// Copyright 2019 The Chromium Authors
// 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.homepage;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.VisibleForTesting;
import org.chromium.base.ObserverList;
import org.chromium.base.ResettersForTesting;
import org.chromium.base.shared_preferences.SharedPreferencesManager;
import org.chromium.chrome.browser.init.ChromeBrowserInitializer;
import org.chromium.chrome.browser.preferences.ChromePreferenceKeys;
import org.chromium.chrome.browser.preferences.ChromeSharedPreferences;
import org.chromium.chrome.browser.preferences.Pref;
import org.chromium.chrome.browser.preferences.PrefChangeRegistrar;
import org.chromium.chrome.browser.preferences.PrefChangeRegistrar.PrefObserver;
import org.chromium.chrome.browser.profiles.ProfileManager;
import org.chromium.components.prefs.PrefService;
import org.chromium.components.user_prefs.UserPrefs;
import org.chromium.url.GURL;
/**
* Provides information for the home page related policies.
* Monitors changes for the homepage preference.
*/
public class HomepagePolicyManager implements PrefObserver {
/** An interface to receive updates from {@link HomepagePolicyManager}. */
public interface HomepagePolicyStateListener {
/**
* Will be called when homepage policy status change. Though cases are rare, when homepage
* policy has changed during runtime, listeners will receive updates.
*/
void onHomepagePolicyUpdate();
}
private static HomepagePolicyManager sInstance;
private static PrefService sPrefServiceForTesting;
private boolean mIsHomepageLocationPolicyEnabled;
@NonNull private GURL mHomepage;
private boolean mIsInitializedWithNative;
private PrefChangeRegistrar mPrefChangeRegistrar;
private final SharedPreferencesManager mSharedPreferenceManager;
private final ObserverList<HomepagePolicyStateListener> mListeners = new ObserverList<>();
/**
* @return The singleton instance of {@link HomepagePolicyManager}.
*/
static HomepagePolicyManager getInstance() {
if (sInstance == null) {
sInstance = new HomepagePolicyManager();
}
return sInstance;
}
/**
* If policies such as HomepageLocation are enabled on this device, the home page will be marked
* as managed.
* @return True if the current home page is managed by enterprise policy.
*/
public static boolean isHomepageManagedByPolicy() {
return getInstance().isHomepageLocationPolicyEnabled();
}
/**
* Returns whether the HomepagePolicyManager has been initialized with native. The
* HomepagePolicyManager can only return valid result after initialing with native.
*/
public static boolean isInitializedWithNative() {
return getInstance().isInitialized();
}
/**
* @return The homepage URL from the homepage preference.
*/
public static @NonNull GURL getHomepageUrl() {
return getInstance().getHomepagePreference();
}
/**
* Adds a HomepagePolicyStateListener to receive updates when the homepage policy changes.
* @param listener Object that would like to listen to changes from homepage policy.
*/
public void addListener(HomepagePolicyStateListener listener) {
mListeners.addObserver(listener);
}
/**
* Stop observing pref changes and destroy the singleton instance.
* Will be called from {@link org.chromium.chrome.browser.ChromeActivitySessionTracker}.
*/
public static void destroy() {
sInstance.destroyInternal();
sInstance = null;
}
public static void setInstanceForTests(HomepagePolicyManager instance) {
var oldValue = sInstance;
sInstance = instance;
ResettersForTesting.register(() -> sInstance = oldValue);
}
@VisibleForTesting
HomepagePolicyManager() {
mIsInitializedWithNative = false;
mPrefChangeRegistrar = null;
// Update feature flag related setting
mSharedPreferenceManager = ChromeSharedPreferences.getInstance();
String homepageLocationPolicyGurlSerialized =
mSharedPreferenceManager.readString(
ChromePreferenceKeys.HOMEPAGE_LOCATION_POLICY_GURL, null);
if (homepageLocationPolicyGurlSerialized != null) {
mHomepage = GURL.deserialize(homepageLocationPolicyGurlSerialized);
} else {
String homepageLocationPolicy;
homepageLocationPolicy =
mSharedPreferenceManager.readString(
ChromePreferenceKeys.DEPRECATED_HOMEPAGE_LOCATION_POLICY, null);
if (homepageLocationPolicy != null) {
// This url comes from a native gurl that is written into PrefService as a string,
// so we shouldn't need to call fixupUrl.
mHomepage = new GURL(homepageLocationPolicy);
} else {
mHomepage = GURL.emptyGURL();
}
}
mIsHomepageLocationPolicyEnabled = !mHomepage.isEmpty();
ChromeBrowserInitializer.getInstance()
.runNowOrAfterFullBrowserStarted(this::onFinishNativeInitialization);
}
/**
* Constructor for unit tests.
