Merge pull request #22862 from brave/toggle_window_android

[Android] Toggle window

android/java/apk_for_test.flags

@@ -525,6 +525,30 @@
     public <init>(...);
 }
 
+-keep class org.chromium.chrome.browser.multiwindow.MultiInstanceManagerApi31 {
+    *** mInstanceId;
+    moveTabAction(...);
+    handleMenuOrKeyboardAction(...);
+    <init>(...);
+}
+
+-keep class org.chromium.chrome.browser.multiwindow.BraveMultiInstanceManagerApi31 {
+    <init>(...);
+}
+
+-keep class org.chromium.chrome.browser.multiwindow.MultiWindowUtils {
+    *** shouldShowManageWindowsMenu(...);
+    *** isOpenInOtherWindowSupported(...);
+    *** isMoveToOtherWindowSupported(...);
+    *** canEnterMultiWindowMode(...);
+    <init>(...);
+}
+
+-keep class org.chromium.chrome.browser.multiwindow.BraveMultiWindowUtils {
+    *** shouldShowManageWindowsMenu(...);
+    public <init>(...);
+}
+
 -keep class org.chromium.chrome.browser.notifications.permissions.NotificationPermissionRationaleDialogController {
     *** wrapDialogDismissalCallback(...);
     public <init>(...);

android/java/org/chromium/base/BravePreferenceKeys.java

@@ -54,6 +54,8 @@ public final class BravePreferenceKeys {
     public static final String BRAVE_CLEAR_ON_EXIT = "clear_on_exit";
     public static final String BRAVE_QUICK_ACTION_SEARCH_AND_BOOKMARK_WIDGET_TILES =
             "org.chromium.chrome.browser.widget.quickactionsearchandbookmark.QuickActionSearchAndBookmarkWidgetProvider.TILES";
+    public static final String ENABLE_MULTI_WINDOWS = "enable_multi_windows";
+    public static final String ENABLE_MULTI_WINDOWS_UPGRADE = "enable_multi_windows_upgrade";
 
     public static final String BRAVE_LEO_AUTOCOMPLETE =
             "org.chromium.chrome.browser.Brave_Leo_AutoComplete";

android/java/org/chromium/chrome/browser/app/BraveActivity.java

@@ -123,6 +123,9 @@ import org.chromium.chrome.browser.fullscreen.BrowserControlsManager;
 import org.chromium.chrome.browser.informers.BraveSyncAccountDeletedInformer;
 import org.chromium.chrome.browser.misc_metrics.MiscAndroidMetricsConnectionErrorHandler;
 import org.chromium.chrome.browser.misc_metrics.MiscAndroidMetricsFactory;
+import org.chromium.chrome.browser.multiwindow.BraveMultiWindowUtils;
+import org.chromium.chrome.browser.multiwindow.MultiInstanceManager;
+import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
 import org.chromium.chrome.browser.notifications.BraveNotificationWarningDialog;
 import org.chromium.chrome.browser.notifications.permissions.NotificationPermissionController;
 import org.chromium.chrome.browser.notifications.retention.RetentionNotificationUtil;
@@ -1188,6 +1191,17 @@ public abstract class BraveActivity extends ChromeActivity
             calender.add(Calendar.DATE, DAYS_7);
             BraveRewardsHelper.setRewardsOnboardingIconTiming(calender.getTimeInMillis());
         }
+
+        // Check multiwindow toggle for upgrade case
+        if (!isFirstInstall
+                && !BraveMultiWindowUtils.isCheckUpgradeEnableMultiWindows()
+                && MultiWindowUtils.getInstanceCount() > 1
+                && !BraveMultiWindowUtils.shouldEnableMultiWindows()) {
+            BraveMultiWindowUtils.setCheckUpgradeEnableMultiWindows(true);
+            BraveMultiWindowUtils.updateEnableMultiWindows(true);
+        } else if (!BraveMultiWindowUtils.isCheckUpgradeEnableMultiWindows()) {
+            BraveMultiWindowUtils.setCheckUpgradeEnableMultiWindows(true);
+        }
     }
 
     @Override
@@ -2232,4 +2246,10 @@ public abstract class BraveActivity extends ChromeActivity
     public RootUiCoordinator getRootUiCoordinator() {
         return mRootUiCoordinator;
     }
+
+    public MultiInstanceManager getMultiInstanceManager() {
+        return (MultiInstanceManager)
+                BraveReflectionUtil.getField(
+                        ChromeTabbedActivity.class, "mMultiInstanceManager", this);
+    }
 }

android/java/org/chromium/chrome/browser/app/appmenu/BraveAppMenuPropertiesDelegateImpl.java

