f = densityDpi * (1.0f / DEFAULT_DENSITY) * fontScale * sp;
	return (int) ((f >= 0) ? (f + 0.5f) : (f - 0.5f));
	}

	private static Pattern sDeviceDensityPattern = Pattern.compile("^(.+): fontActivityDpi=(.+)$");

	private int getActivityDensityDpi(ComponentName activityName, LogSeparator logSeparator)
	throws Exception {
	final String[] lines = getDeviceLogsForComponents(logSeparator, getLogTag(activityName));
	for (int i = lines.length - 1; i >= 0; i--) {
	final String line = lines[i].trim();
	final Matcher matcher = sDeviceDensityPattern.matcher(line);
	if (matcher.matches()) {
	return Integer.parseInt(matcher.group(2));
	}
	}
	fail("No fontActivityDpi reported from activity " + activityName);
	return -1;
	}

	private static final Pattern sFontSizePattern = Pattern.compile("^(.+): fontPixelSize=(.+)$");

	/** Read the font size in the last log line. */
	private void assertExpectedFontPixelSize(ComponentName activityName, int fontPixelSize,
	LogSeparator logSeparator) throws Exception {
	final String[] lines = getDeviceLogsForComponents(logSeparator, getLogTag(activityName));
	for (int i = lines.length - 1; i >= 0; i--) {
	final String line = lines[i].trim();
	final Matcher matcher = sFontSizePattern.matcher(line);
	if (matcher.matches()) {
	assertEquals("Expected font pixel size does not match", fontPixelSize,
	Integer.parseInt(matcher.group(2)));
	return;
	}
	}
	fail("No fontPixelSize reported from activity " + activityName);
	}
	}