* @param prefChangeRegistrar Instance of {@link PrefChangeRegistrar} or test mocking.
* @param listener Object extends {@link HomepagePolicyStateListener}. Will be added between
* singleton {@link HomepagePolicyManager} created, and have it initialized with {@link
* #initializeWithNative(PrefChangeRegistrar)} so that it will get the update from
* {@link HomepagePolicyStateListener#onHomepagePolicyUpdate()}.
*/
@VisibleForTesting
HomepagePolicyManager(
@NonNull PrefChangeRegistrar prefChangeRegistrar,
@Nullable HomepagePolicyStateListener listener) {
this();
if (listener != null) addListener(listener);
initializeWithNative(prefChangeRegistrar);
}
/**
* Initialize the instance with preference registrar, and start listen to changes for homepage
* preference.
* @param prefChangeRegistrar Instance of {@link PrefChangeRegistrar} or test mocking.
*/
@VisibleForTesting
void initializeWithNative(PrefChangeRegistrar prefChangeRegistrar) {
mPrefChangeRegistrar = prefChangeRegistrar;
mPrefChangeRegistrar.addObserver(Pref.HOME_PAGE, this);
mIsInitializedWithNative = true;
refresh();
}
@Override
public void onPreferenceChange() {
refresh();
}
private void destroyInternal() {
if (mPrefChangeRegistrar != null) mPrefChangeRegistrar.destroy();
mListeners.clear();
}
private void refresh() {
assert mIsInitializedWithNative;
PrefService prefService = getPrefService();
boolean isEnabled = prefService.isManagedPreference(Pref.HOME_PAGE);
GURL homepage = GURL.emptyGURL();
if (isEnabled) {
String homepagePref = prefService.getString(Pref.HOME_PAGE);
assert homepagePref != null;
// This url comes from a native gurl that is written into PrefService as a string,
// so we shouldn't need to call fixupUrl.
homepage = new GURL(homepagePref);
}
// Early return when nothing changes
if (isEnabled == mIsHomepageLocationPolicyEnabled
&& homepage != null
&& homepage.equals(mHomepage)) {
return;
}
mIsHomepageLocationPolicyEnabled = isEnabled;
mHomepage = homepage;
// Update shared preference
mSharedPreferenceManager.writeString(
ChromePreferenceKeys.HOMEPAGE_LOCATION_POLICY_GURL, mHomepage.serialize());
// Update the listeners about the status
for (HomepagePolicyStateListener listener : mListeners) {
listener.onHomepagePolicyUpdate();
}
}
/** Called when the native library has finished loading. */
private void onFinishNativeInitialization() {
if (!mIsInitializedWithNative) initializeWithNative(new PrefChangeRegistrar());
}
private PrefService getPrefService() {
if (sPrefServiceForTesting != null) return sPrefServiceForTesting;
return UserPrefs.get(ProfileManager.getLastUsedRegularProfile());
}
public static void setPrefServiceForTesting(PrefService prefService) {
sPrefServiceForTesting = prefService;
ResettersForTesting.register(() -> sPrefServiceForTesting = null);
}
@VisibleForTesting
public boolean isHomepageLocationPolicyEnabled() {
return mIsHomepageLocationPolicyEnabled;
}
@VisibleForTesting
public @NonNull GURL getHomepagePreference() {
assert mIsHomepageLocationPolicyEnabled;
return mHomepage;
}
@VisibleForTesting
boolean isInitialized() {
return mIsInitializedWithNative;
}
ObserverList<HomepagePolicyStateListener> getListenersForTesting() {
return mListeners;
}
}
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