@@ -21,6 +21,7 @@ import org.chromium.chrome.browser.ActivityTabProvider;
 import org.chromium.chrome.browser.bookmarks.BookmarkModel;
 import org.chromium.chrome.browser.incognito.reauth.IncognitoReauthController;
 import org.chromium.chrome.browser.layouts.LayoutStateProvider;
+import org.chromium.chrome.browser.multiwindow.BraveMultiWindowUtils;
 import org.chromium.chrome.browser.multiwindow.MultiWindowModeStateDispatcher;
 import org.chromium.chrome.browser.readaloud.ReadAloudController;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
@@ -121,4 +122,15 @@ public class BraveAppMenuPropertiesDelegateImpl extends AppMenuPropertiesDelegat
             }
         }
     }
+
+    @Override
+    protected boolean shouldShowNewWindow() {
+        return BraveMultiWindowUtils.shouldEnableMultiWindows() && super.shouldShowNewWindow();
+    }
+
+    @Override
+    protected boolean shouldShowMoveToOtherWindow() {
+        return BraveMultiWindowUtils.shouldEnableMultiWindows()
+                && super.shouldShowMoveToOtherWindow();
+    }
 }

android/java/org/chromium/chrome/browser/multiwindow/BraveMultiInstanceManagerApi31.java

@@ -0,0 +1,94 @@
+/* Copyright (c) 2024 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+package org.chromium.chrome.browser.multiwindow;
+
+import android.app.Activity;
+
+import org.chromium.base.supplier.ObservableSupplier;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.app.tabmodel.TabModelOrchestrator;
+import org.chromium.chrome.browser.app.tabmodel.TabWindowManagerSingleton;
+import org.chromium.chrome.browser.lifecycle.ActivityLifecycleDispatcher;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.tabmodel.TabModelSelector;
+import org.chromium.chrome.browser.ui.messages.snackbar.Snackbar;
+import org.chromium.chrome.browser.ui.messages.snackbar.SnackbarManager;
+import org.chromium.chrome.browser.ui.messages.snackbar.SnackbarManager.SnackbarController;
+import org.chromium.chrome.browser.ui.messages.snackbar.SnackbarManagerProvider;
+import org.chromium.components.browser_ui.widget.MenuOrKeyboardActionController;
+import org.chromium.ui.modaldialog.ModalDialogManager;
+
+class BraveMultiInstanceManagerApi31 extends MultiInstanceManagerApi31 {
+
+    private static final String TAG = "MultiInstanceApi31";
+    private int mInstanceId;
+    private boolean mIsMoveTabsFromSettings;
+
+    BraveMultiInstanceManagerApi31(
+            Activity activity,
+            ObservableSupplier<TabModelOrchestrator> tabModelOrchestratorSupplier,
+            MultiWindowModeStateDispatcher multiWindowModeStateDispatcher,
+            ActivityLifecycleDispatcher activityLifecycleDispatcher,
+            ObservableSupplier<ModalDialogManager> modalDialogManagerSupplier,
+            MenuOrKeyboardActionController menuOrKeyboardActionController) {
+        super(
+                activity,
+                tabModelOrchestratorSupplier,
+                multiWindowModeStateDispatcher,
+                activityLifecycleDispatcher,
+                modalDialogManagerSupplier,
+                menuOrKeyboardActionController);
+    }
+
+    @Override
+    public boolean handleMenuOrKeyboardAction(int id, boolean fromMenu) {
+        if (id == org.chromium.chrome.R.id.move_to_other_window_menu_id) {
+            mIsMoveTabsFromSettings = !fromMenu;
+        }
+        return super.handleMenuOrKeyboardAction(id, fromMenu);
+    }
+
+    @Override
+    public void moveTabAction(InstanceInfo info, Tab tab, int tabAtIndex) {
+        super.moveTabAction(info, tab, tabAtIndex);
+        if (mIsMoveTabsFromSettings) {
+            mIsMoveTabsFromSettings = false;
+            TabModelSelector selector =
+                    TabWindowManagerSingleton.getInstance().getTabModelSelectorById(mInstanceId);
+            if (selector.getTotalTabCount() == 0) {
+                closeInstance(mInstanceId, INVALID_TASK_ID);
+            }
+            if (MultiWindowUtils.getInstanceCount() == 1) {
+                BraveMultiWindowUtils.updateEnableMultiWindows(false);
+            } else {
+                Snackbar snackbar =
+                        Snackbar.make(
+                                        mActivity
+                                                .getResources()
+                                                .getString(R.string.merge_windows_snackbar),
+                                        new SnackbarController() {
+                                            @Override
+                                            public void onDismissNoAction(Object actionData) {}
+
+                                            @Override
+                                            public void onAction(Object actionData) {
+                                                BraveMultiWindowUtils.mergeWindows(null);
+                                            }
+                                        },
+                                        Snackbar.TYPE_ACTION,
+                                        Snackbar.UMA_UNKNOWN)
+                                .setAction(
+                                        mActivity.getResources().getString(R.string.merge_windows),
+                                        null)
+                                .setSingleLine(false)
+                                .setDuration(10000);
+                SnackbarManager snackbarManager =
+                        SnackbarManagerProvider.from(tab.getWindowAndroid());
+                snackbarManager.showSnackbar(snackbar);
+            }
+        }
+    }
+}

android/java/org/chromium/chrome/browser/multiwindow/BraveMultiWindowDialogFragment.java

@@ -0,0 +1,80 @@
+/* Copyright (c) 2024 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+package org.chromium.chrome.browser.multiwindow;
+
+import android.content.DialogInterface;
+import android.graphics.Color;
+import android.graphics.drawable.ColorDrawable;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.Window;
+import android.widget.Button;
+
+import androidx.annotation.NonNull;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.BraveDialogFragment;
+
+public class BraveMultiWindowDialogFragment extends BraveDialogFragment {
+
+    private static final String TAG = "MultiWindowDialog";
+
+    public interface DismissListener {
+        void onDismiss();
+    }
+
+    private DismissListener mListener;
+
+    public void setDismissListener(DismissListener listener) {
+        mListener = listener;
+    }
+
+    @Override
+    public void onDismiss(@NonNull DialogInterface dialog) {
+        super.onDismiss(dialog);
+        if (mListener != null) {
+            mListener.onDismiss();
+        }
+    }
+
+    public static BraveMultiWindowDialogFragment newInstance() {
+        return new BraveMultiWindowDialogFragment();
+    }
+
+    @Override
+    public View onCreateView(
+            LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+        View view = inflater.inflate(R.layout.fragment_brave_multiwindow_dialog, container, false);
+
+        if (getDialog() != null && getDialog().getWindow() != null) {
+            getDialog().getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
+            getDialog().getWindow().requestFeature(Window.FEATURE_NO_TITLE);
+        }
+        return view;
+    }
+
+    @Override
+    public void onViewCreated(View view, Bundle savedInstanceState) {
+
+        Button mergeBtn = view.findViewById(R.id.btn_merge);
+        mergeBtn.setOnClickListener(
+                btn -> {
+                    BraveMultiWindowUtils.mergeWindows(getActivity());
+                    dismiss();
+                });
+        if (MultiWindowUtils.isMultiInstanceApi31Enabled()) {
+            Button closeBtn = view.findViewById(R.id.btn_close);
+            closeBtn.setVisibility(View.VISIBLE);
+            closeBtn.setOnClickListener(
+                    btn -> {
+                        BraveMultiWindowUtils.closeWindows();
+                        dismiss();
+                    });
+        }
+    }
+}

android/java/org/chromium/chrome/browser/multiwindow/BraveMultiWindowUtils.java

@@ -0,0 +1,109 @@
+/* Copyright (c) 2024 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+package org.chromium.chrome.browser.multiwindow;
+
+import android.app.Activity;
+import android.content.Intent;
+
+import org.chromium.base.BravePreferenceKeys;
+import org.chromium.base.Log;
+import org.chromium.chrome.browser.ChromeTabbedActivity;
+import org.chromium.chrome.browser.app.BraveActivity;
+import org.chromium.chrome.browser.preferences.ChromeSharedPreferences;
+import org.chromium.chrome.browser.tabmodel.TabModelSelector;
+
+import java.util.List;
+
+public class BraveMultiWindowUtils extends MultiWindowUtils {
+
+    private static final String TAG = "MultiWindowUtils";
+
+    public BraveMultiWindowUtils() {
+        super();
+    }
+
+    public static boolean shouldShowManageWindowsMenu() {
+        return shouldEnableMultiWindows() && MultiWindowUtils.shouldShowManageWindowsMenu();
+    }
+
+    @Override
+    public boolean isOpenInOtherWindowSupported(Activity activity) {
+        return shouldEnableMultiWindows() && super.isOpenInOtherWindowSupported(activity);
+    }
+
+    @Override
+    public boolean isMoveToOtherWindowSupported(
+            Activity activity, TabModelSelector tabModelSelector) {
+        return shouldEnableMultiWindows()
+                && super.isMoveToOtherWindowSupported(activity, tabModelSelector);
+    }
+
+    @Override
+    public boolean canEnterMultiWindowMode(Activity activity) {
+        return shouldEnableMultiWindows() && super.canEnterMultiWindowMode(activity);
+    }
+
+    public static boolean shouldEnableMultiWindows() {
+        return ChromeSharedPreferences.getInstance()
+                .readBoolean(BravePreferenceKeys.ENABLE_MULTI_WINDOWS, false);
+    }
+
+    public static void updateEnableMultiWindows(boolean isEnable) {
+        ChromeSharedPreferences.getInstance()
+                .writeBoolean(BravePreferenceKeys.ENABLE_MULTI_WINDOWS, isEnable);
+    }
+
+    public static boolean isCheckUpgradeEnableMultiWindows() {
+        return ChromeSharedPreferences.getInstance()
+                .readBoolean(BravePreferenceKeys.ENABLE_MULTI_WINDOWS_UPGRADE, false);
+    }
+
+    public static void setCheckUpgradeEnableMultiWindows(boolean isUpgradeCheck) {
+        ChromeSharedPreferences.getInstance()
+                .writeBoolean(BravePreferenceKeys.ENABLE_MULTI_WINDOWS_UPGRADE, isUpgradeCheck);
+    }
+
+    public static void mergeWindows(Activity activity) {
+        try {
+            MultiInstanceManager multiInstanceManager =
+                    BraveActivity.getBraveActivity().getMultiInstanceManager();
+            if (multiInstanceManager != null) {
+                multiInstanceManager.handleMenuOrKeyboardAction(
+                        org.chromium.chrome.R.id.move_to_other_window_menu_id, false);
+                if (activity != null) {
+                    Intent intent = new Intent(activity, ChromeTabbedActivity.class);
+                    intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
+                    intent.setAction(Intent.ACTION_VIEW);
+                    activity.startActivity(intent);
+                }
+            }
+        } catch (BraveActivity.BraveActivityNotFoundException e) {
+            Log.e(TAG, "get BraveActivity exception", e);
+        }
+    }
+
+    public static void closeWindows() {
+        try {
+            MultiInstanceManager multiInstanceManager =
+                    BraveActivity.getBraveActivity().getMultiInstanceManager();
+            if (multiInstanceManager != null) {
+                if (multiInstanceManager instanceof MultiInstanceManagerApi31) {
+                    MultiInstanceManagerApi31 multiInstanceManagerApi31 =
+                            ((MultiInstanceManagerApi31) multiInstanceManager);
+                    List<InstanceInfo> allInstances = multiInstanceManagerApi31.getInstanceInfo();
+                    if (allInstances != null && allInstances.size() > 1) {
+                        for (int i = 1; i < allInstances.size(); i++) {
+                            multiInstanceManagerApi31.closeInstance(
+                                    allInstances.get(i).instanceId, allInstances.get(i).taskId);
+                        }
+                    }
+                }
+            }
+        } catch (BraveActivity.BraveActivityNotFoundException e) {
+            Log.e(TAG, "get BraveActivity exception", e);
+        }
+    }
+}

android/java/org/chromium/chrome/browser/settings/AppearancePreferences.java

@@ -14,6 +14,7 @@ import androidx.preference.Preference;
 
 import org.chromium.base.BraveFeatureList;
 import org.chromium.base.BravePreferenceKeys;
+import org.chromium.base.BuildInfo;
 import org.chromium.base.ContextUtils;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.BraveFeatureUtil;
@@ -21,6 +22,9 @@ import org.chromium.chrome.browser.BraveRelaunchUtils;
 import org.chromium.chrome.browser.BraveRewardsNativeWorker;
 import org.chromium.chrome.browser.BraveRewardsObserver;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
+import org.chromium.chrome.browser.multiwindow.BraveMultiWindowDialogFragment;
+import org.chromium.chrome.browser.multiwindow.BraveMultiWindowUtils;
+import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
 import org.chromium.chrome.browser.night_mode.NightModeUtils;
 import org.chromium.chrome.browser.preferences.BravePref;
 import org.chromium.chrome.browser.preferences.ChromeSharedPreferences;
@@ -43,17 +47,20 @@ public class AppearancePreferences extends BravePreferenceFragment
     public static final String PREF_BRAVE_DISABLE_SHARING_HUB = "brave_disable_sharing_hub";
     public static final String PREF_BRAVE_ENABLE_TAB_GROUPS = "brave_enable_tab_groups";
     public static final String PREF_BRAVE_ENABLE_SPEEDREADER = "brave_enable_speedreader";
+    public static final String PREF_ENABLE_MULTI_WINDOWS = "enable_multi_windows";
 
     private BraveRewardsNativeWorker mBraveRewardsNativeWorker;
+    private boolean mIsTablet;
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         getActivity().setTitle(R.string.prefs_appearance);
         SettingsUtils.addPreferencesFromResource(this, R.xml.appearance_preferences);
-        boolean isTablet = DeviceFormFactor.isNonMultiDisplayContextOnTablet(
-                ContextUtils.getApplicationContext());
-        if (isTablet) {
+        mIsTablet =
+                DeviceFormFactor.isNonMultiDisplayContextOnTablet(
+                        ContextUtils.getApplicationContext());
+        if (mIsTablet) {
             removePreferenceIfPresent(BravePreferenceKeys.BRAVE_BOTTOM_TOOLBAR_ENABLED_KEY);
         }
 
@@ -69,6 +76,35 @@ public class AppearancePreferences extends BravePreferenceFragment
         if (!ChromeFeatureList.isEnabled(BraveFeatureList.BRAVE_SPEEDREADER)) {
             removePreferenceIfPresent(PREF_BRAVE_ENABLE_SPEEDREADER);
         }
+
+        if (!shouldShowEnableWindow()) {
+            removePreferenceIfPresent(PREF_ENABLE_MULTI_WINDOWS);
+        }
+    }
+
+    // Copied from shouldShowNewWindow() method AppMenuPropertiesDelegateImpl.java
+    private boolean shouldShowEnableWindow() {
+        if (BuildInfo.getInstance().isAutomotive) return false;
+
+        if (MultiWindowUtils.shouldShowManageWindowsMenu()) return true;
+
+        if (MultiWindowUtils.instanceSwitcherEnabled()
+                && MultiWindowUtils.isMultiInstanceApi31Enabled()) {
+            return mIsTablet
+                    || (!MultiWindowUtils.getInstance()
+                                    .isChromeRunningInAdjacentWindow(getActivity())
+                            && (MultiWindowUtils.getInstance().isInMultiWindowMode(getActivity())
+                                    || MultiWindowUtils.getInstance()
+                                            .isInMultiDisplayMode(getActivity())));
+        } else {
+            if (MultiWindowUtils.getInstance().areMultipleChromeInstancesRunning(getActivity())) {
+                return false;
+            }
+            return (MultiWindowUtils.getInstance().canEnterMultiWindowMode(getActivity())
+                            && mIsTablet)
+                    || MultiWindowUtils.getInstance().isInMultiWindowMode(getActivity())
+                    || MultiWindowUtils.getInstance().isInMultiDisplayMode(getActivity());
+        }
     }
 
     @Override
@@ -152,6 +188,15 @@ public class AppearancePreferences extends BravePreferenceFragment
                                         .getBoolean(BravePref.SPEEDREADER_PREF_ENABLED));
             }
         }
+
+        Preference enableMultiWindow = findPreference(PREF_ENABLE_MULTI_WINDOWS);
+        if (enableMultiWindow != null) {
+            enableMultiWindow.setOnPreferenceChangeListener(this);
+            if (enableMultiWindow instanceof ChromeSwitchPreference) {
+                ((ChromeSwitchPreference) enableMultiWindow)
+                        .setChecked(BraveMultiWindowUtils.shouldEnableMultiWindows());
+            }
+        }
     }
 
     @Override
@@ -205,6 +250,33 @@ public class AppearancePreferences extends BravePreferenceFragment
             UserPrefs.get(ProfileManager.getLastUsedRegularProfile())
                     .setBoolean(BravePref.SPEEDREADER_PREF_ENABLED, (boolean) newValue);
             shouldRelaunch = true;
+        } else if (PREF_ENABLE_MULTI_WINDOWS.equals(key)) {
+            if (!(boolean) newValue) {
+                if (MultiWindowUtils.getInstanceCount() > 1) {
+                    BraveMultiWindowDialogFragment dialogFragment =
+                            BraveMultiWindowDialogFragment.newInstance();
+                    BraveMultiWindowDialogFragment.DismissListener dismissListener =
+                            new BraveMultiWindowDialogFragment.DismissListener() {
+                                @Override
+                                public void onDismiss() {
+                                    if (MultiWindowUtils.getInstanceCount() == 1) {
+                                        if (preference instanceof ChromeSwitchPreference) {
+                                            ((ChromeSwitchPreference) preference).setChecked(false);
+                                            BraveMultiWindowUtils.updateEnableMultiWindows(false);
+                                        }
+                                    }
+                                }
+                            };
+                    dialogFragment.setDismissListener(dismissListener);
+
+                    dialogFragment.show(
+                            getActivity().getSupportFragmentManager(),
+                            "BraveMultiWindowDialogFragment");
+
+                    return false;
+                }
+            }
+            BraveMultiWindowUtils.updateEnableMultiWindows((boolean) newValue);
         }
         if (shouldRelaunch) {
             BraveRelaunchUtils.askForRelaunch(getActivity());

android/java/res/layout/fragment_brave_multiwindow_dialog.xml

@@ -0,0 +1,72 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2024 The Brave Authors. All rights reserved.
+     This Source Code Form is subject to the terms of the Mozilla Public
+     License, v. 2.0. If a copy of the MPL was not distributed with this file,
+     You can obtain one at https://mozilla.org/MPL/2.0/.
+-->
+
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:paddingHorizontal="24dp"
+    android:paddingVertical="16dp"
+    android:background="@drawable/rounded_bookmark_import_export_dialog_bg">
+
+    <TextView
+        android:id="@+id/tv_title"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center_horizontal"
+        android:textSize="16sp"
+        app:layout_constraintTop_toTopOf="parent"
+        android:layout_marginTop="10dp"
+        android:text="@string/multi_windows_dialog_title"
+        android:textColor="@color/bookmark_import_export_dialog_title_color"
+        android:textStyle="bold" />
+
+    <TextView
+        android:id="@+id/tv_summary"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center_horizontal"
+        android:textSize="16sp"
+        app:layout_constraintTop_toBottomOf="@id/tv_title"
+        android:layout_marginTop="5dp"
+        android:text="@string/multi_windows_dialog_summary"
+        android:textColor="@color/bookmark_import_export_dialog_secondary_color"/>
+
+    <android.widget.Button
+        android:id="@+id/btn_merge"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="10dp"
+        app:layout_constraintTop_toBottomOf="@id/tv_summary"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toStartOf="@id/btn_close"
+        android:background="@android:color/transparent"
+        android:textAllCaps="false"
+        android:text="@string/merge_windows"
+        android:textColor="@color/bookmark_import_export_dialog_button_color"
+        android:textSize="16sp"
+        style="?android:attr/borderlessButtonStyle"/>
+
+    <android.widget.Button
+        android:id="@+id/btn_close"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="10dp"
+        android:layout_marginStart="16dp"
+        app:layout_constraintTop_toBottomOf="@id/tv_summary"
+        app:layout_constraintStart_toEndOf="@id/btn_merge"
+        app:layout_constraintEnd_toEndOf="parent"
+        android:background="@android:color/transparent"
+        android:textAllCaps="false"
+        android:text="@string/close_windows"
+        android:textColor="@color/bookmark_import_export_dialog_button_color"
+        android:textSize="16sp"
+        android:visibility="gone"
+        style="?android:attr/borderlessButtonStyle"/>
+
+</androidx.constraintlayout.widget.ConstraintLayout>

android/java/res/xml/appearance_preferences.xml

@@ -44,6 +44,11 @@
         android:summary="@string/enable_speedreader_summary"
         android:defaultValue="true" />
 
+    <org.chromium.components.browser_ui.settings.ChromeSwitchPreference
+        android:key="enable_multi_windows"
+        android:title="@string/enable_multi_windows_title"
+        android:summary="@string/enable_multi_windows_summary" />
+
     <Preference
         android:fragment="org.chromium.chrome.browser.night_mode.settings.BraveThemePreferences"
         android:key="ui_theme"